tag:theconversation.com,2011:/us/topics/tipping-points-11353/articlesTipping points – The Conversation2024-02-05T19:11:18Ztag:theconversation.com,2011:article/2227372024-02-05T19:11:18Z2024-02-05T19:11:18ZDangerous climate tipping points will affect Australia. The risks are real and cannot be ignored<p>In 2023, we saw a raft of news stories about climate tipping points, including the <a href="https://www.bbc.com/news/science-environment-65317469">accelerating loss</a> of <a href="https://theconversation.com/what-will-happen-to-the-greenland-ice-sheet-if-we-miss-our-global-warming-targets-215928">Greenland</a> and <a href="https://theconversation.com/antarctic-tipping-points-the-irreversible-changes-to-come-if-we-fail-to-keep-warming-below-2-207410">Antarctic</a> ice sheets, the <a href="https://www.theguardian.com/environment/2023/oct/04/south-american-monsoon-heading-towards-tipping-point-likely-to-cause-amazon-dieback">potential dieback</a> of the Amazon rainforest and the <a href="https://theconversation.com/the-atlantic-oceans-major-current-system-is-slowing-down-but-a-21st-century-collapse-is-unlikely-214647">likely weakening</a> of the Atlantic Meridional Ocean Circulation.</p>
<p>The ice sheets, Amazon rainforest and the Atlantic <a href="https://www.nature.com/articles/s41467-023-39810-w">ocean circulation</a> are among nine recognised <a href="https://www.science.org/doi/10.1126/science.abn7950">global climate tipping elements</a>. Once a tipping point is crossed, changes are often irreversible for a very long time. In many cases, additional greenhouse gases will be released into the atmosphere, further warming our planet.</p>
<p>New <a href="https://www.science.org/doi/10.1126/science.abn7950">scientific research and reviews</a> suggest at least one of Earth’s “tipping points” could be <a href="https://theconversation.com/climate-tipping-points-are-nearer-than-you-think-our-new-report-warns-of-catastrophic-risk-219243">closer than we hoped</a>. A <a href="https://global-tipping-points.org/">milestone review</a> of global tipping points was launched at last year’s COP28.</p>
<p>What will these tipping points mean for Australia? We don’t yet have a good enough understanding to fully answer this question. </p>
<p><a href="https://www.csiro.au/-/media/Environment/CSIRO_Tipping-Points-Report.pdf">Our report</a>, released overnight, includes conclusions in three categories: we need to do more research; tipping points must be part of climate projections, hazard and impact analyses; and adaptation plans must take the potential impacts into account.</p>
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Read more:
<a href="https://theconversation.com/climate-tipping-points-are-nearer-than-you-think-our-new-report-warns-of-catastrophic-risk-219243">Climate tipping points are nearer than you think – our new report warns of catastrophic risk</a>
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<h2>What are climate tipping points?</h2>
<p>Climate scientists have <a href="https://theconversation.com/what-climate-tipping-points-should-we-be-looking-out-for-27108">known for a while</a>, through paleoclimate records and other evidence, that there are “tipping elements” in the climate system. These elements can undergo an abrupt change in state, which becomes self-perpetuating and irreversible for a very long time.</p>
<p>An example is the loss of Greenland ice. Once ice is lost, climate feedbacks lead to further loss, and major ice loss becomes “committed”. It becomes unlikely the ice sheet will reform for tens of thousands of years and only if the climate cools again. </p>
<p>Triggering climate tipping points would lead to changes in addition to those commonly included in <a href="https://www.climatechangeinaustralia.gov.au/en/">climate projections</a>. These changes include a significant rise in sea level at double the rate (or even more) of usual projections, as well as extra warming, altered weather systems, climate variability and extremes. </p>
<p>Triggering one tipping point may trigger other tipping points. If that happens, the cascading impacts would push many systems outside their adaptive capacity.</p>
<p>Cutting fossil greenhouse gas emissions is the most important thing we can do to limit warming and the risk of triggering tipping points. The faster we reduce emissions, the better our chances.</p>
<p>But as the planet continues to warm, we must consider the consequences of triggering some, or several, tipping points for Australia and the resulting risks for society. We need to have the right tools for adaptation planning to consider these risks.</p>
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<img alt="Seawater floods a coastal property in Brisbane" src="https://images.theconversation.com/files/572956/original/file-20240202-21-jltl0y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/572956/original/file-20240202-21-jltl0y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/572956/original/file-20240202-21-jltl0y.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/572956/original/file-20240202-21-jltl0y.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/572956/original/file-20240202-21-jltl0y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/572956/original/file-20240202-21-jltl0y.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/572956/original/file-20240202-21-jltl0y.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">
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<span class="caption">Adaptation planning must consider the potential impacts of tipping points, such as higher rises in sea level.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/sea-washing-over-wall-flooding-street-169034384">Silken Photography/Shutterstock</a></span>
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Read more:
<a href="https://theconversation.com/antarctic-tipping-points-the-irreversible-changes-to-come-if-we-fail-to-keep-warming-below-2-207410">Antarctic tipping points: the irreversible changes to come if we fail to keep warming below 2℃</a>
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<h2>Grappling with deep uncertainties</h2>
<p>There’s a major gap in the research literature around the implications of tipping points for the southern hemisphere and Australia. Researchers from Australian science agencies and universities came together last year to consider what global climate tipping points could mean for Australia. </p>
