tag:theconversation.com,2011:/au/topics/tropical-cities-75899/articlestropical cities – The Conversation2024-01-19T21:07:32Ztag:theconversation.com,2011:article/2213132024-01-19T21:07:32Z2024-01-19T21:07:32Z1 billion people left dangerously exposed to heat stress by gaps in climate monitoring<figure><img src="https://images.theconversation.com/files/570270/original/file-20240119-19-y6h5wq.jpg?ixlib=rb-1.1.0&rect=0%2C11%2C7360%2C4891&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/ghaziabad-uttar-pradesh-india-may-12-2170143881">PradeepGaurs/Shutterstock</a></span></figcaption></figure><p>2023 was the <a href="https://wmo.int/media/news/wmo-confirms-2023-smashes-global-temperature-record">hottest year on record</a>. <a href="https://www.weforum.org/agenda/2020/12/climate-change-humidity-paradox/">Humidity is rising too</a>. Heat and humidity are a dangerous combination, threatening all aspects of our lives and livelihoods.</p>
<p>Climate change is pushing humid heat dangerously close to the <a href="https://iopscience.iop.org/article/10.1088/1748-9326/ac71b9">upper limits of what people can survive</a>. Parts of the world are <a href="https://doi.org/10.1126/sciadv.adg9297">on track</a> for conditions beyond the limits of human tolerance.</p>
<p>Yet <a href="https://doi.org/10.1016/j.oneear.2023.12.005">our new research</a> shows poor weather station coverage across the tropics leads to underestimates of heat stress in cities. This means global climate change assessments probably overlook the local impacts on people.</p>
<p>Concentrated across tropical Asia and Africa, informal settlements, commonly known as “slums”, are on the <a href="https://unhabitat.org/pro-poor-climate-action-in-informal-settlement">front line of climate exposure</a>. The shortfalls in climate monitoring leave these communities dangerously vulnerable to rising humid heat. With few options to adapt, millions could be forced to seek refuge away from the hottest parts of the tropics.</p>
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<a href="https://images.theconversation.com/files/570282/original/file-20240119-15-ptsagy.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="World map showing percentage of population living in informal settlements by country, with dots indicating weather station sites" src="https://images.theconversation.com/files/570282/original/file-20240119-15-ptsagy.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/570282/original/file-20240119-15-ptsagy.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=355&fit=crop&dpr=1 600w, https://images.theconversation.com/files/570282/original/file-20240119-15-ptsagy.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=355&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/570282/original/file-20240119-15-ptsagy.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=355&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/570282/original/file-20240119-15-ptsagy.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=446&fit=crop&dpr=1 754w, https://images.theconversation.com/files/570282/original/file-20240119-15-ptsagy.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=446&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/570282/original/file-20240119-15-ptsagy.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=446&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">A map showing percentage of population living in informal settlements by country. Dots indicate weather station sites.</span>
<span class="attribution"><span class="source">Emma Ramsay</span></span>
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<hr>
<p>
<em>
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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>
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<h2>Why is heat such a threat in these places?</h2>
<p><a href="https://population.un.org/wup/publications/Files/WUP2018-PopFacts_2018-1.pdf">Rapid urbanisation</a> that outpaces planned, formal development is driving the growth of informal settlements. Their residents usually lack infrastructure and services, such as electricity and water supply, that many city dwellers take for granted. </p>
<p>More than <a href="https://unstats.un.org/sdgs/report/2019/goal-11/">1 billion people live in informal settlements</a>. The United Nations expects this number to grow to <a href="https://unstats.un.org/sdgs/report/2023/The-Sustainable-Development-Goals-Report-2023.pdf">3 billion over the next 30 years</a>. In countries such as Kenya or Bangladesh, nearly half the urban populations lives in informal settlements.</p>
<p>Most informal settlements are located in the tropics. Here it is hot and humid year-round, but their residents have few options to adapt to heat stress. </p>
<p>Most households in these settlements are on low incomes. Many residents <a href="https://doi.org/10.1016/j.uclim.2022.101401">must work outdoors</a> for their livelihoods, which exposes them to heat and humidity. </p>
<p>On top of this, because informal settlements fall outside official systems and regulations, we often lack data about the threats they face.</p>
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<img alt="A farmer works in a rice field next to an informal settlement" src="https://images.theconversation.com/files/570004/original/file-20240118-19-m8smxw.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/570004/original/file-20240118-19-m8smxw.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/570004/original/file-20240118-19-m8smxw.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/570004/original/file-20240118-19-m8smxw.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/570004/original/file-20240118-19-m8smxw.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/570004/original/file-20240118-19-m8smxw.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/570004/original/file-20240118-19-m8smxw.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">
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<span class="caption">People who must work outdoors to make a living, such as many residents of this settlement in Makassar, Indonesia, are highly exposed to heat.</span>
<span class="attribution"><span class="source">Revitalising Informal Settlements and their Environments, Monash University</span></span>
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<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>
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<h2>What’s missing from climate data?</h2>
<p>Most of the world’s population <a href="https://doi.org/10.1088/1748-9326/ac30c0">lives more than 25km from a weather station</a>. This means weather stations rarely capture the full range of temperature and humidity in cities, which are usually hotter than non-urban surrounds – the <a href="https://www.australianenvironmentaleducation.com.au/climate-change/urban-heat-island-effect/">urban heat island effect</a>. These gaps in monitoring are largest across the tropics where most informal settlements are located.</p>
<p>As individuals we experience heat on a local scale, which isn’t captured by sparse weather station networks or meteorological models. If your home is too hot, a weather report telling you otherwise offers little respite. </p>
<p><a href="https://doi.org/10.1016/j.oneear.2023.12.005">Our research</a> compiled local climate monitoring data from informal settlements in seven tropical countries. We compared these data to temperature and humidity measurements at the nearest weather station.</p>
<p>We found weather stations severely underestimate the heat stress that people experience in their homes and local communities. This means global climate assessments and projections also likely underestimate local-scale impacts. </p>
<p>Although these data come from a relatively small number of studies, they highlight a major hurdle for climate adaptation. Without accurate heat stress data, how can we ensure the most vulnerable communities are not left behind?</p>
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<img alt="Looking along a water channel towards an informal settlement in Makassar, Indonesia" src="https://images.theconversation.com/files/570005/original/file-20240118-15-u3alzk.jpeg?ixlib=rb-1.1.0&rect=0%2C0%2C2835%2C1897&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/570005/original/file-20240118-15-u3alzk.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/570005/original/file-20240118-15-u3alzk.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/570005/original/file-20240118-15-u3alzk.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/570005/original/file-20240118-15-u3alzk.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=565&fit=crop&dpr=1 754w, https://images.theconversation.com/files/570005/original/file-20240118-15-u3alzk.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=565&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/570005/original/file-20240118-15-u3alzk.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=565&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Lack of accurate local data means climate adaptation efforts could overlook communities exposed to extreme heat and humidity.</span>
<span class="attribution"><span class="source">Grant Duffy, Revitalising Informal Settlements and their Environments, Monash University</span></span>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/why-40-c-is-bearable-in-a-desert-but-lethal-in-the-tropics-206237">Why 40°C is bearable in a desert but lethal in the tropics</a>
