tag:theconversation.com,2011:/au/topics/urban-heat-25654/articles
Urban heat – The Conversation
2024-02-22T23:18:56Z
tag:theconversation.com,2011:article/221870
2024-02-22T23:18:56Z
2024-02-22T23:18:56Z
When homes already hit 40°C inside, it’s better to draw on residents’ local know-how than plan for climate change from above
<figure><img src="https://images.theconversation.com/files/577208/original/file-20240222-16-ui7tgy.png?ixlib=rb-1.1.0&rect=0%2C0%2C1413%2C945&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Sebastian Pfautsch/Western Sydney University</span></span></figcaption></figure><p>Weather extremes driven by climate change <a href="https://theconversation.com/climate-change-hits-low-income-earners-harder-and-poor-housing-in-hotter-cities-is-a-disastrous-combination-180960">hit low-income communities harder</a>. The reasons include poor housing and lack of access to safe and comfortable public spaces. This makes “climate readiness” a pressing issue for <a href="https://wsroc.com.au/heat-smart-western-sydney-community">governments</a>, <a href="https://theconversation.com/what-is-climate-ready-infrastructure-some-cities-are-starting-to-adapt-91784">city planners</a> and <a href="https://www.redcross.org.au/emergencies/climate-ready-communities/">emergency services</a> in fast-growing areas such as Western Sydney. </p>
<p>We work with culturally diverse residents and social housing providers in Western Sydney to explore how they’re adapting to <a href="https://theconversation.com/why-western-sydney-is-feeling-the-heat-from-climate-change-more-than-the-rest-of-the-city-201477">increasing heat</a>. Residents hosted heat data loggers inside and outside their homes. </p>
<p>Last summer was relatively mild, but we recorded temperatures as high as 40°C inside some homes. Recalling a heatwave in 2019, one resident said: “The clay had cracks in the grass that you could almost twist your ankles.”</p>
<p>We correlated these data with what residents and social housing providers told us about managing the heat and what is needed to do this better. Different cultural groups used different strategies. Through the project, residents shared a wealth of collective knowledge about what they can do to adapt to the extremes of a changing climate.</p>
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Read more:
<a href="https://theconversation.com/why-western-sydney-is-feeling-the-heat-from-climate-change-more-than-the-rest-of-the-city-201477">Why Western Sydney is feeling the heat from climate change more than the rest of the city</a>
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<h2>Air conditioning has limitations</h2>
<p>Official responses to climate extremes typically rely on a <a href="https://basc.pnnl.gov/resource-guides/creating-cool-room-extreme-heat-events">retreat indoors</a>. These “last resort” shelters depend in most cases on a reliable electricity supply, which can be cut during heatwaves. </p>
<p>There have been efforts, but not in Australia, to establish a “<a href="https://www.buildinggreen.com/op-ed/passive-survivability">passive survivability</a>” building code. The aim is to ensure homes remain tolerably cool during a heatwave (or warm during a cold snap) even if power is cut for a number of days.</p>
<p>We recognise air conditioning is vital for vulnerable populations, including older people and those with <a href="https://www.abc.net.au/news/2024-02-13/disability-pensioner-social-housing-no-air-conditioning-heatwave/103456146">health conditions</a>, but we do not want to give up on going outside! </p>
<p>Outdoors, approaches such as <a href="https://theconversation.com/australias-first-mobile-cooling-hub-is-ready-for-searing-heat-this-summer-and-people-who-are-homeless-helped-design-it-218829">pop-up cooling hubs</a> for the homeless are <a href="https://www.sydney.edu.au/medicine-health/our-research/research-centres/heat-and-health-research-incubator/pop-up-mobile-cooling-hubs.html?#uniqueId_muBzCemD_5_button">compassionate</a>. While important, such approaches don’t get beyond “coping”. </p>
<p>There’s also a risk of perpetuating a deficit narrative that sees the city’s poorest as lacking capacity to act on their circumstances. Our strengths-based action research approach looks for alternative solutions that draw on the collective knowledge and practices already found in communities. </p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/Qyynr2MibdI?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">‘My house is an oven’ – a look at the problem of hot housing in Western Sydney.</span></figcaption>
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Read more:
<a href="https://theconversation.com/australias-first-mobile-cooling-hub-is-ready-for-searing-heat-this-summer-and-people-who-are-homeless-helped-design-it-218829">Australia's first mobile cooling hub is ready for searing heat this summer – and people who are homeless helped design it</a>
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<h2>How was the research done?</h2>
<p><a href="https://www.westernsydney.edu.au/ics/projects/living_with_urban_heat_becoming_climate-ready_in_social_housing">Our project</a>, Living with Urban Heat: Becoming Climate Ready in Social Housing, is part of a broader research program, <a href="https://www.coolingthecommons.com/">Cooling the Commons</a>. Its focus is the role of shared spaces and knowledge in designing climate-resilient cities. </p>
<p>We use participatory design methods. Adaptation strategies are developed by <a href="https://www.tandfonline.com/doi/full/10.1080/15710880701875068">working with people</a> who are already attuned to their place and community. </p>
<p>In a first step, to get a better grasp on the micro-climates at each site, residents hosted data loggers in their homes. The data show that the location, degree of urban density and type of housing influence residents’ experience of heat. </p>
<p>In Windsor, for example, the extremes are felt inside the home. Last summer, loggers in Windsor and Richmond recorded 69 days above 30°C. On average, temperatures inside were 6°C warmer than outside and hit 40°C four occasions. </p>
<p>Further east in Riverwood and Parramatta recorded lower temperatures. However, for project researcher Sebastian Pfautsch, these data also highlighted the urban heat island effect. In Riverwood, the average day and night temperatures were 25.8°C and 25.4°C respectively, as brick surfaces hold the heat. </p>
<p>We correlated these data with what residents and social housing providers told us about how they manage heat and comfort in their different places.</p>
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<img alt="Inside a home showing a chest of drawers with ornaments on top and a data logger installed in the corner" src="https://images.theconversation.com/files/577466/original/file-20240222-28-sq5u4m.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/577466/original/file-20240222-28-sq5u4m.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/577466/original/file-20240222-28-sq5u4m.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/577466/original/file-20240222-28-sq5u4m.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/577466/original/file-20240222-28-sq5u4m.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/577466/original/file-20240222-28-sq5u4m.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/577466/original/file-20240222-28-sq5u4m.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">A heat data logger installed in one of the homes in the study.</span>
<span class="attribution"><span class="source">Climate-Ready in Social Housing Team</span></span>
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Read more:
<a href="https://theconversation.com/too-many-renters-swelter-through-summer-efficient-cooling-should-be-the-law-for-rental-homes-214483">Too many renters swelter through summer. Efficient cooling should be the law for rental homes</a>
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<h2>So how do residents manage the heat?</h2>
<p>At bilingual design workshops across the locations, themes from the interviews between groups of residents were shared.</p>
<p>Residents who said “I retreat” felt trapped rather than safe in their poorly adapted homes. </p>
<p>“Taking comfort” meant using ice, water spray, sheets and towels to cool spaces and bodies. Chinese residents used foods such as rice porridge congee to cool down. Residents also took comfort from housing providers and neighbours checking on their wellbeing on hot days.</p>
<p>Residents with access to a car “chased the air”. This meant moving between air-conditioned spaces: friends’ homes, coffee shops and supermarkets. </p>
<p>Residents without cars used cool spots, such as public libraries, that they could get to by public transport. Others whose families have lived in the area for decades used their local knowledge to chase the “Dee Why Doctor” and other local breezes, as well as <a href="https://theconversation.com/when-the-heat-hits-inland-waters-look-inviting-heres-how-we-can-help-people-swim-safely-at-natural-swimming-spots-219333">sitting in the river</a>. </p>
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Read more:
<a href="https://theconversation.com/when-the-heat-hits-inland-waters-look-inviting-heres-how-we-can-help-people-swim-safely-at-natural-swimming-spots-219333">When the heat hits, inland waters look inviting. Here's how we can help people swim safely at natural swimming spots</a>
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<p>Residents often return, though, to a home that has baked in the heat all day.</p>
<p>They had ingenious ways to get air moving with windows, doors and fans. “Making the air” was an important pattern across the groups. </p>
<p>Air movement was as important for bodily comfort as a cooler temperature, particularly for people who found it hard to breathe in the heat. As one participant said: “It’s stuffy in the bedroom. It’s really hard sometimes […] I feel I can’t open the window because of the smells and noise.”</p>
<p>Residents also created “rules” to manage the heat in their homes. These ranged from opening and closing doors and windows at certain times, to keeping lights off, to avoiding baking, to <a href="https://apo.org.au/node/119256">rationing air conditioning</a>.</p>
<p>The groups benefited from sharing these themes. For example, the Chinese community, most of whom did not drive, had never thought of “chasing the air”. On the other hand, using congee to feel cooler was news for others.</p>
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<a href="https://images.theconversation.com/files/577469/original/file-20240222-22-fu1tlp.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Post-it notes in Chinese and English from the workshop" src="https://images.theconversation.com/files/577469/original/file-20240222-22-fu1tlp.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/577469/original/file-20240222-22-fu1tlp.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=453&fit=crop&dpr=1 600w, https://images.theconversation.com/files/577469/original/file-20240222-22-fu1tlp.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=453&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/577469/original/file-20240222-22-fu1tlp.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=453&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/577469/original/file-20240222-22-fu1tlp.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=570&fit=crop&dpr=1 754w, https://images.theconversation.com/files/577469/original/file-20240222-22-fu1tlp.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=570&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/577469/original/file-20240222-22-fu1tlp.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=570&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">In the workshops, different cultural groups shared their experiences of heat and strategies to manage it.</span>
<span class="attribution"><span class="source">Climate-Ready in Social Housing Team</span></span>
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<h2>Collective adaptation works best</h2>
<p>In each community, sharing these approaches prompted a broader conversation about more collective forms of adaptation, including shared spaces and practices in the built and natural environments. </p>
<p>This research is raising questions. There is a tension, for example, between the enclosure that air conditioning requires and the movement of fresh air many residents see as healthy. What implications might this have for a <a href="https://www.tandfonline.com/doi/full/10.1080/15710880701875068">cooling hubs blueprint</a> and the future of social housing, particularly where a need for security often means blocked openings and locked doors? </p>
<p>Climate-readiness does not mean reinforcing inadequate technical solutions that shut us in, or barely remedial solutions. These reduce us to what philosopher Georgio Agamben termed a “<a href="https://www.oxfordreference.com/display/10.1093/oi/authority.20110803095446660">bare life</a>”, a condition that precludes the possibility of a good one. That need not be so. </p>
<p>Our research is trialling adaptive practices, drawing on local knowledge of cool spaces (both natural and built), and sharing these practices across cultures. It shows we can reimagine climate-readiness as part of a flourishing community.</p>
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<p><em>The authors would like to acknowledge the contribution of all co-researchers in the <a href="https://www.westernsydney.edu.au/ics/projects/living_with_urban_heat_becoming_climate-ready_in_social_housing">Climate-Ready in Social Housing</a> team.</em></p><img src="https://counter.theconversation.com/content/221870/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Abby Mellick Lopes receives funding from the Australian Research Council (ARC) Linkage Program Project number: LP210200622</span></em></p><p class="fine-print"><em><span>Cameron Tonkinwise receives funding from the Australian Research Council (ARC) Linkage Program Project number: LP210200622. </span></em></p><p class="fine-print"><em><span>Stephen Healy receives funding from the Australian Research Council (ARC) Linkage Program Project number: LP210200622</span></em></p>
Western Sydney residents whose homes often get hotter inside than outside during heatwaves have learnt to be resourceful in adapting to the increasing heat.
Abby Mellick Lopes, Associate Professor, Design Studies, Faculty of Design, Architecture and Building, University of Technology Sydney
Cameron Tonkinwise, Professor, School of Design, University of Technology Sydney
Stephen Healy, Associate Professor, Human Geography and Urban Studies School of Social Sciences/ Institute for Culture and Society, Western Sydney University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/218829
2023-12-07T23:36:02Z
2023-12-07T23:36:02Z
Australia’s first mobile cooling hub is ready for searing heat this summer – and people who are homeless helped design it
<figure><img src="https://images.theconversation.com/files/564053/original/file-20231206-19-ykkamk.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C3498%2C2323&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/sunset-busy-roads-major-cities-135274718">Shutterstock</a></span></figcaption></figure><p>Heatwaves are a major public health hazard. Socially disadvantaged people are especially exposed to extreme heat and other impacts of climate change. Many people experiencing homelessness – <a href="https://www.abs.gov.au/statistics/people/housing/estimating-homelessness-census/latest-release">more than 120,000</a> on any given day in Australia – are exposed to extreme temperatures sleeping on the street, in cars or <a href="https://www.sciencedirect.com/science/article/pii/S2666535223000964">tents</a>, or in overcrowded and substandard housing. </p>
<p>Researchers are working with people experiencing homelessness, St Vincent’s Hospital and the City of Sydney to design, deliver and evaluate a mobile “cooling hub” this summer. The Bureau of Meteorology is <a href="https://media.bom.gov.au/releases/1205/the-bureau-forecasts-an-unusually-warm-summer/">predicting</a> an unusually hot summer. The pilot project in Surry Hills will use low-cost strategies, including misting fans, to keep 54 people at a time cool on the hottest of days.</p>
<p>We’ll use the <a href="https://heatwatch.sydney.edu.au">HeatWatch</a> app, developed by the University of Sydney, to know when to set up the cooling hub. It’s the first time the app, as a preparedness tool, and a mobile hub like this have been deployed in Australia. Renewable energy will power the hub, so this response isn’t itself contributing to climate change.</p>
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<a href="https://images.theconversation.com/files/564054/original/file-20231206-35091-smw7n5.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Map of Australia showing chances of exceeding median maximum temperatures in summer" src="https://images.theconversation.com/files/564054/original/file-20231206-35091-smw7n5.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/564054/original/file-20231206-35091-smw7n5.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/564054/original/file-20231206-35091-smw7n5.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/564054/original/file-20231206-35091-smw7n5.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/564054/original/file-20231206-35091-smw7n5.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=505&fit=crop&dpr=1 754w, https://images.theconversation.com/files/564054/original/file-20231206-35091-smw7n5.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=505&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/564054/original/file-20231206-35091-smw7n5.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=505&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">The Bureau of Meteorology is predicting a hotter-than-usual summer across Australia.</span>
<span class="attribution"><a class="source" href="http://www.bom.gov.au/climate/outlooks/?msdynttrid=JZ63jjeqFdOIivfF1EiqYZgQ8jlNnCpStkMT7GaPC7c#/temperature/maximum/median/seasonal/0">Bureau of Meteorology</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
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Read more:
<a href="https://theconversation.com/cruel-summer-ahead-why-is-australia-so-unprepared-219015">Cruel summer ahead – why is Australia so unprepared?</a>
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<h2>Homelessness increases heat risks</h2>
<p>Climate change represents a <a href="https://www.ama.com.au/position-statement/ama-position-statement-climate-change-and-human-health-2004-revised-2015">health emergency</a>. The extremes of climate change can be devastating for the <a href="https://ajph.aphapublications.org/doi/full/10.2105/AJPH.2023.307351">health of people experiencing homelessness</a>. They are more exposed to heat as it can be very <a href="https://pubmed.ncbi.nlm.nih.gov/22950903/">hard for them to find cool spaces</a>, particularly in cities. </p>
<p>People in this situation are also more likely to be vulnerable to the impacts of heat, as many have <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5803132/">chronic health conditions</a>, such as heart disease. Some <a href="https://pubmed.ncbi.nlm.nih.gov/26073686/">medications</a>, for both physical and mental health conditions, can reduce a person’s ability to regulate their body temperature.</p>
<p>Extreme heat places enormous strain on a person’s body, including their <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4950975/">heart</a>. It can <a href="https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(21)01208-3/fulltext">lead to serious illness</a> and even death. </p>
<p>Severe heat also creates significant costs. In a 2020 Sydney heatwave, the cost of treating heat illness in just two people who were homeless was <a href="https://www.mdpi.com/1660-4601/19/24/16565">A$70,184</a>. </p>
<p>The World Health Organization <a href="https://www.who.int/health-topics/climate-change#tab=tab_1">estimates</a> climate change will cause 250,000 deaths a year from 2030, at a cost of US$2-4 billion ($A3-6 billion). </p>
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Read more:
<a href="https://theconversation.com/homelessness-today-sees-workers-and-families-with-nowhere-stable-to-live-no-wonder-their-health-is-suffering-202955">Homelessness today sees workers and families with nowhere stable to live. No wonder their health is suffering</a>
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<h2>Ensuring the hub meets people’s needs</h2>
<p>Our team plans to help hundreds of people stay cooler and safer in Sydney this summer. The cooling hub has been <a href="https://mhcc.org.au/wp-content/uploads/2023/06/CMHDARN-Co-design-kickstarter-FINAL.pdf">co-designed</a> with people experiencing homelessness. This process will help ensure the hub meets the needs of the people it’s meant to assist at times of extreme heat. </p>
<p>People with experience of homelessness worked with researchers and health workers to determine where to set up the cooling hub, what to include inside, how to make the community aware of the service, and how to reach out from the hub and bring people to it. For example, for many people experiencing homelessness, being able to access health care, connect with others, bring their pets and store belongings are all important. </p>
<p>The cooling hub will be set up at Ward Park, Surry Hills, and will be open in the daytime during extreme heat. It will comprise a marquee and low-tech equipment that maximises cooling and health support. The hub can be set up quickly and easily and relocated as required. </p>
<p>Nurses, doctors and peer support workers of St Vincent’s Hospital Sydney, Homeless Health Service and City of Sydney public liaison officers will staff the hub. They will provide <a href="https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(21)01209-5/fulltext">evidence-based</a> cooling strategies and monitor body temperature, blood pressure and heart and breathing rates to identify early signs of heat illness. </p>
<p>People who are at high risk of heat illness will leave the hub with a pedestal or handheld fan and water spray bottle. All will receive information on how best to stay cool. </p>
<p>Hub users will be advised to stay hydrated and in the shade, limit activity in the heat of the day and remove heavy clothing. Each of these measures can be very effective in keeping cool.</p>
<p>The hub will also offer food and opportunities to access social and housing supports. </p>
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Read more:
<a href="https://theconversation.com/melbourne-now-has-chief-heat-officers-heres-why-we-need-them-and-what-they-can-do-192248">Melbourne now has chief heat officers. Here's why we need them and what they can do</a>
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<h2>Creating a blueprint for others</h2>
<p>In 2021, St Vincent’s Hospital Sydney and others set up a <a href="https://www.mdpi.com/1660-4601/19/23/15686">vaccination hub</a> for people experiencing homelessness during the COVID pandemic. The lessons from that initiative were written into a <a href="https://apo.org.au/node/314543">blueprint</a> for others to use.</p>
<p>Our evaluation of the cooling hub will include satisfaction and experience surveys along with environmental and health data to estimate its acceptability, effectiveness and cost efficiency. This will include its impact on attendances for heat illness at St Vincent’s Hospital emergency department. </p>
<p>Drawing on what is learned, we will write a cooling hub blueprint for other services to apply. </p>
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Read more:
<a href="https://theconversation.com/efforts-to-find-safe-housing-for-homeless-youth-have-gone-backwards-heres-what-the-new-national-plan-must-do-differently-210704">Efforts to find safe housing for homeless youth have gone backwards. Here's what the new national plan must do differently</a>
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</em>
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<hr>
<h2>Climate justice in action</h2>
<p>People experiencing homelessness are poorly represented in disaster planning. The consequences can be devastating. Yet simple preventive strategies, carefully applied with communities, are likely to reduce the health impact of heatwaves. </p>
<p>Heat is one of the many impacts of climate change that are not felt equally. People who are most <a href="https://www.taylorfrancis.com/books/oa-mono/10.4324/9780367441265/learning-live-climate-change-blanche-verlie">disadvantaged</a> bear the greatest cost.</p>
<p>A climate justice response to climate change is essential, one that works with the most disadvantaged people in our community to meet their needs. Our initiative will provide a blueprint for co-designing a cooling hub with disadvantaged people and responding to their needs in the climate crisis.</p><img src="https://counter.theconversation.com/content/218829/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Professor Jane Currie holds an honorary appointment with St Vincent's Hospital Sydney for the purposes of research. For this cooling hub pilot project, she received funding from the City of Sydney, St Vincent's Hospital Sydney and Queensland University of Technology.
</span></em></p><p class="fine-print"><em><span>Associate Professor Jo River, UTS and Northern Sydney Local Health District, has expertise in co-design research and received funding from the City of Sydney and St. Vincent's Hospital Sydney for the cooling hub co-design pilot project.</span></em></p><p class="fine-print"><em><span>Dr. Timothy English is the Humanitarian Settings Co-lead for the Heat and Health Research Incubator at the University of Sydney and received funding from the City of Sydney and St Vincent's Hospital Sydney for this cooling hub pilot project.</span></em></p>
The pilot project opening in Sydney will use the best available evidence to keep vulnerable people cool on the hottest of days.
Jane Currie, Professor of Nursing, Queensland University of Technology
Jo River, Associate Professor, Mental Health Drug and Alcohol, UTS & Northern Sydney LHD, University of Technology Sydney
Timothy English, Lecturer, Co-lead of the Humanitarian Settings research theme within the Heat and Health Research Incubator, Sydney School of Health Sciences, University of Sydney
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/212844
2023-09-05T05:27:37Z
2023-09-05T05:27:37Z
The illegal killing of 265 trees on Sydney’s North Shore is not just vandalism. It’s theft on a grand scale
<figure><img src="https://images.theconversation.com/files/546266/original/file-20230904-15-ve2ktp.jpg?ixlib=rb-1.1.0&rect=0%2C8%2C6000%2C3988&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>In most illegal tree removals, you might see perhaps a handful of trees removed or poisoned. That’s why the recent felling and <a href="https://www.abc.net.au/news/2023-08-30/tree-vandalism-in-castle-cove/102792692">poisoning of 265 old trees</a> in Sydney’s Castle Cove has been so breathtaking and appalling.</p>
<p>This act – perpetrated by persons unknown – was not vandalism but theft of valuable community assets. </p>
<p>Future generations have been robbed of the benefits these trees – some of which were more than 80 years old – provided to our environment, the climate and as habitat for other plants and animals. It was theft on a grand scale.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1697126351172751720"}"></div></p>
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Read more:
<a href="https://theconversation.com/dodgy-tree-loppers-are-scamming-elderly-homeowners-and-hacking-up-healthy-trees-heres-what-you-need-to-know-164629">Dodgy tree loppers are scamming elderly homeowners and hacking up healthy trees. Here's what you need to know</a>
</strong>
</em>
</p>
<hr>
<h2>Tree loss will cost us as the climate changes</h2>
<p>In contrast to Indigenous people, most Australians have undervalued large old trees for nearly two centuries. But many of the ecological and environmental benefits these trees provide increase as they age over decades and perhaps centuries. These benefits are crucial to urban liveability and sustainability.</p>
<p>A global <a href="https://www.soiladvocates.ca/ancient-trees-why-we-need-to-preserve-them-for-future-generations/">movement</a> is gaining momentum in urban forestry to preserve old trees for as long as we can to maximise the benefits they provide. </p>
<p>It is not about preservation at all cost, but a recognition that in a proper cost/benefit <a href="https://e360.yale.edu/features/why-keeping-mature-forests-intact-is-key-to-the-climate-fight#:%7E:text=As%20trees%20get%20older%2C%20they,bigger%20they%20store%20more%20carbon">analysis</a>, large old trees outperform younger trees. Unnecessary removal of large old trees is unsustainable both environmentally and economically.</p>
<p>This does not mean we should not replace dangerous trees or those that are rapidly declining. </p>
<p>It does mean, however, there should be no removal of large old trees without significant and demonstrably sound reasons. </p>
<p>Too many large, old, urban trees are being removed unnecessarily because other management options are not considered. </p>
<p>Whether via theft or bureaucratic-sanctioned tree removals, the general loss of old trees will cost us and our society dearly as the climate changes. </p>
<h2>Old trees do things that young trees simply cannot</h2>
<p>One of the significant benefits that trees provide over other vegetation types is that their leaf area is often more than double their canopy cover. This creates a great <a href="https://andrewsforest.oregonstate.edu/sites/default/files/lter/pubs/pdf/pub2060.pdf">cooling effect</a> via both shade and evapotranspiration (the movement of water into the atmosphere, some of which comes through leaves).</p>
<p>Large trees are unequalled in cooling the environment around them. Old trees simply do things on a scale that small young trees cannot.</p>
<p>This means a slow-growing old tree can take in and store more carbon than a quick-growing young seedling. Every gram of carbon stored in this way is carbon saved from going into the atmosphere as greenhouse gas emissions.</p>
<p>Both carbon stores and shade are crucial to mitigating future climate change.</p>
<p>All of this is lost when trees are illegally or unnecessarily removed. The impact is felt not just now but for decades into the future.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1696762503496396803"}"></div></p>
<h2>The loss of even a single tree comes at a huge price</h2>
<p>The loss of <a href="https://www.abc.net.au/news/2023-08-30/tree-vandalism-in-castle-cove/102792692">so many trees</a> in Sydney’s Castle Cove represents theft of environmental benefits and services from at least two, if not more, future generations of Australians. The trees lost were largely native coastal species that had decades (and in some cases more than a century) of growth before them.</p>
<p>We have known for many decades trees are often associated with between 30 and 50 other species – birds, mammals, reptiles, insects, fungi, algae and others. The removal of a tree affects most, if not all, of these other species. Some of these plants and animals will die as a result.</p>
<p>The number of associated species increases as the tree ages, and we have probably been underestimating species lost with large old tree removals in urban and natural forests. </p>
<p>Oaks in the UK, for example, are associated with over 2,300 other <a href="https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/british-trees/oak-tree-wildlife/">species</a>. One can only wonder how many other species will be affected by the felling and poisoning of the trees at Castle Cove. The illegal loss of even a single tree comes at a huge price.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1697211764994392470"}"></div></p>
<h2>Simply planting new trees doesn’t fix the problem</h2>
<p>We tend to undervalue the shade provided by trees when considering urban development, or even road works. But tree removals lead to more <a href="https://theconversation.com/why-western-sydney-is-feeling-the-heat-from-climate-change-more-than-the-rest-of-the-city-201477">urban heat</a>, which usually means higher electricity bills (as people crank up the air conditioner). </p>
<p>Large old trees are seen by some as an expendable nuisance. Some local council laws aim to protect trees of a certain size, but fines for illegal removals are small.</p>
<p>In some instances, a one-for-one tree replacement is offered. But to replace the carbon stored in one large, mature tree would require a vast number of seedlings, many of which <a href="https://www.bloomberg.com/news/features/2021-07-30/what-happens-after-pledges-to-plant-millions-of-trees">fail to survive</a> the first few years. </p>
<p>And it can take many years before planted trees reach carbon neutrality. The production, planting and maintenance processes all use resources, energy and fossil fuels, which means it can take <a href="https://joa.isa-arbor.com/article_detail.asp?JournalID=1&VolumeID=49&IssueID=1&ArticleID=10544">decades</a> before a tree is carbon positive.</p>
<p>This situation is unsustainable environmentally and ludicrous economically, but it seems to go largely unnoticed. We accrue all of the costs of these plantings and recoup precious little benefit.</p>
<p>It would be far more sensible and sustainable if we retained our large old trees, making every effort to maximise and prolong their life spans.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-humble-spotted-gum-is-a-world-class-urban-tree-heres-why-212540">The humble spotted gum is a world class urban tree. Here's why</a>
</strong>
</em>
</p>
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<img src="https://counter.theconversation.com/content/212844/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Gregory Moore does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
The loss of so many trees in Sydney’s Castle Cove represents the theft of environmental benefits and services from future generations of Australians.