<p>We launched <a href="https://www.csiro.au/-/media/Environment/CSIRO_Tipping-Points-Report.pdf">our report</a> last night at the national conference of the <a href="https://www.amos.org.au/">Australian Meteorological & Oceanographic Society</a>. We identified several priority areas for the research community, risk analysts and policymakers.</p>
<p>We considered the nine global climate tipping points – and one of the most relevant regional tipping points for Australia, coral reef die-offs – as defined in a recent <a href="https://www.science.org/doi/10.1126/science.abn7950">scientific review</a>.</p>
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<img alt="" src="https://images.theconversation.com/files/572736/original/file-20240201-25-1bc4jc.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/572736/original/file-20240201-25-1bc4jc.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=368&fit=crop&dpr=1 600w, https://images.theconversation.com/files/572736/original/file-20240201-25-1bc4jc.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=368&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/572736/original/file-20240201-25-1bc4jc.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=368&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/572736/original/file-20240201-25-1bc4jc.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=462&fit=crop&dpr=1 754w, https://images.theconversation.com/files/572736/original/file-20240201-25-1bc4jc.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=462&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/572736/original/file-20240201-25-1bc4jc.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=462&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">The nine global climate tipping points and the one most relevant regional tipping point of seven listed in Armstrong-McKay et al review (2022), and their assessed ranges of global warming where the tipping may be triggered (some other evidence or studies may differ from these ranges).</span>
<span class="attribution"><a class="source" href="https://www.science.org/doi/10.1126/science.abn7950">Adapted from: Armstrong-McKay et al. 2022</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
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Read more:
<a href="https://theconversation.com/what-will-happen-to-the-greenland-ice-sheet-if-we-miss-our-global-warming-targets-215928">What will happen to the Greenland ice sheet if we miss our global warming targets</a>
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<p>For almost all tipping points, we don’t understand all the relevant processes. There are deep uncertainties about what conditions would trigger tipping points, how they would play out and their likely impacts. </p>
<p>Along with recognising the most urgent point – that deep emission cuts will limit the chances of triggering tipping points – our conclusions cover three areas.</p>
<p><strong>1. We need more research</strong></p>
<p>We need to expand research on paleoclimate records, theory and process understanding, observations, monitoring and modelling. Australia leads world-class research, including on Antarctica, the Southern Ocean, the carbon cycle, weather processes and ecosystems. It is essential we support and expand the work, bringing a southern hemisphere perspective to global efforts.</p>
<p><strong>2. Climate projections, hazard and impact analyses must include tipping points</strong> </p>
<p>Triggering some climate tipping points would have direct impacts on our coasts, ecosystems and society. In an interconnected world, other tipping points would have major indirect impacts – through climate migration, conflict, disrupted trade and more. </p>
<p>We need credible projections of what the climate looks like if tipping points are triggered. Our climate impact and risk analyses should illustrate what it really means for us. Given the limited state of knowledge, the <a href="https://link.springer.com/article/10.1007/s10584-018-2317-9">“storyline” approach</a> – linking past, current and future unfolding of events in a narrative or pathway framework – is particularly useful, informed by all the available evidence.</p>
<p><strong>3. We need to consider what it means for adaptation</strong></p>
<p>We can consider where, when and how we can act to reduce potential impacts if tipping points are triggered. Appropriate risk management accounts for likelihood, consequence and timeframe. </p>
<p>For example, planning for major coastal infrastructure with a long lifetime and low tolerance for failure could draw on the sea-level projections of “low likelihood, high impact” storylines that include the west Antarctic ice sheet collapsing. This would safeguard critical infrastructure against one worst-case risk. Of course, there is much more to adaptation than this. </p>
<p>We still have much to learn, but we cannot wait for perfect knowledge before we start planning. It’s clear the risks are real and cannot be ignored. </p>
<p>We need to focus on what we can do to avoid triggering tipping points, manage risk and build our climate resilience. There are also <a href="https://global-tipping-points.org/section4/4-0-positive-tipping-points-in-technology-economy-and-society/">positive tipping points</a> in technology, economy and society that are part of the solution. If we get it right, positive change can happen more rapidly than we might think.</p>
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Read more:
<a href="https://theconversation.com/climate-tipping-points-can-be-positive-too-our-report-sets-out-how-to-engineer-a-domino-effect-of-rapid-changes-219291">Climate 'tipping points' can be positive too – our report sets out how to engineer a domino effect of rapid changes</a>