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<h2>Even if they get a heat warning, options are limited</h2>
<p>During a heatwave in Australia we are usually told to <a href="https://www.redcross.org.au/heatwaves/#:%7E:text=non%2Dperishable%20foods.-,During%20a%20heatwave,you%20don't%20feel%20thirsty.">stay inside and drink lots of water</a>. For residents of an informal settlement, this advice might actually increase their risk of health impacts.</p>
<p>Heat can be even <a href="https://doi.org/10.1016/j.isci.2021.103248">worse indoors in informal housing</a> with poor ventilation and insulation. Very few households have air conditioning (or could afford to run it if they did). Residents might not have access to safe drinking water, adding to the health risks of heat stress.</p>
<p>What’s more, advice and alerts are unlikely even to reach informal settlements. A <a href="https://www.undrr.org/media/91954/download?startDownload=true">2023 World Meteorological Organisation report</a> found only half of the world’s countries have early-warning systems. </p>
<p>These systems are activated if forecast heat is above certain trigger levels. Health advice and alerts to the public can be backed by extra public health measures. <a href="https://www.icpac.net/">Regional climate centres</a> currently issue broad-scale alerts, but forecasts and responses need to operate at smaller scales to be effective.</p>
<p>And, as we have shown, forecasts are based on weather station data that underestimate heat in informal settlements. This means early-warning systems could fail to activate even though residents of these settlements will experience dangerous heat stress.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/climate-explained-will-the-tropics-eventually-become-uninhabitable-145174">Climate explained: will the tropics eventually become uninhabitable?</a>
</strong>
</em>
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<hr>
<h2>What can be done to protect people?</h2>
<p>Current climate monitoring efforts have left millions of vulnerable people at risk of heat stress. This has direct <a href="https://journals.plos.org/climate/article?id=10.1371/journal.pclm.0000339">impacts on individual health and wellbeing</a>, with <a href="https://doi.org/10.1016/S0140-6736(23)01859-7">broader knock-on effects</a> for societies and national economies. </p>
<p>Meteorological institutes in developing countries need urgent support to strengthen climate monitoring and improve early-warning systems. The new head of the World Meteorological Organisation has <a href="https://wmo.int/news/media-centre/celeste-saulo-of-argentina-takes-office-secretary-general-of-wmo">promised to do just that</a>. We need to ensure governments and agencies, such as development banks and NGOs, capitalise on this opportunity and include informal settlements in new monitoring networks.</p>
<p>Inequalities in resources and adaptive capacities must also be overcome. Community-based initiatives such as urban greening and improved housing <a href="https://doi.org/10.1016/S0140-6736(21)01209-5">show promise to reduce urban heat</a>. Investing in these solutions must be a priority of adaptation efforts. </p>
<p>The alternative to adapting is to move. Climate-related migration is <a href="https://www.visionofhumanity.org/wp-content/uploads/2023/11/ETR-2023-web-261023.pdf">already happening</a> due to sea-level rise and heat, <a href="https://www.abc.net.au/news/2019-12-16/climate-migrants-moving-south-to-tasmania/11800152">including here in Australia</a>. </p>
<p>People don’t leave their homes and uproot their lives without good reason. Finding solutions that help them adapt to climate change should be the priority. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/climigration-when-communities-must-move-because-of-climate-change-122529">'Climigration': when communities must move because of climate change</a>
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</em>
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<img src="https://counter.theconversation.com/content/221313/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Emma Ramsay received funding from the Australian Government Research Training Program and Monash University. This research was conducted as part of the Revitalising Informal Settlements and their Environments (RISE) program, funded by the Wellcome Trust, the New Zealand Ministry of Foreign Affairs and Trade, the Australian Department of Foreign Affairs and Trade, the Asian Development Bank, the Government of Fiji, the City of Makassar and Monash University, and involves partnerships and in-kind contributions from the Cooperative Research Centre for Water Sensitive Cities, Fiji National University, Hasanuddin University, Southeast Water, Melbourne Water, Live and Learn Environmental Education, UN-Habitat, UNU-IIGH, WaterAid International and Oxfam</span></em></p>Most of the 1 billion people in informal settlements are in the tropics where the threat of humid heat is rising. Poor weather station coverage that misses local hotspots puts them even more at risk.Emma Ramsay, Postdoctoral Research Fellow, Nanyang Technological University, and Research Affiliate, School of Biological Sciences, Monash UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1839442022-06-14T14:37:53Z2022-06-14T14:37:53ZAir pollution in fast-growing African cities presents a risk of premature death<figure><img src="https://images.theconversation.com/files/468341/original/file-20220611-18059-dln7lp.jpg?ixlib=rb-1.1.0&rect=28%2C0%2C4682%2C3142&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Road traffic is one of the causes of air pollution in Lagos, Nigeria.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/motorists-queue-in-a-chaotic-traffic-gridlock-following-news-photo/1142442342?adppopup=true">Photo by Pius Utomi Ekpei/AFP via Getty Images</a></span></figcaption></figure><p>Ten more African cities have signed on to the <a href="https://www.c40.org/news/african-cities-clean-air-declaration/">C40 Clean Air Cities Declaration</a> to improve air quality. C40 is an international group of mayors collaborating to make cities more environmentally sustainable. </p>
<p>In May 2022, Abidjan, Accra, Addis Ababa, Dakar, Ekurhuleni, Freetown, Johannesburg, Lagos, Nairobi and Tshwane joined Durban, the first African city to sign the declaration.</p>
<p>As part of the C40 pledge, city leaders have committed to actions to tackle air pollution and slow human-caused changes in climate. These include actions such as setting targets that follow the World Health Organisation’s clean air <a href="https://www.who.int/news-room/feature-stories/detail/what-are-the-who-air-quality-guidelines">guidelines</a>. </p>
<p>This is a welcome commitment, as air pollution is a leading burden on global health. More than <a href="https://doi.org/10.1016/S2542-5196(22)00090-0">6.5 million</a> people die prematurely from exposure to air pollution each year worldwide. And air quality is worsening in African cities during a period of rapid growth and development. African cities are forecast to grow by <a href="https://doi.org/10.1177/0956247816663557">3 - 31% annually</a> from now until the end of the century. This is far steeper than growth rates in Indian cities, at about 1 - 3% per year. </p>
<p>A major challenge in combating air pollution in Africa’s cities is the scarcity of data. Air quality <a href="https://www.sciencedirect.com/science/article/pii/S2590162119300437">is not monitored</a> in most cities and resources to compile inventories of the types and sizes of sources contributing to air pollution are lacking. All these efforts are costly and require sustained, long-term funding. </p>
<p>Publicly available data from <a href="https://acp.copernicus.org/articles/21/6275/2021/">satellite observations</a> provide a picture of multiple air pollutants. <a href="https://www.science.org/doi/10.1126/sciadv.abm4435">In our recent study</a>, we sampled these data over fast-growing cities in the tropics, including 26 in Africa. Our investigation covered a 14-year period between 2005 and 2018. </p>
<p>We determined that the quality of air is declining at unprecedented rates. We found that the cause is a shift from rural to urban sources and that combined worsening air quality and population growth is linked to 180,000 additional premature deaths. </p>
<p>Such harmful effects will persist without bold air quality policies.</p>
<h2>Shift in pollution</h2>
<p>For centuries, air pollution in Africa has been dominated by <a href="https://cp.copernicus.org/articles/9/289/2013/cp-9-289-2013.pdf">open burning of biomass</a>. This is a common practice by farmers in the dry season to clear land and to prepare for the next sowing season. The smoke produced is full of <a href="https://openknowledge.worldbank.org/bitstream/handle/10986/29504/124342-BRI-p153343-PUBLIC-march-22-9-pm-WB-Knowledge-Burning.pdf?sequence=1">pollutants</a>, bad for people and the environment.</p>
<p>This is now changing, in cities at least. </p>
<p>In our <a href="https://www.science.org/doi/10.1126/sciadv.abm4435">analysis</a> we identified that urban pollution sources have surpassed rural biomass burning as the main cause for worsening air pollution in cities. Satellite observations are too coarse (~10 km) to pinpoint the exact sources, but we can speculate that these include road traffic, burning of waste, and household use of fuels like <a href="https://pubs.acs.org/doi/abs/10.1021/acs.est.0c03754">charcoal</a> and wood. </p>