Gregory Moore, Senior Research Associate, School of Ecosystem and Forest Sciences, The University of Melbourne
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/206737
2023-06-20T12:29:12Z
2023-06-20T12:29:12Z
Saving lives from extreme heat: Lessons from the deadly 2021 Pacific Northwest heat wave
<figure><img src="https://images.theconversation.com/files/531486/original/file-20230612-248839-sft9gx.jpg?ixlib=rb-1.1.0&rect=11%2C17%2C3918%2C2598&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Volunteers pick up water to deliver to homeless people during a 2021 heat wave.</span> <span class="attribution"><a class="source" href="https://newsroom.ap.org/detail/NorthwestHeatWave/5811cb2415d048d584b0162ec7011a61/photo">AP Photo/Nathan Howard</a></span></figcaption></figure><p>The heat dome that descended upon the Pacific Northwest in late June 2021 met a population radically unprepared for it.</p>
<p>Almost <a href="https://www.nytimes.com/2021/06/25/us/western-heat-wave.html">two-thirds of households earning US$50,000 or less</a> and <a href="https://www.seattletimes.com/seattle-news/data/seattle-is-a-lot-more-air-conditioned-than-it-used-to-be/">70% of rented houses</a> in Washington’s King, Pierce and Snohomish counties had no air conditioning. In Spokane, <a href="https://www.gonzaga.edu/center-for-climate-society-environment/our-work/climate-resilience-project/beat-the-heat/survey">nearly one-quarter of survey respondents</a> didn’t have in-home air conditioning, and among those who did, 1 in 5 faced significant, often financial, barriers to using it.</p>
<p>Imagine having no way to cool your home as temperatures spiked to <a href="https://www.ncei.noaa.gov/monitoring-content/extremes/scec/reports/20220210-Washington-Maximum-Temperature.pdf">108 degrees Fahrenheit (43 Celsius), and 120 F (49 C) in some places</a>. People in <a href="https://www.epa.gov/heatislands">urban heat islands</a> – areas with few trees and lots of asphalt and concrete that can absorb and radiate heat – saw temperatures as much as <a href="https://repository.gonzaga.edu/ccsereach/2/">14 F (7.8 C) higher</a> than that. </p>
<p><a href="https://www.nytimes.com/2021/07/10/world/canada/canadian-wildfire-british-columbia.html">Extreme heat disasters</a> like this are becoming <a href="https://theconversation.com/dangerous-urban-heat-exposure-has-tripled-since-the-1980s-with-the-poor-most-at-risk-169153">increasingly common</a> in regions where high heat used to be rare. Blackouts during severe heat waves can also leave residents who believe they are protected because they have in home air conditioners at unexpected risk. To prepare, cities, neighborhoods, companies and individuals can take steps now that can reduce the harm.</p>
<figure class="align-center ">
<img alt="A man and two women sit in the shade while kids play in a fountain. The man has cool cloth on his head and cold soda in his hand. June is nicknamed 'Juneuary' in Seattle for its clouds and usual chill, but that isn't what residents endured in June 2021." src="https://images.theconversation.com/files/531491/original/file-20230612-16-c47rc9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/531491/original/file-20230612-16-c47rc9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=425&fit=crop&dpr=1 600w, https://images.theconversation.com/files/531491/original/file-20230612-16-c47rc9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=425&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/531491/original/file-20230612-16-c47rc9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=425&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/531491/original/file-20230612-16-c47rc9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=535&fit=crop&dpr=1 754w, https://images.theconversation.com/files/531491/original/file-20230612-16-c47rc9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=535&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/531491/original/file-20230612-16-c47rc9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=535&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Designing shady spots for sitting and public fountains for kids to play in, like these people found in Seattle on June 27, 2021, can provide some relief from extreme heat.</span>
<span class="attribution"><a class="source" href="https://newsroom.ap.org/detail/PacificNorthwestHeatWave/176e2e948dea47efbc9753259e0d27f4/photo">AP Photo/John Froschauer</a></span>
</figcaption>
</figure>
<p>In a <a href="https://cig.uw.edu/resources/special-reports/in-the-hot-seat-saving-lives-from-extreme-heat-in-washington-state/">new report</a>, written with colleagues at universities and the Washington State Department of Health and released ahead of the two-year anniversary of the heat wave, we show how municipal planning agencies, parks departments, local health agencies, community-based organizations like churches and nonprofits, multiple state agencies, hospitals, public health professionals and emergency response personnel, as well as individuals and families, can play a vital role in reducing risk.</p>
<p>The 2021 heat dome was Washington’s deadliest weather disaster on record. It contributed to <a href="https://cig.uw.edu/resources/special-reports/in-the-hot-seat-saving-lives-from-extreme-heat-in-washington-state/">441 deaths in the state between June 27 and July 3</a>, our research shows. Medical systems were overwhelmed. </p>
<p>There are numerous ways to avoid this deadly of an outcome in the future. Many emerge from thinking about extreme heat as long-term risk reduction, not just short-term emergency response.</p>
<h2>Designing environments for cooling</h2>
<p>Greening the urban environment can reduce heat exposure and save lives. For example, planting trees and building shade structures where people are most exposed to heat can provide local relief from extreme temperatures. That includes providing shade at buildings without air conditioning and exposed public spaces, such as bus stops and parks.</p>
<p>Planting rooftops with vegetation, known as <a href="https://www.sciencedirect.com/science/article/abs/pii/S0038092X12002447">green roofs</a>, or painting them white so they reflect heat rather than absorb it, can also <a href="https://www.epa.gov/heatislands/using-green-roofs-reduce-heat-islands">lower roof temperatures by tens of degrees</a>. Used widely, they can reduce an entire neighborhood’s heat island effect by several degrees.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/531162/original/file-20230609-21291-onib7f.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="An illustration showing a cross-section of a region, with a city and rural areas, and two chart lines showing day and night temperatures. The temps rise over areas with lots of concrete and asphalt, particularly dense areas that hold the heat." src="https://images.theconversation.com/files/531162/original/file-20230609-21291-onib7f.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/531162/original/file-20230609-21291-onib7f.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=389&fit=crop&dpr=1 600w, https://images.theconversation.com/files/531162/original/file-20230609-21291-onib7f.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=389&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/531162/original/file-20230609-21291-onib7f.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=389&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/531162/original/file-20230609-21291-onib7f.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=488&fit=crop&dpr=1 754w, https://images.theconversation.com/files/531162/original/file-20230609-21291-onib7f.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=488&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/531162/original/file-20230609-21291-onib7f.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=488&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Developed areas tend to heat up more than natural landscapes, such as parks. That can increase heat stress on humans.</span>
<span class="attribution"><a class="source" href="https://cig.uw.edu/resources/special-reports/in-the-hot-seat-saving-lives-from-extreme-heat-in-washington-state/">Climate Impacts Group/University of Washington, adapted from EPA</a></span>
</figcaption>
</figure>
<p>Efforts like these, along with tree planting campaigns in public parks and rights of way, and ordinances requiring shade trees for parking lots and private development projects, can transform the urban heat landscape.</p>
<h2>Reaching vulnerable people</h2>
<p>When heat waves are coming, culturally nuanced outreach efforts focused on <a href="https://doi.org/10.1016/j.uclim.2022.101392">the most vulnerable populations</a> – and involving sources they trust – can save lives.</p>
<p>Government heat advisories in traditional media like radio, newspapers, TV and the internet have been shown to have limited success in changing people’s behavior. In the <a href="https://www.gonzaga.edu/center-for-climate-society-environment/our-work/climate-resilience-project/beat-the-heat/survey">2022 Spokane survey</a>, 88% of respondents indicated they were unlikely to leave their home during an extreme heat event to go to a cooling center, for example. The reasons varied, including misperception of personal risk, fear of leaving homes unoccupied, not wanting to leave pets behind and mistrust of government. </p>
<p>Culturally specific resources led by community-based organizations can get around the government trust issue and can be tailored to the local population. </p>
<figure class="align-center ">
<img alt="A woman in a wheel chair leans back with cooling clothes on her forehead and chest during the 2021 Pacific Northwest heat wave. The heat wave killed hundreds of people." src="https://images.theconversation.com/files/531487/original/file-20230612-29-i0013b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/531487/original/file-20230612-29-i0013b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/531487/original/file-20230612-29-i0013b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/531487/original/file-20230612-29-i0013b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/531487/original/file-20230612-29-i0013b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/531487/original/file-20230612-29-i0013b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/531487/original/file-20230612-29-i0013b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A woman puts cold cloths on her forehead at a cooling center in Portland, Ore., on June 27, 2021.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/tracy-wallace-puts-ice-cold-cloths-on-her-forehead-and-news-photo/1233728368">Alisha Jucevic for The Washington Post via Getty Images</a></span>
</figcaption>
</figure>
<p>That might mean opening cooling centers in churches or common community gathering places and launching heat awareness campaigns driven by trusted community messengers. New York City developed a door-to-door wellness check program that <a href="https://climate.cityofnewyork.us/initiatives/be-a-buddy/">uses neighborhood volunteers</a> to check on elderly and other at-risk residents.</p>
<p>Under this model, churches, libraries, community centers and community nonprofits take center stage, supported with resources from local and state governments. Baltimore developed more than a dozen “<a href="https://www.baltimoresustainability.org/baltimore-resiliency-hub-program/">resiliency hubs</a>” using this model to provide water, cooling, power for charging devices and other support.</p>
<p>Community-based organizations can also direct energy assistance to lower-income community members. In Spokane, one community organization created a “<a href="https://www.snapwa.org/cool">cooling fund</a>” to provide portable air conditioners to those who cannot afford one. </p>
<p>Our report lays out <a href="https://cig.uw.edu/resources/special-reports/in-the-hot-seat-saving-lives-from-extreme-heat-in-washington-state/">many other strategies</a> to achieve long-term heat risk reduction.</p>
<h2>Landlords, employers and utilities have a role</h2>
<p>Addressing extreme heat over the long term requires the participation of many other groups not tasked with protecting public health.</p>
<p>For example, landlords of multifamily housing and rental homes have an important role to play. After the 2021 heat wave, <a href="https://olis.oregonlegislature.gov/liz/2022R1/Downloads/MeasureDocument/SB1536/Enrolled">Oregon passed a law</a> prohibiting landlords from restricting tenants’ ability to install window air conditioners.</p>
<p>Employers of people who work outdoors, or indoors in buildings without air conditioning, can protect workers by allowing more breaks, providing shade and water and adjusting work hours to avoid heat exposure – although concerns persist about rule enforcement and reduced pay. </p>
<figure class="align-center ">
<img alt="A worker standing in shade holds a " src="https://images.theconversation.com/files/531488/original/file-20230612-23-wcvsxn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/531488/original/file-20230612-23-wcvsxn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/531488/original/file-20230612-23-wcvsxn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/531488/original/file-20230612-23-wcvsxn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/531488/original/file-20230612-23-wcvsxn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/531488/original/file-20230612-23-wcvsxn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/531488/original/file-20230612-23-wcvsxn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Outdoor workers may face extreme heat for hours on end. More frequent breaks and providing shade can help when work can’t stop.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/construction-workers-guide-traffic-along-hot-pavement-on-news-photo/1227714772">Jahi Chikwendiu/The Washington Post via Getty Images</a></span>
</figcaption>
</figure>
<p>Utilities can make a difference by ensuring the power stays on during high-demand periods, particularly in vulnerable neighborhoods, and working with communities to reduce costs for vulnerable people that may prevent them from using air conditioning.</p>
<p>Ultimately, reducing extreme heat vulnerability through multiple strategies is crucial because lives are at stake.</p>
<h2>Coordination is essential</h2>
<p>Extreme heat waves are forecast to <a href="https://science2017.globalchange.gov/chapter/6/">occur more frequently</a> across the globe as greenhouse gas emissions continue to warm the climate. Between 1971 and 2021, Washington state experienced an average of three extreme heat days per year. By the 2050s, climate models project that will rise to between 17 and 30 extreme heat days per year – <a href="https://cig.uw.edu/resources/special-reports/in-the-hot-seat-saving-lives-from-extreme-heat-in-washington-state/">a fivefold increase</a>. </p>
<figure class="align-center ">
<img alt="Five maps show observed temperature change and much higher changes by mid and late century, particularly with high-emissions scenarios." src="https://images.theconversation.com/files/531244/original/file-20230611-23-w48erd.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/531244/original/file-20230611-23-w48erd.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=703&fit=crop&dpr=1 600w, https://images.theconversation.com/files/531244/original/file-20230611-23-w48erd.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=703&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/531244/original/file-20230611-23-w48erd.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=703&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/531244/original/file-20230611-23-w48erd.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=884&fit=crop&dpr=1 754w, https://images.theconversation.com/files/531244/original/file-20230611-23-w48erd.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=884&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/531244/original/file-20230611-23-w48erd.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=884&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Annual average temperatures are projected to increase, with proportionally greater changes at higher latitudes. The top map shows observed temperature changes from 1986-2016 relative to 1901-1960. The lower maps show projected changes for mid-century (2036–2065) and late century (2070–2099) depending on high and low greenhouse gas emissions.</span>
<span class="attribution"><a class="source" href="https://toolkit.climate.gov/image/515">Fourth National Climate Assessment/NOAA NCEI/CICS-NC</a></span>
</figcaption>
</figure>
<p>In the end, saving lives from extreme heat is a complicated challenge requiring coordination across multiple levels of government, agencies and the civic and private sectors.</p>
<p>Some cities, including Phoenix, are <a href="https://www.phoenix.gov/heat">experimenting with heat offices</a> tasked with this coordination. But individuals have an important role to play as well. </p>
<p>In addition to knowing how to protect themselves, their loved ones and their neighbors, individuals can add their voices to the rising chorus calling on all levels of government and the private and civic sectors to take urgent steps to reduce heat risk.</p><img src="https://counter.theconversation.com/content/206737/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jason Vogel receives funding from Washington state that supports the University of Washington's Climate Impacts Group to conduct data modeling and provide technical assistance on climate impact analysis to Washington communities, businesses, and governments.</span></em></p><p class="fine-print"><em><span>Brian G. Henning receives funding from Gonzaga Center for Climate, Society, and the Environment to support teaching, scholarship, consulting, and capacity building. </span></em></p>
A new report lays out steps communities can take to help their residents survive heat waves as the risk of dangerous temperatures rises.
Jason Vogel, Interim Director, Climate Impacts Group, University of Washington
Brian G. Henning, Professor of Philosophy and Environmental Studies, Gonzaga University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/203932
2023-05-08T05:43:22Z
2023-05-08T05:43:22Z
Bold and innovative planning is delivering Australia’s newest city. But it will be hot – and can we ditch the colonial name?
<p>A massive project is unfolding in Sydney’s Western Parkland region. The building of a new city from the ground up is central to an infrastructure-led restructuring of metropolitan Sydney. The catalysts are the <a href="https://www.wpca.sydney/coordination/western-sydney-city-deal/">Western Sydney City Deal</a> and the <a href="https://infrastructurepipeline.org/project/western-sydney-airport">Western Sydney Airport</a> being built alongside the new Bradfield City. </p>
<p>Bradfield city is being developed on unceded Aboriginal land with complex ongoing settler-colonial legacies and high stakes for diverse First Nations communities – including the <a href="https://www.abs.gov.au/statistics/people/aboriginal-and-torres-strait-islander-peoples/census-population-and-housing-counts-aboriginal-and-torres-strait-islander-australians/latest-release">largest urban Indigenous population</a> in Australia. Yet it is named after a <a href="https://southwestvoice.com.au/bradfield-aerotropolis/">colonial figure with no connection to the land</a>.</p>
<p>Our <a href="https://www.sydney.edu.au/henry-halloran-trust/research-grants-and-programs/infrastructure-governance-incubator.html">case study research</a> acknowledges what is happening in the <a href="https://www.wpca.sydney/">Western Parkland development</a> as being at the forefront of urban and infrastructure governance across Australia. It’s particularly notable how all three tiers of government – federal, state and local – have come together in this massive project. </p>
<p>Yet we have also identified a range of concerns, including public consultation, project funding, urban heat and water demand, the need for affordable and public housing, and other social equity issues.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/523570/original/file-20230501-18-l8bw6m.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/523570/original/file-20230501-18-l8bw6m.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=362&fit=crop&dpr=1 600w, https://images.theconversation.com/files/523570/original/file-20230501-18-l8bw6m.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=362&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/523570/original/file-20230501-18-l8bw6m.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=362&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/523570/original/file-20230501-18-l8bw6m.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=455&fit=crop&dpr=1 754w, https://images.theconversation.com/files/523570/original/file-20230501-18-l8bw6m.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=455&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/523570/original/file-20230501-18-l8bw6m.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=455&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The new Western Parkland city and airport lie about 55km west of the Sydney CBD.</span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/3-planning-strategies-for-western-sydney-jobs-but-do-they-add-up-139386">3 planning strategies for Western Sydney jobs, but do they add up?</a>
</strong>
</em>
</p>
<hr>
<h2>City’s name is not a good start</h2>
<p>The case study is part of a three-year (2020-2023) research project, the <a href="https://www.sydney.edu.au/henry-halloran-trust/research-grants-and-programs/infrastructure-governance-incubator.html">Infrastructure Governance Incubator</a>, across three universities – Sydney, Melbourne and Monash. Our study includes 55 interviews with key stakeholders from all tiers of government, as well as non-government and community voices. </p>
<p>Participants from across the board have seen the “Bradfield” naming as a shameful decision. It’s in stark contrast to the positive steps towards supporting Indigenous voices throughout the project. These steps include the <a href="https://www.planning.org.au/aboutpianew/nsw-citations/presidents-award">award-winning</a> Recognise Country guidelines, Indigenous-led design projects, <a href="https://www.wpca.sydney/get-involved/koori-perspectives-circle/">a Koori Perspectives Circle</a>, and new Indigenous roles within government authorities to support engagement efforts. </p>
<p>In Australian cities, it is critical we explore the role of infrastructure in perpetuating settler-coloniality and in making space for Indigenous-led futures. The complex challenges of a case like this can inform important discussions about how we might improve infrastructure planning to produce just and sustainable approaches.</p>
<p>Our research participants saw a need for governments to give meaningful attention to building relationships and developing cross-cultural understandings. This involves early conversations with Aboriginal groups and adequate resourcing for engagement. Too often, these groups are brought on late in processes after key decisions are already made. </p>
<p>Interviewees stressed the importance of governments “learning to listen”. This requires having the openness to hear what is being said even if inconvenient. Many participants wanted to see Indigenous voices empowered in decision-making, not simply advisory.</p>
<p>“Listening” also means “listening to Country”. Part of demonstrating commitment to relationship building involves sustainably protecting Country. Early and ongoing public scrutiny is essential to ensure the project’s short-term approaches align with long-term perspectives on sustainable outcomes. It may also mean taking steps more slowly and carefully to get it right.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/indigenous-peoples-across-the-globe-are-uniquely-equipped-to-deal-with-the-climate-crisis-so-why-are-we-being-left-out-of-these-conversations-171724">Indigenous peoples across the globe are uniquely equipped to deal with the climate crisis – so why are we being left out of these conversations?</a>
</strong>
</em>
</p>
<hr>
<p>The state government could take some key actions. These include committing resources to advancing the <a href="https://theconversation.com/in-nsw-there-have-been-significant-wins-for-first-nations-land-rights-but-unprocessed-claims-still-outnumber-the-successes-186121">many Indigenous land claims</a> and applying exemptions to development barriers such as biodiversity offset obligations. These currently treat First Nation stakeholders like a developer, ignoring their long and ongoing care for Country.</p>
<p>Many participants also raised <a href="https://www.climatecouncil.org.au/urban-heat-island-effect-western-sydney/">serious environmental concerns</a>, including water management and <a href="https://wsroc.com.au/projects/project-turn-down-the-heat">extreme heat</a> in the new city. Heatwaves can be <a href="https://theconversation.com/why-western-sydney-is-feeling-the-heat-from-climate-change-more-than-the-rest-of-the-city-201477">5-10°C hotter</a> there than the rest of Sydney. </p>
<p>Some fundamentally questioned a massive greenfield development in such a vulnerable environment. Others saw this as a chance to make much-needed transformational changes to our planning systems. </p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1647826405013483522"}"></div></p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/why-western-sydney-is-feeling-the-heat-from-climate-change-more-than-the-rest-of-the-city-201477">Why Western Sydney is feeling the heat from climate change more than the rest of the city</a>
</strong>
</em>
</p>
<hr>
<h2>Focus on jobs overshadows other issues</h2>
<p>The political focus is on creating jobs in Western Sydney. Participants generally agreed it’s important to <a href="https://theconversation.com/jobs-deficit-drives-army-of-daily-commuters-out-of-western-sydney-139384">rebalance the metropolitan job market</a> and economy.</p>
<p>However, many were concerned this focus has come at the expense of attention to other aspects of inequity, including access to affordable and public housing, public health and social services.</p>
<p>In terms of metropolitan planning, the centralised way the new strategy was adopted is a problem. The concept came from the then Greater Sydney Commission and was supported by the <a href="https://www.wpca.sydney/about/the-western-parkland-city/">region’s councils</a>. </p>
<p>The communities of the wider Sydney region, however, were not given strategic alternatives to consider. In particular, the concept was not put to traditional Indigenous custodians before being adopted. </p>
<p>One of the alternatives might have acknowledged the outer west as the hottest part of Sydney. It could instead have considered development in cooler parts such as Dural or the Central Coast. These sites might have been better placed to manage global warming challenges. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/WSisVB00ZzA?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">A Western Sydney Parkland Authority video outlines the plans for Australia’s newest city.</span></figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/half-of-western-sydney-foodbowl-land-may-have-been-lost-to-development-in-just-10-years-190148">Half of Western Sydney foodbowl land may have been lost to development in just 10 years</a>
</strong>
</em>
</p>
<hr>
<h2>Governance is still a work in progress</h2>
<p>Our participants agreed the complexity of urban challenges requires a concerted effort to better integrate infrastructure decision-making. Part of the challenge is to overcome legacies of fragmented urban governance. It’s a result of divisions of responsibilities between tiers of government and siloed decision-making across and within these tiers.</p>
<p>The Western Sydney City Deal is generally seen as a major step towards better integration of all levels of government. Nevertheless, participants note important shortfalls. </p>
<p>City Deal funding committed to date is likely too little, given the major place-making ambitions. While it’s useful for short-term projects, local governments need solutions for their major long-term funding issues, especially in the face of new growth pressures. Lack of funding fuels existing cultures of competition between authorities.</p>
<p>The Western Sydney City Deal has had some welcome successes in improving collaboration between the three levels of government. Local governments have secured “<a href="https://theparks.nsw.gov.au/">seats at the table</a>”, where they have been able to renegotiate the terms of collaboration and governance.</p>
<p>However, important questions remain about how governments collaborate with community infrastructure sectors, non-government organisations and community advocates. Many have raised concerns about lack of meaningful inclusion or being engaged too late for meaningful impact.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/as-western-sydney-residents-grapple-with-climate-change-they-want-political-action-200917">As Western Sydney residents grapple with climate change, they want political action</a>
</strong>
</em>
</p>
<hr>
<p>An example of these issues is the three-year review required under the Western Sydney City Deal signed in 2018. An independent university group completed the review in 2021. It has never been released to the public. </p>
<p>Interviewees told us the review was productive and made useful governance recommendations. However, some suggested it was not released due to state government discomfort with the findings. </p>
<p>We strongly urge the newly elected state government to make the review public and commit to a timely release of all similar documents in future. This will help build trust with the community.</p><img src="https://counter.theconversation.com/content/203932/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Tooran Alizadeh receives funding from Henry Halloran Research Trust and Australian Research Council. The Infrastructure Governance Incubator is funded by the trust and partnered by the Planning Institute of Australia.</span></em></p><p class="fine-print"><em><span>Glen Searle receives funding from the Australian Housing and Urban Research Institute. </span></em></p><p class="fine-print"><em><span>Rebecca Clements receives funding from the Henry Halloran Research Trust. </span></em></p>
The new city bears a colonial name and there are questions about locating it in the hottest part of Sydney, but we are also seeing all 3 tiers of government work together in an innovative way.
Tooran Alizadeh, Associate Professor in Urbanism and Infrastructure, ARC Future Fellow, University of Sydney
Glen Searle, Honorary Associate Professor in Planning, University of Queensland, University of Sydney
Rebecca Clements, Postdoctoral Research Associate, Faculty of Architecture, Building and Planning, University of Sydney
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/201477
2023-03-26T23:17:48Z
2023-03-26T23:17:48Z
Why Western Sydney is feeling the heat from climate change more than the rest of the city
<p>Global warming has led to higher summer temperatures across Sydney over the past 30 years. However, our data analysis shows very hot summer days are becoming much more common in Western Sydney than in coastal Sydney. These hotter summers are also getting longer.</p>
<p>Although January and February are usually the warmest months, Greater Sydney summers now extend from December to March. For example, the city’s <a href="https://www.news.com.au/breaking-news/sydney-breaks-165yo-milestone-after-hottest-four-consecutive-days-in-march-on-record/news-story/d8a422664e86ec5bb78696d013fe756d">record-setting March</a> has been the hottest month this summer. <a href="https://australianinstitute.org.au/wp-content/uploads/2020/12/P834-Out-of-Season-WEB.pdf">Summers are expanding and winters shrinking</a> across subtropical and temperate Australia.</p>
<p>Our <a href="https://www.mdpi.com/2225-1154/11/4/76">newly published analysis</a> of temperature data from 1962-2021 shows one in ten days in summer reached temperatures of 35.4°C or more in Western Sydney. That’s a full 5°C hotter than near the coast, where one in ten days exceeded 30.4°C. One in 20 days reached 37.8°C or more in the west – the equivalent figure near the coast was 33.6°C.</p>
<p>Furthermore, very hot days have become more common over the past 30 years in Western Sydney, but not near the coast. The difference in maximum temperatures between the regions can be as much as 10°C. </p>
<p>So what explains the startling difference between two parts of the same city?
In our research, we show the influence of four climate drivers: El Niño-La Niña, Southern Annular Mode, global temperatures and local Tasman Sea temperatures.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1494049823179546624"}"></div></p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/western-sydney-will-swelter-through-46-days-per-year-over-35-c-by-2090-unless-emissions-drop-significantly-177056">Western Sydney will swelter through 46 days per year over 35°C by 2090, unless emissions drop significantly</a>
</strong>
</em>
</p>
<hr>
<h2>Extreme heat is getting worse in the west</h2>
<p>In <a href="https://www.mdpi.com/2225-1154/11/4/76">our study</a>, we calculated the threshold values for the top 10% and top 5% of summer maximum temperatures (the 90th and 95th percentiles) recorded for coastal Sydney (at Observatory Hill) and Western Sydney (at Richmond, about 50km to the north-west) over the 60 years from 1962-2021. </p>
<p>Comparing the first 30-year period, 1962-1991, to the second 30-year period, 1992-2021, revealed a stark difference in maximum temperature trends in Sydney’s west and nearer the coast.</p>
<p>In Richmond, the number of days with temperatures above 35.4°C and 37.8°C increased by 120 days and 64 days, respectively. In contrast, Observatory Hill recorded decreases of 4 and 52 days in days above the 90th and 95th percentiles (over 30.4°C and 33.6°C). </p>
<h2>What explains these differences?</h2>
<p>Poorly planned development in the west and its distance from coastal sea breezes explains part of the disparity between inland and coastal Sydney. But we also found the increase in extreme heat in Western Sydney is due to Australian climate drivers being amplified by increased global and Tasman Sea temperatures. </p>
<p>Using machine-learning techniques, we were able to attribute temperature differences to the influences of these climate drivers and their interactions with each other. The results show common, highly influential climate drivers for both regions: </p>
<ul>
<li><p>the <a href="http://www.bom.gov.au/climate/ahead/about-ENSO-outlooks.shtml">Niño3.4</a>, (an indicator of sea-surface temperatures in the tropical central Pacific Ocean, which drive El Niño and La Niña events)</p></li>
<li><p>the <a href="http://www.bom.gov.au/climate/enso/history/ln-2010-12/IOD-what.shtml">Indian Ocean Dipole</a> (the difference in ocean temperatures between the eastern and western sides of the Indian Ocean)</p></li>
<li><p>the combination of the <a href="http://www.bom.gov.au/climate/sam/">Southern Annular Mode</a> (the movement of winds and weather systems to Australia’s south) with the <a href="http://www.bom.gov.au/climate/enso/history/ln-2010-12/SOI-what.shtml">Southern Oscillation</a> (large-scale changes in sea-level air pressure between Tahiti and Darwin)</p></li>
<li><p>the combination of global temperature with the Southern Annular Mode. </p></li>
</ul>
<p>Tasman Sea and global sea surface temperatures have had far more influence on coastal Sydney than on inland Western Sydney.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/hYADNIiXVqI?wmode=transparent&start=30" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">An increase in extreme heat days is having wide-ranging impacts on Western Sydney.</span></figcaption>
</figure>
<p>Despite the importance of rising temperatures in Sydney and particularly in Western Sydney, there has been little focus on their links with large-scale climate drivers. Our findings underline the worsening situation in Western Sydney compared with coastal Sydney. </p>
<p>Studies that employ machine-learning techniques or comparative analyses are typically done in regions of smaller populations. Western Sydney is home to <a href="https://www.westernsydney.edu.au/rcegws/rcegws/About/about_greater_western_sydney">more than 2.5 million people</a>. </p>
<p>Its economic development and fast-growing population have led to higher concentrations of buildings and man-made surfaces, which absorb and retain more heat. Known as the <a href="https://www.planning.nsw.gov.au/Policy-and-Legislation/Resilience-and-natural-hazard-risk/Urban-heat">urban heat island effect</a>, it compounds the impacts of climate change. Development on this scale also presents complex challenges for policy planning and resource management.</p>
<figure class="align-center ">
<img alt="Aerial view of new housing development" src="https://images.theconversation.com/files/517098/original/file-20230323-16-1k0hq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/517098/original/file-20230323-16-1k0hq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/517098/original/file-20230323-16-1k0hq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/517098/original/file-20230323-16-1k0hq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/517098/original/file-20230323-16-1k0hq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/517098/original/file-20230323-16-1k0hq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/517098/original/file-20230323-16-1k0hq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The growth of Western Sydney is driving an increase in built-up areas, like this housing estate, that absorb and retain more heat.</span>
<span class="attribution"><span class="source">Image: Western Sydney Regional Organisation of Councils (WSROC)</span></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/half-of-western-sydney-foodbowl-land-may-have-been-lost-to-development-in-just-10-years-190148">Half of Western Sydney foodbowl land may have been lost to development in just 10 years</a>
</strong>
</em>
</p>
<hr>
<h2>What does this mean for the people of Western Sydney?</h2>
<p>Identifying the climate drivers that most influence maximum temperatures is crucial for Sydney’s planning. It matters for infrastructure development, health and socioeconomic wellbeing in Western Sydney in particular. </p>
<p>Two-thirds of Sydney’s population growth by 2036 is projected to be in Western Sydney. By then an estimated <a href="https://westernsydney.org.au/blog/2022/4/22/j41ye3z8pwmrqgsk8gq8avw9ig8ynt">3.5 million residents</a> will be exposed to more extreme summer heat.</p>
<p>The escalating climate crisis is widening Sydney’s health and socioeconomic divide. Western Sydney has <a href="https://www.westernsydney.edu.au/rcegws/rcegws/About/about_greater_western_sydney">higher unemployment and a larger proportion of lower-income families</a> than the rest of the city. </p>
<p>It’s imperative to understand how Western Sydney differs from near-coastal Sydney, and to plan accordingly. Some local councils in the west, such as Blacktown, are already trialling <a href="https://www.smh.com.au/national/nsw/homes-aren-t-safe-western-sydney-preparesevacuation-shelters-for-hot-summers-20220505-p5aioj.html">heat refuges</a> to reduce the growing risks for residents.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1349466372024094720"}"></div></p>
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<strong>
Read more:
<a href="https://theconversation.com/as-western-sydney-residents-grapple-with-climate-change-they-want-political-action-200917">As Western Sydney residents grapple with climate change, they want political action</a>
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<p>Longer and more intense summers are driving longer heatwaves and droughts. It’s leading to more bushfires of greater intensity, such as the <a href="https://apo.org.au/node/309191">2019-20 bushfires</a>. </p>
<p>The <a href="https://www.themandarin.com.au/182988-policymakers-on-notice-human-induced-climate-change/">economic burden</a> of dealing with these disastrous events is increasing. <a href="https://www.climatecouncil.org.au/wp-content/uploads/2021/01/hitting-home-report-V7-210122.pdf">According to the Climate Council</a>, the costs associated with extreme weather events in Australia have more than doubled since the 1970s. Australians are now five times more likely to be displaced by such events than people living in Europe.</p>
<p>The urban heat island effect already <a href="https://www.climatecouncil.org.au/urban-heat-island-effect-western-sydney/">permeates Western Sydney</a>. Recent extreme temperatures have been close to the limits of human endurance. The human body’s ability to cool itself <a href="https://australiainstitute.org.au/wp-content/uploads/2022/01/HeatWatch-2022-WEB.pdf">declines above 35°C</a>, especially in humid conditions.</p>
<p>The impacts of more frequent extreme heat, compounded by heat island effects, are greatest for vulnerable populations such as children in classrooms without air conditioning or low-income family households. Their situation is in stark contrast to the experience of residents of cooler coastal areas. </p>
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<strong>
Read more:
<a href="https://theconversation.com/climate-change-hits-low-income-earners-harder-and-poor-housing-in-hotter-cities-is-a-disastrous-combination-180960">Climate change hits low-income earners harder – and poor housing in hotter cities is a disastrous combination</a>
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<img src="https://counter.theconversation.com/content/201477/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
Very hot days in Western Sydney are typically 5 degrees hotter than parts of the city close to the coast and are becoming more common, but only in the west. Four climate drivers explain the difference.
Milton Speer, Visiting Fellow, School of Mathematical and Physical Sciences, University of Technology Sydney
Anjali Gupta, Lecturer, School of Mathematical and Physical Sciences, and Researcher, Centre for Forensic Science, University of Technology Sydney
Joanna Wang, Senior Lecturer, School of Mathematics and Physical Sciences, University of Technology Sydney
Joshua Hartigan, PhD Candidate, School of Mathematical and Physical Sciences, University of Technology Sydney
Lance M Leslie, Professor, School of Mathematical And Physical Sciences, University of Technology Sydney
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/200917
2023-03-06T19:03:12Z
2023-03-06T19:03:12Z
As Western Sydney residents grapple with climate change, they want political action
<p><a href="https://www.westernsydney.edu.au/rcegws/rcegws/About/about_greater_western_sydney">Western Sydney</a> is being <a href="https://theconversation.com/half-of-western-sydney-foodbowl-land-may-have-been-lost-to-development-in-just-10-years-190148">developed rapidly</a>, increasing its already high vulnerability to climate change. One day in January 2020, Penrith was the <a href="https://www.smh.com.au/national/nsw/the-sydney-suburbs-that-hit-50c-last-summer-20201002-p561by.html">hottest place on Earth</a>. Residents who have endured searing heat, <a href="https://theconversation.com/what-do-sydney-and-other-cities-have-in-common-dust-127515">bushfires</a>, heavy rain, <a href="https://theconversation.com/under-resourced-and-undermined-as-floods-hit-south-west-sydney-our-research-shows-councils-arent-prepared-178293">floods</a> and <a href="https://www.abc.net.au/news/2022-03-10/enormous-repair-bill-for-flood-damaged-across-sydney-nsw/100896228">huge damage bills</a> in recent years are <a href="https://www.bushfiresurvivors.org/">now a political force</a>. </p>
<p>In addition to being overwhelmed by such events, residents sometimes feel they are not heard. During the COVID-19 lockdowns, essential workers in Western Sydney felt alienated and over-policed, and demanded their predicaments be taken into account. In the recent federal election, <a href="https://www.abc.net.au/news/2022-05-23/mixed-results-in-western-sydney-after-federal-election-2022/101090328">local candidates gained traction</a> due to their trusted presence in the community. </p>
<p>The preferences of the region’s culturally and economically diverse voters are <a href="https://www.abc.net.au/news/2022-05-23/mixed-results-in-western-sydney-after-federal-election-2022/101090328">no longer predictable</a>. They could also have a substantial influence on the March 25 state election. </p>
<p>Our <a href="https://doi.org/10.26183/t4sz-gh64">newly published report</a>, Climate Matters to Western Sydney: Everyday Sustainability Practices in Uncertain Times, documents 100 residents’ responses to our survey about their environmental practices and their struggles to secure their families’ wellbeing. Their aspirations for a sustainable future emerge clearly from the survey responses. </p>
<p>Our findings challenge the idea that Western Sydney residents’ financial concerns, such as costs of living and energy, are somehow separate from and outweigh their environmental concerns. There is a strong desire to adapt creatively to the challenges of an uncertain climate.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/western-sydney-will-swelter-through-46-days-per-year-over-35-c-by-2090-unless-emissions-drop-significantly-177056">Western Sydney will swelter through 46 days per year over 35°C by 2090, unless emissions drop significantly</a>
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<h2>Shared air, shared infrastructure</h2>
<p>In 1837, British inventor and mathematician Charles Babbage wrote: </p>
<blockquote>
<p>The air itself is one vast library on whose pages are forever written all that man has ever said or woman whispered.</p>
</blockquote>
<p>The <a href="https://its-airborne.org/covid19-timeline.html#event-fact-the-principal-mechanism-of-covid-19-infection-is-aerosol">COVID pandemic</a> made it impossible to ignore that the quality of the air around us is measured and qualified, and it’s both intimately <a href="https://culanth.org/fieldsights/viral-nationalism">personal and shared</a>. Air quality is a signature of wellbeing – it’s pivotal to household comfort and sustainable cities. Our respondents understand the complexities of these interactions with air very well.</p>
<p>As with <a href="https://journals.sagepub.com/doi/10.1177/02637758231153399">earlier research</a>, we’ve found a divide between people who have air conditioning and those who don’t. More than half of our study participants didn’t have it at home. </p>
<p>However, air-conditioning users are more attuned to their environment than the idea of a “<a href="https://theconversation.com/the-new-climate-denial-using-wealth-to-insulate-yourself-from-discomfort-and-change-199101">new climate denial</a>” would suggest. Three-quarters said they had a comfort or precise temperature threshold, ranging from 22°C to 40°C, for turning it on. </p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-new-climate-denial-using-wealth-to-insulate-yourself-from-discomfort-and-change-199101">The new climate denial? Using wealth to insulate yourself from discomfort and change</a>
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<p>Most respondents, including those with air conditioning, used blinds to cope with increasing heat. They also used fans and cross-ventilation, shading and planting, and went to air-conditioned shared spaces like libraries and shopping malls to cope with increasing heatwaves. </p>
<h2>It’s not all about cost of living</h2>
<p>Our participants told us the ways that the movement of both air and water is crucial for their wellbeing, household comfort and urban sustainability. For example, one Parramatta resident of mixed heritage in their 50s reported: </p>
<blockquote>
<p>I wrap myself in wet clothes – neck, head, douse myself in water in the yard – when working in the garden.</p>
</blockquote>
<p>Residents adapt to changing environmental conditions using both low and high-tech solutions to balance wellbeing, sustainability and cost. This includes using blinds, fans and other ways of regulating the temperature. They also design solar-passive solutions themselves, such as vines and other external shading. Planners often overlook these solutions, but they are crucial to household comfort. </p>
<p>Air is both common and private, affected by energy, architecture and urban gardening. Coming out of the COVID experience, being at home in Western Sydney increasingly extends beyond the walls of the house to <a href="https://doi.org/10.26190/unsworks/20059">include community and creative spaces</a>, parks and gardens. While half our respondents reported staying put during heatwaves, the other half sought out public pools and beaches or common air-conditioned spaces, such as shopping centres. </p>
<p>Our respondents were emphatic: the cost of living is not just its price. While households play a significant role in climate change and contribute to environmental pollution and greenhouse gas emissions, they also act in ways that promote ecological sustainability. These extend from preserving local parks and creating community gardens to pressuring federal and state governments to act on their responsibilities. For example, a resident told us: </p>
<blockquote>
<p>Insist that green cover be measured and monitored very publicly […] insist that
tree cover remains. Identify all sites that can remain parks and totally protect
them from any private enterprises, leases and developments.</p>
</blockquote>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/half-of-western-sydney-foodbowl-land-may-have-been-lost-to-development-in-just-10-years-190148">Half of Western Sydney foodbowl land may have been lost to development in just 10 years</a>
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</em>
</p>
<hr>
<h2>Shared solutions for shared problems</h2>
<p>Councils, <a href="https://www.endeavourenergy.com.au/modern-grid/resilience-strategy">electricity networks</a> and other organisations at the front lines of the climate crisis are asking profound questions about how we live together: where will people go during the next catastrophic fires? How can we create community refuges that will be safe and have dependable communications and electricity? </p>
<p>These are not questions that can be answered simply with more housing supply or lower interest rates. While private homes can offer a <a href="https://theconversation.com/future-home-havens-australians-likely-to-use-more-energy-to-stay-in-and-save-money-199672">refuge in times of crisis</a>, acknowledging our air, water and even electricity are common resources – our “vast library” – helps start a different discussion about responsibilities, rights and our shared existence. </p>
<p>The voters of Western Sydney understand this, and politicians ignore it at their peril.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/future-home-havens-australians-likely-to-use-more-energy-to-stay-in-and-save-money-199672">Future home havens: Australians likely to use more energy to stay in and save money</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/200917/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Declan Kuch has received funding from the Australian Research Council, Australian Renewable Energy Agency and Cooperative Research Centres.</span></em></p><p class="fine-print"><em><span>Stephen Healy has received funding from the Australian Research Council. </span></em></p><p class="fine-print"><em><span>Malini Sur and Sukhmani Khorana do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
Voters in the region have long been seen as caring more about their finances than green issues. But living through extreme heat, rain and floods has them focused on living with climate change.