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<img src="https://counter.theconversation.com/content/222737/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Michael Grose receives funding from the National Environmental Science Program and the Australian Climate Service.</span></em></p><p class="fine-print"><em><span>Andy Pitman receives funding from the Australian Research Council.</span></em></p>We don’t yet fully understand what global climate tipping points mean for Australia. But we know enough to conclude the impacts of passing one or more tipping points must now be considered.Michael Grose, Climate Projections Scientist, CSIROAndy Pitman, Director of the ARC Centre of Excellence for Climate Extremes, UNSW SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2203462023-12-29T18:38:10Z2023-12-29T18:38:10ZFour good news climate stories from 2023<p>We don’t want to give you the wrong idea: things are bad. Antarctic ice sheets are melting, the fossil fuel lobby was everywhere <a href="https://theconversation.com/how-fossil-fuel-companies-won-cop28-211212">at the COP talks</a>, and even solutions like electric cars have their problems. And that just covers the past few weeks of this newsletter.</p>
<p>But to end 2023 we’d like to focus on a few of the more optimistic stories we have run over the past year. </p>
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<img alt="Imagine weekly climate newsletter" src="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p><em><strong>This roundup of The Conversation’s 2023 climate coverage comes from our <a href="https://theconversation.com/uk/newsletters/imagine-57?utm_source=TCUK&utm_medium=linkback&utm_campaign=Imagine&utm_content=DontHaveTimeTop">weekly climate action newsletter</a>.</strong> Every Wednesday, The Conversation’s environment editor writes Imagine, a short email that goes a little deeper into just one climate issue. <a href="https://theconversation.com/uk/newsletters/imagine-57?utm_source=TCUK&utm_medium=linkback&utm_campaign=Imagine&utm_content=DontHaveTimeBottom">Join the 30,000+ readers who’ve subscribed.</a></em></p>
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<h2>1. We have skyscraper-sized wind turbines now</h2>
<p>Back in January, we asked Simon Hogg, executive director of Durham Energy Institute, about huge new wind turbines <strong><a href="https://theconversation.com/wind-turbines-are-already-skyscraper-sized-is-there-any-limit-to-how-big-they-will-get-196131">being built in the North Sea</a></strong>. </p>
<p>These turbines, he wrote, “stand more than a quarter of a kilometre high from the surface of the sea to the highest point of the blade tip”.</p>
<p>“If you placed one in London, it would be the third-tallest structure in the city, taller than One Canada Square in Canary Wharf and just 50 metres shorter than the Shard. Each of its three blades would be longer than Big Ben’s clock tower is tall.”</p>
<p>The sheer size has some benefits: “A bigger blade extracts energy from the wind over a greater area as it rotates, which generates more electricity.” Each rotation can power an average home for two days. </p>
<p>In theory, Hogg notes, turbines could keep getting bigger and bigger. They will soon run into some practical problems though, as huge blades are harder to maintain and we are running out of ports and ships big enough for them. </p>
<p>Nonetheless, ever bigger wind turbines have been a key reason why Britain has managed to shift much of its electricity generation from <a href="https://theconversation.com/britain-likely-to-generate-more-electricity-from-wind-solar-and-hydro-than-fossil-fuels-for-the-first-year-ever-in-2023-219936">fossil fuels to renewables</a> over the past decade.</p>
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Read more:
<a href="https://theconversation.com/wind-turbines-are-already-skyscraper-sized-is-there-any-limit-to-how-big-they-will-get-196131">Wind turbines are already skyscraper-sized – is there any limit to how big they will get?</a>
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<h2>2. Solar power keeps getting cheaper and more adaptable</h2>
<p>Britain is, of course, more windy than sunny. But in much of the world, solar power is the real game changer. </p>
<p>Yet one issue with solar is that we may run out of material needed to produce silicon cells – the main sort of solar panels you see in solar farms or on rooftops. Therefore many academics are looking for alternatives. </p>
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<a href="https://images.theconversation.com/files/567495/original/file-20231229-19-87ep5g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Aerial view of large solar farm" src="https://images.theconversation.com/files/567495/original/file-20231229-19-87ep5g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/567495/original/file-20231229-19-87ep5g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=121&fit=crop&dpr=1 600w, https://images.theconversation.com/files/567495/original/file-20231229-19-87ep5g.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=121&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/567495/original/file-20231229-19-87ep5g.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=121&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/567495/original/file-20231229-19-87ep5g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=153&fit=crop&dpr=1 754w, https://images.theconversation.com/files/567495/original/file-20231229-19-87ep5g.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=153&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/567495/original/file-20231229-19-87ep5g.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=153&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">Solar fills the horizon in Broken Hill, Australia.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/industrial-solar-panel-farm-power-plant-2100988024">Taras Vyshnya / shutterstock</a></span>
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<p>One of these academics is David Benyon of Swansea University. In March he wrote about his new research, which involved developing “the world’s first rollable and fully printable <strong><a href="https://theconversation.com/perovskite-new-type-of-solar-technology-paves-the-way-for-abundant-cheap-and-printable-cells-202579">solar cell made from perovskite</a></strong>, a material that is much less expensive to produce than silicon.” The technology is still in its early stages and needs to become more efficient but, he writes, “this points to the possibility of making cheaper solar cells on a much greater scale than ever before”.</p>