<p><a href="https://www.science.org/doi/10.1126/sciadv.abm4435">Our study</a> focused on the fastest growing cities in the tropics. Amongst these are Lagos (<a href="https://www.macrotrends.net/cities/22007/lagos/population">population 15.4 million people growing at 3.5% per year</a>) in Nigeria, Dar es Salaam (<a href="https://www.macrotrends.net/cities/22894/dar-es-salaam/population">population 7.4 million people, 5.1% per year</a>) in Tanzania, and Kinshasa (<a href="https://www.macrotrends.net/cities/20853/kinshasa/population">population 15.6 million people, 4.4% per year</a>) in the Democratic Republic of the Congo. </p>
<p>The air quality indicators we tracked were fine particulate matter pollution (PM2.5) and the gas-phase compounds nitrogen dioxide (NO2), ammonia (NH3), and volatile organic compounds (VOCs). These either directly impact health (PM2.5, NO2) or form air pollutants that do (VOCs, NH3). These can all be produced from traffic, and burning of household waste and fuel. </p>
<figure class="align-center ">
<img alt="Many people gathered together" src="https://images.theconversation.com/files/468344/original/file-20220611-31449-n1s348.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/468344/original/file-20220611-31449-n1s348.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/468344/original/file-20220611-31449-n1s348.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/468344/original/file-20220611-31449-n1s348.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/468344/original/file-20220611-31449-n1s348.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/468344/original/file-20220611-31449-n1s348.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/468344/original/file-20220611-31449-n1s348.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">
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<span class="caption">Dar es Salaam has a population of 7.4 million people. Photo by Daniel Hayduk/AFP via Getty Images)</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/congolese-men-collect-plastic-bottles-on-the-edge-of-the-news-photo/967066148?adppopup=true">Getty Images</a></span>
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<h2>Health hazards</h2>
<p>The shift from rural to urban sources, combined with rapid population growth, is leading to more people living in closer proximity to air pollution and worsening population health. </p>
<p>Of most concern is PM2.5, as these particles are about 30 times smaller than the diameter of a strand of human hair. PM2.5 penetrate deep into our lungs and go on to have a <a href="https://www.theguardian.com/environment/ng-interactive/2019/may/17/air-pollution-may-be-damaging-every-organ-and-cell-in-the-body-finds-global-review">range of effects on health</a>, leading to premature death. Most prominent are heart disease, stroke, chronic obstructive pulmonary disease, lung cancer, and lower respiratory infections. </p>
<p>We used health risk assessment and atmospheric chemistry models, along with the satellite data, to estimate that premature mortality from sustained exposure to these small particles has steadily increased in 21 of the fastest growing cities in Africa. It’s risen from <a href="https://www.science.org/doi/10.1126/sciadv.abm4435">84,000 in 2005 to 110,000 in 2018</a>. This is on average about 2,000 avoidable deaths each year. </p>
<figure class="align-center ">
<img alt="Map of some African cities" src="https://images.theconversation.com/files/468785/original/file-20220614-22-e9f42t.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/468785/original/file-20220614-22-e9f42t.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=248&fit=crop&dpr=1 600w, https://images.theconversation.com/files/468785/original/file-20220614-22-e9f42t.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=248&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/468785/original/file-20220614-22-e9f42t.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=248&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/468785/original/file-20220614-22-e9f42t.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=312&fit=crop&dpr=1 754w, https://images.theconversation.com/files/468785/original/file-20220614-22-e9f42t.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=312&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/468785/original/file-20220614-22-e9f42t.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=312&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Map showing premature deaths in cities studied.</span>
<span class="attribution"><span class="source">Karn Vohra</span></span>
</figcaption>
</figure>
<p>A third of these deaths are in five of the 10 cities that have signed on to the C40 declaration: Abidjan, Addis Ababa, Dakar, Lagos and Nairobi. The steepest increase in early deaths of about 300 people per year is in Kinshasa, a city yet to join the pledge. </p>
<figure class="align-center ">
<img alt="Many people gathered for a rally" src="https://images.theconversation.com/files/468345/original/file-20220611-43412-x1lmsw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/468345/original/file-20220611-43412-x1lmsw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/468345/original/file-20220611-43412-x1lmsw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/468345/original/file-20220611-43412-x1lmsw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/468345/original/file-20220611-43412-x1lmsw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/468345/original/file-20220611-43412-x1lmsw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/468345/original/file-20220611-43412-x1lmsw.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">Kinshasa is yet to sign the clean air cities declaration. Photo: John Wessels/AFP via Getty Images.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/congolese-men-collect-plastic-bottles-on-the-edge-of-the-news-photo/967066148?adppopup=true">Getty Images</a></span>
</figcaption>
</figure>
<p>The number of people dying prematurely from exposure to air pollution is three times lower in African cities than in Asia, where the shift to urban sources of air pollution is <a href="https://acp.copernicus.org/preprints/acp-2019-1122/acp-2019-1122.pdf">well under way or has already occurred</a>. This is in part because improvements in healthcare in Africa are counteracting the adverse effects of air pollution on health leading to decline in overall mortality. In Addis Ababa in Ethiopia, for example, the number of deaths could have been almost double the values we estimated without improvements in healthcare. But this offsetting won’t last if air quality continues to degrade and healthcare improvements taper off.</p>
<p>Twenty-six cities in Africa are <a href="https://journals.sagepub.com/doi/10.1177/0956247816663557">predicted to be megacities by 2100</a>, reaching unprecedented sizes. By 2100, Lagos may be home to 80 million people; more than double the current largest city of Tokyo. </p>
<p>Access to emission control and renewable energy technologies are cheaper and easier to use than ever before. The C40 pledges are a step in the right direction, but more cities need to join to safeguard public health across the continent.</p><img src="https://counter.theconversation.com/content/183944/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Karn Vohra received funding from the University of Birmingham Global Challenges Studentship.</span></em></p><p class="fine-print"><em><span>Eloise Marais receives funding from UK Research Councils, the European Commission, and the Stockholm Environment Institute. </span></em></p>Twenty-six fast-growing African cities may battle health challenges if air pollution is not addressed.Karn Vohra, Research Fellow, UCLEloise Marais, Associate Professor in Physical Geography, UCLLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1208252019-09-09T20:10:21Z2019-09-09T20:10:21ZUrban 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 UniversitySilvia Tavares, Lecturer in Urban Design, James Cook UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1160642019-06-13T20:16:05Z2019-06-13T20:16:05ZCity 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 UniversityTaha Chaiechi, Senior Lecturer, James Cook UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1120692019-03-27T18:40:51Z2019-03-27T18:40:51ZHealthy, happy and tropical – world’s fastest-growing cities demand our attention<figure><img src="https://images.theconversation.com/files/264513/original/file-20190319-28468-17lwede.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Marine Drive in Mumbai, viewed here from across Chowpatty Beach, is an 'accidental' planning legacy that's now one of the most popular places in the city.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/chowpatty-beach-mumbai-india-skyline-photo-49318582">Dirk Ott/Shutterstock</a></span></figcaption></figure><p>What does it take to be a happy and healthy city? In any city, myriad factors go into the mix – and of course we are not dealing with just one kind of city. But, due to the world history of colonisation, models are still too often European-centric. In particular, we need to adjust how we think about cities in the tropics. </p>