Declan Kuch, Vice Chancellor's Research Fellow, Institute for Culture and Society, Western Sydney University
Malini Sur, Senior Research Fellow, Institute for Culture and Society, Western Sydney University
Stephen Healy, Associate Professor, Human Geography and Urban Studies School of Social Sciences/ Institute for Culture and Society, Western Sydney University
Sukhmani Khorana, Associate Professor, Faculty of Arts, Design and Architecture, UNSW Sydney
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/198960
2023-02-01T13:51:25Z
2023-02-01T13:51:25Z
Planting more trees could reduce premature heat-related deaths in European cities by a third – new research
<figure><img src="https://images.theconversation.com/files/507592/original/file-20230201-583-dxwqbe.jpg?ixlib=rb-1.1.0&rect=7%2C0%2C5259%2C3482&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Amsterdam, Netherlands.
Planting trees in urban areas can reduce the impacts of urban heat islands.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/amsterdam-netherlands-12-june-2022-couple-2179666331">Dutch_Photos/Shutterstock</a></span></figcaption></figure><p>Urban development leads to fewer shaded areas and more heat-absorbing paved surfaces. Cities tend to be warmer than their rural surroundings as a result, a phenomenon known as the <a href="https://www.epa.gov/green-infrastructure/reduce-urban-heat-island-effect#:%7E:text=%22Urban%20heat%20islands%22%20occur%20when,heat%2Drelated%20illness%20and%20mortality.">urban heat island (UHI) effect</a>. During the summer daytime, cities can be <a href="https://www.epa.gov/heatislands/heat-island-compendium">up to 12°C</a> hotter than rural areas.</p>
<p>UHIs are a major environmental hazard for urban dwellers. <a href="https://jech.bmj.com/content/64/9/753.short">Research</a> suggests that for each 1°C rise in temperature, the risk of death increases by between 1% and 3%. Heat exposure also increases the risk of suffering <a href="https://www.sciencedirect.com/science/article/pii/S2542519622001176">cardiovascular</a> and <a href="https://pubmed.ncbi.nlm.nih.gov/22531668/">respiratory illnesses</a>. </p>
<p><a href="https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(22)02585-5/fulltext">Our research</a> calculated the death rates of urban inhabitants across 93 European cities (57 million people in total) between June and August 2015. We found that 6,700 premature deaths during this period were linked to UHIs. </p>
<p>But the pace of <a href="https://www.climate.gov/news-features/understanding-climate/climate-change-global-temperature">global warming</a> is accelerating and <a href="https://iopscience.iop.org/article/10.1088/1748-9326/ab4b71">2 billion to 3 billion</a> people are expected to live in cities by 2050. The health impacts of UHIs will likely worsen in the coming years. </p>
<p>Several strategies exist to protect urban residents from the impacts of heat. These include <a href="https://www.sciencedirect.com/science/article/abs/pii/S0378778814009700?via%3Dihub">covering roofs and facades in vegetation</a> (green roofs), decorating them in lighter colours, and replacing paved surfaces with areas of vegetation. Our modelling revealed that one-third (2,644) of UHI deaths in Europe could be prevented by increasing tree canopy cover to 30% in every urban neighbourhood.</p>
<figure class="align-center ">
<img alt="A graphic showing why urban areas are hotter than nearby rural areas." src="https://images.theconversation.com/files/507545/original/file-20230201-21-prrajt.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/507545/original/file-20230201-21-prrajt.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/507545/original/file-20230201-21-prrajt.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/507545/original/file-20230201-21-prrajt.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/507545/original/file-20230201-21-prrajt.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/507545/original/file-20230201-21-prrajt.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/507545/original/file-20230201-21-prrajt.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The urban heat island effect.</span>
<span class="attribution"><a class="source" href="https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(22)02585-5/fulltext">Èlia Pons/ISGlobal</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<h2>Urban tree guidelines</h2>
<p>This <a href="https://link.springer.com/article/10.1007/s11676-022-01523-z">target</a> was established last year by a study published in the <a href="https://www.springer.com/journal/11676/">Journal of Forestry Research</a>. Since then it has been adopted by several cities worldwide, including <a href="https://www.c40knowledgehub.org/s/article/Trees-for-Life-Master-Plan-for-Barcelona-s-Trees-2017-2037?language=en_US">Barcelona</a> (Spain), <a href="https://bristolgreencapital.org/new-ambitious-target-launched-double-city-tree-canopy-cover-2050/">Bristol</a> (UK), <a href="https://www.phila.gov/programs/greenworks/">Philadelphia</a> (US), <a href="https://www.environment.act.gov.au/cc">Canberra</a> (Australia) and <a href="https://www.seattle.gov/documents/Departments/Trees/Mangement/Canopy/Seattle2016CCAFinalReportFINAL.pdf">Seattle</a> (US). </p>
<p>Urban forests regulate a city’s microclimates effectively. <a href="https://www.sciencedirect.com/science/article/pii/S2210670721008301?via%3Dihub">Research</a> found that urban forests cooled the average temperature of 601 European cities by 1.1°C and by as much as 2.9°C.</p>
<p>Leafy neighbourhoods are also linked to improved mental and physical health. In California, a <a href="https://www.sciencedirect.com/science/article/abs/pii/S1353829216301332">10% increase</a> in neighbourhood tree cover has been associated with a 19% reduction in rates of obesity and type 2 diabetes.</p>
<p>Surrounding greenness, particularly greenness at schools, can be important in the <a href="https://www.pnas.org/doi/abs/10.1073/pnas.1503402112">cognitive development</a> of children. Cognitive testing of schoolchildren in Barcelona revealed a 6% better working memory development in children at schools with the highest levels of greenness compared to those at the least-green schools.</p>
<h2>More trees means less heat</h2>
<p>We found substantial variation in UHI death rates across European cities. In 2015, Gothenburg in Sweden recorded no premature UHI deaths, while urban heat was responsible for 32 premature deaths per 100,000 people in the Romanian city Cluj-Napoca.</p>
<p>The cities with the highest UHI death rates were in southern and eastern Europe. Most of these cities generally had low tree coverage and recorded the highest UHI effect. </p>
<p>Just 3.3% of Thessaloniki in Greece is covered by trees, resulting in urban temperatures 2.8°C higher than the surrounding area. By contrast, 27% of Gothenburg is covered by trees, delivering an UHI effect of just 0.4°C. </p>
<p>Overall, southern European cities will benefit most from increasing their tree cover. Our model estimates that Barcelona could reduce its UHI death rate by 60% by meeting the 30% tree coverage target.</p>
<figure class="align-center ">
<img alt="A street view of Gothenburg with trees lining the road and colourful buildings in the background." src="https://images.theconversation.com/files/507559/original/file-20230201-17-5z86tz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/507559/original/file-20230201-17-5z86tz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/507559/original/file-20230201-17-5z86tz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/507559/original/file-20230201-17-5z86tz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/507559/original/file-20230201-17-5z86tz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/507559/original/file-20230201-17-5z86tz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/507559/original/file-20230201-17-5z86tz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The urban heat island effect is minimal in Gothenburg, Sweden.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/goteborg-sweden-august-25-2016-view-756809815">trabantos/Shutterstock</a></span>
</figcaption>
</figure>
<h2>The way forward</h2>
<p>But the intensity of the UHI effect depends on multiple factors and is specific to each city. While vegetation cover influences urban temperatures during the day, nighttime temperatures are driven by the height of the <a href="https://en.wikipedia.org/wiki/Urban_canyon">urban canyon</a>.</p>
<p>The cooling capacity of a tree canopy also varies. This depends on the type and size of trees, which are themselves contingent on the city’s natural climate and the degree to which trees are maintained.</p>
<p>Drier climates, like Thessaloniki, favour smaller trees that have fewer leaves. By contrast, Gothenburg’s cooler and wetter climate favours larger and leafier trees that provide better protection from daytime heat.</p>
<p>Due to this variation, we built a tool called the Cooling Efforts Index. The index assesses how much cooling can be achieved in each city for every 1% increase in tree cover. We also generated high-resolution maps for each city to identify the areas where tree coverage is needed most urgently.</p>
<p>In some cities, the majority of urban forests will grow on private land. Tree planting programmes must therefore encourage residents to plant trees.</p>
<p>In Victoria, a city on Canada’s western coast, <a href="https://www.victoria.ca/EN/main/residents/parks/urban-forest/trees-in-cities-challenge.html">neighbourhoods are offered</a> a CAD$1,000 (£610) grant to plant residential trees. So far, over 78 trees have been planted on private property across the city.</p>
<p>Space can also be a major constraint in compact urban areas. So increasing tree cover to 30% may be challenging for some European cities. </p>
<p>But each city can adapt this target to its local context. For example, a lower tree canopy target can be combined with alternative measures like green roofs in compact urban areas. </p>
<p>Terrace roofs account for 67% of <a href="https://www.c40knowledgehub.org/s/article/Trees-for-Life-Master-Plan-for-Barcelona-s-Trees-2017-2037?language=en_US">Barcelona’s</a> roof surface area. As the city’s urban population continues to rise, the city council has launched a <a href="https://www.c40knowledgehub.org/s/article/Guide-to-living-terrace-roofs-and-green-roofs?language=en_US">guide</a> to transform roofs into areas with partial or total plant cover. The guide sets out the social and environmental benefits of green roofs and offers advice for choosing the right kind of terrace roof for the building.</p>
<figure class="align-center ">
<img alt="View from the rooftop terrace overlooking Barcelona's skyline." src="https://images.theconversation.com/files/507565/original/file-20230201-3729-xvmqx2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/507565/original/file-20230201-3729-xvmqx2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/507565/original/file-20230201-3729-xvmqx2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/507565/original/file-20230201-3729-xvmqx2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/507565/original/file-20230201-3729-xvmqx2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/507565/original/file-20230201-3729-xvmqx2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/507565/original/file-20230201-3729-xvmqx2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Terrace roofs account for 67% of Barcelona’s roof surface area.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/barcelona-spain-june-1-2022-view-2187870367">Kirk Fisher/Shutterstock</a></span>
</figcaption>
</figure>
<p>Incorporating urban green infrastructure into cities should make them more resilient to climate change. But planting trees may not be enough. Tree growth is a long processes and around half of newly-planted trees <a href="https://www.sciencedirect.com/science/article/pii/S1618866711000422">die within two years</a>. Preserving existing trees and complementing tree planting schemes with other measures that reduce the intensity of UHIs, such as reducing car use, are similarly important.</p>
<p>Urban trees provide substantial public health and environmental benefits. Our study suggests that by increasing tree coverage, premature UHI deaths in European cities can be reduced. But for the resilience of cities to increase, it remains important to combine greater tree coverage with other urban green infrastructure.</p>
<p><em>The headline of this article was amended to make clear it referred to heat-related deaths and not all premature deaths.</em></p>
<hr>
<figure class="align-right ">
<img alt="Imagine weekly climate newsletter" src="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p><strong><em>Don’t have time to read about climate change as much as you’d like?</em></strong>
<br><em><a href="https://theconversation.com/uk/newsletters/imagine-57?utm_source=TCUK&utm_medium=linkback&utm_campaign=Imagine&utm_content=DontHaveTimeTop">Get a weekly roundup in your inbox instead.</a> Every Wednesday, The Conversation’s environment editor writes Imagine, a short email that goes a little deeper into just one climate issue. <a href="https://theconversation.com/uk/newsletters/imagine-57?utm_source=TCUK&utm_medium=linkback&utm_campaign=Imagine&utm_content=DontHaveTimeBottom">Join the 10,000+ readers who’ve subscribed so far.</a></em></p>
<hr><img src="https://counter.theconversation.com/content/198960/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mark Nieuwenhuijsen receives funding from European Union Horizon funding </span></em></p><p class="fine-print"><em><span>Meelan Thondoo and Tamara Iungman do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
In 2015, 6,700 premature deaths were caused by urban heat – this can be reduced by a third by planting more trees.
Meelan Thondoo, Research Associate, MRC Epidemiology Unit, University of Cambridge
Mark Nieuwenhuijsen, Research Professor ISGlobal Barcelona and Professorial Fellow, ACU Melbourne, Australian Catholic University
Tamara Iungman, PhD researcher, Barcelona Institute for Global Health (ISGlobal)
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/196389
2023-01-17T01:11:23Z
2023-01-17T01:11:23Z
As heatwaves and floods hit cities worldwide, these places are pioneering solutions
<p>Climate change is going just as badly for cities as we have been warned it would. Extreme weather is <a href="https://www.theguardian.com/environment/2022/nov/16/devastating-floods-in-nigeria-were-80-times-more-likely-because-of-climate-crisis">increasingly common</a> and <a href="https://www.bbc.com/news/world-asia-india-61242341">severe</a> globally. Australian cities have endured <a href="https://www.hrw.org/news/2022/03/21/australia-extreme-heat-threatens-lives">a number</a> of recent <a href="https://www.theage.com.au/politics/federal/floods-cost-economy-5-billion-last-year-20230112-p5cc1t.html">disastrous events</a>. </p>
<p>It’ll get worse, too. The Intergovernmental Panel on Climate Change (IPCC) <a href="https://www.ipcc.ch/report/ar6/wg2/downloads/outreach/IPCC_AR6_WGII_FactSheet_HumanSettlements.pdf">factsheet</a> outlining impacts on human settlements is a very sobering read. It also pithily sums up the situation cities face:</p>
<blockquote>
<p>Concentrated risk and concentrated opportunity for action.</p>
</blockquote>
<p>Implicit in this wording is a hopeful truth: adapting to climate change is a daunting task, but the “how” is not a mystery. The opportunity is right in front of us, in our streets, buildings and parklands. Around the world we are seeing effective retrofitting of cities to adapt to more extreme weather. </p>
<p>Here are a few inspiring exemplars. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/a-climate-scientist-on-the-planets-simultaneous-disasters-from-pakistans-horror-floods-to-europes-record-drought-189626">A climate scientist on the planet's simultaneous disasters, from Pakistan’s horror floods to Europe’s record drought</a>
</strong>
</em>
</p>
<hr>
<h2>Keeping the city cool</h2>
<p>Planting trees to create shade is an obvious response to hot weather. However, in many cities it’s still a <a href="https://theconversation.com/thousands-of-city-trees-have-been-lost-to-development-when-we-need-them-more-than-ever-132356">struggle just to stop the losses of trees</a>. Future hot, dry climates will <a href="https://theconversation.com/climate-change-threatens-up-to-100-of-trees-in-australian-cities-and-most-urban-species-worldwide-188807">add to the challenge</a> of urban greening. </p>
<p>Medellin in Colombia is one city making inspiring progress on this front. With an urban greening budget of US$16.3 million, it has created a network of 30 “<a href="https://www.c40knowledgehub.org/s/article/Cities100-Medellin-s-interconnected-green-corridors?language=en_US">green corridors</a>” through the city. These have reduced urban heat island effects by 2°C three years into the program. As these densely vegetated corridors mature, they are expected to eventually deliver 4-5°C of cooling. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/503937/original/file-20230111-12-lxrzxd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/503937/original/file-20230111-12-lxrzxd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/503937/original/file-20230111-12-lxrzxd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/503937/original/file-20230111-12-lxrzxd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/503937/original/file-20230111-12-lxrzxd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/503937/original/file-20230111-12-lxrzxd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/503937/original/file-20230111-12-lxrzxd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">One of Medellin’s 30 green corridors with dense tree and understorey plantings runs along La Playa Avenue.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/climate-change-threatens-up-to-100-of-trees-in-australian-cities-and-most-urban-species-worldwide-188807">Climate change threatens up to 100% of trees in Australian cities, and most urban species worldwide</a>
</strong>
</em>
</p>
<hr>
<p>Vienna, Austria, has had an <a href="https://www.wien.gv.at/umweltschutz/raum/uhi-strategieplan.html">urban heat island strategy</a> in place since 2018. It includes planting 4,500 trees each year and <a href="https://www.wien.gv.at/amtshelfer/umwelt/umweltschutz/naturschutz/fassadenbegruenung.html">subsidies</a> for street-facing green walls.</p>
<p>The city has developed a series of “<a href="https://www.wien.gv.at/verkehr/strassen/coole-strassen-plus.html">cool streets</a>” – traffic-calmed spaces with light-coloured road surfaces, “fog showers” that activate on hot days, water features, shade trees and drinking fountains. Eighteen cool streets were delivered as pop-ups, with another four in place permanently to provide refuges on hot days. Vienna also has an extensive network of <a href="https://www.politico.eu/article/cities-save-lives-heat-wave-green-vienna-paris-nuremberg-madrid/">public swimming pools</a> where residents can cool off. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/503942/original/file-20230111-24-nqlofo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Park with trees and fountains" src="https://images.theconversation.com/files/503942/original/file-20230111-24-nqlofo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/503942/original/file-20230111-24-nqlofo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=363&fit=crop&dpr=1 600w, https://images.theconversation.com/files/503942/original/file-20230111-24-nqlofo.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=363&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/503942/original/file-20230111-24-nqlofo.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=363&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/503942/original/file-20230111-24-nqlofo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=456&fit=crop&dpr=1 754w, https://images.theconversation.com/files/503942/original/file-20230111-24-nqlofo.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=456&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/503942/original/file-20230111-24-nqlofo.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=456&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Esterhazy park was redesigned in 2020 as Vienna’s first ‘cooling park’, with mist sprays lowering the temperature on hot days.</span>
<span class="attribution"><a class="source" href="https://www.wien.gv.at/presse/bilder/2020/04/26/20191106_est_lo_schaubild-1_coolspot-c-carla-lo-jpg">Carla Lo/City of Vienna</a></span>
</figcaption>
</figure>
<h2>Limiting flood damage</h2>
<p>Urban green space can also be valuable for intercepting and absorbing stormwater to prevent flooding. </p>
<p>A spectacular example is <a href="https://www.governmentarchitect.nsw.gov.au/resources/case-studies/2017/11/bishan-ang-mo-kio-park">Bishan-Ang Mo Kio Park</a> in Singapore. It was the site of a concrete drainage canal that was transformed into a 3.2km winding stream in 2012. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/-KLtr-vKmDw?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Bishan Park has become one of Singapore’s most popular parks since a utilitarian concrete channel was transformed into a naturalised river landscape.</span></figcaption>
</figure>
<p>The 62-hectare park along the gently sloping banks of the stream serves a densely developed residential area. In wet conditions, the stream swells up to 100 metres wide. As stormwater gently flows downstream, it drains away into the landscape. </p>
<p>Since the park was created, visitor numbers have doubled to 6 million a year. Biodiversity has increased 30%. </p>
<p>A very urban version of this approach is the “floodable square”. A good example is Rotterdam’s <a href="https://www.urbanisten.nl/work/benthemplein">Watersquare Benthemplein</a>, a sunken public plaza and basketball court that becomes a major stormwater basin when it rains. </p>
<figure class="align-center ">
<img alt="Stairs surround a sunken city plaza being used by people to play with a basketball" src="https://images.theconversation.com/files/503956/original/file-20230111-12-yrdh2u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/503956/original/file-20230111-12-yrdh2u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/503956/original/file-20230111-12-yrdh2u.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/503956/original/file-20230111-12-yrdh2u.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/503956/original/file-20230111-12-yrdh2u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/503956/original/file-20230111-12-yrdh2u.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/503956/original/file-20230111-12-yrdh2u.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Benthemplein has a series of pools that fill after heavy rain, connected by channels that control stormwater flows through the city.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/michiel_brouwer_mbdso/51993158378/in/photolist-27aTqmw-GhbMZ4-eQQZdK-eQQZya-eR3n8E-eR3npA-fKTZjT-fKU1wa-o8E5ZP-27aTpQb-L8pii5-2ndv1Lx-2ndv22x-2ndswz9-JBpukH-26W1iVr-GhbN4H-icFdha-JDH7Bz-icFPqp-icFpP9-23HFwHQ-LaJm9L-icFBBf-icFdSi-FmJLdN-27db6sU-25xB4tb-2ndswuK-2ndn5P5-2ndsd37-2ndn5VC-FmJLc5-2ndtCwy-G95RG1-2ndsd5X-2ndsd5g-23HFwMN-GhexKg-2jxVsTR-28ekcH5-28ek7nf-LaJpfq-sa3TUk-2nwTxCE-2nwTxxV-26pQc1m-2jxS6De-2jxVkQY-25ozXDf">Michiel Brouwer/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span>
</figcaption>
</figure>
<p>While this approach is a win-win on large development sites, it can be tricky to retrofit built-up areas. Fortunately, there are many more compact approaches that can deliver large benefits when delivered at scale. </p>
<p>New York City, for example, has spent over US$1 billion on <a href="https://www.nyc.gov/site/dep/water/types-of-green-infrastructure.page">smaller, distributed solutions</a> in flood-prone streets. These measures include “raingardens” that drain water from streets, and infiltration basins that divert and store stormwater. </p>
<figure class="align-center ">
<img alt="Women walks past a kerbside raingarden" src="https://images.theconversation.com/files/503957/original/file-20230111-24-32zsaz.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/503957/original/file-20230111-24-32zsaz.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/503957/original/file-20230111-24-32zsaz.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/503957/original/file-20230111-24-32zsaz.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/503957/original/file-20230111-24-32zsaz.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/503957/original/file-20230111-24-32zsaz.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/503957/original/file-20230111-24-32zsaz.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Raingardens like this one in Brooklyn, New York, divert water from hard surfaces, so it sinks into the soil instead of overloading drains.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Right_of_Way_Bioswale.jpg">Chris Hamsby/Wikimedia Commons</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/not-if-but-when-city-planners-need-to-design-for-flooding-these-examples-show-the-way-157578">Not 'if', but 'when': city planners need to design for flooding. These examples show the way</a>
</strong>
</em>
</p>
<hr>
<p>Green roofs that capture rainwater also help reduce flood risk in built-up areas. Again, Rotterdam’s approach is interesting; while reducing stormwater flows is a focus, the city’s rooftop greening program focuses on <a href="https://www.rotterdam.nl/en/multifunctional-roofs">multifunctionality</a> by integrating solar panels, social spaces and rooftop farming. The retrofitted “<a href="https://dakakker.nl/site/?lang=en">Dakakker</a>” (rooftop farm) has advanced stormwater storage, vegetable beds, beehives, a few chickens and a popular café.</p>
<figure class="align-center ">
<img alt="rooftop farm with cafe on top of office block" src="https://images.theconversation.com/files/503962/original/file-20230111-24-diuhdv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/503962/original/file-20230111-24-diuhdv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=397&fit=crop&dpr=1 600w, https://images.theconversation.com/files/503962/original/file-20230111-24-diuhdv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=397&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/503962/original/file-20230111-24-diuhdv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=397&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/503962/original/file-20230111-24-diuhdv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=499&fit=crop&dpr=1 754w, https://images.theconversation.com/files/503962/original/file-20230111-24-diuhdv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=499&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/503962/original/file-20230111-24-diuhdv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=499&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Rotterdam’s ‘Dakakker’ inspired a large rooftop greening program.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>Of course, a green roof program usually requires private building owners to get on board. Rotterdam <a href="https://www.rotterdam.nl/subsidie-klimaatadaptatie">subsidises</a> owners who deliver rooftop greening that intercepts significant amounts of stormwater. In 2021, Rotterdam had <a href="https://www.rotterdam.nl/groene-daken">46 hectares</a> of green roofs, equating to around 0.5 square metres per resident. </p>
<p>The Swiss city of Basel leads the world with <a href="https://climate-adapt.eea.europa.eu/en/metadata/case-studies/green-roofs-in-basel-switzerland-combining-mitigation-and-adaptation-measures-1">5.7m² of green roofs per person</a> (as of 2019). Basel has had incentives as well as laws requiring green roofs <a href="https://climate-adapt.eea.europa.eu/en/metadata/case-studies/green-roofs-in-basel-switzerland-combining-mitigation-and-adaptation-measures-1">since the late 1990s</a>; this highlights the value of putting regulations in place early. </p>
<p>The principle seems to work for bigger cities too: Tokyo has mandated green roofs since 2000, and has around <a href="https://link.springer.com/article/10.1007/s00267-022-01625-8">250ha of them</a>. </p>
<figure class="align-center ">
<img alt="rooftop gardens on multistorey city buildings" src="https://images.theconversation.com/files/503963/original/file-20230111-4890-vqkwcd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/503963/original/file-20230111-4890-vqkwcd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=373&fit=crop&dpr=1 600w, https://images.theconversation.com/files/503963/original/file-20230111-4890-vqkwcd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=373&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/503963/original/file-20230111-4890-vqkwcd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=373&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/503963/original/file-20230111-4890-vqkwcd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=469&fit=crop&dpr=1 754w, https://images.theconversation.com/files/503963/original/file-20230111-4890-vqkwcd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=469&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/503963/original/file-20230111-4890-vqkwcd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=469&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Tokyo has about 250 hectares of green roofs.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/rachidh/18135820243/in/photolist-o7AoEk-nQpqir-o9FqCt-nQpaRw-o5RGLC-nQpD3W-nQqbYX-o7NbS9-o5RrKf-o7AYjK-gLsqh5-gLsmQY-gLsBDp-gLssNE-gLtsvF-gLsGj6-gLsv15-gLtvBF-gLsDCf-gLtzDi-o7LBAJ-gLskhC-oh9RKT-tCANGR-5L1NKC-k5GGJ-gLsno9-tCAPvV-ux8bHq-2xZHqt-77MrzT-4HLSvc-5bhUu1-4HLSsM-nS4NQ-7B5WWw-4HLSmc-4HR85s-eb8a7G-9r9RX2-5LQj9B-di8Bz-8rf7vH-uzrXPD-77qh7S-4HR73S-9d22FQ-S8APVH-5b1soy-3hHJgV">Rachid H/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/greening-our-grey-cities-heres-how-green-roofs-and-walls-can-flourish-in-australia-139478">Greening our grey cities: here's how green roofs and walls can flourish in Australia</a>
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</em>
</p>
<hr>
<h2>What does this mean for Australia?</h2>
<p>Our cities remain woefully unprepared for extreme weather. But many of the above approaches are starting to crop up in Australia. The challenge is to move from a handful of trials to a large-scale, systematic roll out of infrastructure to adapt our cities to climate change.</p>
<p>The experience of the cities profiled above points to a few crucial ingredients. </p>
<p>First, cities must be willing to invest heavily, both in new green spaces and in subsidies to encourage greening by private property owners. </p>
<p>Second, reallocation of existing grey space, like roads and canals, must be pursued fearlessly and systematically. Paris’s elected mayor since 2014, Anne Hidalgo, is a spectacular example of the <a href="https://www.politico.eu/article/anne-hidalgo-paris-mayor-urban-revolution/">political courage</a> required for <a href="https://www.timeout.com/paris/en/things-to-do/paris-green-sustainable-city-plan-2030">large-scale greening</a>. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/VfhAdD4Cvsc?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">The mayor of Paris has announced plans to turn the Champs-Élysées into an ‘extraordinary garden’.</span></figcaption>
</figure>
<p>Third, the law can play a real role in guiding development, through measures such as mandating greening on buildings. This can be achieved through fairly simple tools like Toyko’s green roof requirement, or more sophisticated area-based instruments that require a portion of a development to have green walls and/or roofs. Cities like <a href="https://www.seattle.gov/sdci/codes/codes-we-enforce-(a-z)/seattle-green-factor">Seattle</a> and <a href="https://www.brisbane.qld.gov.au/planning-and-building/urban-design-in-brisbane/design-strategy-and-guidelines/brisbane-green-buildings-incentive-policy">Brisbane</a> are using these tools, which are also being mooted in <a href="https://www.melbourne.vic.gov.au/community/greening-the-city/green-infrastructure/Pages/green-factor-tool.aspx">Melbourne</a>. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/melbourne-now-has-chief-heat-officers-heres-why-we-need-them-and-what-they-can-do-192248">Melbourne now has chief heat officers. Here's why we need them and what they can do</a>
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</p>
<hr>
<p>Recent disasters have made clear the urgent need to step up urban climate adaptation. The costs of not acting decisively to protect ourselves and our cities will be considerable, but the playbook is ready for us.</p><img src="https://counter.theconversation.com/content/196389/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Thami Croeser receives funding from the Australian Research Council and the European Comission.</span></em></p>
Australian cities remain woefully unprepared for the more extreme weather we are already seeing with climate change. But some cities overseas stand out for having developed readymade solutions.