<p>Perhaps perovskite will become the new silicon, or maybe some other technology will dominate in future, but what’s clear is that solar power is fast becoming even cheaper and more accessible. The challenge for perovskite researchers, Benyon says, is to focus on “converting what’s happening in the labs into real-world devices”. </p>
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Read more:
<a href="https://theconversation.com/perovskite-new-type-of-solar-technology-paves-the-way-for-abundant-cheap-and-printable-cells-202579">Perovskite: new type of solar technology paves the way for abundant, cheap and printable cells</a>
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<h2>3. On the menu: mammoth meatball</h2>
<p>Scientists recently created a meatball made of the flesh of extinct woolly mammoth. This in itself isn’t the good news: no one is proposing we fix climate change with prehistoric food. </p>
<p>But it’s proof that cellular agriculture, sometimes called “lab-grown meat”, can work. As Silvia Malagoli at Strathclyde University writes: “Lab-grown meat has the potential to offer a <strong><a href="https://theconversation.com/italy-is-set-to-ban-lab-grown-meat-heres-why-it-should-think-again-203251">much more sustainable food</a></strong> source than traditional animal farming that could also help reduce the spread of disease.”</p>
<p>This could unlock huge amounts of land for rewilding or recreation. “If scaled up, lab-grown meat would use substantially less land and water. Research finds that around 99% less land is required to produce 1kg of lab-grown meat than would have to be used by European farms to produce the same amount.”</p>
<p>Malagoli also points out that lab-grown meat wouldn’t require the same volume of antibiotics that animal farmers use to prevent the spread of disease: “Their overuse is contributing to a rise of antibiotic resistance. The United Nations estimates that, by 2050, antibiotic resistance will lead to more deaths than cancer worldwide.”</p>
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Read more:
<a href="https://theconversation.com/italy-is-set-to-ban-lab-grown-meat-heres-why-it-should-think-again-203251">Italy is set to ban lab-grown meat – here’s why it should think again</a>
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<h2>4. Climate change tipping points can be a good thing too</h2>
<p>You’ve probably heard about the doomsday scenario of a part of the climate system – an ice sheet, perhaps, or a rainforest – suddenly passing a “tipping point” beyond which it is impossible to stop it changing into something else (perhaps barren rock or dried out savanna, respectively). The Conversation has covered these scenarios extensively over the years, most recently in a piece by authors of the major new <a href="https://theconversation.com/climate-tipping-points-are-nearer-than-you-think-our-new-report-warns-of-catastrophic-risk-219243">tipping points report</a>. </p>
<p>But that same report also contained some positives. Climate-related technologies or social and political behaviour can also pass similar tipping points, beyond which something better becomes inevitable. Steven Smith at the University of Sussex and his colleagues wrote about these sorts of <a href="https://theconversation.com/climate-tipping-points-can-be-positive-too-our-report-sets-out-how-to-engineer-a-domino-effect-of-rapid-changes-219291">“positive” tipping points</a> which they say are “already happening, in areas ranging from renewable energy and electric vehicles, to social movements and plant-based diets”.</p>
<p>Their report sets out “ways to intervene in these systems to enable positive tipping points to be triggered – for example by making the desired change the cheapest, most convenient or morally acceptable option”.</p>
<p>They say that passing one tipping point can even set off a domino effect:</p>
<p>“For example, as we cross the tipping point that sees electric vehicles become the dominant form of road transport, battery technology will continue to get better and cheaper.</p>
<p>"This could trigger another positive tipping point in the use of batteries for storing renewable energy, reinforcing another in the use of heat pumps in our homes, and so on. And there are what we call ‘super-leverage points’ – places where we can deliberately intervene with information campaigns, mandates and incentives to create widespread change across sectors.”</p>
<p>Good news then for anyone who feels like we’ve been getting nowhere with climate action despite decades of effort. Things might suddenly look very different once past a certain point. As the saying almost goes, mammoth burgers are impossible until they are inevitable.</p>
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Read more:
<a href="https://theconversation.com/climate-tipping-points-can-be-positive-too-our-report-sets-out-how-to-engineer-a-domino-effect-of-rapid-changes-219291">Climate 'tipping points' can be positive too – our report sets out how to engineer a domino effect of rapid changes</a>
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<img src="https://counter.theconversation.com/content/220346/count.gif" alt="The Conversation" width="1" height="1" />
Including a positive way to think about tipping points.Will de Freitas, Environment + Energy Editor, UK editionLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2192912023-12-07T17:28:16Z2023-12-07T17:28:16ZClimate ‘tipping points’ can be positive too – our report sets out how to engineer a domino effect of rapid changes<figure><img src="https://images.theconversation.com/files/564330/original/file-20231207-17-i186rg.jpg?ixlib=rb-1.1.0&rect=16%2C679%2C4931%2C2957&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/business-man-kick-first-domino-piece-1160821330">fran_kie / shutterstock</a></span></figcaption></figure><p>A young boy is forced to sit at a dinner table with grown-ups talking endlessly about grown-up stuff. He’s bored. He finds it hard at first, to push with his feet against the table frame, tip his chair onto its back legs, and straighten his legs. But towards the pivot point it becomes an almost effortless, floating experience, requiring only the slightest toe poke, now and then.</p>
<p>And then … disaster. One toe poke too many is all it takes to pass the point of no return and the boy crash lands on his back.</p>