<p>For a start, <a href="https://en.wikipedia.org/wiki/Tropics">almost half of the world’s population lives in the tropics</a> and <a href="https://www.jcu.edu.au/state-of-the-tropics/project/10-reasons">more than half of the world’s children</a>. This makes it the <a href="https://www.weforum.org/agenda/2018/05/why-the-world-s-fastest-growing-populations-are-in-the-middle-east-and-%20africa/">fastest-growing region on the planet</a>. The pace of <a href="https://www.jcu.edu.au/state-of-the-tropics/project/10-reasons">economic and technological development is fastest in the tropics</a>, too.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-the-world-is-turning-tropical-before-our-eyes-26973">How the world is turning tropical before our eyes</a>
</strong>
</em>
</p>
<hr>
<p>The tropics are also home to the <a href="https://www.jcu.edu.au/state-of-the-tropics/project/10-reasons">greatest diversity</a> of architectural styles and urban places. Sandwiched between the Tropic of Cancer and the Tropic of Capricorn, nearly 50 countries display singular <a href="https://www.foreground.com.au/cities/tropical-urbanism/">tropical urbanism</a>, which reflects first settlements, colonial history and the more friendly contact with other cultures. Nowhere else on Earth can we see such a mingling of vernacular, pre-Columbian, Gothic, Baroque, Renaissance and Modernist buildings and urban plans.</p>
<p>Designing for the tropics differs considerably from designing for temperate areas. The climate can be very hot and humid, causing extreme discomfort for city residents.</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>Of course, they too aspire to the good health and well-being that have been promoted as being at the heart of urbanisation from the 18th-century hygienists onwards. Sustainable development entered the picture in the 20th century – the 1987 <a href="http://www.un-documents.net/our-common-future.pdf">Brundtland Report</a> coined the term. </p>
<p>Paul James took sustainable development beyond the original social-economic-environmental triad with the <a href="http://www2.abruem.org.br/wp-content/uploads/2017/11/2015_James-Urban-Sustainability.pdf">circles of sustainability</a>. This draws attention to other significant elements, including culture (e.g. creativity, belief and meaning, etc.) and politics (e.g. organisation and governance, dialogue and reconciliation, etc.). </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/264511/original/file-20190319-28468-1cifj5s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/264511/original/file-20190319-28468-1cifj5s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/264511/original/file-20190319-28468-1cifj5s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=578&fit=crop&dpr=1 600w, https://images.theconversation.com/files/264511/original/file-20190319-28468-1cifj5s.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=578&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/264511/original/file-20190319-28468-1cifj5s.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=578&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/264511/original/file-20190319-28468-1cifj5s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=727&fit=crop&dpr=1 754w, https://images.theconversation.com/files/264511/original/file-20190319-28468-1cifj5s.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=727&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/264511/original/file-20190319-28468-1cifj5s.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=727&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Paul James developed the concept of circles of sustainability that incorporate elements of politics and culture (this one represents Melbourne in 2011).</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Circles_of_Sustainability">SaintGeorgeIV/Wikipedia</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<h2>How do cities achieve all these goals?</h2>
<p>With the prominence of good health and well-being in the <a href="http://habitat3.org/wp-content/uploads/NUA-English-With-Index-1.pdf">New Urban Agenda</a> and UN <a href="https://sustainabledevelopment.un.org/?menu=1300">Sustainable Development Goals</a>, cities are paying more attention to well-being and <a href="http://happyplanetindex.org/">happiness indexes</a> and reports. So how exactly can urban design and experience design – the design of how the visitor will live, appreciate and remember the place – <a href="http://worldhappiness.report/ed/2018/">enhance well-being and happiness</a> in the world’s growing cities? </p>
<p>The Healthy Happy Cities in Tropical Environment (<a href="https://healthy-happy-cities-in-a-tropical-environment-66.webself.net/">HHCTE</a>) network was founded in 2018 to investigate these questions and report on best practices, as well as providing for critical exchange through workshops and conferences. Recently, at the inaugural two-day HHCTE workshop, urban researchers, professionals, civil society actors and decision-makers came together to identify challenges in achieving happy healthy cities in tropical environments and to propose solutions. Several significant findings emerged.</p>
<p>Firstly, and very fortunately, we can learn from many examples of best practice in urban design all around the world. These range from free public open-air swimming pools (e.g. in Cairns and Brisbane, both in Australia) to <a href="http://www.gardensbythebay.com.sg/en.html">Gardens by the Bay</a> in Singapore and <a href="https://www.mumbai.org.uk/marine-drive/marine-drive.html">Mumbai Marine Drive</a> in India. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/265497/original/file-20190325-36276-x2u5fm.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/265497/original/file-20190325-36276-x2u5fm.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/265497/original/file-20190325-36276-x2u5fm.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/265497/original/file-20190325-36276-x2u5fm.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/265497/original/file-20190325-36276-x2u5fm.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/265497/original/file-20190325-36276-x2u5fm.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/265497/original/file-20190325-36276-x2u5fm.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/265497/original/file-20190325-36276-x2u5fm.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">Gardens by the Bay in Singapore is an outstanding example of urban design for a tropical city.</span>
<span class="attribution"><span class="source">Pasi Virtamo</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<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>
<p>However, when prompted to identify and describe the processes and principles that delivered such successful urban designs, HHCTE participants articulated very few of these clearly. This can partly explain why we so often face problems with transferring models or principles (besides the change of context, local features, etc.). It demonstrates how the understanding of experiences might be difficult to access and express. This sort of communication needs to be developed.</p>
<p>Second, we all come with bias. Our cultural background might determine, for example, whether it is important to have free or consumption-based urban experiences. For instance, for some the quality of shading and sitting areas through the journey from one place to another might be plenty, while for others the opening of a bright new shopping mall might symbolise a great urban experience.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/265498/original/file-20190325-36267-1o8hooe.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/265498/original/file-20190325-36267-1o8hooe.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/265498/original/file-20190325-36267-1o8hooe.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/265498/original/file-20190325-36267-1o8hooe.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/265498/original/file-20190325-36267-1o8hooe.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/265498/original/file-20190325-36267-1o8hooe.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/265498/original/file-20190325-36267-1o8hooe.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/265498/original/file-20190325-36267-1o8hooe.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">Pacific Fair on the Gold Coast, one of Queensland’s largest shopping centres, puts the focus on providing an urban experience.</span>
<span class="attribution"><span class="source">Karine Dupre</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The idea that urban design should cater for multicultural diversity is not new, but the emphasis on money-based urban experiences raises questions about the role and meaningfulness of public spaces. Is this a shift from our traditional paradigm?</p>
<p>Third, when asked “what makes you feel happy and healthy in the city?”, all groups of participants, without exception, mentioned ease of walking, bike paths, greenery, public transport and safety. These urban infrastructures really do matter for everyone. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/cities-can-grow-without-wrecking-reefs-and-oceans-heres-how-107263">Cities can grow without wrecking reefs and oceans. Here's how</a>
</strong>
</em>
</p>
<hr>