Thami Croeser, Research Officer, Centre for Urban Research, RMIT University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/192248
2022-10-16T19:02:16Z
2022-10-16T19:02:16Z
Melbourne now has chief heat officers. Here’s why we need them and what they can do
<p>The appointment of chief heat officers in Melbourne is a vital acknowledgement of how serious urban heat is for Australia. It’s a first for the country and part of an international movement to improve how cities handle heat in a warming world. </p>
<p>In partnership with the US-based <a href="https://onebillionresilient.org/who-we-are/">Adrienne Arsht-Rockefeller Foundation Resilience Center</a>, <a href="https://onebillionresilient.org/2022/10/06/melbourne-chief-heat-officers/">six cities</a> around the world now have chief heat officers dedicated to reducing heat risks. </p>
<p>Urban heat does more than cause discomfort for city residents. It’s a threat to their lives. The City of Melbourne’s new chief heat officers, Tiffany Crawford and Krista Milne, will oversee the work of managing the risks of extreme heat in the city.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1578150867332730880"}"></div></p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/cities-could-get-more-than-4-c-hotter-by-2100-to-keep-cool-in-australia-we-urgently-need-a-national-planning-policy-152680">Cities could get more than 4°C hotter by 2100. To keep cool in Australia, we urgently need a national planning policy</a>
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</em>
</p>
<hr>
<h2>Why do cities need heat officers?</h2>
<p>There is growing recognition urban heat problems are not simply an external environmental impact. They are tied to the ways we live in and use urban areas. </p>
<p>While rising temperatures and heat waves are hazardous for cities, Australia has a cultural expectation of living in a harsh environment. As Melbourne’s first <a href="https://www.melbourne.vic.gov.au/SiteCollectionDocuments/climate-change-adaptation-strategy.pdf">climate adaptation strategy</a> from back in 2009 explains, Australians have a “propensity to participate in events in very hot conditions”.</p>
<p>Even with increasing <a href="https://www.nature.com/articles/d41586-022-01445-0">public recognition</a> of the threat of climate change, these kinds of background social assumptions (and of course economic agendas) set up the public and <a href="https://www.bbc.com/news/world-australia-57606398">political debates</a> about how we should respond to our warming environment.</p>
<p>Melbourne is a particularly challenging city to plan for heat in a changing climate. It’s known for its variable weather – “four seasons in one day” – and temperatures can flip from hot to cold in the space of ten minutes. </p>
<p>Alongside overall warming, Melbourne suffers from dangerous heatwaves. As the 2019 <a href="https://resilientmelbourne.com.au/living-melbourne/">Living Melbourne Strategy</a> summarises:</p>
<blockquote>
<p>“In Melbourne, deaths begin to rise when the mean daily temperature reaches 28°C, with hospital admissions for heart attack increasing by 10.8 per cent when the mean daily temperature reaches 30°C. When the average temperature is higher than 27°C for three consecutive days, hospital admissions increase by 37.7 per cent. This suggests that even a small reduction in temperature during a heatwave will reduce the numbers of deaths.”</p>
</blockquote>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/climate-change-hits-low-income-earners-harder-and-poor-housing-in-hotter-cities-is-a-disastrous-combination-180960">Climate change hits low-income earners harder – and poor housing in hotter cities is a disastrous combination</a>
</strong>
</em>
</p>
<hr>
<h2>So what can heat officers do?</h2>
<p>The appointments of heat officers are a recent <a href="https://www.melbourne.vic.gov.au/about-council/vision-goals/eco-city/Pages/adapting-to-climate-change.aspx">response</a> to <a href="http://www.bom.gov.au/state-of-the-climate/documents/State-of-the-Climate-2020.pdf">projections</a> of a hotter climate alongside more frequent and intense heat waves. The first chief heat officer was installed in Miami-Dade County in the United States in 2021. Appointments followed in Athens, Greece; Freetown, Sierra Leone; Santiago, Chile; and Monterrey, Mexico. </p>
<p>In less than two years, these officers have overseen projects such as developing new ways to monitor urban heat, trialling cool pavement materials and creating refuges from the heat. </p>
<p>In Freetown, the chief heat officer, Eugenia Kargbo, has focused on the <a href="https://www.theguardian.com/global-development/2021/nov/15/eugenia-kargbo-freetown-sierra-leone-first-chief-heat-officer-climate-crisis">informal settlements and markets</a> most exposed to increasing heat. New shading and tree plantings will help <a href="https://www.bloomberg.com/news/features/2022-01-21/how-africa-s-first-heat-officer-confronts-climate-change">protect</a> these economically important spaces.</p>
<p><a href="https://onebillionresilient.org/hot-cities-chilled-economies-santiago/">In Santiago</a>, Cristina Huidobro is sponsoring the roll-out of green roofs across state-owned buildings such as schools and hospitals. The Hospital de Maipú is being retrofitted with more than 1,000 square metres of vegetated rooftop to help keep the building cooler.</p>
<p>As these examples show, responses to heat must draw on both climate knowledge and local social understanding. Problems of heat in Melbourne are different to those of Sydney’s western suburbs or Darwin’s tropical intensity. Developing resilience to heat requires actions that work with the form of each city, the rules governing its spaces and how locals behave.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/requiem-or-renewal-this-is-how-a-tropical-city-like-darwin-can-regain-its-cool-102839">Requiem or renewal? This is how a tropical city like Darwin can regain its cool</a>
</strong>
</em>
</p>
<hr>
<p>For Melbourne, practical actions might include trials of urban forms that allow for mixed <a href="https://www.melbourne.vic.gov.au/SiteCollectionDocuments/quantifying-benefits-green.pdf">plantings across buildings</a>, infrastructure and streets. </p>
<p>Another option is to manage traffic to take account of local climate patterns. Melbourne’s heat waves often peak in the very late afternoon as people travel home. Reducing car traffic and adding cooled trams and buses at these times will help move more people safely.</p>
<h2>We do know what to do</h2>
<p>We already have a huge body of science, local research and tools to help keep cool in our cities. </p>
<p>For example, the <a href="https://www.melbourne.vic.gov.au/parking-and-transport/streets-and-pedestrians/Pages/cool-routes.aspx">Cool Routes project</a> allows you to plot a path through Melbourne based on live temperature data. There are also heat health alerts, <a href="https://www.melbourne.vic.gov.au/community/safety-emergency/emergency-management/pages/heatwaves.aspx#coolplaces">cool places mapping</a> and heat-specific <a href="https://www.melbourne.vic.gov.au/community/safety-emergency/emergency-management/pages/heatwaves.aspx#homelessness">support</a> for people who are homeless. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/489700/original/file-20221014-896-cmyp4e.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Screenshot of map of Melbourne from the Cool Routes website" src="https://images.theconversation.com/files/489700/original/file-20221014-896-cmyp4e.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/489700/original/file-20221014-896-cmyp4e.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=282&fit=crop&dpr=1 600w, https://images.theconversation.com/files/489700/original/file-20221014-896-cmyp4e.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=282&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/489700/original/file-20221014-896-cmyp4e.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=282&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/489700/original/file-20221014-896-cmyp4e.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=354&fit=crop&dpr=1 754w, https://images.theconversation.com/files/489700/original/file-20221014-896-cmyp4e.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=354&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/489700/original/file-20221014-896-cmyp4e.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=354&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Cool Routes online tool lets users find the path to their destination that best protects them from the heat.</span>
<span class="attribution"><a class="source" href="https://www.coolroutes.com.au/">Cool Routes/City of Melbourne</a></span>
</figcaption>
</figure>
<p>We have a world-leading <a href="https://www.melbourne.vic.gov.au/community/greening-the-city/urban-forest/Pages/urban-forest.aspx">Urban Forest Strategy</a> to guide urban planning and design. Toolkits such as the <a href="http://www.lowcarbonlivingcrc.com.au/sites/all/files/publications_file_attachments/rp2024_guide_to_urban_cooling_strategies_2017_web.pdf">Guide to Urban Cooling Strategies</a> and the <a href="https://www.melbourne.vic.gov.au/community/greening-the-city/green-infrastructure/Pages/green-factor-tool.aspx">Green Factor Tool</a> are available.</p>
<p>Despite this, Melbourne is still vulnerable to heat. Extreme heat increases the risk of power failure and buildings then overheat. And most of our outdoor spaces were never designed for heat in the first place. </p>
<p>Even with the knowledge and tools at our disposal, it is voluntary for designers and developers to use them.</p>
<p>There is no single solution to manage increasing heat. While trees are <a href="https://theconversation.com/a-solution-to-cut-extreme-heat-by-up-to-6-degrees-is-in-our-own-backyards-133082">fantastic for natural cooling</a>, they aren’t a cure-all. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-new-design-patterns-can-enable-cities-and-their-residents-to-change-with-climate-change-152749">How new design patterns can enable cities and their residents to change with climate change</a>
</strong>
</em>
</p>
<hr>
<h2>Keeping cities cool is a complex task</h2>
<p>Resilience to urban heat requires work across multiple physical scales. It involves negotiating the political and economic contests about how the city should grow. </p>
<p>The biggest task Melbourne’s heat officers face will be co-ordinating between partners – both within government and with the developers and private agencies that shape so much of the city. The officers have to create ties between policy, strategy, planners, designers, developers, research and tools. </p>
<p>They will also need to be on the ground and talk to the communities who experience heat stress. Much of our existing work on urban heat has been done from desktops and satellites. It’s time to hit the streets and start negotiating the technical, social and political worlds that determine how Australian cities respond to heat.</p><img src="https://counter.theconversation.com/content/192248/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Wendy Walls does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
The first chief heat officers appointed in Australia are part of a global partnership that’s responding to the dangers of rising city temperatures and the need to manage the risks.
Wendy Walls, Lecturer in Landscape Architecture, The University of Melbourne
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/188807
2022-09-19T20:15:20Z
2022-09-19T20:15:20Z
Climate change threatens up to 100% of trees in Australian cities, and most urban species worldwide
<figure><img src="https://images.theconversation.com/files/483411/original/file-20220908-21-5qto3i.jpg?ixlib=rb-1.1.0&rect=6%2C84%2C2006%2C1324&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Photo: Jaana Dielenberg</span>, <span class="license">Author provided</span></span></figcaption></figure><p>To anyone who has stepped off a hot pavement into a shady park, it will come as little surprise that trees (and shrubs) have a <a href="https://theconversation.com/a-solution-to-cut-extreme-heat-by-up-to-6-degrees-is-in-our-own-backyards-133082">big cooling effect</a> on cities. </p>
<p>Our study published today in <a href="https://www.nature.com/articles/s41558-022-01465-8">Nature Climate Change</a> found climate change will put 90-100% of the trees and shrubs planted in Australian capital cities at risk by 2050. Without action, two-thirds of trees and shrubs in cities worldwide will be at potential risk from climate change. </p>
<p>Increasing city temperatures mean their trees are becoming more important than ever. More than just shade umbrellas, the natural air-conditioning magic of trees happens as water moves up from the soil through their roots and evaporates out of their leaves into the air.</p>
<p>But how will the trees themselves cope with climate change as conditions shift beyond their natural tolerance limits for high temperatures or lack of water? Our team of scientists from Australia and France examined the impacts of temperature and rainfall changes projected for coming decades on 3,129 tree and shrub species planted in 164 cities across 78 countries. </p>
<p>About half of these urban tree and shrub species are already experiencing climate conditions beyond their natural tolerance limits. </p>
<p>These findings sound bleak – but read on. We have also identified steps people can take to help their local trees survive, thrive and keep on cooling. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/a-solution-to-cut-extreme-heat-by-up-to-6-degrees-is-in-our-own-backyards-133082">A solution to cut extreme heat by up to 6 degrees is in our own backyards</a>
</strong>
</em>
</p>
<hr>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/483947/original/file-20220912-26-so06fl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="people walking through a tree-lined public space in Barcelona" src="https://images.theconversation.com/files/483947/original/file-20220912-26-so06fl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/483947/original/file-20220912-26-so06fl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/483947/original/file-20220912-26-so06fl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/483947/original/file-20220912-26-so06fl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/483947/original/file-20220912-26-so06fl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/483947/original/file-20220912-26-so06fl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/483947/original/file-20220912-26-so06fl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Imagine this public space in Barcelona without trees – it would be unbearably hot in the Spanish summer.</span>
<span class="attribution"><span class="source">Photo: Jorge Fernández Salas/Unsplash</span></span>
</figcaption>
</figure>
<h2>Risks in Australia are higher</h2>
<p>In Australia, reduced rainfall will be the most common stress on urban trees, but increasing temperatures will also be a major factor, especially in Darwin.</p>
<p>By 2050, the proportion of urban tree species that might be at risk of projected temperature increases in Australian cities is very high. Among the major cities with inventories of urban plantings, those with high percentages at risk include: Cairns 82%, Melbourne 93%, Perth 95%, Hobart 95%, Sydney 96%, Canberra 98% and Darwin 100%.</p>
<p>Common native species, including manna gum, swamp gum, yellow box, narrow-leaved peppermint, blackwood and brush box, and well-loved introduced species, such as jacaranda, oaks, elms, poplars and silver birch, are among the trees that could be at risk in Australia.</p>
<p>By at risk, we mean these species might be experiencing stressful climatic conditions that could affect their health and performance. However, we could buffer the risk for these species by providing water or creating other microclimate conditions. Also, urban trees may exhibit plasticity in traits that govern survival, growth and environmental tolerance, which can help them to <a href="https://www.sciencedirect.com/science/article/pii/S1618866720305884?casa_token=jrNUEMp2MJwAAAAA:HUpUQvJyWVho0zAE7IZCrHroBOtPtXl9cdMMhIbKqN6iu3SOUk9gGZ8eJu9HNNbGTIp53wA4BE3x">adapt to local environmental conditions</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/483446/original/file-20220908-14-ctxok4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A green house surrounded by trees and shrubs" src="https://images.theconversation.com/files/483446/original/file-20220908-14-ctxok4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/483446/original/file-20220908-14-ctxok4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/483446/original/file-20220908-14-ctxok4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/483446/original/file-20220908-14-ctxok4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/483446/original/file-20220908-14-ctxok4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/483446/original/file-20220908-14-ctxok4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/483446/original/file-20220908-14-ctxok4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Houses surrounded by trees and shrubs stay cooler in warm weather.</span>
<span class="attribution"><span class="source">Photo: Jaana Dielenberg</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/our-cities-need-more-trees-but-some-commonly-planted-ones-wont-survive-climate-change-120493">Our cities need more trees, but some commonly planted ones won't survive climate change</a>
</strong>
</em>
</p>
<hr>
<h2>More than 1,000 tree species at risk globally</h2>
<p>Worldwide, we found common species of cherry plums, oaks, maples, poplars, elms, pines, lindens, wattles, eucalypts and chestnuts are among more than 1,000 species that have been flagged at risk due to climate change in most cities where they occur.</p>
<p>Even more worryingly, the number of species affected, and the scale of the impacts, will increase markedly by 2050 as temperatures increase. These trends jeopardise the health and longevity of urban forests and the benefits they provide to society.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/483413/original/file-20220908-9329-hg03kz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A shady street through a cemetery" src="https://images.theconversation.com/files/483413/original/file-20220908-9329-hg03kz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/483413/original/file-20220908-9329-hg03kz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/483413/original/file-20220908-9329-hg03kz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/483413/original/file-20220908-9329-hg03kz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/483413/original/file-20220908-9329-hg03kz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/483413/original/file-20220908-9329-hg03kz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/483413/original/file-20220908-9329-hg03kz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Urban forests like these horse chesnut trees in the Père Lachaise Cemetery in Paris are valuable for cooling cities and making them more liveable.</span>
<span class="attribution"><span class="source">Photo: Akvile Jureviciute-Lenoir</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The United Nations predicts the world’s population will grow to around <a href="https://www.un.org/development/desa/pd/content/World-Population-Prospects-2022">8.5 billion by 2030</a>, with more than half of those people living in cities. Climate change will further heat up the <a href="https://education.nationalgeographic.org/resource/urban-heat-island">urban heat islands</a> created by millions of people, vehicles and industries generating heat that’s retained among buildings and other infrastructure. </p>
<p>Urban trees have a vital role to play in keeping cities liveable. As they cool their surroundings, they reduce our electricity use for air conditioning, while also <a href="https://onetreeplanted.org/blogs/stories/how-much-co2-does-tree-absorb">absorbing carbon dioxide</a>, <a href="https://edu.rsc.org/feature/how-do-trees-clean-our-air/4010864.article#:%7E:text=As%20well%20as%20improving%20our,benefits%20both%20locally%20and%20globally.">purifying the air</a>, <a href="https://www.conserve-energy-future.com/can-trees-reduce-noise-pollution.php">reducing city noise</a> and <a href="https://theconversation.com/yes-the-state-of-the-environment-is-grim-but-you-can-make-a-difference-right-in-your-own-neighbourhoood-187259">providing wildlife habitat</a>. They are also inherently beautiful, living things that underpin much of the biodiversity on Earth. </p>
<p>Being around their natural greenness also <a href="https://www.mdpi.com/1660-4601/18/5/2227">improves our mental health and well-being</a>. Trees have helped us through stressful times such as <a href="https://www.frontiersin.org/articles/10.3389/ffgc.2021.672909/full">pandemics</a>.</p>
<p>However, when <a href="https://nph.onlinelibrary.wiley.com/doi/full/10.1002/ppp3.10240">climatic conditions</a> exceed the natural tolerance of trees, not only can this lead to poor tree health and limited growth, but it can also reduce their cooling effect and eventually lead to tree dieback. <a href="https://www.sciencedirect.com/science/article/pii/S0048969722050148">During drought or heat stress</a>, trees can stop releasing water vapour from their leaves or shed leaves to reduce tissue damage. This means that at a time when we most need their natural air conditioning, they are more likely to be switching off.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/cities-could-get-more-than-4-c-hotter-by-2100-to-keep-cool-in-australia-we-urgently-need-a-national-planning-policy-152680">Cities could get more than 4°C hotter by 2100. To keep cool in Australia, we urgently need a national planning policy</a>
</strong>
</em>
</p>
<hr>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/483412/original/file-20220908-23-fi4dcf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/483412/original/file-20220908-23-fi4dcf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/483412/original/file-20220908-23-fi4dcf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/483412/original/file-20220908-23-fi4dcf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/483412/original/file-20220908-23-fi4dcf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/483412/original/file-20220908-23-fi4dcf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/483412/original/file-20220908-23-fi4dcf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/483412/original/file-20220908-23-fi4dcf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">People enjoying trees in Copenhagen, Denmark.</span>
<span class="attribution"><span class="source">Photo: Rachael Gallagher</span></span>
</figcaption>
</figure>
<h2>What can we do to protect our trees?</h2>
<p>Increasing the number of trees and shrubs in our cities, collectively called urban forests, is a key climate change adaptation and liveability strategy being used around the world. Until now, though, <a href="https://nph.onlinelibrary.wiley.com/doi/full/10.1002/ppp3.10240">little information was available</a> on whether or not current climatic conditions exceed what urban forests can stand, or how these conditions compare with projected changes in temperature and precipitation (drought, rain and snow) around the world.</p>
<p>Our study provides guidance to urban forest managers in 164 cities about which species might be at risk and should be monitored. It also identifies which species are likely to be resilient to climate change and so suitable for future plantings.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/rX-0szAK9Bg?wmode=transparent&start=81" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">The authors explain their findings and what they mean for trees and shrubs planted in our cities.</span></figcaption>
</figure>
<p>People can help urban forests to survive and keep providing their many benefits in a few simple ways:</p>
<p>1) reduced rainfall and soil moisture are a big threat to many species, so you can help rain soak into the ground to ensure precious water is not wasted down the drain – consider diverting water from your downpipe to a <a href="https://www.melbournewater.com.au/building-and-works/stormwater-management/options-treating-stormwater/raingardens">raingarden</a> or a <a href="https://www.melbournewater.com.au/building-and-works/stormwater-management/options-treating-stormwater/rainwater-tanks">rainwater tank</a> that trickle-feeds the garden (this also <a href="https://www.melbournewater.com.au/building-and-works/stormwater-management/introduction-wsud">helps your local creek</a>). </p>
<p>2) plant even more trees and shrubs, which helps to keep city temperatures comfortable for them and us – get advice from your local council or horticulturalists about suitable climate-resilient species for your area.</p>
<p>3) leave trees and shrubs in place – think twice before cutting down trees and shrubs, as they are providing you with more benefits than you realise.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/483415/original/file-20220908-13-b0vrgc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A scientist inspecting a young urban tree" src="https://images.theconversation.com/files/483415/original/file-20220908-13-b0vrgc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/483415/original/file-20220908-13-b0vrgc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/483415/original/file-20220908-13-b0vrgc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/483415/original/file-20220908-13-b0vrgc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/483415/original/file-20220908-13-b0vrgc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/483415/original/file-20220908-13-b0vrgc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/483415/original/file-20220908-13-b0vrgc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Author Manuel Esperon-Rodriguez checks on a young tree – the more we plant, the more they can cool their surroundings and improve their odds of coping with climate change.</span>
<span class="attribution"><span class="source">Author provided</span></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/residential-green-spaces-protect-growing-cities-against-climate-change-183513">Residential green spaces protect growing cities against climate change</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/188807/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Manuel Esperon-Rodriguez is employed by Western Sydney University and received funding from the Which Plant Where project via the Hort Frontiers Green Cities Fund developed by Hort Innovation with co-investment from Macquarie University, Western Sydney University, the New South Wales Department of Planning and Environment, and the Australian Government.</span></em></p><p class="fine-print"><em><span>Mark G Tjoelker received funding from the Which Plant Where project via the Hort Frontiers Green Cities Fund developed by Hort Innovation with co-investment from Macquarie University, Western Sydney University, the New South Wales Department of Planning and Environment, and the Australian Government.</span></em></p><p class="fine-print"><em><span>Rachael Gallagher receives funding from Hort Innovation Australia. </span></em></p><p class="fine-print"><em><span>Jaana Dielenberg and Jonathan Lenoir do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
Urban plantings are part of the solution to living in warmer cities, but most tree and shrub species in the world’s cities will struggle too. The impacts on liveability could be huge.
Manuel Esperon-Rodriguez, Lecturer and Research Fellow, Hawkesbury Institute for the Environment, Western Sydney University
Jaana Dielenberg, University Fellow, Charles Darwin University
Jonathan Lenoir, Senior Researcher in Ecology & Biostatistics (CNRS), Université de Picardie Jules Verne (UPJV)
Mark G Tjoelker, Professor and Associate Director, Hawkesbury Institute for the Environment, Western Sydney University
Rachael Gallagher, Associate Professor, Hawkesbury Institute for the Environment, Western Sydney University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/180960
2022-05-11T19:55:25Z
2022-05-11T19:55:25Z
Climate change hits low-income earners harder – and poor housing in hotter cities is a disastrous combination
<figure><img src="https://images.theconversation.com/files/462374/original/file-20220511-16-y6yqol.jpg?ixlib=rb-1.1.0&rect=0%2C5%2C3968%2C2964&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Cost of living is a major focus in this election campaign, and yet political leaders have been unacceptably silent on the disproportionate impact of climate change on Australians with low incomes. This is particularly true for <a href="https://australiainstitute.org.au/wp-content/uploads/2020/12/Western-Sydney-Heatwatch-WEB.pdf">Western Sydney</a>, home to <a href="https://www.westernsydney.edu.au/rcegws/rcegws/About/about_greater_western_sydney">around 2.5 million people</a>. </p>
<p>Over the last half century, the balance of Sydney’s <a href="https://theconversation.com/we-still-live-here-public-housing-tenants-fight-for-their-place-in-the-city-107188">social housing</a> has been pushed to the west, where it can be up to 10°C hotter than the breeze-cooled coast. Meanwhile, rapid housing development reduces existing tree canopy daily, <a href="https://researchdirect.westernsydney.edu.au/islandora/object/uws:52453">further intensifying heat</a>. </p>
<p>This situation locks in cycles of disadvantage for decades and generations to come. Even if we limit global warming to 1.5°C this century, Western Sydney will still experience fewer than <a href="https://theconversation.com/western-sydney-will-swelter-through-46-days-per-year-over-35-c-by-2090-unless-emissions-drop-significantly-177056">17 days</a> of 35°C per year by 2090. </p>
<p>Australia needs a more holistic, forward-thinking approach to the design of hot cities, one that’s up to the task of changing with the climate. </p>
<h2>Living with urban heat now</h2>
<p>Low-income communities are more likely to live in poorly constructed, heat-affected rental accommodation and least able to afford air conditioning. What’s more, those <a href="https://wsroc.com.au/projects/project-turn-down-the-heat/turn-down-the-heat-resources-2">living in community housing</a> may be restricted from installing air conditioning units.</p>
<p><a href="https://www.westernsydney.edu.au/__data/assets/pdf_file/0020/1161470/cooling-the-commons-report.pdf">Our research</a> from 2016 found residents expend a lot of mental and physical energy during summer just to keep their homes bearable, while worrying about how much cooling might be costing.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/we-still-live-here-public-housing-tenants-fight-for-their-place-in-the-city-107188">We still live here: public housing tenants fight for their place in the city</a>
</strong>
</em>
</p>
<hr>
<p>After interviewing vulnerable groups of people in Western Sydney – such as elderly citizens, disability carers and young mothers in social housing – we found people turn to lessons from their parents to find relief from heat.</p>
<p>This includes soaking sheets in water, directing fans to blow air over them and create cool pockets in the house, confine themselves to cooler rooms, and cover west-facing windows with blankets or aluminium foil.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/462378/original/file-20220511-10405-facgpk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Fan beside bed" src="https://images.theconversation.com/files/462378/original/file-20220511-10405-facgpk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/462378/original/file-20220511-10405-facgpk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/462378/original/file-20220511-10405-facgpk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/462378/original/file-20220511-10405-facgpk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/462378/original/file-20220511-10405-facgpk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/462378/original/file-20220511-10405-facgpk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/462378/original/file-20220511-10405-facgpk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Switching on fans in the bedroom is one way people without air conditioning try to keep cool.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>This summer’s La Niña weather pattern may have spared Western Sydney from scorching daytime highs, but residents had to contend with hotter and more humid <a href="http://www.bom.gov.au/climate/updates/articles/a020.shtml">nights</a>. Wet conditions and cloud cover inhibit the capacity of poorly designed houses to shed the heat, leading to sleeplessness. </p>
<p>Many Western Sydneysiders work from home, too. Community organisation <a href="https://www.betterrenting.org.au/renter_researchers_summer21-22">Better Renting</a> recently produced a report detailing the impact of poor housing on worker productivity during the pandemic. It found those working from home without the means or capacity to improve their environments said they were stressed, couldn’t focus, and needed to finish work early during summer.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/western-sydney-will-swelter-through-46-days-per-year-over-35-c-by-2090-unless-emissions-drop-significantly-177056">Western Sydney will swelter through 46 days per year over 35°C by 2090, unless emissions drop significantly</a>
</strong>
</em>
</p>
<hr>
<p>Air-conditioning can provide relief and is critical for some residents, such as some people living with a disability who depend on cool homes and cars for survival. But air-conditioning displaces the indoor heat to the outside, contributing to a more hostile outdoor environment. </p>
<p>So while air-conditioning offers a short-term solution, it does nothing to address long-term disadvantage.</p>
<h2>‘Solutions’ don’t go far enough</h2>
<p>Social disadvantage underscores the limitations of well-meaning technical solutions, such as the New South Wales government’s program to <a href="https://www.dpie.nsw.gov.au/premiers-priorities/greening-our-city">plant five million trees</a> by 2030, or City of Sydney’s <a href="https://www.cityofsydney.nsw.gov.au/governance-decision-making/resilient-sydney">project</a> of committing to renewable-powered air conditioning. </p>
<p>These solutions don’t go anywhere near far enough to address the fundamental short-sightedness in how we design and plan our cities. </p>
<p>For example, young trees need far more care to reach maturity through extreme weather, unlike older trees, of which many have been cut down to make way for development. And solar-powered air conditioning will not undo the compounding impacts of urban heat, which research shows make us <a href="https://www.westernsydney.edu.au/newscentre/news_centre/story_archive/2019/urban_heat_makes_us_sedentary,_passive_and_lonely_western_sydney_university_research">sedentary, passive and lonely and insecure</a> because it keeps us indoors and isolated from each other. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/462388/original/file-20220511-16-uhl0id.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/462388/original/file-20220511-16-uhl0id.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/462388/original/file-20220511-16-uhl0id.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/462388/original/file-20220511-16-uhl0id.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/462388/original/file-20220511-16-uhl0id.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/462388/original/file-20220511-16-uhl0id.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/462388/original/file-20220511-16-uhl0id.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/462388/original/file-20220511-16-uhl0id.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Installing light-coloured roof tiles are a low hanging fruit for keeping homes cool.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>Indeed, Western Sydney’s current trajectory of urban growth will see urban heat and its impacts worsen, particularly as the state government resists mandating lighter-coloured roof tiles as a <a href="https://www.smh.com.au/national/nsw/people-may-well-die-of-heat-because-the-planning-minister-scrapped-a-good-plan-20220406-p5ab91.html">perceived impediment to development</a>. Lighter-coloured roof tiles are better at reflecting rather than absorbing heat, and are a low-hanging fruit for cooling homes.</p>
<p>This trajectory will subject future generations of Western Sydney residents to a city that may become <a href="https://www.theguardian.com/australia-news/2021/nov/16/ultimately-uninhabitable-western-sydneys-legacy-of-planning-failure">ultimately uninhabitable</a> for months at a time. <a href="https://researchdirect.westernsydney.edu.au/islandora/object/uws:57237">These predictions</a>
may seem dire, but we cannot afford to ignore them. </p>
<p>One stark prospect is that even newer and more expensive homes being built in Western Sydney’s growth areas may become stranded assets in a future, when <a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2017GL074612">50°C summer days</a> are a norm and the area is subject to regular flooding. </p>
<h2>So what do we do?</h2>
<p>Researchers and policy makers are turning their attention to making Australian cities more “<a href="https://theconversation.com/what-is-climate-ready-infrastructure-some-cities-are-starting-to-adapt-91784">climate-ready</a>”. </p>
<p>While catastrophic for communities, the recent <a href="https://theconversation.com/one-of-the-most-extreme-disasters-in-colonial-australian-history-climate-scientists-on-the-floods-and-our-future-risk-178153">floods</a>, <a href="https://theconversation.com/summer-bushfires-how-are-the-plant-and-animal-survivors-6-months-on-we-mapped-their-recovery-142551">fires</a> and other disasters carry valuable lessons about design failures and community-led solutions that have ultimately kept people safe. </p>
<p>We’ve learnt “climate-readiness” cannot be done in a piecemeal way or achieved in the background of everyday life, like set-and-forget technologies. Instead, it means noticing how the natural and built environments <a href="https://theconversation.com/how-new-design-patterns-can-enable-cities-and-their-residents-to-change-with-climate-change-152749">interact</a>, and the social practices that contribute to cooler, more liveable futures. </p>
<p>This might include enrolling communities in the care of young trees around their homes, maintaining breeze ways or shade through neighbourhoods, outdoor cooking during summer to reduce heat inside, or shifting the rhythms of social life to cooler night time hours. </p>
<p>This is encompassed in a process called “<a href="https://www.tandfonline.com/toc/rfdp20/13/1">transition design</a>”, which takes holistic, long-term view of urban planning to forge a sustainable future. This means starting with what residents want and know works – whether its creating cool pockets in the home or reaching out to neighbours when heat is on its way.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-new-design-patterns-can-enable-cities-and-their-residents-to-change-with-climate-change-152749">How new design patterns can enable cities and their residents to change with climate change</a>
</strong>
</em>
</p>
<hr>
<p>Planners, designers and policymakers should practically link these social solutions to designs that make these more accessible, manageable, engaging and safe. </p>
<p>Parts of everyday life will look very different in future as we grapple with <a href="https://opus.lib.uts.edu.au/handle/10453/156803">managing energy</a> and adapting homes to changing climates. But we must also recognise and hold on to what’s important, including reclaiming what we’ve lost to rampant development. </p>
<p><a href="https://www.westernsydney.edu.au/__data/assets/pdf_file/0020/1161470/cooling-the-commons-report.pdf">Long-term residents</a> of Western Sydney may recall a more liveable city, with shaded pedestrian links between homes and shops, seating and facilities in parks and better access to public transport. </p>
<p>These basic amenities are a commonwealth that allow us to remain at home in an increasingly less hospitable world.</p><img src="https://counter.theconversation.com/content/180960/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Stephen Healy received funding from the Australian Research Council for a project focused on climate readiness in social housing. This story is part of The Conversation's Breaking the Cycle series, which is about escaping cycles of disadvantage. It is supported by a philanthropic grant from the Paul Ramsay Foundation.</span></em></p><p class="fine-print"><em><span>Abby Mellick Lopes receives funding from the Australian Research Council for a project focused on climate readiness in social housing.</span></em></p>
Western Sydney can be up to 10°C hotter than the coast. Poorly constructed housing can’t handle the heat.
Stephen Healy, Senior Research Fellow, Institute for Culture and Society, Western Sydney University
Abby Mellick Lopes, Associate Professor, Design Studies, Faculty of Design, Architecture and Building, University of Technology Sydney
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/169153
2021-10-04T19:00:02Z
2021-10-04T19:00:02Z
Dangerous urban heat exposure has tripled since the 1980s, with the poor most at risk
<figure><img src="https://images.theconversation.com/files/424561/original/file-20211004-21-1o7ivzi.jpg?ixlib=rb-1.1.0&rect=377%2C269%2C4116%2C2647&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Rising global temperatures are increasing heat risks for outdoor workers and the urban poor.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/man-stands-by-fans-spraying-air-mixed-with-water-vapour-news-photo/1233732179">Ahmad Al-Rubaye/AFP via Getty Images</a></span></figcaption></figure><p>Extreme urban heat exposure has dramatically increased since the early 1980s, with the total exposure tripling over the past 35 years. Today, about 1.7 billion people, nearly one-quarter of the global population, live in urban areas where extreme heat exposure has risen.</p>
<p>Most reports on urban heat exposure are based on broad estimates that overlook millions of at-risk residents. We looked closer. Using satellite estimates of where every person on the planet lived each year from 1983 to 2016, we counted the number of days per year that people in over 13,000 urban areas were exposed to extreme heat. The <a href="https://www.pnas.org/content/118/41/e2024792118">results were released</a> on Oct. 4, 2021.</p>
<p>The story that emerges is one of rapidly increasing heat exposure, with poor and marginalized people particularly at risk.</p>
<p>Nearly two-thirds of the global increase in urban exposure to extreme heat was in sub-Saharan Africa and southern Asia. This is in part because of climate change and the urban <a href="https://doi.org/10.1038/s41586-019-1512-9">heat island effect</a> – temperatures in urban areas are higher because of the materials used to build roads and buildings. But it is also because the number of people living in dense urban areas has rapidly increased.</p>
<p>Urban populations have <a href="https://population.un.org/wup/">ballooned</a>, from 2 billion people living in cities and towns in 1985 to 4.4 billion today. While the <a href="https://iopscience.iop.org/article/10.1088/1748-9326/ab2432/meta">patterns vary from city to city</a>, urban population growth has been fastest among African cities where governments did not plan or build infrastructure to meet the needs of new urban residents.</p>
<figure class="align-center ">
<img alt="Three charts showing total exposure and the trends due to population and climate change increase" src="https://images.theconversation.com/files/424586/original/file-20211004-15-12sw5gq.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/424586/original/file-20211004-15-12sw5gq.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=231&fit=crop&dpr=1 600w, https://images.theconversation.com/files/424586/original/file-20211004-15-12sw5gq.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=231&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/424586/original/file-20211004-15-12sw5gq.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=231&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/424586/original/file-20211004-15-12sw5gq.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=290&fit=crop&dpr=1 754w, https://images.theconversation.com/files/424586/original/file-20211004-15-12sw5gq.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=290&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/424586/original/file-20211004-15-12sw5gq.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=290&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Extreme heat is defined as at least one day with a wet-bulb globe temperature greater than 30 C. Wet-bulb globe temperature takes into account temperature, humidity, wind and radiation to gauge the effect on humans.</span>
<span class="attribution"><a class="source" href="http://doi.org/10.1073/pnas.2024792118">Tuholske et al, 2021</a></span>
</figcaption>
</figure>
<h2>Climate change is raising the heat risk</h2>
<p>It is clear that there is a dangerous interaction of increasing temperatures and rapid urban population growth in countries that are already very warm.</p>
<p>How much worse will it get, and who will be most affected? Chris Funk explores these heat exposure projections for 2030 and 2050 in his new Cambridge University Press book “<a href="https://www.cambridge.org/core/books/drought-flood-fire/96E0EB1519F5175B68079D294D0B0E93">Drought Flood Fire</a>.”</p>
<p>Urban population growth is expected to continue, and if greenhouse gases continue on their rapid growth path, we will see massive increases in heat exposure among urban dwellers. The planet has already warmed just over 1 degree Celsius (1.8 F) since pre-industrial times, and research shows warming is <a href="https://www.ipcc.ch/report/ar6/wg1/">translating to more dangerous weather and climate extremes</a>. We are almost certain to experience another degree of warming by 2050, and likely more. </p>
<p>This amount of warming, combined with urban population growth, could lead to a 400% increase in extreme heat exposure by 2050. The vast majority of people affected will live in South Asia and Africa, in river valleys like the Ganges, Indus, Nile and Niger. Hot, humid, populated and poor cradles of civilization are becoming epicenters of heat risk.</p>
<figure class="align-center ">
<img alt="A boy in T-shirt with USA on it stands in a room sweating, his hands on his hips." src="https://images.theconversation.com/files/424562/original/file-20211004-15-1trwuyi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/424562/original/file-20211004-15-1trwuyi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/424562/original/file-20211004-15-1trwuyi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/424562/original/file-20211004-15-1trwuyi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/424562/original/file-20211004-15-1trwuyi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/424562/original/file-20211004-15-1trwuyi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/424562/original/file-20211004-15-1trwuyi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A 14-year-old sweats in hot, dangerous conditions while working at a shipyard in Dhaka, Bangladesh. Hot days become more dangerous for workers in jobs like these.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/ferdous-in-a-14-year-old-child-sweating-after-hard-work-at-news-photo/525861504">Mohammad Ponir Hossain/NurPhoto via Getty Images</a></span>
</figcaption>
</figure>
<p>At the same time, research shows that marginalized people – the poor, women, children, the elderly – may lack access to resources that could help them stay safer in extreme heat, such as air conditioning, rest during the hottest parts of the day and health care.</p>
<h2>Counting who’s at risk</h2>
<p>To count the number of urban residents exposed to extreme heat, we used data and models that incorporate advances in both social and physical sciences.</p>
<p>More than 3 billion urban residents live 25 kilometers or farther from a weather station with a robust reporting record. Climate model simulations that estimate past weather were not designed to measure a single person’s risk; rather, they were used to gauge broad-scale trends. This means the effects of extreme heat for hundreds of millions of impoverished urban residents worldwide have simply not been documented.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/424354/original/file-20211004-16-1nqmjso.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Map showing heat exposure increases by color" src="https://images.theconversation.com/files/424354/original/file-20211004-16-1nqmjso.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/424354/original/file-20211004-16-1nqmjso.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=284&fit=crop&dpr=1 600w, https://images.theconversation.com/files/424354/original/file-20211004-16-1nqmjso.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=284&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/424354/original/file-20211004-16-1nqmjso.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=284&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/424354/original/file-20211004-16-1nqmjso.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=357&fit=crop&dpr=1 754w, https://images.theconversation.com/files/424354/original/file-20211004-16-1nqmjso.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=357&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/424354/original/file-20211004-16-1nqmjso.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=357&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The increase in extreme heat exposure in cities around the world from 1983 to 2016.</span>
<span class="attribution"><a class="source" href="http://doi.org/10.1073/pnas.2024792118">Tuholske et al, 2021</a></span>
</figcaption>
</figure>
<p>In fact, <a href="https://doi.org/10.1038/s41558-020-0851-8">the official record</a> states that only two extreme heat events have had significant effects on sub-Saharan Africa since the 1900s. <a href="https://doi.org/10.1073/pnas.2024792118">Our results</a> show that this official record is not true.</p>
<h2>Reasons for action</h2>
<p>Urban population growth itself is not the problem. But the convergence of changes in extreme heat with large urban populations calls into question the conventional wisdom that urbanization uniformly reduces poverty. </p>
<p>Historically, urbanization was associated with a shift in the workforce, from farming to manufacturing and services, in tandem with industrialization of agricultural production that increased efficiency. But in parts of sub-Saharan Africa, there has been <a href="https://doi.org/10.1111/j.1728-4457.2012.00493.x">urbanization without economic growth</a>. This may be due to post-colonial technological changes that improve health. People are living longer and more children are surviving past infancy thanks to medical advances, but post-colonial governments often don’t have or don’t mobilize the resources to support huge numbers of people moving to cities.</p>
<figure class="align-center ">
<img alt="A construction worker, in a hard hat and drinking from a water bottle, holds a stop sign as people cross the street on a hot day in New York City." src="https://images.theconversation.com/files/424564/original/file-20211004-17-cnnuxp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/424564/original/file-20211004-17-cnnuxp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/424564/original/file-20211004-17-cnnuxp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/424564/original/file-20211004-17-cnnuxp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/424564/original/file-20211004-17-cnnuxp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/424564/original/file-20211004-17-cnnuxp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/424564/original/file-20211004-17-cnnuxp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Rising global temperatures are increasing heat risks for outdoor workers and low-income residents without air conditioning in cities.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/construction-worker-takes-a-sip-of-water-during-the-first-news-photo/81502812?adppopup=true">Spencer Platt/Getty Images</a></span>
</figcaption>
</figure>
<p>What worries us is that because urban extreme heat exposure has largely been left off the development policy radar, poor urban residents will have a harder time escaping poverty. Numerous studies have shown that <a href="https://doi.org/10.1038/nclimate2623">extreme heat reduces labor productivity</a> <a href="https://doi.org/10.1038/nclimate1827">and economic output</a>. Low-income workers tend to have fewer worker protections. They are also burdened with <a href="https://link.springer.com/content/pdf/10.1007/s12571-020-01011-4.pdf">high costs for food</a> and shelter, and often lack air conditioning.</p>
<h2>Steps cities can take</h2>
<p>The coronavirus pandemic and the Black Lives Matter movement have amplified demands for greater political and scientific attention to inequality and injustice. Better data that helps to capture the true lived experiences of individuals is a key feature of more integrated and socially relevant climate-health science. Collaborations <a href="https://scholar.google.com/citations?user=qgKdJWMAAAAJ&hl=en">across scientific</a> <a href="https://scholar.google.com/citations?user=oQkEq9gAAAAJ&hl=en">disciplines</a> <a href="https://scholar.google.com/citations?user=q7sk2bAAAAAJ&hl=en">like ours</a> can help governments and businesses accommodate new urban residents and reduce harm from heat.</p>
<p>Implementing early warning systems, for example, can reduce risks if they are accompanied by actions like opening cooling centers. Governments can also implement <a href="https://www.whitehouse.gov/briefing-room/statements-releases/2021/09/20/fact-sheet-biden-administration-mobilizes-to-protect-workers-and-communities-from-extreme-heat/">occupational heat standards</a> to reduce heat risks for marginalized people and empower them to avoid exposure. But these interventions need to reach the people most in need. </p>
<p>Our research offers a map for policies and technologies alike, not just to reduce harm from urban extreme heat exposure in the future, but today.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/a-major-federal-response-to-occupational-extreme-heat-is-here-at-last-168629">A major federal response to occupational extreme heat is here at last</a>
</strong>
</em>
</p>
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<img src="https://counter.theconversation.com/content/169153/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Cascade Tuholske receives funding from Columbia University. </span></em></p><p class="fine-print"><em><span>Chris Funk receives funding from the US Agency for International Development, the Bill and Melinda Gates Foundation, and the NASA Global Precipitation Measurement Mission. </span></em></p><p class="fine-print"><em><span>Kathryn Grace receives funding from the NSF, the Bill and Melinda Gates Foundation, the NIH, and NASA</span></em></p>
Hot, humid population centers are becoming epicenters of heat risk as climate changes worsens. It’s calling into question the conventional wisdom that urbanization uniformly reduces poverty.