<p>The boy had gone past the “tipping point” after which change became inevitable. And on a much larger scale, this same process can see glaciers suddenly disappear or rainforests dry up.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/564263/original/file-20231207-19-d7th5j.gif?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="man falls backwards off chair" src="https://images.theconversation.com/files/564263/original/file-20231207-19-d7th5j.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/564263/original/file-20231207-19-d7th5j.gif?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/564263/original/file-20231207-19-d7th5j.gif?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/564263/original/file-20231207-19-d7th5j.gif?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/564263/original/file-20231207-19-d7th5j.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/564263/original/file-20231207-19-d7th5j.gif?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/564263/original/file-20231207-19-d7th5j.gif?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Once past the tipping point, change becomes inevitable.</span>
<span class="attribution"><a class="source" href="https://tenor.com/view/fall-off-chair-falling-lean-back-slow-mo-fail-gif-12696663">MattBigFat / Tenor</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
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<p>We are part of an international team of over 200 authors to have contributed to the new <a href="https://global-tipping-points.org/">Global Tipping Points Report</a> launched at the COP 28 climate change talks in Dubai.</p>
<p>At least five tipping points in the Earth system require only a slight toe poke to be triggered – including the collapse of major ice sheets, and coral reefs, and an abrupt shift in North Atlantic ocean circulation. These <a href="https://theconversation.com/climate-tipping-points-are-nearer-than-you-think-our-new-report-warns-of-catastrophic-risk-219243">“negative” tipping points</a> are now so close that urgent action needs to be taken to prevent them.</p>
<p>Fortunately, tipping points with good outcomes – “positive” tipping points – are also possible in human technology, economics, politics and social behaviour. In fact, they’re already happening, in areas ranging from renewable energy and electric vehicles, to social movements and plant-based diets. Our report sets out ways to intervene in these systems to enable positive tipping points to be triggered – for example by making the desired change the cheapest, most convenient or morally acceptable option. </p>
<p>Multiple systems can even tip in a domino effect of cascading beneficial change. For example, as we cross the tipping point that sees electric vehicles become the dominant form of road transport, battery technology will continue to get better and cheaper.</p>
<p>This could trigger another positive tipping point in the use of batteries for storing renewable energy, reinforcing another in the use of heat pumps in our homes, and so on. And there are what we call “super-leverage points” – places where we can deliberately intervene with information campaigns, mandates and incentives to create widespread change across sectors.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/564298/original/file-20231207-25-klvg87.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Two workers in an electric car battery factory" src="https://images.theconversation.com/files/564298/original/file-20231207-25-klvg87.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/564298/original/file-20231207-25-klvg87.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/564298/original/file-20231207-25-klvg87.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/564298/original/file-20231207-25-klvg87.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/564298/original/file-20231207-25-klvg87.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/564298/original/file-20231207-25-klvg87.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/564298/original/file-20231207-25-klvg87.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Improvements in electric car batteries can in turn make it easier to heat your home sustainably.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/inside-electric-vehicle-battery-pack-shop-2112208565">NamLong Nguyen / shutterstock</a></span>
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<p>These actions might sound rather effortless, a final little toe poke that nudges a system past its point of no return and accelerates it towards a new (in this case desired) state. “Just” make the desired technology the cheaper option; bring in a new regulation or mandate; invest in new infrastructure; create new institutions; change habits or social norms; and wait for the system to tip. </p>
<p>But, returning to the image of our young boy, this overlooks all the demanding legwork, especially at the beginning, that it takes to get to that final, pivotal threshold. Any typical example of transformative change that one cares to point to – whether it’s Denmark’s transition to wind power, Columbia’s signature on the Fossil Fuel Non-Proliferation Treaty, or Ecuador’s vote to ban oil drilling in the Amazon – involves a much longer backstory of political struggle. </p>
<p>Curiously, in the case of Norway’s pioneering transition to electric vehicles (EVs) – over 80% of new car sales in Norway are now fully electric – it also involves the pop band a-ha, best known internationally for their 1985 hit Take On Me, appropriately enough for what followed.</p>
<h2>The a-ha moment</h2>
<p>Back in the late 1980s a-ha’s lead singer Morten Harket and keyboardist “Mags” Furuholmen teamed up with a professor of architecture, Harald Røstvik, and environmentalist Frederic Hauge, and together they began <a href="https://www.theguardian.com/environment/2020/apr/19/norway-and-the-a-ha-moment-that-made-electric-cars-the-answer">sowing the seeds of a Norwegian transport revolution</a>. Beginning with a campaign to get the public on their side, the group travelled to Switzerland to take part in the solar EV race, the Tour de Sol, with the Norwegian press in tow. They also test-drove a converted electric Fiat Panda: range, 46 kilometres. </p>
<p>Suitably impressed, they set about importing a similar specimen into Norway. They exploited every photo opportunity, and campaigned to make EVs the cheapest, most convenient option by abolishing importation, registration and company car taxes for EVs, exempting EVs from VAT and road tolls, and giving them free access to bus lanes and ferries. </p>