<p>But then, surprisingly, all participants seemed to don their urban designer hats and forgot to express their more personal feelings. The aim seemed to be to use a neutral vocabulary, as well as trying to reach a professional identity and consensus. Yet, when back home, will everyone not dream about something else – such as colours, music, smells, <a href="https://www.tandfonline.com/doi/abs/10.1080/20507828.2015.1066996">urban atmosphere</a> and so forth – for the city they live in?</p>
<h2>What next?</h2>
<p>The main aim of participation workshops is to give voice to a variety of stakeholders and engage in bottom-up actions that lead to improvements. While we need to be aware of the <a href="https://www.sciencedirect.com/science/article/pii/B9780080450155000186">pitfalls of participation</a>, such as unbalanced processes, it remains a great tool to take the pulse of one society.</p>
<p>On the specific topic of healthy happy cities, the workshop again demonstrated that citizens have good ideas and are ready to be engaged. Yet it also showed that the broad city scale of the discussion influenced the proposals. Perhaps a discussion at the level of the house or street scales would have been closer to the heart of each participant. </p>
<p>We also learned it takes many little steps and aspirations to become a happy healthy city, all of which are feasible. What, then, are we waiting for?</p><img src="https://counter.theconversation.com/content/112069/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Karine Dupré received funding from AFRAN (Australian-French Research Association Network) for the HHCTE workshop.</span></em></p><p class="fine-print"><em><span>Jane Coulon and Silvia Tavares 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>When we plan a better future for an increasingly urbanised world, we need to be aware that more than half of all children now live in the tropics. That calls for solutions with a tropical character.Karine Dupré, Associate Professor in Architecture, Griffith UniversityJane Coulon, Lecturer, School of Architecture, Reunion branch, École Nationale Supérieure d'Architecture Montpellier (ENSAM)Silvia Tavares, Lecturer in Urban Design, James Cook UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1072632018-12-10T18:55:42Z2018-12-10T18:55:42ZCities can grow without wrecking reefs and oceans. Here’s how<figure><img src="https://images.theconversation.com/files/248335/original/file-20181203-194953-1yx65zo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Cairns has lots of hard grey infrastructure but much less green infrastructure that would reduce the impacts of the city's growth.</span> <span class="attribution"><span class="source">Karine Dupré</span>, <span class="license">Author provided</span></span></figcaption></figure><p>“<a href="https://www.iyor2018.org/">What happens if the water temperature rises by a few degrees?</a>” is the 2018 <a href="https://www.icriforum.org/about-icri/iyor">International Year of the Reef</a> leading question. While the ocean is the focus, <a href="https://www.un.org/development/desa/en/news/population/2018-revision-of-world-urbanization-prospects.html">urbanisation</a> is the main reason for the rising temperatures and water pollution. Yet it receives little attention in this discussion. </p>
<p>In turn, rising temperatures <a href="https://theconversation.com/urban-floods-we-can-pay-now-or-later-96160">increase downpours and urban floods</a>, adding to the pressures on urban infrastructure. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/design-for-flooding-how-cities-can-make-room-for-water-105844">Design for flooding: how cities can make room for water</a>
</strong>
</em>
</p>
<hr>
<h2>Protecting the reef as Cairns grows</h2>
<p>Cairns is an expanding Queensland city located between two World Heritage sites – the <a href="http://www.greatbarrierreef.org/about-the-reef">Great Barrier Reef</a> and the <a href="https://en.wikipedia.org/wiki/Daintree_Rainforest">Daintree Rainforest</a>. While important research focuses on these sites themselves, not much is known about how the surrounding urban areas influence these natural environments. Similarly, little is known about how urban planning and design contribute to the health of the inner city and surrounding water bodies, including the ocean. </p>
<p>Cairns is a major Australian tourism destination with a unique coastal setting of rainforest and reef. This attracts growing numbers of visitors. One effect of this success is increased urbanisation to accommodate these tourists. </p>
<p>There are many opportunities to promote sustainable and socially acceptable growth in Cairns. Yet this growth is not without challenges. These include:</p>
<ul>
<li>impacts of climate change, including sea-level rise and ocean warming</li>
<li>lack of comprehensive urban infrastructure strategy</li>
<li>lack of comprehensive assessment of the benefits of integrated urban design to maximise coastal resilience and the health of streams and oceans. </li>
</ul>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/249156/original/file-20181206-186055-r0mm58.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/249156/original/file-20181206-186055-r0mm58.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/249156/original/file-20181206-186055-r0mm58.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=900&fit=crop&dpr=1 600w, https://images.theconversation.com/files/249156/original/file-20181206-186055-r0mm58.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=900&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/249156/original/file-20181206-186055-r0mm58.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=900&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/249156/original/file-20181206-186055-r0mm58.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1131&fit=crop&dpr=1 754w, https://images.theconversation.com/files/249156/original/file-20181206-186055-r0mm58.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1131&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/249156/original/file-20181206-186055-r0mm58.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1131&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Rain gardens are common in Singapore.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/rogersoh/4742030401/in/photolist-8e39qR-8cTrF9-5ZVakG-6SD8Xr-dYNhd-5ZVULb-5ZVkTj-9WFvAV-d39rTQ-9WFtHH-9WJmQ1-9WFvgn-ojCd4B-8e3c2R-ojCdzB-5ZVUtA-5ZV7BU-8ur9JW-9SnZ4W-ov8N8x-9WFwY6-5ZV8Nf-c5y1kE-uLxdpo-o1nqXY-9WFwaa-ohFgoE-ot6Rgd-55jr8c-7jH9xY-2mMoCW-fVdLWn-6zSj5d-94ndL2-omyHjz-fzRSHi-oBpfnr-6dnEtg-m79GPr-FVFE9-eKdaHR-oi6UuW-einXy8-mKHUHk-5cFXGA-omswap-oV1kxp-oChdwV-oudGjB-9WFumT">Roger Soh/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>As with most Australian cities, Cairns has an urban layout based on wide streets, mostly with little or no greenery. <a href="https://www.melbournewater.com.au/community-and-education/help-protect-environment/raingardens">Rain gardens</a>, for instance, are rare. <a href="https://en.wikipedia.org/wiki/Bioswale">Bioswales</a> that slow and filter stormwater are present along highways, but seldom within the city. </p>
<p>The arguments for not adding greenery to the urban environment are familiar. These typically relate to costs of implementation and maintenance, but also to the speed with which water is taken out of streets during the tropical rainy season. This is because green stormwater solutions, if not well planned, can slow down the water flow, thus increasing floods.</p>
<p>However, cities can be designed in a way to <a href="https://theconversation.com/stormwater-innovations-mean-cities-dont-just-flush-rainwater-down-the-drain-40129">imitate nature</a> with solutions that are an integral part of the urban system. This can include dedicated areas of larger wetlands and parks, which capture water and filter pollution and undesired nutrients more efficiently, reducing polluted runoff to the reef.</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>Integrated urban design</h2>
<p>Integrated urban design is an aspect of city planning and design that could be further developed to ensure the whole system works more efficiently. This involves integrating the three elements that make up urban infrastructure: </p>
<ol>
<li><a href="https://theconversation.com/our-cities-need-more-trees-and-water-not-less-to-stay-liveable-22166">the green</a> – parks, residential gardens, rain gardens, green roofs and walls, bioswales, etc</li>
<li>the grey – built drains, footpaths, buildings, <a href="http://www.envacgroup.com/products/our_products/envac-stationary-vacuum-system">underground vacuum
system</a>, etc</li>
<li><a href="https://www.amazon.com/Blue-Urbanism-Exploring-Connections-Between/dp/1610914058">the blue</a> – streams, stormwater systems, etc.</li>
</ol>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/248338/original/file-20181203-194953-1cjc3uf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/248338/original/file-20181203-194953-1cjc3uf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/248338/original/file-20181203-194953-1cjc3uf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/248338/original/file-20181203-194953-1cjc3uf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/248338/original/file-20181203-194953-1cjc3uf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/248338/original/file-20181203-194953-1cjc3uf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/248338/original/file-20181203-194953-1cjc3uf.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">A rain garden, which absorbs rain and stores water to help control run-off from impervious hard surfaces, in Wellington, New Zealand.</span>