Cascade Tuholske, Postdoctoral Research Scientist, Center for International Earth Science Information Network (CIESIN), Columbia Climate School, Columbia University
Chris Funk, Director of the Climate Hazards Center, University of California, Santa Barbara
Kathryn Grace, Associate Professor of Geography, Environment and Society, University of Minnesota
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/152749
2021-02-16T18:49:53Z
2021-02-16T18:49:53Z
How new design patterns can enable cities and their residents to change with climate change
<figure><img src="https://images.theconversation.com/files/382919/original/file-20210208-15-1naxqur.jpg?ixlib=rb-1.1.0&rect=533%2C0%2C6067%2C3984&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">cunaplus/Shutterstock</span></span></figcaption></figure><p>Our cities, designed for one set of climatic ranges, are increasingly “out of place” as average temperatures rise. The days above 40°C and nights above 30°C are <a href="https://www.climatecouncil.org.au/resources/angry-summer-report/">increasing</a>, especially in the expanding suburbs of Australian cities. This presents us with a massive redesign project. </p>
<p>Our <a href="https://www.coolingthecommons.com/">Cooling the Commons</a> <a href="https://www.landcom.com.au/assets/Approach/Cooling-the-Commons-Report.pdf">research</a> project, funded by Landcom, has launched a new approach using design patterns to guide how we design, and redesign, how we live in response to a changing climate. </p>
<p>A design pattern is first an observation: “People in that kind of designed situation tend to do this sort of thing”. It is then possible to design an intervention that redirects those tendencies. If that intervention succeeds, it can become a recommended pattern to help other designers: “If you encounter this kind of situation, try to make these kinds of interventions”.</p>
<p>Based on an international survey of what has worked well elsewhere, we have compiled a <a href="https://www.coolingthecommons.com/pattern%20deck/">bank of patterns</a>. These range from current patterns that increase heat and discomfort, through to remedial patterns for improving existing urban areas, to ideal patterns for new developments.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/cities-could-get-more-than-4-c-hotter-by-2100-to-keep-cool-in-australia-we-urgently-need-a-national-planning-policy-152680">Cities could get more than 4°C hotter by 2100. To keep cool in Australia, we urgently need a national planning policy</a>
</strong>
</em>
</p>
<hr>
<h2>The problems with current approaches</h2>
<p>Conventionally, designing is done in three ways:</p>
<ol>
<li><p>a designer can try to (re)design everything all at once and for all time, an approach closest to current planning practices, particularly of “greenfield” sites involving building from scratch</p></li>
<li><p>a designer can seek a technical solution that can be widely replicated – think of mass-produced products, from phones to cars</p></li>
<li><p>a designer can produce a bespoke design for each client, crafting context-specific solutions one at a time. This is often how architects work.</p></li>
</ol>
<p>Given the scale of our cities, we are not in a position to start again – though climate change might force <a href="https://www.nytimes.com/interactive/2020/07/23/magazine/climate-migration.html">large numbers of people to move</a>.</p>
<p>Some places in China and the Middle East are experimenting with <a href="https://www.neom.com/en-us/">building wholly new cities</a>. However, such total designs can prove unable to adapt to changing circumstances <a href="https://www.weforum.org/agenda/2019/01/the-world-s-coastal-cities-are-going-under-here-is-how-some-are-fighting-back/">like climatic shifts</a> that demand cities be remade – “<a href="https://www.bloomsbury.com/uk/remaking-cities-9781474224154/">metrofitting</a>”. It is better to have modular designs that piece together, can pull apart and aim to remain modifiable over time. </p>
<p>The second, technical approach is what many people expect of designers these days. But this often adds to the problem by missing important differences from one place or community to another. </p>
<p>Air conditioners are a good example. While they may offer immediate relief in buildings that weren’t designed to promote natural ventilation, they also <a href="https://theconversation.com/australias-rising-air-con-use-makes-us-hot-and-bothered-20258">create problems</a>. </p>
<p>Not everyone can afford to buy and run air <a href="https://theconversation.com/high-energy-costs-make-vulnerable-households-reluctant-to-use-air-conditioning-study-86624">conditioners</a>, which greatly increase energy use. And many buildings are not designed to be air-conditioned <a href="https://theconversation.com/why-bad-housing-design-pumps-up-power-prices-for-everyone-22651">efficiently</a>. There are also social impacts such as blowing heat on neighbours and pedestrians, noisy external fans, and people <a href="https://www.westernsydney.edu.au/__data/assets/pdf_file/0020/1161470/cooling-the-commons-report.pdf">being isolated in their homes</a> on hot days.</p>
<figure class="align-center ">
<img alt="row of air conditioner units outside apartments" src="https://images.theconversation.com/files/382905/original/file-20210208-19-k5d9om.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/382905/original/file-20210208-19-k5d9om.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/382905/original/file-20210208-19-k5d9om.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/382905/original/file-20210208-19-k5d9om.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/382905/original/file-20210208-19-k5d9om.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/382905/original/file-20210208-19-k5d9om.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/382905/original/file-20210208-19-k5d9om.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Running air conditioners forces people to stay indoors to remain comfortable while adding to the heat outside.</span>
<span class="attribution"><span class="source">Konstantin L/Shutterstock</span></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/if-planners-understand-its-cool-to-green-cities-whats-stopping-them-55753">If planners understand it's cool to green cities, what's stopping them?</a>
</strong>
</em>
</p>
<hr>
<p>We need more systemic solutions than one-size-fits-all technologies like air conditioning.</p>
<p>However, the third kind of designing – creating tailored solutions for each unique situation – is too slow in the face of already changed climates.</p>
<p>This means designers need to adopt a fourth approach, known as pattern thinking. It helps designers to see what is not working well, where and when, and so how to redirect those situations toward more preferable ones. </p>
<h2>How does pattern thinking work?</h2>
<p>One kind of pattern is a set of rules specifying something that can be repeated over and over. This is the meaning of pattern normally associated with decorative forms, or with making clothes, templates for furniture, or blueprints for buildings.</p>
<p>But the patterns we are talking about, context-specific interactions between people and things, are more like habits. They are tendencies that lead to repeated actions. For example, consider the patterns of car-oriented urban development. </p>
<p>Hard-surfaced roads and driveways are major sources of urban heat. Car-oriented planning downplays patterns of walking, through the lack of footpaths, shade and pedestrian-oriented night lighting, or the distances between shops, schools and work. This means people who can afford it might get into the habit of staying in air-conditioned houses, only occasionally going in their air-conditioned cars to air-conditioned shopping malls.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/381699/original/file-20210201-19-1gffo5j.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="single car parked in parking lot with exposed path leading to building" src="https://images.theconversation.com/files/381699/original/file-20210201-19-1gffo5j.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/381699/original/file-20210201-19-1gffo5j.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/381699/original/file-20210201-19-1gffo5j.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/381699/original/file-20210201-19-1gffo5j.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/381699/original/file-20210201-19-1gffo5j.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/381699/original/file-20210201-19-1gffo5j.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/381699/original/file-20210201-19-1gffo5j.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">New cities, old car-oriented patterns: the car park and path to this library provide no relief from the hot sun.</span>
<span class="attribution"><span class="source">Photo: Helen Armstrong</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>To counter this, we need to create patterns for street shading along footpaths and around public transport stops. Generic tree plantings to meet <a href="https://www.greenerspacesbetterplaces.com.au/">abstract canopy coverage targets</a> are not enough. They must take into account the soil and moisture conditions of different neighbourhoods, and different use patterns, including <a href="https://www.coolingthecommons.com/pattern/caring-for-trees/">patterns of tree care</a>. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/a-solution-to-cut-extreme-heat-by-up-to-6-degrees-is-in-our-own-backyards-133082">A solution to cut extreme heat by up to 6 degrees is in our own backyards</a>
</strong>
</em>
</p>
<hr>
<p>Related adaptive patterns might shift daytime activities into cooler night times. Some places already have these patterns: night markets and night-time use of outdoor spaces. </p>
<p>If locally adapted versions of these patterns encourage people to adopt new habits, other patterns will be needed. These will include, for example, ways to remind those cooling off outdoors in the evening that others might be trying to sleep with their naturally ventilating windows open. Such interlinked patterns point to the way pattern thinking moves from the big scale to the small. </p>
<p>To make the time to adapt each pattern to its local context, and then ensure those designs establish a pattern of long-lasting practice, requires a different <a href="https://theconversation.com/if-planners-understand-its-cool-to-green-cities-whats-stopping-them-55753">pattern of planning</a>. Planners need to be thinking about “staying with” what they plan, helping what they design to adapt to changing conditions and communities. For example, developers of <a href="https://theconversation.com/build-to-rent-could-shake-up-real-estate-but-wont-take-off-without-major-tax-changes-119603">build-to-rent</a> sites could hire “community liaison officers” to help tenants establish sustainable patterns of living. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/keeping-the-city-cool-isnt-just-about-tree-cover-it-calls-for-a-commons-based-climate-response-120491">Keeping the city cool isn't just about tree cover – it calls for a commons-based climate response</a>
</strong>
</em>
</p>
<hr>
<p><em>In addition to the authors, the Cooling the Commons research team includes: Professor Katherine Gibson, Associate Professor Louise Crabtree, Dr Stephen Healy and Dr Emma Power from the Institute for Culture and Society (ICS) at Western Sydney University (WSU), and Emeritus Professor Helen Armstrong from Queensland University of Technology (QUT).</em></p><img src="https://counter.theconversation.com/content/152749/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Cameron Tonkinwise received funding from Landcom. </span></em></p><p class="fine-print"><em><span>Abby Mellick Lopes receives funding from Landcom. </span></em></p>
As our cities get hotter, rebuilding whole suburbs better suited to the heat is not an option. Instead, we can draw from the best examples of how to adapt neighbourhoods and behaviours.
Cameron Tonkinwise, Professor, School of Design, University of Technology Sydney
Abby Mellick Lopes, Associate Professor, Design Studies, Faculty of Design, Architecture and Building, University of Technology Sydney
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/152625
2021-01-15T12:59:55Z
2021-01-15T12:59:55Z
Climate change: what would 4°C of global warming feel like?
<figure><img src="https://images.theconversation.com/files/379011/original/file-20210115-21-8t2sqi.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C5125%2C3421&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/summer-heat-wave-distort-city-background-1402227464">Lunatictm/Shutterstock</a></span></figcaption></figure><p>Another year, another climate record broken. Globally, 2020 tied with 2016 as the <a href="https://climate.copernicus.eu/2020-warmest-year-record-europe-globally-2020-ties-2016-warmest-year-recorded">warmest year ever</a> recorded. This was all the more remarkable given that cool conditions in the Pacific Ocean – <a href="https://www.metoffice.gov.uk/weather/learn-about/weather/oceans/el-nino">known as La Niña</a> – began to emerge in the second half of the year. The Earth’s mean surface temperature in 2020 was 1.25°C above the global average between 1850 and 1900 – one data point maybe, but part of an unrelenting, upward trend that’s largely driven by greenhouse gases from human activities.</p>
<p>Limiting the average global temperature increase to 1.5°C could help avoid some of the <a href="https://www.ipcc.ch/sr15/">most harmful impacts of climate change</a>. This target will feature prominently at the <a href="https://ukcop26.org/">COP26</a> discussions, scheduled for Glasgow in November 2021. But whether the world warms by 1.5°C or 4°C, it won’t translate into the same amount of warming for everyone. <a href="https://www.nature.com/articles/nature16542">Previous research</a> with climate models has shown that the Arctic, central Brazil, the Mediterranean basin, and the mainland US could warm by much more than the global average.</p>
<p>So what might that mean for you in the years and decades to come? Statistics for “global mean temperatures” and “regional hotspots” are abstract concepts – helpful for policymakers, but not something anyone can actually feel. What’s more, temperature projections from global climate models are typically for wild or agricultural landscapes, averaged over tens to hundreds of square kilometres. </p>
<p>These projections are far removed from the conditions that will be encountered on city streets, inside workplaces, public spaces, and our homes. But these are the places where health, comfort and productivity will be decided during the more intense heatwaves that climate change will bring.</p>
<h2>Feeling the heat</h2>
<p>One way of bridging the gap between climate models and the real world is to draw on personal memories of <a href="https://doi.org/10.1016/j.crm.2016.01.004">past extreme heat</a>. Stop to think about the highest temperatures you’ve ever experienced outdoors in the shade. For me, it was 43°C in a suburb of Melbourne, Australia. This felt hot but was much less than the highest temperature ever reliably recorded above ground – <a href="https://doi.org/10.1002/wea.3858">54.4°C</a> in Death Valley National Park, California, on <a href="https://yaleclimateconnections.org/2020/08/death-valley-california-may-have-recorded-hottest-temp-in-world-history/#:%7E:text=Death%20Valley%2C%20California%20hit%20an,the%20final%20report%20from%20NOAA.">August 16 2020</a>.</p>
<p>How about the hottest you’ve ever felt indoors? If I ignore saunas, mine was inside a home in Accra, Ghana. The room had wooden walls, a metal roof, and no air conditioning. Here, the temperature reached 38°C. Even though this was lower than in Melbourne, with the poor ventilation and humid air, the heat felt stifling. </p>
<figure class="align-center ">
<img alt="A view of metal rooftops in an urban community in Ghana." src="https://images.theconversation.com/files/379008/original/file-20210115-19-chzrml.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/379008/original/file-20210115-19-chzrml.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/379008/original/file-20210115-19-chzrml.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/379008/original/file-20210115-19-chzrml.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/379008/original/file-20210115-19-chzrml.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/379008/original/file-20210115-19-chzrml.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/379008/original/file-20210115-19-chzrml.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A neighbourhood in Accra, Ghana.</span>
<span class="attribution"><span class="source">Robert Wilby</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The highest outdoor temperature ever measured in the UK was 38.7°C on July 25 2019 in the Cambridge University Botanic Garden. According to <a href="https://www.metoffice.gov.uk/pub/data/weather/uk/ukcp18/science-reports/UKCP18-Overview-report.pdf">UK Met Office analyses</a>, global temperatures that are 4°C above pre-industrial levels may be reached as soon as the 2060s. Climate projections at the <a href="https://www.bbc.co.uk/news/resources/idt-d6338d9f-8789-4bc2-b6d7-3691c0e7d138">postcode level</a> suggest that 4°C of global warming could bring temperatures of 43°C to Cambridge. I can now recall what the suburb felt like in Australia, and understand that this could be Cambridge in 40 years’ time.</p>
<p>But this projection for the hottest summer day for Cambridge in the 2060s involved tuning climate models with temperatures <a href="https://hess.copernicus.org/articles/21/2649/2017/">averaged from weather stations</a>. These tend to be located away from artificial heat sources and often in areas with grass and vegetation. Asphalt surfaces and high-density city centres are typically <a href="https://journals.sagepub.com/doi/abs/10.1068/b33066t">several degrees warmer</a> and behave very differently to rural weather stations.</p>
<p>Even when climate models simulate temperatures for urban areas, <a href="https://www.nature.com/articles/s41558-020-00958-8">projections may be simplified</a> in other ways. To produce monthly temperature averages, models might smooth out the peaks and troughs of individual days. Urban land may be fixed at its present extent and possible actions that cities might take to adapt to rising temperatures – such as more green spaces or reflective roofs – are ignored. Complex variations in temperature between streets are still not resolved either. This means that even state-of-the-art models probably underestimate the true severity of future warming in urban areas.</p>
<h2>Bringing climate science indoors</h2>
<p>We also spend much of our lives indoors so, if we really want to translate climate change into human experiences, we have to simulate conditions within homes and workplaces. To capture this “felt” temperature, the heat we experience, <a href="https://doi.org/10.1080/09613218.2015.1033875">other factors</a> have to be considered, such as humidity, ventilation, and heat radiating from hot surfaces, plus the metabolic rate of occupants and their clothing. An air temperature of 38°C is dangerous at 30% relative humidity but can be lethal at 80%. This is because high humidity reduces the effectiveness of sweating – our <a href="https://theconversation.com/global-warming-now-pushing-heat-into-territory-humans-cannot-tolerate-138343">natural mechanism for keeping cool</a>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/global-warming-now-pushing-heat-into-territory-humans-cannot-tolerate-138343">Global warming now pushing heat into territory humans cannot tolerate</a>
</strong>
</em>
</p>
<hr>
<p>What might that room in Accra feel like with 4°C of global warming? Indoor conditions will track outdoor temperatures because the room has no air conditioning. Worldwide, more than <a href="https://unstats.un.org/sdgs/report/2019/goal-11/">one billion people</a> live in similar conditions. Without any adaptations, high indoor temperatures with high humidity could become unbearable – <a href="https://advances.sciencemag.org/content/6/19/eaaw1838">even deadly</a> – for millions.</p>
<p><a href="https://iopscience.iop.org/article/10.1088/1748-9326/abdbf2">Our research</a> showed that an insulated ceiling beneath a metal roof could hold peak indoor temperatures at their current levels even if it gets 4°C warmer outside. Unfortunately, this modification would raise night temperatures, because heat that builds up inside during the day is less able to escape at night. Already, indoor temperatures may not fall below 30°C during some nights in Accra. There’s a trade-off between lower indoor temperatures by day or by night, so affordable adaptations have to be tailored carefully to each home.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/379012/original/file-20210115-19-g1kx3r.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A graph comparing daily temperatures at a weather station, an insulated room and an uninsulated room in the same house." src="https://images.theconversation.com/files/379012/original/file-20210115-19-g1kx3r.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/379012/original/file-20210115-19-g1kx3r.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=341&fit=crop&dpr=1 600w, https://images.theconversation.com/files/379012/original/file-20210115-19-g1kx3r.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=341&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/379012/original/file-20210115-19-g1kx3r.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=341&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/379012/original/file-20210115-19-g1kx3r.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=429&fit=crop&dpr=1 754w, https://images.theconversation.com/files/379012/original/file-20210115-19-g1kx3r.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=429&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/379012/original/file-20210115-19-g1kx3r.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=429&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Weather stations which feed data to climate models fail to capture the heat many urban residents already experience.</span>
<span class="attribution"><a class="source" href="https://iopscience.iop.org/article/10.1088/1748-9326/abdbf2">Wilby et al. (2021)</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Without action, the number of unbearably hot homes is set to grow. By 2050, 68% of humanity may live in <a href="https://www.un.org/development/desa/en/news/population/2018-revision-of-world-urbanization-prospects.html">urban areas</a> and populations in the tropics will be <a href="https://www.nature.com/articles/nclimate3322">most exposed</a> to extreme humid heat. We know surprisingly little about these front lines of climate change, especially within the streets and homes of low-income communities. </p>
<p>I will not forget that room in Accra, especially during the climate negotiations in Glasgow.</p><img src="https://counter.theconversation.com/content/152625/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Robert Wilby receives research funding from the British Academy, the European Union Horizon 2020 programme, and the Natural Environment Research Council. He is a scientific adviser to and owns shares in Previsico – a global flood forecasting company.</span></em></p>
Climate models are likely underestimating the true severity of future warming in urban areas.
Robert Wilby, Professor of Hydroclimatic Modelling, Loughborough University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/128918
2020-04-14T19:54:04Z
2020-04-14T19:54:04Z
Climate explained: how white roofs help to reflect the sun’s heat
<figure><img src="https://images.theconversation.com/files/313599/original/file-20200204-41485-1n70hqk.jpg?ixlib=rb-1.1.0&rect=50%2C184%2C5557%2C3547&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">www.shutterstock.com</span></span></figcaption></figure><p><em><strong><a href="https://theconversation.com/nz/topics/climate-explained-74664">Climate Explained</a></strong> is a collaboration between The Conversation, Stuff and the New Zealand Science Media Centre to answer your questions about climate change.</em> </p>
<p><em>If you have a question you’d like an expert to answer, please send it to climate.change@stuff.co.nz</em></p>
<blockquote>
<p><strong>Does the white roof concept really work? If so, is it suitable for New Zealand conditions?</strong></p>
</blockquote>
<p>Generally, white materials reflect more light than dark ones, and this is also true for buildings and infrastructure. The outside and roof of a building soak up the heat from the sun, but if they are made of materials and finishes in lighter or white colours, this can minimise this solar absorption. </p>
<p>During the warmer part of the year, this can keep the temperature inside the building cooler. This is especially important for building and construction materials such as concrete, stone and asphalt, which store and re-radiate heat. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/climate-explained-which-countries-are-likely-to-meet-their-paris-agreement-targets-128855">Climate explained: which countries are likely to meet their Paris Agreement targets</a>
</strong>
</em>
</p>
<hr>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/313603/original/file-20200204-41485-16nvg47.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/313603/original/file-20200204-41485-16nvg47.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/313603/original/file-20200204-41485-16nvg47.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/313603/original/file-20200204-41485-16nvg47.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/313603/original/file-20200204-41485-16nvg47.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/313603/original/file-20200204-41485-16nvg47.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/313603/original/file-20200204-41485-16nvg47.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">On a hot day, a white roof can keep the temperature cooler inside the building.</span>
<span class="attribution"><span class="source">from www.shutterstock.com</span></span>
</figcaption>
</figure>
<p>A <a href="https://www.tandfonline.com/doi/abs/10.1080/2093761X.2016.1167644">New Zealand study</a> tested near-identical buildings in Auckland with either a red or white roof. It found that even in Auckland’s temperate climate, white roofs reduced the need for air conditioning during hotter periods, without reducing comfort during cooler seasons. </p>
<p>The study also identified several large-scale white-roof installations, including at Auckland International Airport, shopping centres and commercial buildings, but the effect was less clear. </p>
<p>This research suggests that there is potential for white-roof installations to significantly reduce the amount of energy needed to cool buildings. This would in turn reduce greenhouse gas emissions and also help us to adapt to rising temperatures. </p>
<p>It is difficult to quantify the impact for New Zealand’s housing stock because existing studies are mostly limited to larger commercial buildings. But research carried out so far suggests white roofs could be a viable approach to minimising the heat taken up by buildings during hotter parts of the year. </p>
<h2>Cooling cities</h2>
<p>White roofs can also help <a href="https://e360.yale.edu/features/urban-heat-can-white-roofs-help-cool-the-worlds-warming-cities">reduce the temperature of whole cities</a>. Many city centres include large buildings made of concrete or other materials that collect and store solar heat during the day. In a phenomenon known as the “<a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2010GL042845">urban heat island</a>” effect, city centres can often be several degrees warmer than the surrounding countryside. </p>
<p>When cities are hotter, they use more energy for cooling. This usually results in more greenhouse gas emissions, due in part to the energy consumed, and contributes further to climate change. </p>
<p>New Zealand is different because our land mass has a maximum width of 400 kilometres. This means that unlike many urban islands on the African, Asian or American continents, New Zealand’s city centres benefit from the cooling effects of being near the ocean. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/climate-explained-why-some-people-still-think-climate-change-isnt-real-124763">Climate explained: why some people still think climate change isn't real</a>
</strong>
</em>
</p>
<hr>
<p>There are many <a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2010GL042845">international</a> <a href="https://www.sciencedirect.com/science/article/abs/pii/S221209551530002X">studies</a> showing white roofs are effective in mitigating the urban heat island effect in densely populated cities. But there is little evidence that using white roofs in New Zealand cities could result in significant energy reductions. </p>
<p>A growing number of <a href="https://phys.org/news/2019-04-roofs-overheating-cities-heatwaves.html">studies</a> suggest making the surfaces of buildings and infrastructure more light reflecting could significantly lower extreme temperatures, particularly <a href="https://www.sciencedaily.com/releases/2019/08/190814093856.htm">during heat waves</a>, not just in cities but in rural areas as well. A <a href="https://e360.yale.edu/features/urban-heat-can-white-roofs-help-cool-the-worlds-warming-cities">recent study</a> shows strategic replacement of dark surfaces with white could lower heatwave maximum temperatures by 2°C or more, in a range of locations. </p>
<p>But studies have also identified some practical limitations and potential side effects, including the possibility of <a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2011JD016281">reduced evaporation and rainfall in urban areas in drier climates</a>. </p>
<p>In conclusion, white roofs could be a good idea for New Zealand to keep homes and cities slightly cooler. As temperatures continue to rise, this could reduce the energy needed for cooling. We should consider this option more often, particularly for commercial-scale buildings made of heat-retaining materials in larger cities.</p><img src="https://counter.theconversation.com/content/128918/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Dr Maibritt Pedersen Zari is a Senior Lecturer at the Wellington School of Architecture, Victoria University of Wellington.</span></em></p><p class="fine-print"><em><span>Nilesh Bakshi does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
Buildings soak up the sun’s heat, but research shows that white roofs and surfaces can reduce temperatures inside, particularly during heat waves.