<p>For many years the Norwegian government remained unmoved by a-ha’s demands. In response, a-ha refused to pay the tolls and parking fines. Eventually the car was impounded and auctioned off, to the delight of the national press, who took front row seats. Someone sympathetic to the cause made the winning bid and promptly handed the car back to the pop group. </p>
<p>This cycle was repeated, over and over, until in 1997 EVs were exempted from road tolls in Norway. By 2009, all the campaigners’ demands had been met and the government began investing heavily in public EV charging infrastructure. All the enabling conditions for a positive tipping point had been met and from 2011 Norway’s EV car market started to <a href="https://theconversation.com/how-to-spread-norways-success-with-electric-cars-21452">grow very rapidly</a>.</p>
<p>To limit global heating to as near to +1.5°C as possible we need rapid, exponential change. The whole world needs to replicate Norway’s rapid tipping of the EV market across all sectors and domains of society. The Global Tipping Points Report offers a blueprint for how to achieve a more sustainable future.</p>
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<img alt="Imagine weekly climate newsletter" src="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p><strong><em>Don’t have time to read about climate change as much as you’d like?</em></strong>
<br><em><a href="https://theconversation.com/uk/newsletters/imagine-57?utm_source=TCUK&utm_medium=linkback&utm_campaign=Imagine&utm_content=DontHaveTimeTop">Get a weekly roundup in your inbox instead.</a> Every Wednesday, The Conversation’s environment editor writes Imagine, a short email that goes a little deeper into just one climate issue. <a href="https://theconversation.com/uk/newsletters/imagine-57?utm_source=TCUK&utm_medium=linkback&utm_campaign=Imagine&utm_content=DontHaveTimeBottom">Join the 20,000+ readers who’ve subscribed so far.</a></em></p>
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<p class="fine-print"><em><span>Steven R. Smith is also Tipping Points Research Impact Fellow at the Global Systems Institute, University of Exeter. </span></em></p><p class="fine-print"><em><span>Caroline Zimm receives funding from the Earth Commission.</span></em></p><p class="fine-print"><em><span>Tim Lenton does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>One positive change can lead to another.Steven R. Smith, Visiting Research Fellow, Centre for the Understanding of Sustainable Prosperity (CUSP), University of SurreyCaroline Zimm, Research Scholar, Transition to New Technologies, International Institute for Applied Systems Analysis (IIASA)Tim Lenton, Director, Global Systems Institute, University of ExeterLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2192432023-12-06T16:43:11Z2023-12-06T16:43:11ZClimate tipping points are nearer than you think – our new report warns of catastrophic risk<figure><img src="https://images.theconversation.com/files/563946/original/file-20231206-23-j8coxl.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C3866%2C2585&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/glacier-collapse-perito-moreno-argentina-2127502928">lugazzotti / shutterstock</a></span></figcaption></figure><p>It’s now almost inevitable that 2023 will be the <a href="https://climate.copernicus.eu/copernicus-november-2023-remarkable-year-continues-warmest-boreal-autumn-2023-will-be-warmest-year">warmest year ever recorded by humans</a>, probably the warmest for at least 125,000 years. </p>
<p><a href="https://theconversation.com/what-el-nino-means-for-the-worlds-perilous-climate-tipping-points-209083">Multiple temperature records were smashed</a> with global average temperatures for some periods well above 1.5°C. Antarctic sea ice loss is accelerating at frightening rates along with many other indicators of rapid climate change. Does this mean 2023 is the year parts of the climate tip into a much more dangerous state?</p>
<p>Most people expect that if a system, like someone’s body, an ecosystem, or part of the climate system, becomes stressed, it’ll respond fairly predictably – double the pressure, double the impact, and so on. This holds in many cases, but is not always true. Sometimes a system under stress changes steadily (or “linearly”) up to a point, but beyond that far bigger or abrupt changes can be locked in.</p>
<p>An example of such “nonlinear” changes are “tipping points”, which happen when a system is pushed past a threshold beyond which <a href="https://theconversation.com/climate-tipping-points-could-lock-in-unstoppable-changes-to-the-planet-how-close-are-they-191043">change becomes self-sustaining</a>. This means that even if the original pressure eased off the change would keep on going until the system reaches a sometimes completely different state. </p>
<p>Think of rolling a boulder up a hill. This takes a lot of energy. If that energy input is stopped then the ball will roll back down. But when the top of the hill is reached and the boulder is balanced right at the very top, a tiny push, perhaps even a gust of wind, can be enough to send it rolling down the other side. </p>
<p>The climate system has many potential tipping points, such as ice sheets disappearing or dense rainforests becoming significantly drier and more open. It would be very difficult, effectively impossible, to recover these systems once they go beyond a tipping point. </p>
<p>We along with 200 other scientists from around the world just published the new <a href="https://global-tipping-points.org/">Global Tipping Points Report</a> at the COP28 UN climate talks in Dubai. Our report sets out the science on the “negative” tipping points in the Earth system that could harm both nature and people, as well as the potential “positive” societal tipping points that could accelerate sustainability action. </p>
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Read more:
<a href="https://theconversation.com/climate-tipping-points-can-be-positive-too-our-report-sets-out-how-to-engineer-a-domino-effect-of-rapid-changes-219291">Climate 'tipping points' can be positive too – our report sets out how to engineer a domino effect of rapid changes</a>