<span class="attribution"><span class="source">Karine Dupré</span></span>
</figcaption>
</figure>
<p>Urban infrastructure, therefore, can and should be planned and designed to provide <a href="https://link.springer.com/article/10.1007%2Fs11355-017-0346-6">multiple services</a>, including coastal resilience and healthier water streams and oceans. To achieve this, a neighbourhood or city-wide strategy needs to be implemented, instead of intermittent and ad hoc urban design solutions. Importantly, <a href="http://webpages.uidaho.edu/larc380/new380/assets/images/StormwaterFiles/images/HighPtSect.jpg">each element should coordinate with the others</a> to avoid overlaps, gaps and pitfalls. </p>
<p>This is what integrated urban design is about. So why don’t we implement it more often?</p>
<h2>Challenges and opportunities</h2>
<p><a href="https://www.sciencedirect.com/science/article/pii/S0013935117317115?via%3Dihub">Research has shown</a> that planning, designing and creating climate-resilient cities that are energy-optimised, revitalise urban landscapes and restore and support <a href="http://www.agriculture.gov.au/ag-farm-food/natural-resources/ecosystem-services">ecosystem services</a> is a major challenge at the planning scale. To generate an urban environment that promotes urban protection and resilience while minimising urbanisation impacts and restoring natural systems, we need to better anticipate the risks and have the means to take actions. In other words, it is a two-way system: well planned and designed green and blue infrastructures not only deliver better urbanised areas but will also protect the ocean from pollution. Additionally, it helps to manage future risks of severe weather. </p>
<p>The <a href="https://www.sciencedirect.com/science/article/pii/S1462901117305282?via%3Dihub">uncertainties of green infrastructure capacity and costs of maintenance, combined with inflexible finance schemes</a>, are obstacles to integrated urban solutions. Furthermore, the lack of <a href="https://www.tandfonline.com/doi/full/10.1080/01426397.2017.1353069">inter- and transdisciplinary approaches</a> results in <a href="http://www.arj.no/2012/03/12/disciplinarities-2/">disciplinary barriers</a> in research and policymaking to long-term planning of the sort that generates urban green infrastructure and its desired outcomes.</p>
<p>On the bright side, there is also strong evidence to suggest sound policy can <a href="http://sciencedirect.com/science/article/pii/S1618866716305027?via%3Dihub">help overcome these barriers</a> through technical guides based on scientific research, standards and financial incentives. </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>
<p><a href="https://linkinghub.elsevier.com/retrieve/pii/S1877343514001110">Collaborative partnerships</a> are promising, too. Partnerships between academia and industry tend to be more powerful than streamlined industry project developments. </p>
<p>Finally, and very promisingly, <a href="https://www.sciencedirect.com/science/article/pii/S0013935117316778?via%3Dihub">Australia has its own successful green infrastructure examples</a>. <a href="https://www.melbourne.vic.gov.au/community/parks-open-spaces/urban-forest/Pages/urban-forest-strategy.aspx">Melbourne’s urban forest strategy</a> has been <a href="https://www.sciencedirect.com/science/article/pii/S0013935117316778?via%3Dihub">internationally acclaimed</a>. Examples like these provide valuable insights into local green infrastructure governance. </p>
<p>Cairns has stepped up with some stunning blue <a href="http://www.qldbeaches.com/cairns-esplanade.html">infrastructure on the Esplanade</a> which raises awareness of both locals and visitors about the protection of our oceans. </p>
<p>This is only the start. Together academics, local authorities, industry stakeholders and communities can lead the way to resilient cities and healthier oceans.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/249195/original/file-20181206-128208-ixjv4.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/249195/original/file-20181206-128208-ixjv4.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/249195/original/file-20181206-128208-ixjv4.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=266&fit=crop&dpr=1 600w, https://images.theconversation.com/files/249195/original/file-20181206-128208-ixjv4.PNG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=266&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/249195/original/file-20181206-128208-ixjv4.PNG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=266&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/249195/original/file-20181206-128208-ixjv4.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=335&fit=crop&dpr=1 754w, https://images.theconversation.com/files/249195/original/file-20181206-128208-ixjv4.PNG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=335&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/249195/original/file-20181206-128208-ixjv4.PNG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=335&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Cairns Esplanade Lagoon helps raise awareness of the need to protect the ocean as the city grows.</span>
<span class="attribution"><span class="source">Karine Dupré</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-green-is-our-infrastructure-helping-cities-assess-its-value-for-long-term-liveability-50528">How green is our infrastructure? Helping cities assess its value for long-term liveability</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/107263/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>Urbanisation is the main reason for rising temperatures and water pollution, but receives little attention in discussions about the health of water streams, reefs and oceans.Silvia Tavares, Lecturer in Urban Design, James Cook UniversityKarine Dupré, Associate Professor in Architecture, Griffith UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1028392018-10-22T19:57:11Z2018-10-22T19:57:11ZRequiem or renewal? This is how a tropical city like Darwin can regain its cool<figure><img src="https://images.theconversation.com/files/240705/original/file-20181015-165897-1sa3rgp.jpeg?ixlib=rb-1.1.0&rect=0%2C0%2C1274%2C879&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A vine shade structure being installed in Cavenagh Street will help cool the hottest street in Darwin city centre.</span> <span class="attribution"><span class="license">Author provided</span></span></figcaption></figure><p>On my way to work, I walk across the intersection of Knuckey and Wood streets. Most days a homeless man on his haunches is mouthing bureaucratic platitudes:</p>
<blockquote>
<p>Let’s workshop this? We need to have meeting about this! Can you give me the heads-up on this? Do we have numbers on this? Has a C/B been done?</p>
</blockquote>
<p>Is he an old bureaucrat? Or is he just a parable of planning – platitudes, words and little action? Wishes, words and workshops are not the currency of urban design; skilled drawings, urban history, science and continuous public dialogue are.</p>
<p>The concern in most Australian cities, and particularly in Darwin, should be with the public form of the city – with building frontage, with the streets, squares and parks, and with what is needed to make them safe, cool and enjoyable. Such street-form-based planning should replace “tidy town” zoning planning and code-based roads that ignore heat, landscape and the public. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/240716/original/file-20181016-165891-c4eubi.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/240716/original/file-20181016-165891-c4eubi.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/240716/original/file-20181016-165891-c4eubi.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/240716/original/file-20181016-165891-c4eubi.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/240716/original/file-20181016-165891-c4eubi.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/240716/original/file-20181016-165891-c4eubi.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/240716/original/file-20181016-165891-c4eubi.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">The vine shade structure will be equivalent to 24 trees but will shelter the street in months rather than taking years to grow.</span>
<span class="attribution"><span class="license">Author provided</span></span>
</figcaption>
</figure>
<p><a href="http://www.bom.gov.au/climate/dwo/201807/html/IDCJDW8014.201807.shtml">July 2018</a> in Darwin was <a href="http://www.bom.gov.au/climate/current/annual/aus/">2°C hotter than any previous July</a> and the <a href="https://www.news.com.au/national/northern-territory/darwin-records-hottest-august-on-record-according-to-weather-bureau/news-story/87a16f3ad1579b216465ec34b0f3656b">record heat</a> has <a href="http://www.bom.gov.au/climate/current/month/nt/archive/201809.summary.shtml">continued</a> in recent months. <a href="https://dcm.nt.gov.au/__data/assets/pdf_file/0005/488138/Population-Research-Report-Summary-final.pdf">Surveys show</a> that people are leaving Darwin because of the heat.</p>
<h2>What has gone wrong?</h2>
<p>In the city centre, every second shop is closed and dark. Shops, offices and apartments have a 50% vacancy rate. There is no appreciation of the urban history of the decline: the growth of outer urban shopping malls, the closing of Woolworths in Knuckey Street in 2010; the changing in 2012 of the key Smith Street Mall – removing trees, installing canopies and dark pavement, and thus increasing temperatures. </p>