Nilesh Bakshi, Lecturer, Te Herenga Waka — Victoria University of Wellington
Maibritt Pedersen Zari, Senior Lecturer in Sustainable Architecture, Te Herenga Waka — Victoria University of Wellington
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/110817
2020-03-19T18:54:32Z
2020-03-19T18:54:32Z
After another hot summer, here are 6 ways to cool our cities in future
<figure><img src="https://images.theconversation.com/files/317250/original/file-20200226-24690-16saofs.jpg?ixlib=rb-1.1.0&rect=573%2C34%2C5220%2C3483&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/kangaroo-sculpture-drinking-form-water-feature-1545920828">Nigel Jarvis/Shutterstock</a></span></figcaption></figure><p>Australia is a “<a href="http://www.lowcarbonlivingcrc.com.au/sites/all/files/event_file_attachments/discussion_paper_cooling_cities_final.pdf">land of climate extremes</a>”. This is especially true for our cities, which have become <a href="https://www.climatecouncil.org.au/uploads/8e9c2b91ce3c3ebb7d97e403a6fdf38e.pdf">hubs of extreme summer temperatures</a>. This past summer was the <a href="http://www.bom.gov.au/climate/current/season/aus/summary.shtml">second-hottest on record</a> for Australia, following the 2018-19 record, with average maximum temperatures more than 2°C above the long-term average.</p>
<p>Frequent and long heatwaves are having <a href="https://www.tandfonline.com/doi/abs/10.1080/00038628.2014.903568">serious impacts on energy consumption</a>, <a href="https://www.sciencedirect.com/science/article/pii/S1462901114000999">public health</a>, <a href="https://www.nature.com/articles/nclimate2623?dom=pscau&src=syn">labour productivity</a> and <a href="http://www.hume.vic.gov.au/files/46a4d08c-9a31-4c6d-bed0-9e1c00c093b3/Garnaut_Climate_Change_Review_Report.pdf">the economy</a>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/after-a-summer-of-extremes-heres-what-to-expect-this-autumn-132862">After a summer of extremes, here's what to expect this autumn</a>
</strong>
</em>
</p>
<hr>
<p>Even without global warming, cities already face a problem — the <a href="https://theconversation.com/why-are-cities-warmer-than-the-countryside-53160">urban heat island</a> effect, whereby inner urban areas are hotter than the surrounding rural areas. Urban heat islands are caused by factors such as pollution, energy consumption, industrial activities, large dark concrete buildings, asphalt roads and closely spaced structures. </p>
<p><a href="http://www.lowcarbonlivingcrc.com.au/sites/all/files/event_file_attachments/discussion_paper_cooling_cities_final.pdf">Evidence</a> from Australia’s major cities shows average temperatures are 2-10°C higher in highly urbanised areas than in their rural surroundings. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/urban-growth-heat-islands-humidity-climate-change-the-costs-multiply-in-tropical-cities-120825">Urban growth, heat islands, humidity, climate change: the costs multiply in tropical cities</a>
</strong>
</em>
</p>
<hr>
<p>Governments and policymakers can use a variety of cooling strategies combined with community engagement, education and adaptation measures to cool Australian cities. </p>
<h2>1. Green infrastructure</h2>
<p>Green infrastructure includes parks, street trees, community gardens, green roofs and vertical gardens. In tropical and subtropical climate zones, like much of Australia, <a href="https://www.sciencedirect.com/science/article/abs/pii/S0038092X16306004">green infrastructure is a cost-effective cooling strategy</a>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/requiem-or-renewal-this-is-how-a-tropical-city-like-darwin-can-regain-its-cool-102839">Requiem or renewal? This is how a tropical city like Darwin can regain its cool</a>
</strong>
</em>
</p>
<hr>
<p><a href="http://www.lowcarbonlivingcrc.com.au/sites/all/files/event_file_attachments/discussion_paper_cooling_cities_final.pdf">Evidence</a> suggests a 10% increase in tree canopy cover can lower afternoon ambient temperatures by as much as 1-1.5C, as the chart below shows. Similarly, in parks with adequate irrigation ambient temperatures can be 1-1.5°C lower than nearby unvegetated or built-up areas. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/269111/original/file-20190413-76827-mph4tu.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/269111/original/file-20190413-76827-mph4tu.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/269111/original/file-20190413-76827-mph4tu.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=386&fit=crop&dpr=1 600w, https://images.theconversation.com/files/269111/original/file-20190413-76827-mph4tu.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=386&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/269111/original/file-20190413-76827-mph4tu.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=386&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/269111/original/file-20190413-76827-mph4tu.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=485&fit=crop&dpr=1 754w, https://images.theconversation.com/files/269111/original/file-20190413-76827-mph4tu.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=485&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/269111/original/file-20190413-76827-mph4tu.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=485&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Maximum (above) and average (below) temperature reduction potential of different urban greenery techniques.</span>
<span class="attribution"><a class="source" href="http://www.lowcarbonlivingcrc.com.au/sites/all/files/event_file_attachments/discussion_paper_cooling_cities_final.pdf">Komali Yenneti et al</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/269110/original/file-20190413-76856-11jkd1r.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/269110/original/file-20190413-76856-11jkd1r.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/269110/original/file-20190413-76856-11jkd1r.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=332&fit=crop&dpr=1 600w, https://images.theconversation.com/files/269110/original/file-20190413-76856-11jkd1r.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=332&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/269110/original/file-20190413-76856-11jkd1r.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=332&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/269110/original/file-20190413-76856-11jkd1r.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=417&fit=crop&dpr=1 754w, https://images.theconversation.com/files/269110/original/file-20190413-76856-11jkd1r.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=417&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/269110/original/file-20190413-76856-11jkd1r.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=417&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p>We can increase street tree canopy cover by planting more shade trees on footpaths, lanes and street medians. Where there is little space for parks and street trees, green roofs and walls may be viable options. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/heres-how-green-infrastructure-can-easily-be-added-to-the-urban-planning-toolkit-57277">Here’s how green infrastructure can easily be added to the urban planning toolkit</a>
</strong>
</em>
</p>
<hr>
<h2>2. Water-sensitive urban design</h2>
<p>The use of water as a way to cool cities has been known for thousands of years. Water-based landscapes such as rivers, lakes, wetlands and bioswales can reduce urban ambient temperatures by 1-2°C. This is a result of water heat retention and evaporative cooling. </p>
<p>In addition to natural water bodies, various other water-based technologies are now available for both decorative and climatic reasons. Examples include passive water systems, like ponds, pools and fountains, and active or hybrid systems, such as evaporative wind towers and sprinklers. Active and passive systems can decrease ambient temperatures by 3-8°C, as the charts below show.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/269112/original/file-20190413-76862-1ln6oeo.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/269112/original/file-20190413-76862-1ln6oeo.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/269112/original/file-20190413-76862-1ln6oeo.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=374&fit=crop&dpr=1 600w, https://images.theconversation.com/files/269112/original/file-20190413-76862-1ln6oeo.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=374&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/269112/original/file-20190413-76862-1ln6oeo.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=374&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/269112/original/file-20190413-76862-1ln6oeo.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=470&fit=crop&dpr=1 754w, https://images.theconversation.com/files/269112/original/file-20190413-76862-1ln6oeo.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=470&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/269112/original/file-20190413-76862-1ln6oeo.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=470&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Maximum (above) and average (below) temperature reduction potential of different active and passive water systems.</span>
<span class="attribution"><a class="source" href="http://www.lowcarbonlivingcrc.com.au/sites/all/files/event_file_attachments/discussion_paper_cooling_cities_final.pdf">Komali Yenneti et al</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/269113/original/file-20190413-76853-1mx6q9w.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/269113/original/file-20190413-76853-1mx6q9w.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/269113/original/file-20190413-76853-1mx6q9w.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=363&fit=crop&dpr=1 600w, https://images.theconversation.com/files/269113/original/file-20190413-76853-1mx6q9w.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=363&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/269113/original/file-20190413-76853-1mx6q9w.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=363&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/269113/original/file-20190413-76853-1mx6q9w.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=456&fit=crop&dpr=1 754w, https://images.theconversation.com/files/269113/original/file-20190413-76853-1mx6q9w.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=456&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/269113/original/file-20190413-76853-1mx6q9w.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=456&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p>Water-based systems are usually combined with green infrastructure to enhance urban cooling, improve air quality, aid in flood management and provide attractive public spaces. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/when-the-heat-is-on-we-need-city-wide-plans-to-keep-cool-70738">When the heat is on, we need city-wide plans to keep cool</a>
</strong>
</em>
</p>
<hr>
<h2>3. Cool materials</h2>
<p>Building materials are major contributors to the urban heat island effect. The use of cool materials on roofs, streets and pavements is an important cooling strategy. A cool surface material has low heat conductivity, low heat capacity, high solar reflectance and high permeability. </p>
<p><a href="http://www.lowcarbonlivingcrc.com.au/sites/all/files/event_file_attachments/discussion_paper_cooling_cities_final.pdf">Evidence suggests</a> that using cool materials for roofs and facades can reduce indoor temperature by 2-5°C, improve indoor comfort and cut energy use.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/269115/original/file-20190413-76862-1229xmw.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/269115/original/file-20190413-76862-1229xmw.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/269115/original/file-20190413-76862-1229xmw.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=382&fit=crop&dpr=1 600w, https://images.theconversation.com/files/269115/original/file-20190413-76862-1229xmw.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=382&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/269115/original/file-20190413-76862-1229xmw.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=382&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/269115/original/file-20190413-76862-1229xmw.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=480&fit=crop&dpr=1 754w, https://images.theconversation.com/files/269115/original/file-20190413-76862-1229xmw.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=480&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/269115/original/file-20190413-76862-1229xmw.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=480&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Maximum (above) and average (below) temperature reduction potential of different cool surfaces.</span>
<span class="attribution"><a class="source" href="http://www.lowcarbonlivingcrc.com.au/sites/all/files/event_file_attachments/discussion_paper_cooling_cities_final.pdf">Komali Yenneti et al</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/269114/original/file-20190413-76856-1uc1p3m.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/269114/original/file-20190413-76856-1uc1p3m.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/269114/original/file-20190413-76856-1uc1p3m.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=379&fit=crop&dpr=1 600w, https://images.theconversation.com/files/269114/original/file-20190413-76856-1uc1p3m.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=379&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/269114/original/file-20190413-76856-1uc1p3m.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=379&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/269114/original/file-20190413-76856-1uc1p3m.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=477&fit=crop&dpr=1 754w, https://images.theconversation.com/files/269114/original/file-20190413-76856-1uc1p3m.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=477&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/269114/original/file-20190413-76856-1uc1p3m.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=477&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p>Cool materials commonly applied to buildings include white paints, elastomeric, acrylic or polyurethane coating, ethylene propylenediene tetrolymer membrane, chlorinated polyethylene, polyvinyl chloride, thermoplastic polyolefin, and chlorosulfonated polyethylene. </p>
<p>Lighter aggregates and binders in asphalt and concrete, permeable pavers made from foam concrete, permeable asphalt and resin concrete are standard cool pavement materials. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/building-cool-cities-for-a-hot-future-57489">Building cool cities for a hot future</a>
</strong>
</em>
</p>
<hr>
<h2>4. Shading</h2>
<p>Shading can decrease radiant temperature and greatly improve outdoor thermal comfort. Providing shading on streets, building entries and public venues using greenery, artificial structures or a combination of both can block solar radiation and increase outdoor thermal comfort. Examples of artificial structures include temporary shades, sunshades and shades using solar panels. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/in-a-heatwave-the-leafy-suburbs-are-even-more-advantaged-53307">In a heatwave, the leafy suburbs are even more advantaged</a>
</strong>
</em>
</p>
<hr>
<h2>5. Combined cooling strategies</h2>
<p>Performance analysis of various projects in Australia suggests the cooling potential of the combined use of the different strategies discussed above is much higher than the sum of the contributions of each individual technology, as the charts below show. The average maximum temperature reduction with just one technology is close to 1.5°C. When two or more technologies are used together the reduction exceeds 2.5°C. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/269116/original/file-20190413-76859-vgcd7l.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/269116/original/file-20190413-76859-vgcd7l.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/269116/original/file-20190413-76859-vgcd7l.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=411&fit=crop&dpr=1 600w, https://images.theconversation.com/files/269116/original/file-20190413-76859-vgcd7l.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=411&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/269116/original/file-20190413-76859-vgcd7l.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=411&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/269116/original/file-20190413-76859-vgcd7l.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=516&fit=crop&dpr=1 754w, https://images.theconversation.com/files/269116/original/file-20190413-76859-vgcd7l.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=516&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/269116/original/file-20190413-76859-vgcd7l.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=516&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Maximum (above) and average (below) temperature reduction potential for a combination of technologies.</span>
<span class="attribution"><a class="source" href="http://www.lowcarbonlivingcrc.com.au/sites/all/files/event_file_attachments/discussion_paper_cooling_cities_final.pdf">Komali Yenneti et al</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/269117/original/file-20190413-76846-13553lg.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/269117/original/file-20190413-76846-13553lg.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/269117/original/file-20190413-76846-13553lg.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=387&fit=crop&dpr=1 600w, https://images.theconversation.com/files/269117/original/file-20190413-76846-13553lg.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=387&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/269117/original/file-20190413-76846-13553lg.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=387&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/269117/original/file-20190413-76846-13553lg.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=486&fit=crop&dpr=1 754w, https://images.theconversation.com/files/269117/original/file-20190413-76846-13553lg.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=486&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/269117/original/file-20190413-76846-13553lg.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=486&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p>The chart below shows the peak temperature reduction for all cooling strategies. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/269118/original/file-20190413-76850-13b4dv.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/269118/original/file-20190413-76850-13b4dv.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/269118/original/file-20190413-76850-13b4dv.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=269&fit=crop&dpr=1 600w, https://images.theconversation.com/files/269118/original/file-20190413-76850-13b4dv.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=269&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/269118/original/file-20190413-76850-13b4dv.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=269&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/269118/original/file-20190413-76850-13b4dv.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=338&fit=crop&dpr=1 754w, https://images.theconversation.com/files/269118/original/file-20190413-76850-13b4dv.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=338&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/269118/original/file-20190413-76850-13b4dv.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=338&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
<span class="attribution"><a class="source" href="http://www.lowcarbonlivingcrc.com.au/sites/all/files/event_file_attachments/discussion_paper_cooling_cities_final.pdf">Komali Yenneti et al</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>6. Behaviour changes</h2>
<p>People are significant contributors to urban heat through their use of air conditioning. The waste heat from air conditioners heats up surrounding outdoor spaces. </p>
<p>Projections show cooling demand in Australian cities may increase by up to 275% by 2050. Such a trend will have a great impact on urban climate, as well as increasing electricity use. If this is powered by fossil fuels, it will add billions of tons of carbon pollution. </p>
<p>Climate-responsive building design and adaptive design techniques in existing buildings can minimise occupants’ demand for cooling energy by reducing indoor and outdoor temperatures.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/we-have-the-blueprint-for-liveable-low-carbon-cities-we-just-need-to-use-it-121615">We have the blueprint for liveable, low-carbon cities. We just need to use it</a>
</strong>
</em>
</p>
<hr>
<h2>Cities must take a holistic, long-term approach</h2>
<p>Local governments can prepare for and respond to heat events through emergency response plans. However, emergency responses alone cannot address other challenges of urban heat, including human vulnerability, energy disruptions and the economic costs of lower workplace productivity and infrastructure failures. </p>
<p>Long-term cooling strategies are needed to keep city residents, buildings and communities cool and save energy, health and economic costs.</p><img src="https://counter.theconversation.com/content/110817/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Komali Yenneti does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
Half-a-dozen strategies are effective for cooling urban areas. Used in combination, these strategies can drop the temperature even more.
Komali Yenneti, Honorary Academic Fellow, Australia India Institute, The University of Melbourne
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/133082
2020-03-10T19:04:11Z
2020-03-10T19:04:11Z
A solution to cut extreme heat by up to 6 degrees is in our own backyards
<figure><img src="https://images.theconversation.com/files/319252/original/file-20200309-118913-15x472v.jpg?ixlib=rb-1.1.0&rect=459%2C293%2C2776%2C1862&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/early-morning-drone-aerial-view-south-1027776355">Milleflore Images/Shutterstock</a></span></figcaption></figure><p>Australia just experienced <a href="http://www.bom.gov.au/climate/current/season/aus/archive/202002.summary.shtml">the second-warmest summer on record</a>, with <a href="http://www.bom.gov.au/climate/current/annual/aus/">2019 being the hottest year</a>. Summer temperatures soared across the country, causing great economic and human loss. The good news is we can do something about this in our own backyards. We have found trees and vegetation can lower local land temperatures by up to 5-6°C on days of extreme heat.</p>
<p>Our <a href="https://researchers.mq.edu.au/en/publications/ef2a5051-0d75-4571-b920-1741de04429c">newly published research</a> into a summer heatwave in Adelaide suggests that a simple solution to extreme heat is literally at everyone’s doorstep. It relies on the trees, the grasses and the vegetation in our own backyards. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/out-in-the-heat-why-poorer-suburbs-are-more-at-risk-in-warming-cities-66213">Out in the heat: why poorer suburbs are more at risk in warming cities</a>
</strong>
</em>
</p>
<hr>
<h2>What did the study show?</h2>
<p>During a three-day heatwave that hit Adelaide in 2017, <a href="https://www.adaptwest.com.au/">AdaptWest</a> took to the skies to measure land surface temperatures from an aircraft. Our analysis of the data collected on that day suggests urban trees and grasses can lower daytime land temperatures by up to 5-6°C during extreme heat. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/318820/original/file-20200305-106579-aeplgv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/318820/original/file-20200305-106579-aeplgv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/318820/original/file-20200305-106579-aeplgv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=580&fit=crop&dpr=1 600w, https://images.theconversation.com/files/318820/original/file-20200305-106579-aeplgv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=580&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/318820/original/file-20200305-106579-aeplgv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=580&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/318820/original/file-20200305-106579-aeplgv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=729&fit=crop&dpr=1 754w, https://images.theconversation.com/files/318820/original/file-20200305-106579-aeplgv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=729&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/318820/original/file-20200305-106579-aeplgv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=729&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Effect of vegetated and non-vegetated cover on daytime land surface temperatures recorded in 120,000 land units in western Adelaide during a three-day heatwave.</span>
<span class="attribution"><span class="source">Ossola et al., 2020. https://doi.org/10.25949/5df2ef1637124</span></span>
</figcaption>
</figure>
<p>The largest temperature reductions were in the hottest suburbs and those further away from the coast. These significant reductions were mostly achieved thanks to backyard trees. </p>
<p>So this benefit that urban trees provide has two key aspects:</p>
<ul>
<li><p>maximum cooling happens <em>when needed the most</em> – during days of unbearable heat.</p></li>
<li><p>maximum cooling happens <em>where needed the most</em> – close to us, the people, in the communities where we live. </p></li>
</ul>
<p>Our analysis also shows the humble home garden more than pulls its weight when it comes to reducing extreme urban heat and its harmful effects. Although yards and gardens cover only about <a href="https://researchers.mq.edu.au/en/publications/ef2a5051-0d75-4571-b920-1741de04429c">20% of urban land</a>, these private spaces provide more than <a href="https://researchers.mq.edu.au/en/publications/ef2a5051-0d75-4571-b920-1741de04429c">40% of the tree cover and 30% of grass cover</a> across western Adelaide. This is comparable to what can be found in many other Australian cities and towns. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/318999/original/file-20200306-106584-kjxcze.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/318999/original/file-20200306-106584-kjxcze.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/318999/original/file-20200306-106584-kjxcze.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=425&fit=crop&dpr=1 600w, https://images.theconversation.com/files/318999/original/file-20200306-106584-kjxcze.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=425&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/318999/original/file-20200306-106584-kjxcze.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=425&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/318999/original/file-20200306-106584-kjxcze.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=534&fit=crop&dpr=1 754w, https://images.theconversation.com/files/318999/original/file-20200306-106584-kjxcze.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=534&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/318999/original/file-20200306-106584-kjxcze.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=534&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Daytime thermal imaging of land surface temperature in Walkley Heights, Adelaide, taken from an aircraft (inset) on February 9 2017 at the peak of a three-day 40°C heatwave. The area on the right is cooler (blue shades) because of greater vegetation cover. In the hotter area on the left (red shades) a residential development built in 2003 has smaller yards with less tree cover.</span>
<span class="attribution"><span class="source">AdaptWest and Airborne Research Australia</span></span>
</figcaption>
</figure>
<p>In fact, <a href="https://www.sciencedirect.com/science/article/pii/S0169204618312064">private tree canopy cover is considerably greater than that of typical urban parks or public green areas</a>. This means these private green spaces are a vital yet often overlooked resource for fighting extreme heat.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/our-land-abounds-in-nature-strips-surely-we-can-do-more-than-mow-a-third-of-urban-green-space-124781">Our land abounds in nature strips – surely we can do more than mow a third of urban green space</a>
</strong>
</em>
</p>
<hr>
<h2>Planning climate-ready cities</h2>
<p>Climate models and projections predict extreme heat days and heatwaves will become more frequent and intense. Penrith reached 48.9°C on January 4 this year, making Western Sydney <a href="https://www.sbs.com.au/news/sydney-s-penrith-the-hottest-place-on-earth-amid-devastating-bushfires">the hottest place on Earth that day</a>. Given that heatwaves are already <a href="https://researchers.mq.edu.au/files/62276382/Publisher%20version.pdf">considered Australia’s deadliest climate-related disaster</a>, the forecast temperatures pose an urgent threat to human livelihoods. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/319251/original/file-20200309-118890-ye0u2p.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/319251/original/file-20200309-118890-ye0u2p.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/319251/original/file-20200309-118890-ye0u2p.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/319251/original/file-20200309-118890-ye0u2p.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/319251/original/file-20200309-118890-ye0u2p.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/319251/original/file-20200309-118890-ye0u2p.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/319251/original/file-20200309-118890-ye0u2p.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/319251/original/file-20200309-118890-ye0u2p.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Number of very hot days (maximum above 40°C) per year and trend line (running 10-year average) for Australia.</span>
<span class="attribution"><a class="source" href="http://www.bom.gov.au/cgi-bin/climate/change/extremes/timeseries.cgi?graph=HD40&ave_yr=10">Bureau of Meteorology</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Urban planning is increasingly having to take extreme temperatures into account. For instance, the City of Sydney recently announced an ambitious policy to increase <a href="https://meetings.cityofsydney.nsw.gov.au/documents/s38491/Sustainable%20Sydney%202050%20Update%20-%20Environment%20and%20Resilience%20Strategic%20Directions%201%20and%205%20-%20A%20Leadi.pdf">urban green cover to 40% by 2050</a> for climate change resilience. Currently, this level of green cover is found in only a <a href="https://202020vision.com.au/media/7141/final-report_140930.pdf">handful of suburbs in cities like Melbourne, Sydney and Adelaide</a>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-do-we-save-ageing-australians-from-the-heat-greening-our-cities-is-a-good-start-112613">How do we save ageing Australians from the heat? Greening our cities is a good start</a>
</strong>
</em>
</p>
<hr>
<p>To achieve such ambitious and life-sustaining goals, our results point to the need to retain, protect and enhance urban greenery in our own yards. As our cities <a href="https://theconversation.com/density-sprawl-growth-how-australian-cities-have-changed-in-the-last-30-years-65870">become increasingly dense</a>, people’s trees and yards can play an invaluable role in adapting to climate change. </p>
<p>Most council, state and federal policies to date have neglected yards and their trees when thinking about climate change adaptation. When envisioning how Australian cities should grow, develop and thrive, more attention has to be given to the spaces where our yards and trees can help reduce the catastrophic effects of a warming climate on people and communities, right at our doorstep.</p>
<p>Climate change is causing a social, cultural and political revolution. It calls for bold, decisive and immediate action. This is a lifetime opportunity for smart and proactive planning, policy-making and community action. This work needs to begin now. </p>
<p>Urban forests don’t grow quickly, however. We need to be encouraging low-water-use grass and shrub covers as a fast interim strategy for urban cooling. </p>
<p>This is a stopgap measure until a large army of climate-ready tree soldiers, that we can decide to plant today, take over the job of fighting climate change and extreme heat in our future cities. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/our-cities-need-more-trees-but-some-commonly-planted-ones-wont-survive-climate-change-120493">Our cities need more trees, but some commonly planted ones won't survive climate change</a>
</strong>
</em>
</p>
<hr>
<p><em>You can find more information and updates at <a href="https://www.mq.edu.au/research/research-centres-groups-and-facilities/secure-planet/centres/centre-for-green-cities">Macquarie University’s Smart Green Cities</a> and <a href="https://www.adaptwest.com.au/">Adelaide’s AdaptWest</a>.</em></p><img src="https://counter.theconversation.com/content/133082/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Alessandro Ossola receives in-kind support from the AdaptWest consortium with co-investment from Macquarie University.. </span></em></p><p class="fine-print"><em><span>Leigh Staas receives in-kind support from the AdaptWest consortium with co-investment from Macquarie University..</span></em></p><p class="fine-print"><em><span>Michelle Leishman receives in-kind support from the AdaptWest consortium with co-investment from Macquarie University..</span></em></p>
At the peak of a summer heatwave in Adelaide, an aerial survey of land surface temperatures reveals just how much cooler neighbourhoods with good tree and vegetation cover can be.
Alessandro Ossola, Research Coordinator - Smart Green Cities, Macquarie University
Leigh Staas, Associate Director for Engagement & Research Partnerships | Smart Green Cities, Macquarie University
Michelle Leishman, Distinguished Professor, Director of Smart Green Cities, Macquarie University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/132356
2020-02-26T18:57:05Z
2020-02-26T18:57:05Z
Thousands of city trees have been lost to development, when we need them more than ever
<p>Climate change is on everyone’s lips this summer. We’ve had <a href="https://theconversation.com/some-say-weve-seen-bushfires-worse-than-this-before-but-theyre-ignoring-a-few-key-facts-129391">bushfires</a>, <a href="https://theconversation.com/even-for-an-air-pollution-historian-like-me-these-past-weeks-have-been-a-shock-129141">smoke haze</a>, <a href="https://theconversation.com/weather-bureau-says-hottest-driest-year-on-record-led-to-extreme-bushfire-season-129447">heatwaves</a>, <a href="https://theconversation.com/heavy-rains-are-great-news-for-sydneys-dams-but-they-come-with-a-big-caveat-131668">flooding</a>, <a href="https://www.theguardian.com/australia-news/gallery/2020/jan/11/bushfires-crisis-world-rallies-to-demand-climate-action-as-australia-burns-in-pictures">mass protests</a> and a <a href="https://www.climateemergencysummit.org/">National Climate Emergency Summit</a>, all within a few months. The search is on for solutions. Trees often feature prominently when talking about solutions, but <a href="https://aus01.safelinks.protection.outlook.com/?url=https:%2F%2Fauthors.elsevier.com%2Fa%2F1ad%7Ez7sfVY-xSY&data=02%7C01%7C%7Ce84fd09032aa476ecce208d7ba73598e%7Cd1323671cdbe4417b4d4bdb24b51316b%7C0%7C1%7C637182876951440509&sdata=LPgywaoetiFXNg4OyILyLfxGLsQF%2BnexXtof3YE0crE%3D&reserved=0">our research</a> shows trees are being lost to big developments – about 2,000 within a decade in inner Melbourne. </p>
<p>Big development isn’t the only challenge for urban tree cover. During the period covered by our <a href="https://aus01.safelinks.protection.outlook.com/?url=https:%2F%2Fauthors.elsevier.com%2Fa%2F1ad%7Ez7sfVY-xSY&data=02%7C01%7C%7Ce84fd09032aa476ecce208d7ba73598e%7Cd1323671cdbe4417b4d4bdb24b51316b%7C0%7C1%7C637182876951440509&sdata=LPgywaoetiFXNg4OyILyLfxGLsQF%2BnexXtof3YE0crE%3D&reserved=0">newly published study</a>, the inner city lost a further 8,000 street trees to a variety of causes – vandals, establishment failures of young trees, <a href="https://doi.org/10.1016/j.landurbplan.2017.06.012">drought</a>, smaller developments and vehicle damage. </p>
<p>Still, thanks to <a href="https://www.melbourne.vic.gov.au/community/greening-the-city/urban-forest/Pages/urban-forest-strategy.aspx">a program that plants 3,000 trees a year</a>, canopy growth has <a href="https://www.theage.com.au/politics/victoria/melbourne-s-green-spaces-are-being-lost-in-rush-to-build-more-housing-20190728-p52bir.html">kept just ahead</a> of losses in the City of Melbourne. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/our-cities-need-more-trees-but-some-commonly-planted-ones-wont-survive-climate-change-120493">Our cities need more trees, but some commonly planted ones won't survive climate change</a>
</strong>
</em>
</p>
<hr>
<p>Canopy cover is crucial for keeping urban areas liveable, shading our streets to <a href="https://theconversation.com/keeping-the-city-cool-isnt-just-about-tree-cover-it-calls-for-a-commons-based-climate-response-120491">help us cope with hot weather</a> and to counter the powerful <a href="https://www.abc.net.au/news/2020-02-13/climate-warning-over-heat-island-effect-as-city-greenery-decline/11923890">urban heat island effect</a>. Trees can also be a <a href="https://theconversation.com/can-we-really-prevent-floods-by-planting-more-trees-52160">flood-proofing tool</a>. </p>
<p>Trees add beauty and character to our streets, and (so far) they’re not a political wedge issue in the <a href="https://www.theguardian.com/australia-news/2018/may/02/labor-says-australia-will-fail-on-emissions-targets-unless-climate-culture-war-ends">ongoing culture war</a> that is Australian climate policy. In short, they’re a very good idea, at just the right time.</p>
<h2>Counting the trees lost to development</h2>
<p>The thing is, this good idea happens in the midst of a <a href="https://www.afr.com/property/commercial/construction-boom-gets-an-extra-year-s-boost-from-non-residential-work-20191126-p53e67">construction boom</a>. In Melbourne alone, this includes <a href="https://www.planning.vic.gov.au/__data/assets/pdf_file/0017/250730/Inner-Metro-HDD-summary-2016.pdf">thousands of new dwellings</a> and <a href="https://www.abc.net.au/news/2020-02-26/construction-infrastructure-disruption-can-we-ever-get-ahead/11892930">billions of dollars of new infrastructure</a>. Many of the new buildings are very large – there’s a handy <a href="https://www.developmentactivity.melbourne.vic.gov.au/">open database</a> that shows these developments.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/317226/original/file-20200225-24701-trd4bt.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/317226/original/file-20200225-24701-trd4bt.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/317226/original/file-20200225-24701-trd4bt.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=393&fit=crop&dpr=1 600w, https://images.theconversation.com/files/317226/original/file-20200225-24701-trd4bt.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=393&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/317226/original/file-20200225-24701-trd4bt.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=393&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/317226/original/file-20200225-24701-trd4bt.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=494&fit=crop&dpr=1 754w, https://images.theconversation.com/files/317226/original/file-20200225-24701-trd4bt.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=494&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/317226/original/file-20200225-24701-trd4bt.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=494&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">This map shows the scale of development under way in the inner city.</span>
<span class="attribution"><a class="source" href="https://www.developmentactivity.melbourne.vic.gov.au/">City of Melbourne</a></span>
</figcaption>
</figure>
<p>Next time you’re walking past a large construction site, look for empty tree pits – the square holes in footpaths where trees have been removed. Maybe you’ve already seen these and wondered what all the construction means for our trees. Well, now we know.</p>
<p><a href="https://doi.org/10.1016/j.scs.2020.102096">Our study</a> puts a number on the impact of major development on city trees. In the City of Melbourne – that’s just the innermost suburbs and the CBD – major developments cost our streets about 2,000 trees from 2008-2017. </p>
<p>Using council databases and a mapping tool, we tracked removals of trees within ten metres of hundreds of major developments. We found much higher rates of tree removal around major development sites than in control sites that weren’t developed.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/317018/original/file-20200225-24672-1tbbdlg.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/317018/original/file-20200225-24672-1tbbdlg.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=421&fit=crop&dpr=1 600w, https://images.theconversation.com/files/317018/original/file-20200225-24672-1tbbdlg.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=421&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/317018/original/file-20200225-24672-1tbbdlg.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=421&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/317018/original/file-20200225-24672-1tbbdlg.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=529&fit=crop&dpr=1 754w, https://images.theconversation.com/files/317018/original/file-20200225-24672-1tbbdlg.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=529&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/317018/original/file-20200225-24672-1tbbdlg.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=529&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">An example of our analysis, comparing tree losses around sites with major development (orange) to control sites (blue). Trees within 10m of major developments were much more likely to be removed.</span>
<span class="attribution"><span class="source">https://doi.org/10.1016/j.scs.2020.102096</span></span>
</figcaption>
</figure>
<p>Even with the City of Melbourne’s <a href="https://www.melbourne.vic.gov.au/sitecollectiondocuments/tree-protection-fact-sheet-developers-builders.pdf">robust tree-protection</a> rules, trees can be removed or damaged due to site access needs, scaffolding, <a href="http://joa.isa-arbor.com/request.asp?JournalID=1&ArticleID=3145&Type=2">compacted soil</a>, root conflicts with services access, and even the occasional <a href="https://www.abc.net.au/news/2013-06-25/poisoned-plane-tree-wrapped-in-bandages-in-melbourne27s-cbd/4778258">poisoning</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/317228/original/file-20200225-24651-ef7ceu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/317228/original/file-20200225-24651-ef7ceu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/317228/original/file-20200225-24651-ef7ceu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=552&fit=crop&dpr=1 600w, https://images.theconversation.com/files/317228/original/file-20200225-24651-ef7ceu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=552&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/317228/original/file-20200225-24651-ef7ceu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=552&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/317228/original/file-20200225-24651-ef7ceu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=694&fit=crop&dpr=1 754w, https://images.theconversation.com/files/317228/original/file-20200225-24651-ef7ceu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=694&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/317228/original/file-20200225-24651-ef7ceu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=694&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The City of Melbourne invited artist Louise Lavarack to create a roadside memorial to a poisoned plane tree, which was then shrouded in gauze bandages.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/bonitoclub/9376064786/in/photolist-5Zk5cj-eWt3FJ-eXfNkN-fhwMpq-eWt3Tb-eWgBWp-eWgC86-eWt46Y-fnZman-foeBtJ-eXMvhw-f6BRue/">Tony & Wayne/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/were-investing-heavily-in-urban-greening-so-how-are-our-cities-doing-83354">We're investing heavily in urban greening, so how are our cities doing?</a>
</strong>
</em>
</p>
<hr>
<h2>Tree protection limits losses</h2>
<p>The silver lining in this story is that the city council’s tree-protection policy seems to be quite effective at saving our bigger trees. The vast majority of removals we saw were of trees with trunks less than 30cm thick. Only one in 20 of the trees lost was a large mature tree over 60cm thick. </p>
<p>This may partly reflect the fact that the council charges developers for not only tree replacement but also the dollar equivalent of lost amenity and ecological values. It gets very expensive to remove a large tree once you factor in all the valuable services it provides. When a tree is a metre thick, <a href="https://www.melbourne.vic.gov.au/SiteCollectionDocuments/Tree-valuations.DOC">costs can exceed $100,000</a> – and that’s if there are no alternatives to removal.</p>
<p>The protection of bigger trees means Melbourne retained canopy fairly well, despite losing over 2,000 trees. Only 8% of city-wide canopy losses during our study period happened near major development sites. This modest loss is still serious, as removals are having more of an impact on future canopy growth than current cover.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-tree-bonds-can-help-preserve-the-urban-forest-93420">How tree bonds can help preserve the urban forest</a>
</strong>
</em>
</p>
<hr>
<h2>Lessons for our cities</h2>
<p>While Melbourne-centric, there are lessons in this study for cities everywhere. Robust policies to protect and retain trees backed up by clear financial incentives are valuable, as even well-resourced councils with strong policy face an uphill battle when development gets intense.</p>
<p>Our findings highlight that retaining and establishing young trees is especially difficult. This is troubling given these are the trees that must deliver the canopy that will in future shelter the streets in which we live and work. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/keeping-the-city-cool-isnt-just-about-tree-cover-it-calls-for-a-commons-based-climate-response-120491">Keeping the city cool isn't just about tree cover – it calls for a commons-based climate response</a>
</strong>
</em>
</p>
<hr>
<p>Improved investments in how young trees are planted and how long we look after them can help. For example, in <a href="https://www.sciencedirect.com/science/article/pii/S0169204618304420?via%3Dihub">a promising local study</a>, researchers showed that trees planted in a way that catches rainwater run-off from roads grow twice as fast, provided planting design avoids waterlogging.</p>
<p>Finally, in the context of rapid development, buildings themselves can play a positive role. Green roofs, green walls and rain gardens are just a few of the ways developments can help our cities deal with both heat and flooding. </p>
<p>There are <a href="https://theconversation.com/australian-cities-are-lagging-behind-in-greening-up-their-buildings-97088">plenty of precedents overseas</a>. In Berlin, laws <a href="https://climate-adapt.eea.europa.eu/metadata/case-studies/berlin-biotope-area-factor-2013-implementation-of-guidelines-helping-to-control-temperature-and-runoff">requiring building greening</a> have resulted in <a href="https://www.stadtentwicklung.berlin.de/umwelt/umweltatlas/ed611_04.htm">4 million square metres of green roof area</a> – three times the area of Melbourne’s <a href="https://en.wikipedia.org/wiki/Hoddle_Grid">Hoddle Grid</a>. In Singapore, developments must include vegetation with leaf area <a href="https://www.ura.gov.sg/Corporate/Guidelines/Circulars/dc17-06">up to four times the development’s site area</a>, using green roofs and walls. Tokyo has required green roofs on new buildings for <a href="https://www.c40.org/case_studies/nature-conservation-ordinance-is-greening-tokyo-s-buildings">nearly 20 years</a>.</p>
<p>The solutions are out there, and urban greening is <a href="https://www.greenerspacesbetterplaces.com.au/">rising in profile</a>. Recent commitments in <a href="https://www.melbourne.vic.gov.au/about-council/vision-goals/eco-city/climate-change/Pages/taking-action-climate-change.aspx">Melbourne</a>, <a href="https://www.environment.act.gov.au/__data/assets/pdf_file/0005/1413770/Canberras-Living-Infrastructure-Plan.pdf">Canberra</a> and <a href="https://www.environment.sa.gov.au/topics/green-adelaide">Adelaide</a> are promising. Our study findings are a reminder that, even for the willing, we’ll have to take two steps forward, because there’s inevitably going to be one step back.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/for-green-cities-to-become-mainstream-we-need-to-learn-from-local-success-stories-and-scale-up-119933">For green cities to become mainstream, we need to learn from local success stories and scale up</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/132356/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Thami Croeser receives funding from the European Commission and the Australian Research Council. </span></em></p><p class="fine-print"><em><span>Camilo Ordóñez receives funding from the Australian Research Council (ARC).</span></em></p><p class="fine-print"><em><span>Rodney van der Ree has received funding from the City of Melbourne, Australian Research Council, The Baker Foundation and numerous local and state governments.</span></em></p>
Inner Melbourne alone has lost 2,000 street trees to major developments within a decade. Losing tree cover makes it even more difficult for our cities to cope with an increasingly tough climate.