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<p>Here we look at the key messages from report sections on <a href="https://global-tipping-points.org/section1/1-earth-system-tipping-points/">tipping points in the Earth system</a>, their <a href="https://global-tipping-points.org/section2/2-tipping-point-impacts/">effects on people</a>, and how to <a href="https://global-tipping-points.org/section3/3-0-governance-of-earth-system-tipping-points/">govern these changes</a>. </p>
<h2>Tipping points in air, land and sea</h2>
<p>Having scoured scientific evidence of past and current changes, and factored in projections from computer models, we have identified over 25 tipping points in the Earth system. </p>
<p>Six of these are in the icebound parts of the planet (the “cryosphere”), including the collapse of massive ice sheets in Greenland and different parts of Antarctica, as well as localised tipping in glaciers and thawing permafrost. Sixteen are in the “biosphere” – the sum of all the world’s ecosystems – including trees dying on a massive scale in <a href="https://climatetippingpoints.info/2021/07/18/amazon-dieback-explainer/">parts of the Amazon</a> and northern boreal forests, degradation of savannas and drylands, nutrient overloading of lakes, coral reef mass mortality, and many mangroves and seagrass meadows dying off. </p>
<p>Finally, we identified four potential tipping points in the circulation of the oceans and atmosphere, including <a href="https://climatetippingpoints.info/2023/08/15/amoc-collapse-explainer/">collapse of deep ocean mixing</a> in the North Atlantic and in the Southern Ocean around Antarctica, and disruption of the West African monsoon. </p>
<p>Human activities are already pushing some of these close to tipping points. The exact thresholds are uncertain, but at today’s global warming of 1.2°C, the widespread loss of warm water coral reefs is already becoming likely, while <a href="https://theconversation.com/climate-tipping-points-could-lock-in-unstoppable-changes-to-the-planet-how-close-are-they-191043">tipping in another four vital climate systems is possible</a>. These are Greenland and West Antarctic ice sheet collapse, North Atlantic circulation collapse, and widespread localised thaw of permafrost. </p>
<p>Beyond 1.5°C several of these become likely, and other systems like mangroves, seagrass meadows, and parts of the boreal forest start to become vulnerable. Some systems can also tip or have their warming thresholds reduced due to other drivers, such as deforestation in the Amazon.</p>
<p>It can be hard to comprehend the consequences of crossing these tipping points. For example, if parts of the Amazon rainforest die, countless species would be lost, and warming would be further amplified as billions of tons of carbon currently locked up in trees and soils makes its way into the atmosphere. Within the region, this could cause trillions of dollars of economic impacts, and expose millions of people to extreme heat. </p>
<p>Given the sheer scale of risks from tipping points, you may assume that economic assessments of climate change include them. Alas, most assessments effectively ignore tipping point risks. This is perhaps the most frightening conclusion of the new report.</p>
<h2>Human societies could tip into something much worse</h2>
<p>There is also the potential for negative tipping in human societies, causing further financial instability, displacement, conflict or polarisation. These would hamper our efforts to limit further Earth system tipping points, and could even bring about a shift to a social system characterised by greater authoritarianism, hostility and alienation that could entirely <a href="https://esd.copernicus.org/articles/14/1171/2023/">derail sustainability transitions</a>. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/563947/original/file-20231206-25-jo6id1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="White coral with fish" src="https://images.theconversation.com/files/563947/original/file-20231206-25-jo6id1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/563947/original/file-20231206-25-jo6id1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/563947/original/file-20231206-25-jo6id1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/563947/original/file-20231206-25-jo6id1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/563947/original/file-20231206-25-jo6id1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/563947/original/file-20231206-25-jo6id1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/563947/original/file-20231206-25-jo6id1.jpg?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"></a>
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<span class="caption">When water gets too hot, coral can ‘bleach’ and die.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/coral-bleaching-occurs-when-water-temperatures-570782089">Sabangvideo / shutterstock</a></span>
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<p>A further risk is that most of Earth’s tipping systems interact in ways that destabilise one another. In the worst case, tipping one system makes connected systems more likely to tip too. This could produce a “tipping cascade” like falling dominoes. </p>
<p>The Global Tipping Points Report makes clear that climate change is a key driver for most of these tipping points, and the risk of crossing them can be reduced by urgently cutting greenhouse gas emissions to zero (which “<a href="https://global-tipping-points.org/section4/4-0-positive-tipping-points-in-technology-economy-and-society/">positive tipping points</a>” could accelerate). To help prevent tipping points in the biosphere, we’ll also need to rapidly reduce habitat loss and pollution while supporting ecological restoration and sustainable livelihoods.</p>
<p>Ambitious new governance approaches are needed. Our report recommends international bodies like the UN’s climate talks urgently start taking tipping points into account. Their understanding of dangerous climate change needs a serious update.</p>
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<img alt="Imagine weekly climate newsletter" src="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p><strong><em>Don’t have time to read about climate change as much as you’d like?</em></strong>