<p>The decline has not happened overnight but has been accelerated by the completion of a <a href="http://www.abc.net.au/news/rural/2018-10-02/inpex-first-shipment-of-condensate-from-ichthys-field/10329774">vast LNG project</a>, by new shopping malls and chain stores, and by the impact of internet shopping. The Waterfront (mixed uses with a crocodile-safe “<a href="https://en.oxforddictionaries.com/definition/plage">plage</a>”) finished in 2013 is subsidised at a cost of millions every year. It is cut off from the city centre. </p>
<p>Traffic is reducing while more roads are being built. Darwin is over-roaded with roundabouts, pedestrian “seagull” median islands and refuges. </p>
<p>I have calculated that over 35% of the city centre is unshaded blacktop bitumen, which lifts ambient and surface temperatures. There is only 14% green canopy compared to <a href="https://www.cnn.com/travel/article/singapore-greenest-city/index.html">nearly 50%</a> in <a href="https://www.nparks.gov.sg/trees">tree-loving Singapore</a>.</p>
<p>Every day the temperature rises above 30°C. The city centre can be up to 6°C hotter. The bitumen surfaces reach temperatures of 66°C! </p>
<h2>What can be done about this?</h2>
<p>Professor Mat Santamouris of UNSW and the Northern Territory government has been studying heat in central Darwin for the past year using drones and 15 weather stations on light poles. Ambient heat, surface heat, humidity and wind have been mapped, eight heat islands (6°C above ambient) and four heat sinks (cool areas below ambient) have been identified for the northerly (The Wet) and southerly (The Dry) weather regimes.</p>
<p>A predictive computer model has been built to evaluate proposed strategies to reduce heat impacts. Santamouris has recommended across the city centre:</p>
<ul>
<li>fountains and pools (very effective up to 50m away)</li>
<li>white roofs, and green roofs and walls</li>
<li>coating streets, footpaths and surface parking to make “<a href="https://en.wikipedia.org/wiki/Cool_pavement">cool pavement</a>” (very effective)</li>
<li>increases in green canopy shade (effective in the right location).</li>
</ul>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/241190/original/file-20181018-41147-1gxwlkr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/241190/original/file-20181018-41147-1gxwlkr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/241190/original/file-20181018-41147-1gxwlkr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=430&fit=crop&dpr=1 600w, https://images.theconversation.com/files/241190/original/file-20181018-41147-1gxwlkr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=430&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/241190/original/file-20181018-41147-1gxwlkr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=430&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/241190/original/file-20181018-41147-1gxwlkr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=541&fit=crop&dpr=1 754w, https://images.theconversation.com/files/241190/original/file-20181018-41147-1gxwlkr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=541&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/241190/original/file-20181018-41147-1gxwlkr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=541&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">An extensive cooling vine-covered shade structure is being erected in Cavanagh Street.</span>
<span class="attribution"><span class="source">Glenn Campbell</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The government is using one block of Cavenagh Street as a heat mitigation trial. The 30m-wide street is the hottest street in the city centre. Due to lack of shading, surface temperatures in the afternoon exceed 60°C. The street also acts as a breezeway, “ducting” to the inner blocks hot, dry winds in the dry season and hot, humid winds in the wet season. </p>
<p>Black bitumen surface will be treated with more reflective cool pavement coatings and more trees will be planted. At the southern end a long cooling vine shade structure I have designed (with the structural engineer Max Irvine) is being constructed. Equivalent to 24 trees, it completely spans the roadway with a huge curved stringybark lattice prefabricated by the Gumatj in northeast Arnhem Land. </p>
<p>This large living shade structure has advantages over trees. It can be built in four months, does not interrupt underground services and resists cyclones. The vines will cover the roadway in 18 months. Trees take five years. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/240716/original/file-20181016-165891-c4eubi.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/240716/original/file-20181016-165891-c4eubi.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/240716/original/file-20181016-165891-c4eubi.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/240716/original/file-20181016-165891-c4eubi.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/240716/original/file-20181016-165891-c4eubi.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/240716/original/file-20181016-165891-c4eubi.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/240716/original/file-20181016-165891-c4eubi.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/240716/original/file-20181016-165891-c4eubi.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"></a>
<figcaption>
<span class="caption">The vine shade structure will be equivalent to 24 trees but will shelter the street in months rather than taking years to grow.</span>
<span class="attribution"><span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>But Cavenagh Street is only one of 30 blocks in Darwin. If the proposed mitigation strategies were fully implemented across the city centre, ambient temperature could be reduced by 2.7°C. This would not only make the city more comfortable for commerce but save lives and energy.</p>
<h2>Principles for a cool Darwin</h2>
<p>Like most cities, there is no overall urban management and coordination at the street level. Darwin’s centre is formed by the NT Planning Scheme. But within the scheme, public servants can play by their own rules: Planning, Transport, Roads, the Waterfront Authority, the City of Darwin (the council) and PowerWater. The result: Darwin streets are series of accidents. </p>
<p>I propose these administrations be replaced in the city centre by a Cool Darwin Authority (small with highly qualified people, and with a Larrakia elder), to develop and implement, with genuine public dialogue and discourse (not so-called “consultation”), an urban design plan.</p>
<p>The first principle of this plan should be reducing the ambient temperature by 2.7°C. Heat stops walkability and wandering past shops. </p>
<p>This could be accompanied by a second principle – a “toolbox” for cool street design. This would including limiting bitumen area. </p>
<p>A “toolbox” for shop regeneration would be among other important principles. This would involve limits on chain stores, disincentives for landlord keeping shops empty, incentives for filling them (even with temporary uses) and support for historic businesses. Shop closure is contagious. Where shops are empty and streets deserted yoEmpty shops and deserted areas lead to graffiti, sleeping rough and dilapidation.</p>
<p>Streets are central to urban cooling. There is over 300,000m<sup>2</sup> of black unshaded bitumen. Shading and street canopies (that do not trap heat) should be ubiquitous. </p>
<p>The urban order and scale from the 1869 <a href="https://dtc.nt.gov.au/arts-and-museums/northern-territory-archives-service/stories-from-the-archives/surveying-darwin-and-the-northern-territory">Goyder Plan</a> have been lost, as has the central square that would give an urban focus. Cities with closely spaced intersections seem to thrive more than cities with bigger grids. It seems the more corners the better; people bump into each other more often. There is “propinquity”.</p>
<p>Darwin has worked hard over many years closing its arcades and cross streets (Peel, McLachlan and Lindsay). The centre needs more effective interconnection: the high town (the mall/State Square) and low town (Waterfront) with a grand flight of stairs; the mall/State Square to Old Hospital Site/Myilly Point with a cooling lineal park, via a new (old) central square. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/240722/original/file-20181016-165903-1tdjxil.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/240722/original/file-20181016-165903-1tdjxil.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/240722/original/file-20181016-165903-1tdjxil.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=248&fit=crop&dpr=1 600w, https://images.theconversation.com/files/240722/original/file-20181016-165903-1tdjxil.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=248&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/240722/original/file-20181016-165903-1tdjxil.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=248&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/240722/original/file-20181016-165903-1tdjxil.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=312&fit=crop&dpr=1 754w, https://images.theconversation.com/files/240722/original/file-20181016-165903-1tdjxil.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=312&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/240722/original/file-20181016-165903-1tdjxil.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=312&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 view of proposed waterfront stairs providing a shaded link between the high town and the low town.</span>