Thami Croeser, Research Officer, Centre for Urban Research, RMIT University
Camilo Ordóñez, Research Fellow, School of Ecosystem and Forest Sciences, The University of Melbourne
Rodney van der Ree, Adjunct Associate Professor, School of BioSciences. National Technical Executive - Ecology, WSP Pty Ltd, The University of Melbourne
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/128857
2020-01-28T18:55:53Z
2020-01-28T18:55:53Z
How to cope with extreme heat days without racking up the aircon bills
<figure><img src="https://images.theconversation.com/files/311759/original/file-20200124-81336-1vx1xhq.jpg?ixlib=rb-1.1.0&rect=402%2C40%2C6307%2C4074&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Even without air conditioning, there are still many things you can do to prepare for extreme heat and stay comfortable on hot days.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/middleaged-woman-leaned-on-sofa-resting-1575687895">fizkes/Shutterstock</a></span></figcaption></figure><p>Summer in Australia is <a href="http://www.bom.gov.au/climate/updates/articles/a032.shtml">getting hotter</a>. Extreme heat events, with daytime temperatures over 35 degrees Celsius, are becoming more common and we are getting more of these days in a row. </p>
<p>We all need to prepare ourselves, our homes and our neighbourhoods for hot and very hot days. Since 2016, the <a href="https://www.westernsydney.edu.au/__data/assets/pdf_file/0020/1161470/cooling-the-commons-report.pdf">Cooling the Commons</a> research project has been working with people living in some of Sydney’s hottest neighbourhoods to learn how they cope with heat.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/keeping-the-city-cool-isnt-just-about-tree-cover-it-calls-for-a-commons-based-climate-response-120491">Keeping the city cool isn't just about tree cover – it calls for a commons-based climate response</a>
</strong>
</em>
</p>
<hr>
<p>Discussion groups with residents across hotspots in Western Sydney, including Penrith, Cranebrook and St Marys, highlighted a wealth of things we can do to manage heat. We published some of the following tips in a recent <a href="https://www.westernsydney.edu.au/ics/news/new_resource_by_institute_researchers_provides_advice_on_how_to_prepare_for_heat">flier</a>.</p>
<h2>Why can’t we all just rely on air conditioning?</h2>
<p>Official advice for extreme heat is often to stay inside and turn on the air conditioning. While air conditioning can play a role, <a href="https://www.canstarblue.com.au/appliances/air-conditioning-running-costs/">not everyone can afford it</a>. Low-income and older households can be especially vulnerable to bill shock and are more likely to feel the impacts of extreme heat. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/high-energy-costs-make-vulnerable-households-reluctant-to-use-air-conditioning-study-86624">High energy costs make vulnerable households reluctant to use air conditioning: study</a>
</strong>
</em>
</p>
<hr>
<p>There is also the risk that running air conditioners uses <a href="https://www.theguardian.com/australia-news/2019/jul/09/australias-emissions-reach-the-highest-on-record-driven-by-electricity-sector">energy resources that contribute further to global warming</a>. More immediately, hot exhaust air from air-conditioning units can <a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2013JD021225">make the local environment hotter</a>. This means keeping one home cool can make it harder for neighbours to keep their homes cool and make being outside even more uncomfortable.</p>
<p>Air conditioning in private homes creates a cool refuge for only some. Unless those homes have an open-door policy on hot days, many of us will need to find other ways to keep cool. If you do have air conditioning, think about how you could share your air with those near you who might really need it.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-people-can-best-make-the-transition-to-cool-future-cities-80683">How people can best make the transition to cool future cities</a>
</strong>
</em>
</p>
<hr>
<h2>Prepare before the heat hits</h2>
<p><strong><em>Shade is important for creating more comfortable living spaces.</em></strong></p>
<p>Identify which parts of your home get the most afternoon sun in summer. Can you plant trees or vines, or move a pot plant outside the window to create a green screen? Can you attach awnings to shade the windows? </p>
<p>Low-cost temporary solutions can include attaching light-coloured shade cloth outside the window using removable hooks, or installing heavy drapes or blinds inside. Blankets or even aluminium foil are a low-cost creative way of keeping heat out. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/311764/original/file-20200124-81416-aoj5o0.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/311764/original/file-20200124-81416-aoj5o0.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/311764/original/file-20200124-81416-aoj5o0.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=423&fit=crop&dpr=1 600w, https://images.theconversation.com/files/311764/original/file-20200124-81416-aoj5o0.PNG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=423&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/311764/original/file-20200124-81416-aoj5o0.PNG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=423&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/311764/original/file-20200124-81416-aoj5o0.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=531&fit=crop&dpr=1 754w, https://images.theconversation.com/files/311764/original/file-20200124-81416-aoj5o0.PNG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=531&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/311764/original/file-20200124-81416-aoj5o0.PNG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=531&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
<span class="attribution"><a class="source" href="https://www.westernsydney.edu.au/__data/assets/pdf_file/0004/1633585/preparing-for-heat-pamphlet.pdf">Illustration by Thomas Baldwin, from Climate Risk? Climate Ready!</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p><strong><em>Open up to let in cool air at night</em></strong></p>
<p>Can you open the windows and doors overnight to let in cooler air? If you are concerned about security, look for options for locking the windows in an open position, or using flyscreens and security grilles on windows and doors. </p>
<p>A low-cost option to keeping flying insects at bay on hot nights is a mosquito net over the window or around the bed. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/311766/original/file-20200124-81336-22ai3h.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/311766/original/file-20200124-81336-22ai3h.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/311766/original/file-20200124-81336-22ai3h.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=422&fit=crop&dpr=1 600w, https://images.theconversation.com/files/311766/original/file-20200124-81336-22ai3h.PNG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=422&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/311766/original/file-20200124-81336-22ai3h.PNG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=422&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/311766/original/file-20200124-81336-22ai3h.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=530&fit=crop&dpr=1 754w, https://images.theconversation.com/files/311766/original/file-20200124-81336-22ai3h.PNG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=530&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/311766/original/file-20200124-81336-22ai3h.PNG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=530&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
<span class="attribution"><a class="source" href="https://www.westernsydney.edu.au/__data/assets/pdf_file/0004/1633585/preparing-for-heat-pamphlet.pdf">Illustration by Thomas Baldwin</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p><strong><em>Use low-cost resources to prepare in advance.</em></strong></p>
<p>Ceiling or portable fans are one of the best ways to cool your body when it’s hot. But remember fans don’t cool rooms, so turn off the fan when you leave the room or you’re just burning electricity. </p>
<p>Find ice trays and containers to freeze water – cake tins and storage containers are a good option. Putting these in front of a portable fan will mean the fan blows cool air. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/311767/original/file-20200124-81395-1ufrbq5.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/311767/original/file-20200124-81395-1ufrbq5.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/311767/original/file-20200124-81395-1ufrbq5.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=422&fit=crop&dpr=1 600w, https://images.theconversation.com/files/311767/original/file-20200124-81395-1ufrbq5.PNG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=422&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/311767/original/file-20200124-81395-1ufrbq5.PNG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=422&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/311767/original/file-20200124-81395-1ufrbq5.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=531&fit=crop&dpr=1 754w, https://images.theconversation.com/files/311767/original/file-20200124-81395-1ufrbq5.PNG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=531&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/311767/original/file-20200124-81395-1ufrbq5.PNG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=531&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
<span class="attribution"><a class="source" href="https://www.westernsydney.edu.au/__data/assets/pdf_file/0004/1633585/preparing-for-heat-pamphlet.pdf">Illustration by Thomas Baldwin</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Putting a wet face cloth on the insides of your wrists, around your ankles or on the back of your neck will bring down your body temperature. Hanging damp sheets in doorways or in front of a fan will help keep the temperature down – although the trick with the sheets won’t work if it’s a really humid day.</p>
<h2>How to stay cool and comfortable on hot days</h2>
<p>Morning is likely to be the coolest time of the day. Open up your windows and doors to let in the cooler morning air. </p>
<p>It’s the best time to be active – walk the dog, take the kids to the park, go for a swim. If possible, do your cleaning, cooking or outside work now. Plan meals that don’t require an oven. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/311770/original/file-20200124-81399-omxyv3.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/311770/original/file-20200124-81399-omxyv3.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/311770/original/file-20200124-81399-omxyv3.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=425&fit=crop&dpr=1 600w, https://images.theconversation.com/files/311770/original/file-20200124-81399-omxyv3.PNG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=425&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/311770/original/file-20200124-81399-omxyv3.PNG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=425&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/311770/original/file-20200124-81399-omxyv3.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=534&fit=crop&dpr=1 754w, https://images.theconversation.com/files/311770/original/file-20200124-81399-omxyv3.PNG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=534&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/311770/original/file-20200124-81399-omxyv3.PNG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=534&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
<span class="attribution"><a class="source" href="https://www.westernsydney.edu.au/__data/assets/pdf_file/0004/1633585/preparing-for-heat-pamphlet.pdf">Illustration by Thomas Baldwin</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p><strong><em>Close up as it heats up.</em></strong></p>
<p>As the day starts to get hot, close the house up – shut windows, blinds and curtains. This could be as early as 9am on really hot days. If you are heading out to work, do this before you leave home. </p>
<p>Closing internal doors can help to keep the heat in one part of your home. You need to close doors to any parts of the home that get hot before the day gets hot. </p>
<p><strong><em>Stay hydrated.</em></strong></p>
<p>Drink plenty of water throughout the day. Put a jug of tap water in the fridge and remember to top it up. </p>
<p>Don’t forget to move pet water bowls and day beds out of the sun. If you live in a dry area, it can’t hurt to put out extra water bowls for needy wildlife!</p>
<p><strong><em>Find a cooling refuge.</em></strong></p>
<p>If your home gets uncomfortably hot, find the closest cooling refuges in your neighbourhood. These are places where you can go to cool down. Good examples that won’t break the bank are the local swimming pool or library. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/311768/original/file-20200124-81341-1hp0zo.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/311768/original/file-20200124-81341-1hp0zo.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/311768/original/file-20200124-81341-1hp0zo.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=424&fit=crop&dpr=1 600w, https://images.theconversation.com/files/311768/original/file-20200124-81341-1hp0zo.PNG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=424&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/311768/original/file-20200124-81341-1hp0zo.PNG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=424&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/311768/original/file-20200124-81341-1hp0zo.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=533&fit=crop&dpr=1 754w, https://images.theconversation.com/files/311768/original/file-20200124-81341-1hp0zo.PNG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=533&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/311768/original/file-20200124-81341-1hp0zo.PNG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=533&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
<span class="attribution"><a class="source" href="https://www.westernsydney.edu.au/__data/assets/pdf_file/0004/1633585/preparing-for-heat-pamphlet.pdf">Illustration by Thomas Baldwin</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Some local councils provide <a href="http://coolparramatta.com.au/">lists</a> of <a href="https://www.penrithcity.nsw.gov.au/waste-environment/cooling-the-city/beat-the-heat">cooling centres</a> on their websites.</p>
<p><strong><em>Save air conditioning for when it’s most needed.</em></strong></p>
<p>Try to save air conditioning for the hottest parts of the day. It will be most effective and cheapest to run if your home is well insulated and you’ve closed it up for the day. </p>
<p><strong><em>Look after neighbours.</em></strong></p>
<p>Remember to check on elderly or frail neighbours. Along with the very young, they are usually more affected by the heat and may need to cool down sooner than you do. </p>
<p>If your neighbours are in need, consider inviting them into your home to cool down. When it’s hot, let’s <a href="https://www.semanticscholar.org/paper/Infrastructures-of-Care%3A-Opening-up-%E2%80%9CHome%E2%80%9D-as-in-a-Lopes-Healy/1920004e258483d40017ff468370e4892e11fce5">think of our cities as social commons</a> rather than a collection of private spaces.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/311769/original/file-20200124-81346-ung17s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/311769/original/file-20200124-81346-ung17s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/311769/original/file-20200124-81346-ung17s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=423&fit=crop&dpr=1 600w, https://images.theconversation.com/files/311769/original/file-20200124-81346-ung17s.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=423&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/311769/original/file-20200124-81346-ung17s.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=423&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/311769/original/file-20200124-81346-ung17s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=531&fit=crop&dpr=1 754w, https://images.theconversation.com/files/311769/original/file-20200124-81346-ung17s.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=531&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/311769/original/file-20200124-81346-ung17s.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=531&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="attribution"><a class="source" href="https://www.westernsydney.edu.au/__data/assets/pdf_file/0004/1633585/preparing-for-heat-pamphlet.pdf">Illustration by Thomas Baldwin</a>, <span class="license">Author provided</span></span>
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<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/when-the-heat-is-on-we-need-city-wide-plans-to-keep-cool-70738">When the heat is on, we need city-wide plans to keep cool</a>
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<img src="https://counter.theconversation.com/content/128857/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Emma Power has received funding from the Australian Research Council, AHURI and the Landcom Universities Framework Agreement.</span></em></p><p class="fine-print"><em><span>Abby Mellick Lopes has received funding from the Landcom Universities Framework Agreement.</span></em></p><p class="fine-print"><em><span>Louise Crabtree has received funding from the Landcom Universities Framework Agreement, City of Port Phillip, Mount Alexander Community Land Ltd, St Kilda Community Housing Ltd, the Committee for Lorne, Marrickville Council, SEMZ Property Group, Tasman Ecovillage, Servants Community Housing, and Inner Melbourne Action Plan.</span></em></p>
Air conditioning isn’t the answer for everyone, especially for residents of the less affluent – and often hotter – suburbs of our big cities. But there are other ways to make hot days more bearable.
Emma Power, Senior Research Fellow, Geography and Urban Studies, Western Sydney University
Abby Mellick Lopes, Associate Professor, Design, School of Humanities and Communication Arts, Western Sydney University
Louise Crabtree-Hayes, Associate Professor, Institute for Culture and Society, Western Sydney University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/120491
2019-09-16T20:39:16Z
2019-09-16T20:39:16Z
Keeping the city cool isn’t just about tree cover – it calls for a commons-based climate response
<figure><img src="https://images.theconversation.com/files/289755/original/file-20190828-184211-gqe8s7.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C2624%2C2037&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Where’s the shade? Trees are not an immediate or whole answer to keeping cool.</span> <span class="attribution"><span class="source">Cameron Tonkinwise</span>, <span class="license">Author provided</span></span></figcaption></figure><p><em><strong>This story is part of <a href="https://theconversation.com/au/topics/covering-climate-now-75981">Covering Climate Now</a>, a global collaboration of more than 250 news outlets to strengthen coverage of the climate story.</strong></em></p>
<hr>
<p>A <a href="https://www.greater.sydney/performance-indicator-addressing-urban-heat">recent report</a> by the Greater Sydney Commission singles out urban heat as one of four priority areas given our coming climate. It identifies tree canopy as the top response for reducing city temperatures and delivering amenity. However, the public conversation about urban heat often misses the complex relationship between trees, people and the built environment, which challenges this response. </p>
<p>In soon-to-be-published research supported by the <a href="https://www.landcom.com.au/approach/research-and-learning/universities/">Landcom University Roundtable</a> we found that responding to a more extreme climate requires new social practices and new relationships with the <a href="https://www.communityeconomies.org/index.php/publications/articles/commoning-social-life">commons</a>. Commons are the spaces, resources and knowledge shared by a community, who are, ideally, involved in the regeneration and care of those commons. Trees are an important social commons, but they also present multiple challenges.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/our-cities-need-more-trees-but-some-commonly-planted-ones-wont-survive-climate-change-120493">Our cities need more trees, but some commonly planted ones won't survive climate change</a>
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</p>
<hr>
<h2>Closing our doors to the great outdoors</h2>
<p>For one, trees are an outdoor amenity, but we are spending more and more time <a href="https://press.anu.edu.au/publications/journals/human-ecology-review/human-ecology-review-volume-24-number-2">indoors</a>. For those who can afford it, air conditioning delivers cooling in the privacy of your own home or car – no need for trees. </p>
<p>However, staying in cool bedrooms and car rides mean <a href="https://www.smh.com.au/politics/federal/lonely-unfit-and-hooked-on-air-conditioning-is-this-the-summer-of-the-future-20190208-p50whm.html">less time outdoors</a> and with others, which isn’t ideal for human health and well-being.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/increasing-tree-cover-may-be-like-a-superfood-for-community-mental-health-119930">Increasing tree cover may be like a 'superfood' for community mental health</a>
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<hr>
<p>Air conditioning also uses more fossil-fuel-based energy, which generates more greenhouse gas emissions. The result is more climate change.</p>
<h2>Mixed feelings about trees</h2>
<p>As the Greater Sydney Commission <a href="https://www.greater.sydney/performance-indicator-addressing-urban-heat">report</a> makes clear, tree canopy in Greater Sydney is roughly proportional to household wealth. The “leafy suburbs” are the wealthier ones. This means tree planting is an important investment in less wealthy parts of the city, which experience <a href="https://www.tai.org.au/sites/default/files/Western%20Sydney%20Heatwatch%20WEB.pdf">more extreme heat days</a>. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/291435/original/file-20190909-175696-359nzu.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/291435/original/file-20190909-175696-359nzu.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/291435/original/file-20190909-175696-359nzu.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=388&fit=crop&dpr=1 600w, https://images.theconversation.com/files/291435/original/file-20190909-175696-359nzu.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=388&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/291435/original/file-20190909-175696-359nzu.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=388&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/291435/original/file-20190909-175696-359nzu.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=487&fit=crop&dpr=1 754w, https://images.theconversation.com/files/291435/original/file-20190909-175696-359nzu.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=487&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/291435/original/file-20190909-175696-359nzu.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=487&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Number of days over 35°C recorded in various parts of Greater Sydney (July 2018-June 2019).</span>
<span class="attribution"><a class="source" href="https://www.greater.sydney/performance-indicator-addressing-urban-heat">© State of NSW through the Greater Sydney Commission</a></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/in-a-heatwave-the-leafy-suburbs-are-even-more-advantaged-53307">In a heatwave, the leafy suburbs are even more advantaged</a>
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</p>
<hr>
<p>However, <a href="https://www.westernsydney.edu.au/__data/assets/pdf_file/0020/1161470/cooling-the-commons-report.pdf">research</a> also shows people have mixed feelings about trees. In comparison to the neat shrubbery and easily maintained sunny plazas we’ve become used to in our cities, trees can be “messy” and “unpredictable”. Leaf litter can be slippery and natives like eucalypts, with their pendulous leaves, provide limited shade. People worry about large trees falling over or dropping branches. </p>
<p>Trees are often at the <a href="https://lsc.sa.gov.au/resources/TreesandtheLawBooklet.pdf">centre of disputes</a> between neighbours. They can also be perceived as a security problem – if trees reduce visibility they might provide cover for wrongdoers. </p>
<p>In addition, insurance companies can charge a premium if a property is <a href="https://www.gocompare.com/home-insurance/trees/">deemed at risk of damage by large trees</a>. As we experience more extreme weather, laws on vegetation clearing are <a href="https://www.thehills.nsw.gov.au/News-Publications/New-rules-to-give-property-owners-more-say-in-how-their-trees-are-managed">becoming more risk-averse</a>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/if-planners-understand-its-cool-to-green-cities-whats-stopping-them-55753">If planners understand it's cool to green cities, what's stopping them?</a>
</strong>
</em>
</p>
<hr>
<h2>What trees where and when?</h2>
<p>Urban development tends to give priority to roads and delivering the maximum number of dwellings on sites. This leaves little space for trees, which need to fit into crowded footpaths with ever-changing infrastructures. For example, will larger <a href="https://www.smh.com.au/business/telstra-pushes-for-5g-that-works-in-australia-20170109-gto0gz.html">trees interfere with 5G</a>? </p>
<p>When juggling priorities in the streetscape, trees often <a href="https://www.abc.net.au/news/2016-01-27/100-yr-old-sydney-trees-to-be-felled-to-commemorate-anzacs/7116608">lose out</a>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/trees-versus-light-rail-we-need-to-rethink-skewed-urban-planning-values-57206">Trees versus light rail: we need to rethink skewed urban planning values</a>
</strong>
</em>
</p>
<hr>
<p>It’s an obvious point, but trees take time to grow. It can take many years for a planted sapling to become a shade tree. In that time there will be no shelter from the heat. </p>
<p>Also in that growing period, which can sometimes be unpredictable, trees need to be nurtured, especially in times of drought. And, once the tree is mature, fingers crossed that extreme weather events do not undo all those years of waiting.</p>
<p>So, while increasing tree canopy sounds like an obvious solution, trees are in fact a <a href="https://www.landcom.com.au/assets/Downloads/Library/f4e2252c79/Street-tree-design-guidelinesfactsheetlp.pdf">complex social challenge</a>. In our research, we point to ways some of these tree-related tensions can be managed.</p>
<h2>Shade in the meantime</h2>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/291428/original/file-20190909-175696-1wvg9yu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/291428/original/file-20190909-175696-1wvg9yu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/291428/original/file-20190909-175696-1wvg9yu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=800&fit=crop&dpr=1 600w, https://images.theconversation.com/files/291428/original/file-20190909-175696-1wvg9yu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=800&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/291428/original/file-20190909-175696-1wvg9yu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=800&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/291428/original/file-20190909-175696-1wvg9yu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1005&fit=crop&dpr=1 754w, https://images.theconversation.com/files/291428/original/file-20190909-175696-1wvg9yu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1005&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/291428/original/file-20190909-175696-1wvg9yu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1005&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A structure to support fast-growing vines has been built on one of Darwin’s hottest streets, but even these will take some time to grow.</span>
<span class="attribution"><a class="source" href="https://www.facebook.com/Darwinweloveit/posts/cavenagh-st-shade-structure-complete-with-all-the-sunshine-rain-we-are-getting-t/305429293391839/">Darwin We Love It/Facebook</a></span>
</figcaption>
</figure>
<p>Shade is an important <a href="https://placesjournal.org/article/shade-an-urban-design-mandate/">civic resource</a>. Large, mature trees with spreading canopy provide the best shade, so strategic construction bans and <a href="https://climate-adapt.eea.europa.eu/metadata/case-studies/stuttgart-combating-the-heat-island-effect-and-poor-air-quality-with-green-ventilation-corridors">tree preservation orders</a> are an obvious first step. </p>
<p>However, if shady canopy is decades off, we need to think about other, creative ways to provide shade in the meantime to ensure, for example, that people of diverse abilities can walk their city in reasonable comfort. This might include temporary shade structures such as awnings, <a href="https://www.yoursaypenrith.com.au/25909/documents/72131">bus shelters</a> and fast-growing vine-trellised walkways (if there is space to create troughs for soil and the structure doesn’t cause <a href="https://www.abc.net.au/news/2018-07-15/firefighters-limited-access-darwin-cbd-shade-structure/9995608">access problems</a>). </p>
<p>And, as the <a href="https://www.cancer.org.au/preventing-cancer/reduce-your-risk/be-sunsmart.html">Cancer Council</a> consistently reminds us, we all need to adopt more climate-defensive clothing. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/requiem-or-renewal-this-is-how-a-tropical-city-like-darwin-can-regain-its-cool-102839">Requiem or renewal? This is how a tropical city like Darwin can regain its cool</a>
</strong>
</em>
</p>
<hr>
<p>An important alternative is to follow our regional neighbours and start to populate parks and other public spaces at night. This suggests a need for removable shade, so we can take part in activities like <a href="https://www.landcom.com.au/news/media/new-community-lights-up-macarthur/">stargazing</a>.</p>
<h2>Cultivating an intergenerational commons</h2>
<p>Mature trees can die back or die altogether, so other trees should be maturing to take their place. Usually, experts design and maintain landscapes for others to enjoy. </p>
<p>However, users of the cooling services of parks could be invited into the process of planning and realising landscape designs. This would give them a say on the trees of which they have “shared custody”. Planting for succession can create an <a href="https://www.researchgate.net/publication/299720121_Commoning_as_a_postcapitalist_politics/figures?lo=1">intergenerational sense of ownership over a shared place</a>.</p>
<p>Current planning practices tend to ignore wind and solar patterns. The result is urban forms that make heat worse by prioritising comfortable private interior spaces over the commons of public space. Designing cool cities means using trees, water and buildings to create cool corridors that work with cooling breezes – or even <a href="https://link.springer.com/chapter/10.1007%2F978-981-10-6638-2_10">summon</a> these in still, heat-trapping basins like Western Sydney.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-people-can-best-make-the-transition-to-cool-future-cities-80683">How people can best make the transition to cool future cities</a>
</strong>
</em>
</p>
<hr>
<p>These few examples point to new ways of living with trees as social commons, but they also point to new forms of commoning – collaborative forms of care and governance that invite people to <a href="https://www.routledge.com/Sustainable-Practices-Social-Theory-and-Climate-Change-1st-Edition/Shove-Spurling/p/book/9780415540650">adopt new social practices</a> better suited to living well in the coming climate. </p>
<p>It is a positive step that state development agencies like <a href="https://www.landcom.com.au/organisation/about-landcom/">Landcom</a> aim to demonstrate global standards of liveability, resilience, inclusion, affordability and environmental quality. In so doing, they initiate transitions to these more commons-based ways of living.</p>
<hr>
<p><em>In addition to the authors of this article, the Cooling the Commons research team includes: Professor Katherine Gibson, Dr Louise Crabtree, Dr Stephen Healy and Dr Emma Power from the Institute for Culture and Society (ICS) at Western Sydney University (WSU), and Emeritus Professor Helen Armstrong from Queensland University of Technology (QUT).</em></p><img src="https://counter.theconversation.com/content/120491/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>This article is based on independent research funded through the Landcom University Roundtable. Landcom notes the findings as a contribution to the ongoing exploration of opportunities to improve how communities can live in hot cities, but does not endorse specific conclusions.</span></em></p><p class="fine-print"><em><span>Abby Mellick Lopes and Cameron Tonkinwise do not work for, consult, own shares in or receive funding from any other company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
Trees and the shade they provide are one of the best ways of cooling cities. But they also present challenges that are best resolved by managing this shared resource as part of an urban commons.
Abby Mellick Lopes, Senior Lecturer in Design, Western Sydney University
Cameron Tonkinwise, Professor, School of Design, University of Technology Sydney
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/120825
2019-09-09T20:10:21Z
2019-09-09T20:10:21Z
Urban growth, heat islands, humidity, climate change: the costs multiply in tropical cities
<figure><img src="https://images.theconversation.com/files/291396/original/file-20190909-175696-3j3ype.jpg?ixlib=rb-1.1.0&rect=0%2C123%2C1581%2C935&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">During a heatwave in late 2018, Cairns temperatures topped 35°C nine days in a row and sensors at some points in the CBD recorded 45°C. </span> </figcaption></figure><p>Some <a href="https://www.un.org/en/ecosoc/integration/pdf/fact_sheet.pdf">60% of the planet’s expected urban area by 2030</a> is yet to be built. This forecast highlights how rapidly the world’s people are becoming urban. Cities now occupy about 2% of the world’s land area, but are home to about <a href="https://www.un.org/development/desa/en/news/population/2018-revision-of-world-urbanization-prospects.html">55% of the world’s people</a> and generate more than <a href="http://nua.unhabitat.org/details1.asp?ProjectId=33&ln=1">70% of global GDP</a>, plus the associated <a href="https://www.un.org/en/climatechange/cities-pollution.shtml">greenhouse gas emissions</a>.</p>
<p>So what does this mean for people who live in the tropical zones, where <a href="https://www.sciencemag.org/news/2014/06/expanding-tropics-will-play-greater-global-role-report-predicts">40% of the world’s population lives</a>? On current trends, this figure will rise to 50% by 2050. With <a href="https://sustainabledevelopment.un.org/content/documents/974736_Ziembicki%20et%20al._Implications%20of%20an%20expanding%20and%20intensifying%20tropical%20zone%20for%20the%20sustainable%20development%20agenda.pdf">tropical economies growing some 20% faster</a> than the rest of the world, the result is a swift expansion of tropical cities.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/290236/original/file-20190830-115397-n616fu.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/290236/original/file-20190830-115397-n616fu.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/290236/original/file-20190830-115397-n616fu.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=387&fit=crop&dpr=1 600w, https://images.theconversation.com/files/290236/original/file-20190830-115397-n616fu.PNG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=387&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/290236/original/file-20190830-115397-n616fu.PNG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=387&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/290236/original/file-20190830-115397-n616fu.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=486&fit=crop&dpr=1 754w, https://images.theconversation.com/files/290236/original/file-20190830-115397-n616fu.PNG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=486&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/290236/original/file-20190830-115397-n616fu.PNG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=486&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Population and number of cities of the world, by size class, 1990, 2018 and 2030.</span>
<span class="attribution"><a class="source" href="https://population.un.org/wup/Publications/">World Urbanization Prospects 2018, United Nations DESA Population Division</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/healthy-happy-and-tropical-worlds-fastest-growing-cities-demand-our-attention-112069">Healthy, happy and tropical – world's fastest-growing cities demand our attention</a>
</strong>
</em>
</p>
<hr>
<p>The populations of these growing tropical cities already experience high temperatures made worse by high humidity. This means they are highly vulnerable to extreme heat events as a result of climate change. </p>
<p>For example, extremely hot weather overwhelmed Cairns last summer. By December 3 2018, the city had recorded temperatures above 35°C nine days in a row. Four consecutive days were above 40°C.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/289316/original/file-20190825-170935-9uanh3.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/289316/original/file-20190825-170935-9uanh3.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=253&fit=crop&dpr=1 600w, https://images.theconversation.com/files/289316/original/file-20190825-170935-9uanh3.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=253&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/289316/original/file-20190825-170935-9uanh3.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=253&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/289316/original/file-20190825-170935-9uanh3.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=317&fit=crop&dpr=1 754w, https://images.theconversation.com/files/289316/original/file-20190825-170935-9uanh3.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=317&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/289316/original/file-20190825-170935-9uanh3.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=317&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Cairns’ heatwave summer.</span>
<span class="attribution"><span class="source">Authors, using BOM temperature data</span></span>
</figcaption>
</figure>
<p>For our research, temperature and humidity sensors were strategically placed in the Cairns CBD to represent people’s experience of weather at street level. These recorded temperatures consistently higher than the Bureau of Meteorology (BoM) recordings, reaching 45°C at some points.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/291224/original/file-20190906-175682-1p2r1by.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/291224/original/file-20190906-175682-1p2r1by.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/291224/original/file-20190906-175682-1p2r1by.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=650&fit=crop&dpr=1 600w, https://images.theconversation.com/files/291224/original/file-20190906-175682-1p2r1by.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=650&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/291224/original/file-20190906-175682-1p2r1by.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=650&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/291224/original/file-20190906-175682-1p2r1by.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=817&fit=crop&dpr=1 754w, https://images.theconversation.com/files/291224/original/file-20190906-175682-1p2r1by.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=817&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/291224/original/file-20190906-175682-1p2r1by.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=817&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Highest temperatures recorded by James Cook University weather data sensors during the November-December 2018 heatwave in Cairns.</span>
<span class="attribution"><span class="source">Image: Bronson Philippa</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Local effects magnify heatwave impacts</h2>
<p>Urban environments in general are hotter than non-urbanised surroundings that are covered by vegetation. The trapping of heat in cities, known as the <a href="https://www.nationalgeographic.org/encyclopedia/urban-heat-island/">urban heat island</a> effect, has impacts on human health, animal life, social events, tourism, water availability and business performance. </p>
<p>The urban heat island effect intensifies the impacts of increasing heatwaves on cities as a result of climate change.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/291226/original/file-20190906-175678-la15cl.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/291226/original/file-20190906-175678-la15cl.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/291226/original/file-20190906-175678-la15cl.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=1002&fit=crop&dpr=1 600w, https://images.theconversation.com/files/291226/original/file-20190906-175678-la15cl.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=1002&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/291226/original/file-20190906-175678-la15cl.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=1002&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/291226/original/file-20190906-175678-la15cl.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1259&fit=crop&dpr=1 754w, https://images.theconversation.com/files/291226/original/file-20190906-175678-la15cl.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1259&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/291226/original/file-20190906-175678-la15cl.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1259&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Projections of increased heatwave frequency for Cairns region using visualisation platform on Queensland Future Climate Dashboard.</span>
<span class="attribution"><a class="source" href="https://app.longpaddock.qld.gov.au/dashboard/#responseTab2">Queensland Future Climate Dashboard/Queensland Government</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>But it is important to remember that other local factors also influence these impacts. These include the scale, shape, materials, composition and growth of the built environment in a particular location and its surrounding areas. </p>
<p>The differences between the BoM data recorded at Cairns airport and the inner-city recordings show the impacts of urban expansion patterns, built form and choice of materials in tropical cities. </p>
<p>The linear layout of Cairns has, on one hand, enabled the formation of attractive places for commercial activities. As these activity centres evolve into focal points of urban life, they in turn influence all sorts of socioeconomic parameters. </p>
<p>On the other hand, the form the built environment takes changes the patterns of wind, sun and shade. These changes alter the urban <a href="https://theconversation.com/city-temperatures-and-city-economics-a-hidden-relationship-between-sun-and-wind-and-profits-116064">microclimate</a> by trapping heat and slowing or channelling air movements.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/289318/original/file-20190825-170910-sjsrqt.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/289318/original/file-20190825-170910-sjsrqt.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=500&fit=crop&dpr=1 600w, https://images.theconversation.com/files/289318/original/file-20190825-170910-sjsrqt.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=500&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/289318/original/file-20190825-170910-sjsrqt.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=500&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/289318/original/file-20190825-170910-sjsrqt.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=629&fit=crop&dpr=1 754w, https://images.theconversation.com/files/289318/original/file-20190825-170910-sjsrqt.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=629&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/289318/original/file-20190825-170910-sjsrqt.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=629&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The layout and structures of Cairns CBD alter local microclimates by trapping heat and altering air flows.</span>
<span class="attribution"><span class="source">State of Queensland 2019</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/city-temperatures-and-city-economics-a-hidden-relationship-between-sun-and-wind-and-profits-116064">City temperatures and city economics, a hidden relationship between sun and wind and profits</a>
</strong>
</em>
</p>
<hr>
<h2>Shifting the focus to the tropics</h2>
<p>To date, a large body of research has explored the undesired consequences of climate change and urban heat islands. However, the focus has been on capital and metropolitan cities with <a href="https://link.springer.com/article/10.1007/s00704-015-1703-8">humid continental climates</a>. Not many studies have looked at the economic and social impacts in the tropical context, where hot and humid conditions create extra heat stress. </p>
<p>Add the combined effects of climate change and urban heat islands and what are the socio-economic consequences of heatwaves in a tropical city like Cairns? We see that climate change adds another dimension to the relationship between cities, economic growth and development. </p>
<p>This presents a huge opportunity to start thinking about building cities that are not superficially greenwashed, but which instead tackle pressing issues such as climate variability and create sustainable business and social destinations. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/requiem-or-renewal-this-is-how-a-tropical-city-like-darwin-can-regain-its-cool-102839">Requiem or renewal? This is how a tropical city like Darwin can regain its cool</a>
</strong>
</em>
</p>
<hr>
<p>In cold climates, heatwaves and urban heat islands are not necessarily undesired, but their negative impacts are more obvious and harmful in warmer climates. And these harmful impacts of heatwaves on our economy, environment and society are on the rise. </p>
<p>We have scientific evidence of the increasing length, frequency and intensity of heatwaves. The number of record hot days in Australia has <a href="https://www.climatecouncil.org.au/uploads/9901f6614a2cac7b2b888f55b4dff9cc.pdf">doubled in the past five decades</a>.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/289313/original/file-20190825-170956-trlr9q.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/289313/original/file-20190825-170956-trlr9q.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/289313/original/file-20190825-170956-trlr9q.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/289313/original/file-20190825-170956-trlr9q.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/289313/original/file-20190825-170956-trlr9q.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/289313/original/file-20190825-170956-trlr9q.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/289313/original/file-20190825-170956-trlr9q.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Projections of changes in heatwave frequency for northern Queensland in 2030 and 2070.</span>
<span class="attribution"><a class="source" href="https://app.longpaddock.qld.gov.au/dashboard/#responseTab2">Queensland Future Climate Dashboard/Queensland Government</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>What are the costs of heatwaves?</h2>
<p>Increased exposure to heatwaves amplifies the adverse economic impacts on industries that are reliant on the health of their outdoor workers. This is in addition to the extreme heat-related fatalities and health-care costs of heatwave-related medical emergencies. As a <a href="https://www.nccarf.edu.au/localgov/resources/protecting-human-health-and-safety-during-severe-and-extreme-heat-events-national">PwC report to the Commonwealth</a> on extreme heat events stated:</p>
<blockquote>
<p>Heatwaves kill more Australians than any other natural disaster. They have received far less public attention than cyclones, floods or bushfires — they are private, silent deaths, which only hit the media when morgues reach capacity or infrastructure fails. </p>
</blockquote>
<p>Heat also has direct impacts on economic production. A <a href="https://www.researchgate.net/publication/45660010_Temperatures_and_cyclones_strongly_associated_with_economic_production_in_the_Caribbean_and_Central_America">2010 study</a> found a 1°C increase resulted in a 2.4% reduction in non-agricultural production and a 0.1% reduction in agricultural production in 28 Caribbean-basin countries. Another <a href="https://papers.ssrn.com/sol3/papers.cfm?abstract_id=2099798">study in 2012</a> found an 8% weekly loss of production when the temperature exceeded 32°C for six days in a row.</p>
<p>The 2017 <a href="http://www.agriculture.gov.au/abares/research-topics/climate/farm-performance-climate">Farm performance and climate</a> report by the <a href="http://www.agriculture.gov.au/abares">Australian Bureau of Agricultural and Resource Economics and Sciences (ABARES)</a> states:</p>
<blockquote>
<p>The recent changes in climate have had a significant negative effect on the productivity of Australian cropping farms, particularly in southwestern Australia and southeastern Australia. </p>
</blockquote>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/291232/original/file-20190906-175682-1k3i4mj.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/291232/original/file-20190906-175682-1k3i4mj.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/291232/original/file-20190906-175682-1k3i4mj.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=374&fit=crop&dpr=1 600w, https://images.theconversation.com/files/291232/original/file-20190906-175682-1k3i4mj.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=374&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/291232/original/file-20190906-175682-1k3i4mj.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=374&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/291232/original/file-20190906-175682-1k3i4mj.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=470&fit=crop&dpr=1 754w, https://images.theconversation.com/files/291232/original/file-20190906-175682-1k3i4mj.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=470&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/291232/original/file-20190906-175682-1k3i4mj.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=470&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Average climate effect on productivity of cropping farms in southwestern and southeastern Australia since 2000–01 (relative to average conditions from 1914–15 to 2014–15).</span>
<span class="attribution"><a class="source" href="http://www.agriculture.gov.au/abares/research-topics/climate/farm-performance-climate">Farm performance and climate, ABARES</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>It’s not just farming that is vulnerable. A <a href="https://www.climatechange.vic.gov.au/__data/assets/pdf_file/0011/413030/The-economic-impact-of-heatwaves-on-Victoria.pdf">Victorian government report</a> report this year estimated an extreme heatwave event costs the state’s construction sector A$103 million. The impact of heatwaves on the city of Melbourne’s economy is estimated at A$52.9 million a year on average. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/290239/original/file-20190830-115391-128cd7z.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/290239/original/file-20190830-115391-128cd7z.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/290239/original/file-20190830-115391-128cd7z.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=427&fit=crop&dpr=1 600w, https://images.theconversation.com/files/290239/original/file-20190830-115391-128cd7z.PNG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=427&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/290239/original/file-20190830-115391-128cd7z.PNG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=427&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/290239/original/file-20190830-115391-128cd7z.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=537&fit=crop&dpr=1 754w, https://images.theconversation.com/files/290239/original/file-20190830-115391-128cd7z.PNG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=537&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/290239/original/file-20190830-115391-128cd7z.PNG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=537&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Impacts of heatwaves on Victoria’s main economic sectors.</span>
<span class="attribution"><a class="source" href="https://www.climatechange.vic.gov.au/__data/assets/pdf_file/0011/413030/The-economic-impact-of-heatwaves-on-Victoria.pdf">State of Victoria Department of Environment, Land, Water and Planning</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>According to this report, economic costs increase exponentially as the severity of heatwaves increases. This has obvious implications for cities in tropical regions.</p>
<p>As the next step in <a href="https://www.researchgate.net/project/Evidence-based-Economic-Assessment-of-Urban-Comfort">our research</a>, we are examining the relationship between local urban features, urban heat islands, the resulting city temperatures and their direct and indirect (spillover) effects on local and regional economic activities.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/making-a-global-agenda-work-locally-for-healthy-sustainable-living-in-tropical-australia-97069">Making a global agenda work locally for healthy, sustainable living in tropical Australia</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/120825/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
The world’s fastest-growing cities are in the tropics. They are highly exposed to climate change, especially as urban heat island effects and humidity magnify the impacts of increasing heatwaves.