<span class="attribution"><span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Streets are the music of the city. The buildings are the lyrics. Both should come together as a musical or an opera. The music can only begin if there is a network of shade, greenery, easy walking and buildings of all types interacting with the street.</p>
<p>Requiem or renewal? Darwin sees itself as a laid-back larrikin city with crocs and barra. Renewal and a new character can emerge by the implementation of principles. We cannot wish for a new character. </p>
<p>What might emerge? Perhaps a cool-in-both-senses city: a cosmopolitan tropical capital with tree canopy, vine shade structures and fountains. Perhaps a cool international waterfront city – an eight-hour voyage by fast ferry from Indonesia. Perhaps the full urban recognition of the Larrakia, the saltwater people, and their places: beaches, fish traps, middens, yarning circles, meeting places and cultural centres.</p><img src="https://counter.theconversation.com/content/102839/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Lawrence Nield was affiliated with Northern Territory Government as the Government Architect from 2013 to May 2018. He did not renew his contract in 2018. He was responsible for developing the NTG approach to heat mitigation in Darwin. He worked in the Chief Minister's Department. He is a Life Fellow of the Australian Institute of Architects</span></em></p>Darwin’s climate is getting even hotter and it’s one of the main reasons people leave the city. A lot more can be done, though, to make our tropical cities safe, cool and enjoyable.Lawrence Nield, Professor of Practice, School of Architecture and Built Environment, University of NewcastleLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/970692018-06-05T20:07:31Z2018-06-05T20:07:31ZMaking a global agenda work locally for healthy, sustainable living in tropical Australia<figure><img src="https://images.theconversation.com/files/220969/original/file-20180530-120484-2gngra.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Planning and design for healthy, liveable communities in the Australian tropics can involve quite different considerations from those that apply down south.</span> <span class="attribution"><span class="source">Silvia Tavares</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Life in the tropics is often seen as “living in paradise”, a place where everything grows and flourishes. This picture-postcard environment is not the year-round reality. At certain times of year, intense heat, humidity and the wet season affect liveability, making outdoor activity unattractive and thereby reducing social cohesion.</p>
<p>Urban living can already be pretty insular these days. People move from temperature-controlled houses to temperature-controlled cars to temperature-controlled offices, and vice versa. There’s no need to talk to anyone really. And exercise? It’s something you try to fit in if you can – but you probably don’t.</p>
<p>An ideal city life might be one in which you walk or cycle to work easily, say hi to a neighbour, and pick up some fresh produce for lunch along the way. While it is nice to expect that people will do this for a healthier self and planet, the truth is that <a href="https://www.strongtowns.org/journal/2017/2/10/jeff-speck-4-ways-to-make-a-city-more-walkable">daily life choices depend on convenience</a>. </p>
<p>Furthermore, the <a href="https://theconversation.com/designing-the-compassionate-city-to-overcome-built-in-biases-and-help-us-live-better-92726">planning and design (or haphazard evolution) of urban spaces largely dictate the way we live</a>. This in turn <a href="https://www.thefifthestate.com.au/columns/news-from-the-front-desk/on-why-cars-should-come-with-a-health-warning-and-maybe-our-cities-should-too/99077?mc_cid=3505518555&mc_eid=64a8a9dd84">affects our health in many ways</a>. It can, for instance, encourage or discourage active lifestyles, social cohesion and access to healthy food choices.</p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/designing-the-compassionate-city-to-overcome-built-in-biases-and-help-us-live-better-92726">Designing the compassionate city to overcome built-in biases and help us live better</a>
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<p>This is where the New Urban Agenda comes into play. </p>
<h2>The New Urban Agenda and why it matters</h2>
<p>The <a href="http://habitat3.org/wp-content/uploads/NUA-English.pdf">New Urban Agenda</a>, drafted by UN-Habitat and endorsed in late 2016 by the United Nations General Assembly, aims to help everyone to benefit from urbanisation. </p>
<p>Through <a href="https://www.un.org/sustainabledevelopment/cities/">Sustainable Development Goal (SDG) 11 (Sustainable cities and communities)</a>, the agenda provides a guide for developing safe, inclusive, resilient and sustainable new cities that promote social integration and equity. It can also provide the impetus for conversations about the growth, redesign and redevelopment of existing urban spaces.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/what-can-the-new-urban-agenda-and-sustainable-development-goals-do-for-cities-75533">What can the New Urban Agenda and Sustainable Development Goals do for cities?</a>
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<hr>
<p>Making the New Urban Agenda work locally depends on more than overall regulations, or “importing” southern Australian solutions to the tropics. Even within the Australian tropical region, the <a href="http://koeppen-geiger.vu-wien.ac.at/">climate varies</a>. Cairns experiences a tropical monsoon climate (wet tropics), while Townsville is exposed to a tropical savannah climate (dry tropics). </p>
<p>The way public spaces should be designed must, therefore, also vary within the tropical climate zone. We need to listen to locals, understand their behaviour and preferences, then promote these preferred public space qualities through urban planning and design. </p>
<p>Good design can improve the choices we make. But what is good design? And how do we adapt general guidelines to specific places and cultures?</p>
<h2>Urban diaries to understand each city</h2>
<p><a href="https://islandpress.org/book/seeing-the-better-city">Urban diaries</a> are premised on the importance of local history, values and knowledge. This approach aims to “<a href="https://islandpress.org/book/urbanism-without-effort">distinguish underlying organic relationships between people and cities from indiscriminate prescription imposed upon place</a>”. Urban diaries are a powerful tool for personal observation, raising awareness and creating positive urban change. </p>
<p>In our investigation, participants are invited to shoot and caption photographs of their surroundings, noting what makes their lives healthier, happier and stronger, and what does not. These images will be shared through social media and used to capture ideas and start conversations. </p>
<p>These urban diaries will help clarify how Cairns and Townsville function as tropical cities. At the same time this approach will help bring to light ways of improving local lifestyles by implementing the New Urban Agenda principles in this local context.</p>
<h2>Place-based urban planning and design</h2>
<p>Climate-responsive planning and design are important to make sure people can incorporate incidental exercise into their everyday routine. People will use public spaces if these are designed in a way that mediates the negative impacts of tropical climates.</p>
<p>What type of spaces and features will encourage people to walk even if the temperature outside is 40°C? We are particularly interested in three overarching questions. These concern how existing urban infrastructure and amenities promote or restrict:</p>
<ol>
<li>active lifestyles </li>
<li>social inclusion </li>
<li>healthy eating. </li>
</ol>
<p>These questions will be explored through public participation in the upcoming UN-Habitat World Urban Campaign <a href="http://www.worldurbancampaign.org/events/urban-livability-tropical-australia-through-urban-diaries-and-community-engagement">Urban Thinkers Campus events</a> in Cairns on June 8 and Townsville on June 15. Drawing on urban diaries, these events will provide the fundamental basis for understanding these places through a local lens.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/this-is-why-health-has-to-be-at-the-heart-of-the-new-urban-agenda-91009">This is why health has to be at the heart of the New Urban Agenda</a>
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<img src="https://counter.theconversation.com/content/97069/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>There’s no such thing as a one-size-fits-all plan for sustainable, healthy urban living. Urban diaries help identify what works – and doesn’t work – for tropical cities like Cairns or Townsville.Silvia Tavares, Lecturer in Urban Design, James Cook UniversityDavid Sellars, Senior Lecturer – Environmental Health, James Cook UniversityLicensed as Creative Commons – attribution, no derivatives.