Taha Chaiechi, Senior Lecturer, James Cook University
Silvia Tavares, Lecturer in Urban Design, James Cook University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/121615
2019-08-29T20:04:29Z
2019-08-29T20:04:29Z
We have the blueprint for liveable, low-carbon cities. We just need to use it
<figure><img src="https://images.theconversation.com/files/289547/original/file-20190827-8868-v4vdst.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Increasing heat in Sydney and other Australian cities highlights the urgent need to apply our knowledge of how to create liveable low-carbon cities.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/australia-sydney-distant-cbd-silhouette-skyscrapers-168941117?src=-1-3">Taras Vyshnya/Shutterstock</a></span></figcaption></figure><p>Over the past seven years more than 100 research projects at the <a href="http://www.lowcarbonlivingcrc.com.au">Co-operative Research Centre for Low Carbon Living</a>, in collaboration with industry across Australia, have pondered a very big question: How do we build future cities that are sustainable, liveable and affordable?</p>
<p>This is exactly what Australians want, as the recent Greater Sydney Commission report, <a href="https://www.greater.sydney/pulse-of-greater-sydney">The Pulse of Greater Sydney</a>, revealed. People want cities in which they live close to jobs and have reasonable commuting times. They want access to parks and green space, and relief from ever-increasing urban heat.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/if-we-want-liveable-cities-in-2060-well-have-to-work-together-to-transform-urban-systems-119235">If we want liveable cities in 2060 we'll have to work together to transform urban systems</a>
</strong>
</em>
</p>
<hr>
<p>The good news is we already know what it will take to deliver on much of this wish list. Since 2012, I have headed the A$100 million Low Carbon Living CRC, which has brought together Australian businesses, industries, communities and many of our brightest researchers to work out how to steer change.</p>
<p>Our <a href="http://www.lowcarbonlivingcrc.com.au/resources/crc-publications/crclcl-project-reports/sp0012u3-cooling-sydney-strategy">Cooling Sydney Strategy</a>, for instance, is the result of years of research into how to combat urban heatwaves. The burden of this heat is unevenly spread across our cities. </p>
<p>For example, residents of Sydney’s western suburbs are <a href="https://www.smh.com.au/national/nsw/value-jobs-a-quick-commute-and-relief-from-urban-heat-avoid-these-parts-of-sydney-20190714-p5273e.html">exposed to many more days hotter than 35 degrees</a> than Sydneysiders living in the CBD and the city’s north. Last summer that meant over a month’s worth of intense heat in the suburb of Penrith, including <a href="http://www.bom.gov.au/climate/current/season/nsw/archive/201902.sydney.shtml">nine days in a row above 35°C</a>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/building-cool-cities-for-a-hot-future-57489">Building cool cities for a hot future</a>
</strong>
</em>
</p>
<hr>
<p>While the recent winter sun might feel welcome, the negative impacts of increasingly hot cities on our health, lifestyle and energy use greatly outweigh any winter comfort. </p>
<h2>So what are the solutions?</h2>
<p>Our researchers have already found how we can offset increasing heat. The <a href="http://www.lowcarbonlivingcrc.com.au/resources/crc-publications/crclcl-project-reports/cooling-western-sydney-0">strategies</a> includes cool and permeable pavements, water features and evaporative cooling, shade structures, vertical gardens, street trees and other plants – even special heat refuge stations.</p>
<p>Keeping cool inside, without huge power bills, is possible too. During last summer’s heatwave, our <a href="https://joshshouse.com.au/about-the-project/joshs-house-research/">pilot 10-star energy-efficient house in Perth</a> remained a comfortable 24°C inside, without air conditioning, when it was over 40°C outside. The exceptional thermal performance of the house was down to its evidence-based design.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/RqDezVOe9kw?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Josh Byrne explains how his house keeps temperatures comfortable year-round with low energy use and no net emissions.</span></figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/when-the-heat-is-on-we-need-city-wide-plans-to-keep-cool-70738">When the heat is on, we need city-wide plans to keep cool</a>
</strong>
</em>
</p>
<hr>
<p>This work is just one part of our wider remit. Our UNSW-based centre is on track to deliver independently verified cuts of <a href="http://www.lowcarbonlivingcrc.com.au/news/news-archive/2018/11/crc-low-carbon-living-track-reduce-carbon-emissions-10mgts-2020">10 megatonnes of carbon emissions generated by Australia’s built environment by 2020</a>. By integrating renewable energy systems, smart technologies, low-carbon materials and people-centred design into buildings and urban precincts, we have developed a sustainable, liveable and affordable urban blueprint for Australia. A PwC study (yet to be released) estimated cumulative economic benefits totalling A$684 million by 2027.</p>
<p>To put this another way, we have identified and verified evidence-based pathways to cut emissions equivalent to taking some 2.1 million cars off the road.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/cutting-cities-emissions-does-have-economic-benefits-and-these-ultimately-outweigh-the-costs-116986">Cutting cities' emissions does have economic benefits – and these ultimately outweigh the costs</a>
</strong>
</em>
</p>
<hr>
<p>Some of the progress to date is not immediately obvious to the casual observer. Take an otherwise unremarkable stretch of road along the back way to Sydney Airport. Recently, a <a href="http://www.lowcarbonlivingcrc.com.au/news/news-archive/2019/06/crclcl-drives-world-first-green-concrete-trial-sydney-road">30-metre section of concrete was installed</a>, which looks more like an ad hoc road repair than an important scientific pilot study.</p>
<p>But 15 metres is paved with a new geopolymer concrete that slashes greenhouse gas emissions by 50%. The other 15 metres is conventional concrete, the <a href="https://www.rsc.org/images/Construction_tcm18-114530.pdf">most widely used man-made material on the planet</a>. Concrete production, using cement as its binder, accounts for about <a href="https://reader.chathamhouse.org/making-concrete-change-innovation-low-carbon-cement-and-concrete">8% of all global emissions</a>.</p>
<p>The geopolymer concrete developed through our research centre is a similarly high-performance product but its binder safely incorporates otherwise noxious industrial waste streams, such as fly ash from coal-fired power stations and slag from blast furnaces. Australia has stockpiled about <a href="http://media.bze.org.au/ZCIndustry/bze-report-rethinking-cement-short.pdf">400 million tonnes of waste</a> from coal-fired power generation and steelmaking. </p>
<p>In Alexandria, in collaboration with the City of Sydney, we are testing this <a href="http://media.bze.org.au/ZCIndustry/bze-report-rethinking-cement-short.pdf">low-carbon concrete</a> as a road surface that could help clean up industrial waste while slashing emissions. <a href="https://www.youtube.com/watch?v=pF5UzGtlav8&t=12s">Working with NSW Ports</a>, we’ve also shaped it into low-carbon bollards to form a breakwater to protect the coastline at Port Kembla from extreme weather. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/pF5UzGtlav8?wmode=transparent&start=12" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Waste from coal-fired power stations has been used to make low-carbon bollards to protect the coastline at Port Kembla.</span></figcaption>
</figure>
<h2>We now have the know-how to do better</h2>
<p>There are many such success stories, but with 150 CRC Low Carbon Living projects the list is too long to detail. What’s more important, as our funding period comes to an end and Australia loses its only innovation hub committed to lowering carbon in the built environment, is to note how we got to where we are today.</p>
<p>The federal government’s Co-operative Research Centre program fosters co-operation and collaboration on a grand scale. Industries, businesses, government organisations and communities with a stake in solving big, complex challenges partner with researchers from a wide range of academic fields. This structure brings together sectors and people whose paths might otherwise rarely cross. </p>
<p>The cross-fertilisation of ideas, expertise and skills delivers innovative solutions. <a href="https://www.industry.gov.au/sites/default/files/competition_or_collaboration_-_from_which_well_does_innovation_spring_-_speech_may_2018.pdf">Research worldwide</a> has consistently shown that collaboration drives innovation, and that innovation drives economic growth. Our experience confirms that as we partnered with organisations such as Multiplex, AECOM, BlueScope Steel, Sydney Water, ISCA, CSIRO and the United Nations Environment Program.</p>
<p>Cities are complex, exciting beasts, but we have the knowledge and expertise to live better, more comfortable urban lives in Australia while reducing demand for energy, water and materials. That is, we have the blueprint for low-carbon urban living. We must now choose to use it.</p>
<hr>
<p><em>This article has been updated to correct the number of CRC Low Carbon Living projects to 150 and the amount of stockpiled waste from coal-fired power generation and steelmaking to 400 million tonnes.</em></p><img src="https://counter.theconversation.com/content/121615/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Deo Prasad does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
The research has been done. The evidence is in. We know how to create cities that are sustainable, liveable and affordable. But we have yet to apply that knowledge widely across Australian cities.
Deo Prasad, Scientia Professor and CEO, Co-operative Research Centre for Low Carbon Living, UNSW Sydney
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/120493
2019-07-25T20:01:57Z
2019-07-25T20:01:57Z
Our cities need more trees, but some commonly planted ones won’t survive climate change
<figure><img src="https://images.theconversation.com/files/285247/original/file-20190723-91846-16xcjng.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Australian cities could lose some of their most common trees to climate change.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/sydney-housing-aerial-view-1113669581?src=q0htPE1IqjJ-LGmEhQBsXQ-1-19&studio=1">Jamen Percy/Shutterstock</a></span></figcaption></figure><p>We need trees in our lives. This past summer, Adelaide experienced the <a href="https://www.theguardian.com/australia-news/2019/jan/24/australia-heatwave-adelaide-breaks-its-all-time-heat-record-hitting-466c">hottest temperature ever recorded in an Australian state capital</a>, hitting 46.6 degrees on January 24. Trees beautify otherwise grey cities and cool our suburbs during heatwaves. But different species have different levels of tolerance of heat, lack of water and other threats posed by climate change. </p>
<p><a href="https://www.sciencedirect.com/science/article/pii/S0048969719323289?via%3Dihub">In a newly published study</a>, we investigated likely climate change impacts on 176 of the most common tree species planted across Australian cities. Our analysis showed more than 70% of these species will experience harsher climatic conditions across Australian cities by 2070. Some of the most commonly planted trees are unlikely to survive these conditions.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/285269/original/file-20190723-110195-1g0vi9n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/285269/original/file-20190723-110195-1g0vi9n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/285269/original/file-20190723-110195-1g0vi9n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=669&fit=crop&dpr=1 600w, https://images.theconversation.com/files/285269/original/file-20190723-110195-1g0vi9n.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=669&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/285269/original/file-20190723-110195-1g0vi9n.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=669&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/285269/original/file-20190723-110195-1g0vi9n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=841&fit=crop&dpr=1 754w, https://images.theconversation.com/files/285269/original/file-20190723-110195-1g0vi9n.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=841&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/285269/original/file-20190723-110195-1g0vi9n.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=841&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The golden wattle might struggle in our northern cities if they get hotter and drier.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Acacia_longifolia_WZBGSG.JPG">Dryas/Wikimedia Commons</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>So which tree species are best suited to particular places? Which species are more likely to thrive, rather than just survive, under a changing climate? Which of our beloved tree species won’t make it?</p>
<p>Tree species growing in warmer cities are more likely to be affected than those in cooler cities. Some species, such as the golden wattle (<em>Acacia longifolia</em>) or the prickly paperbark (<em>Melaleuca styphelioides</em>), might not make it in northern cities, unless we invest precious resources – such as water – to maintain these civic assets. Other species, such as the native frangipani (<em>Hymenosporum flavum</em>) or the tuckeroo (<em>Cupaniopsis anacardioides</em>), will likely become more suitable for planting in southern cities.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/were-investing-heavily-in-urban-greening-so-how-are-our-cities-doing-83354">We're investing heavily in urban greening, so how are our cities doing?</a>
</strong>
</em>
</p>
<hr>
<h2>Why do cities need trees?</h2>
<p>Trees are wonderfully effective at improving the microclimate of our cities, which makes tree plantings an effective and efficient way to adapt to climate change. The leaves of trees absorb and dissipate much of the sun’s radiation. </p>
<p>Trees cool air and land by several degrees compared to areas of concrete and asphalt. Swipe the heat map below to see how effectively trees cool down our cities. (Red indicates hotter areas, blue cooler areas.) </p>
<iframe width="100%" height="600" frameborder="0" scrolling="no" allowfullscreen="" src="https://arcg.is/1XGz5"></iframe>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/284676/original/file-20190718-116586-1p40y9x.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/284676/original/file-20190718-116586-1p40y9x.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=4&fit=crop&dpr=1 600w, https://images.theconversation.com/files/284676/original/file-20190718-116586-1p40y9x.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=4&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/284676/original/file-20190718-116586-1p40y9x.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=4&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/284676/original/file-20190718-116586-1p40y9x.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=4&fit=crop&dpr=1 754w, https://images.theconversation.com/files/284676/original/file-20190718-116586-1p40y9x.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=4&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/284676/original/file-20190718-116586-1p40y9x.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=4&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Swipe the map to see how much trees cool urban areas. Red indicates hotter areas, blue cooler areas. This temperature map was collected during a heatwave in Adelaide, South Australia, on February 9 2017 by AdaptWest over the cities of West Torrens, Charles Sturt and Port Adelaide-Enfield.</span>
<span class="attribution"><span class="source">Used with permission of AdaptWest Adelaide (https://www.adaptwest.com.au/mapping/heat-maps)</span></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/building-cool-cities-for-a-hot-future-57489">Building cool cities for a hot future</a>
</strong>
</em>
</p>
<hr>
<p>Governments recognise the importance of trees and have developed vital initiatives, such as the national <a href="https://landcareaustralia.org.au/our-programme/20-million-trees/">20 Million Trees</a> program and the <a href="https://5milliontrees.nsw.gov.au/">5 Million Trees</a> program in New South Wales. These are important first steps to increase urban tree cover across Australia. But the question arises: are we planting the right tree species? </p>
<h2>What does the science say?</h2>
<p>Australian cities are blessed with a higher diversity of tree species compared to other cities globally. However, the 30 most commonly planted species make up more than half of Australia’s urban forests. </p>
<p>This poses a great risk for our cities. If we were to lose one or two of these common species, the impact on our urban tree cover would be immense. Consequently, our best insurance is to increase the diversity of our trees. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/284438/original/file-20190717-147275-p1v8mj.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/284438/original/file-20190717-147275-p1v8mj.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/284438/original/file-20190717-147275-p1v8mj.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=598&fit=crop&dpr=1 600w, https://images.theconversation.com/files/284438/original/file-20190717-147275-p1v8mj.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=598&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/284438/original/file-20190717-147275-p1v8mj.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=598&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/284438/original/file-20190717-147275-p1v8mj.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=752&fit=crop&dpr=1 754w, https://images.theconversation.com/files/284438/original/file-20190717-147275-p1v8mj.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=752&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/284438/original/file-20190717-147275-p1v8mj.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=752&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Species composition of Australia’s urban forests across 60 local government areas. The size of each word is proportional to the number of tree stems recorded for each species.</span>
<span class="attribution"><span class="source">Alessandro Ossola </span></span>
</figcaption>
</figure>
<p>Our quest to find climate-ready tree species is only just beginning. Supported by Hort Innovation Australia, the NSW Department of Planning, Industry and Environment, and the Commonwealth government, our team embarked on a project called <a href="https://www.whichplantwhere.com.au/">Which Plant Where</a> in conjunction with researchers at Western Sydney University. Our mission is to find the best plant species for urban landscapes that will be resilient to climate change. </p>
<p>We work with the nursery industry to provide evidence on species’ resilience to extreme heat and drought by testing plants to their limits in research glasshouses. Our work with plant growers and nurseries will inform them on how to adapt their business, by identifying the new challenges posed by climate change, as well as selecting highly diverse palettes of climate-ready species. We advise landscape architects, designers and urban planners about not only the best planting choices, but also how to increase the biodiversity of our cities.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/for-green-cities-to-become-mainstream-we-need-to-learn-from-local-success-stories-and-scale-up-119933">For green cities to become mainstream, we need to learn from local success stories and scale up</a>
</strong>
</em>
</p>
<hr>
<h2>You can help!</h2>
<p>We are committed to do more science in coming years, but you can start making a difference today. Australia’s <a href="https://treeday.planetark.org/">National Tree Day</a> will be celebrated again this year on Sunday, July 28. It’s a great opportunity to teach our families, communities and businesses about the importance of tree planting and environmental stewardship as key elements of adapting to climate change. </p>
<p>An old Chinese adage says:</p>
<blockquote>
<p>The best time to plant a tree was 20 years ago. The second best time is now.</p>
</blockquote>
<p>This weekend is your time. The game is simple – head to your closest plant nursery. Ask your local grower about which tree species are suitable for the local growing conditions and pick one you like. Then, plant a tree in your yard, or <a href="https://treeday.planetark.org/find-a-site/">join one of the many planting events across Australia</a>. </p>
<p>Teach your kids, family and friends about the difference they can start making today – for their future and our common good – one tree at a time. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/284440/original/file-20190717-147284-y1tpu4.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/284440/original/file-20190717-147284-y1tpu4.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/284440/original/file-20190717-147284-y1tpu4.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/284440/original/file-20190717-147284-y1tpu4.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/284440/original/file-20190717-147284-y1tpu4.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/284440/original/file-20190717-147284-y1tpu4.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/284440/original/file-20190717-147284-y1tpu4.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/284440/original/file-20190717-147284-y1tpu4.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A plant nursery growing a diverse range of tree species for the upcoming planting season.</span>
<span class="attribution"><span class="source">Alessandro Ossola</span></span>
</figcaption>
</figure><img src="https://counter.theconversation.com/content/120493/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Alessandro Ossola receives funding from Hort Innovation, using the Hort Innovation Green Cities Fund research and development levy, and co-investments from Macquarie University, Western Sydney University and the NSW Office of Energy, Environment and Science and contributions from the Australian Government.</span></em></p><p class="fine-print"><em><span>Hugh Burley received funding from The Which Plant Where project, which is funded by the Green Cities Fund, as part of the Hort Frontiers Strategic Partnership Initiative developed by Hort Innovation, with co-investment from Macquarie University, Western Sydney University and the NSW Office of Environment and Heritage, and funds from the Australian Government.</span></em></p><p class="fine-print"><em><span>Leigh Staas receives funding from The Which Plant Where project is funded by the Green Cities Fund, as part of the Hort Frontiers Strategic Partnership Initiative developed by Hort Innovation, with co-investment from Macquarie University, Western Sydney University and the NSW Office of Environment and Heritage, and funds from the Australian Government.</span></em></p><p class="fine-print"><em><span>Linda Beaumont receives funding from Hort Innovation and the New South Wales Office of Environment and Heritage.</span></em></p><p class="fine-print"><em><span>Michelle Leishman receives funding from Hort Innovation</span></em></p><p class="fine-print"><em><span>Rachael Gallagher receives funding from the Australian Research Council and Horticulture Innovation Australia. </span></em></p>
Thirty tree species make up more than half of Australia’s urban forests. Some won’t survive climate change, so cities must plant a more diverse mix of the right species to preserve their tree cover.
Alessandro Ossola, Research Coordinator Centre for Smart Green Cities, Macquarie University
Hugh Burley, Spatial analyst, Macquarie University
Leigh Staas, Associate Director for Engagement & Research Partnerships | Smart Green Cities, Macquarie University
Linda Beaumont, Senior Lecturer, Macquarie University
Michelle Leishman, Distinguished Professor, Head of Department, Macquarie University
Rachael Gallagher, Macquarie University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/116064
2019-06-13T20:16:05Z
2019-06-13T20:16:05Z
City temperatures and city economics, a hidden relationship between sun and wind and profits
<figure><img src="https://images.theconversation.com/files/273313/original/file-20190508-183096-18h80td.JPG?ixlib=rb-1.1.0&rect=1268%2C0%2C3483%2C1922&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Cairns Lagoon: as a good response to the tropical climate, it's a very active place but with little business activity.</span> <span class="attribution"><span class="source">Silvia Tavares</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Urban design undoubtedly influences the urban economy. A simple thing like designing an area to make it more walkable can boost local business profits. This can also increase real estate value, <a href="http://www.downtowndevelopment.com/pdf/baltimore_Dec20.pdf">create more and better jobs</a> and <a href="https://www.smartgrowthamerica.org/app/legacy/documents/foot-traffic-ahead.pdf">generate stronger local economies</a>. </p>
<p>Street temperatures also determine their walkability. With climate change bringing <a href="https://app.longpaddock.qld.gov.au/heatwave">longer and more frequent heatwaves</a>, street temperatures will become even higher than at present. This will reduce walkability and, in turn, local business profitability. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/smart-urban-design-could-save-lives-in-future-heatwaves-33246">Smart urban design could save lives in future heatwaves</a>
</strong>
</em>
</p>
<hr>
<h2>Walkability impacts local businesses</h2>
<p>The evidence shows businesses do better with foot traffic than car-based mobility. For example, closing New York’s Times Square to cars <a href="https://broadway.showtickets.com/articles/secrets-of-times-square/">increased business revenue by 71% during an eight-month pilot project in 2009</a>.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/LujWrkYsl64?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">New York transport commissioner Janette Sadik-Khan explains the impact on street and retail activity of the transformation of Times Square.</span></figcaption>
</figure>
<p>The following example helps explain why foot traffic benefits local business. In car-based cities, a take-away coffee on the way to work may involve a series of decisions:</p>
<ol>
<li>driving the car to a certain cafe</li>
<li>finding car parking</li>
<li>leaving and closing the car</li>
<li>joining a queue to buy a coffee</li>
<li>getting back in the car </li>
<li>proceeding on the journey to work. </li>
</ol>
<p>In contrast, when walking down the street we may not even have considered having a coffee, but we can smell it. So: </p>
<ol>
<li>we walk into the cafe</li>
<li>join the queue to buy a coffee</li>
<li>carry on walking to work. </li>
</ol>
<p>The process is shorter, more spontaneous and part of a daily journey. Impulse buys as a result of exposure to stimuli have surprisingly big economic consequences, particularly for the retail industry. </p>
<h2>What is microclimate?</h2>
<p>Microclimate refers to the atmospheric conditions in an area. These can vary not only from the surrounding region but also within the area itself. Both the natural and built environments influence these differences. A well-known example of such differences is in <a href="https://www.abc.net.au/news/2018-03-01/how-western-sydney-is-tackling-the-heat-island-effect/9361156">Sydney’s western suburbs</a>, which are <a href="https://theconversation.com/building-cool-cities-for-a-hot-future-57489">much hotter in summer than the eastern suburbs</a>, which benefit from being close to the sea and cooling breezes. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-people-can-best-make-the-transition-to-cool-future-cities-80683">How people can best make the transition to cool future cities</a>
</strong>
</em>
</p>
<hr>
<p>But can an unpleasant microclimate suppress impulse buys? To a certain extent, yes. The frequency of impulse buys, and ultimately the overall success of most businesses in tropical cities, may be connected to the local microclimate.</p>
<p>For instance, the orientation of streets in relation to sun and breeze exposure can influence the microclimate. This can then determine if people stay and have a second coffee or extra ice cream after lunch, or if they avoid streets because they are too exposed and hot. </p>
<p>Australian cities, however, are too often overzoned and planned in a sprawling pattern. By compromising walkability this represses spontaneous purchases. </p>
<p>CBDs are also too frequently oversized with unshaded wide streets. In hot climates this makes the journey on foot unpleasant and poses health risks to young children, senior citizens and people with health conditions. </p>
<h2>Microclimates and the tropics</h2>
<p>To date, a growing body of research on this question has <a href="https://www.richmondfed.org/-/media/richmondfedorg/publications/research/economic_brief/2018/pdf/eb_18-08.pdf">focused mainly on capital and metropolitan cities with humid continental climates</a>. The assumption is that those cities are more vulnerable to the effects of higher temperatures. However, looking only at these kinds of cities can lead us to overlook important variations. </p>
<p>Coastal tropical cities can also experience unpleasant microclimates. While the tropics are seen as perfect holiday locations, high summer temperatures can compromise street life. </p>
<p>The <a href="https://theconversation.com/building-cool-cities-for-a-hot-future-57489">qualities and materials of buildings and infrastructure</a> such as roads and footpaths also influence local temperatures. Large areas of hard, heat-absorbing surfaces contribute to the <a href="https://www.theguardian.com/sustainable-business/2017/feb/21/urban-heat-islands-cooling-things-down-with-trees-green-roads-and-fewer-cars">urban heat island effect</a>, which makes urban areas hotter than their surroundings. The effects of this on urban life and economic activities become more critical in hot and humid tropical conditions.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/building-cool-cities-for-a-hot-future-57489">Building cool cities for a hot future</a>
</strong>
</em>
</p>
<hr>
<h2>Taking advantage of microclimates</h2>
<p>In essence, microclimate affects the use of the footpath. If the microclimate discourages the use of public space, then a great design may not be enough to create the type of environment that attracts street life and generates strong local economic activity.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/273315/original/file-20190508-183103-fi602e.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/273315/original/file-20190508-183103-fi602e.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/273315/original/file-20190508-183103-fi602e.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/273315/original/file-20190508-183103-fi602e.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/273315/original/file-20190508-183103-fi602e.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/273315/original/file-20190508-183103-fi602e.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/273315/original/file-20190508-183103-fi602e.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Shields and Lake Street corner in Cairns: great design, plenty of trees and shade, but little activation.</span>
<span class="attribution"><span class="source">Silvia Tavares</span></span>
</figcaption>
</figure>
<p>Considering this problem, <a href="https://www.researchgate.net/project/Evidence-based-Economic-Assessment-of-Urban-Comfort">our ongoing research</a> focuses on tropical cities. We are investigating the relationship between urban microclimate, labour productivity, sales revenue and real estate values. </p>
<p>Is there, for instance, an optimum location for certain types of land use according to their suitability and need to use the footpath? If one side of the street is more exposed to the sun than the other, it may be more suitable for establishments that don’t make active use of the streetscape, such as stores and offices, rather than cafes and restaurants. </p>
<p>Another question is does microclimate affect the productivity of businesses differently across urban and non-urban surroundings? </p>
<p>Part of the solution to rising urban temperatures could focus on street orientation and exposure to breezes. Priority could be given to siting cafes, for instance, in pleasant areas, with tables outside to help activate spaces. Instead of creating zoning that kills flexibility and dynamic spaces, planning guidelines for tropical street life should consider the types of businesses suited to specific street microclimates. </p>
<p>In a warming climate, designing for microclimate is more important than ever before to ensure urban life and economies can prosper. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-to-build-a-city-fit-for-50-heatwaves-49560">How to build a city fit for 50℃ heatwaves</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/116064/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
Good urban design and walkability boost local economic activity by increasing public activity, but cities need to pay more attention to the effects of microclimates on streets and public spaces.
Silvia Tavares, Lecturer in Urban Design, James Cook University
Taha Chaiechi, Senior Lecturer, James Cook University
Licensed as Creative Commons – attribution, no derivatives.