<br><em><a href="https://theconversation.com/uk/newsletters/imagine-57?utm_source=TCUK&utm_medium=linkback&utm_campaign=Imagine&utm_content=DontHaveTimeTop">Get a weekly roundup in your inbox instead.</a> Every Wednesday, The Conversation’s environment editor writes Imagine, a short email that goes a little deeper into just one climate issue. <a href="https://theconversation.com/uk/newsletters/imagine-57?utm_source=TCUK&utm_medium=linkback&utm_campaign=Imagine&utm_content=DontHaveTimeBottom">Join the 20,000+ readers who’ve subscribed so far.</a></em></p>
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<p class="fine-print"><em><span>James Dyke receives funding from the Open Society Foundations. He is an advisor to Faculty for a Future.</span></em></p><p class="fine-print"><em><span>David Armstrong McKay is a Research Impact Fellow at the University of Exeter's Global Systems Institute and an Associated Researcher at Stockholm Resilience Centre. He is currently researching Earth system tipping points as part of the Global Tipping Points Report project (funded by the Bezos Earth Fund) and with the Earth Commission (hosted by non-profit research network Future Earth and is the science component of the Global Commons Alliance, a sponsored project of Rockefeller Philanthropy Advisors, with support from Oak Foundation, MAVA, Porticus, Gordon and Betty Moore Foundation, Herlin Foundation, the Global Environment Facility, and Generation Foundation). He is also a freelance research consultant and science communicator.</span></em></p>Coral reefs are already being lost, and four other vital climate systems may tip soon.James Dyke, Associate Professor in Earth System Science, University of ExeterDavid Armstrong McKay, Researcher in Earth System Resilience, Stockholm UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2106412023-07-31T19:59:48Z2023-07-31T19:59:48ZClimate change can drive social tipping points – for better or for worse<p>It’s impossible to turn on the TV, listen to the radio or scroll social media without hearing about real-world climate impacts. July is the hottest month on <a href="https://www.abc.net.au/news/2023-07-27/july-likely-hottest-month-record-united-nations-climate-change/102654812">record</a>. The United Nations has declared an era of <a href="https://www.abc.net.au/radio/programs/am/the-era-of-global-boiling-has-arrived-un/102580034">global boiling</a>. Europe and North America are experiencing record-breaking <a href="https://abcnews.go.com/US/heat-waves-north-america-europe-virtually-impossible-without-climate-change/story?id=101606947">heat waves</a> while Antarctic <a href="https://www.abc.net.au/news/2023-07-11/antarctic-sea-ice-dropping-to-record-low-levels/102587598">sea ice levels</a> have fallen to record lows. </p>
<p>Scientists are concerned changes such as these are rapid and irreversible. If heating continues, the climate could reach <a href="https://iopscience.iop.org/article/10.1088/1748-9326/aaaa75">tipping points</a> and enter <a href="https://www.theguardian.com/environment/2022/sep/08/world-on-brink-five-climate-tipping-points-study-finds">new, dangerous states</a>. </p>
<p>Such upheaval can also lead to marked changes in society. As our <a href="https://besjournals.onlinelibrary.wiley.com/doi/10.1002/pan3.10516">new research shows</a>, climate change is causing social tipping points: fast, fundamental changes in human values, behaviours, relationships, technologies and <a href="https://besjournals.onlinelibrary.wiley.com/doi/epdf/10.1002/pan3.10516">institutions</a> that are hard to undo.</p>
<p>We need to <a href="https://www.vox.com/energy-and-environment/2020/1/29/21083250/climate-change-social-tipping-points">use this knowledge</a> to overcome our long dependency on fossil fuels before climate change causes irreversible social upheavals. </p>
<p>Social science shows we’re more likely to be concerned about an issue when we have experienced it, such as being directly affected by fires or floods. But until then, we’re often unlikely to support policies which may radically change everyday life. We can see this in planning for sea-level rise. Coastal communities that have experienced significant coastal erosion are <a href="https://www.researchgate.net/profile/Leslie-Jackson-5/publication/282313238_Coastal_Zone_Management_Plans_-_The_need_to_Balance_all_Costs_and_Benefits/links/57f715d008ae280dd0bb3cfb/Coastal-Zone-Management-Plans-The-need-to-Balance-all-Costs-and-Benefits.pdf">much more supportive</a> of coastal protection policies than those that haven’t. </p>
<h2>Understanding social tipping points</h2>
<p>Studying social tipping points is hard and messy. Humans and our societies are much less predictable than nature. The status quo is very well entrenched and shifts away from it rarely happen without significant pushback. </p>
<p>But it can happen – especially in times of crisis, as the COVID pandemic demonstrated. Three years ago, many of us shifted to working from home – and the change happened remarkably quickly. Changing back to working in the office every day is turning out to be <a href="https://www.abc.net.au/news/2023-01-17/remote-work-four-day-week-chronotype-fluid-hours-work-from-home/101791266">much harder</a> than first thought. </p>
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<a href="https://theconversation.com/australias-black-summer-of-fire-was-not-normal-and-we-can-prove-it-172506">Australia's Black Summer of fire was not normal – and we can prove it</a>
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<p>Social science tells us natural disasters can provide opportunities for social <a href="https://journals.sagepub.com/doi/10.1177/0309132509105004">tipping points</a>. That’s because natural disasters can change how we allocate resources and our expectations of what governments should do. </p>
<p>For instance, the devastating earthquakes in Christchurch in 2010 and 2011 drove a new approach to disaster response. The New Zealand government created a recovery agency tasked not only with <a href="https://www.emerald.com/insight/content/doi/10.1108/IJDRBE-01-2017-0009/full/pdf?casa_token=KNthAtu9WoUAAAAA:IcNrpPGmCSoUiv2M0blhCyyXPnW-JY5PquopeTVnekgGr1SfGq-UvgG8pKEvoS2nqrwVAGi42nOL7ToF4Mo7cbvEbqnf-vbepcPQ2Yqwc35CUbwgJc1WKg">building back better</a>, but also making sure <a href="https://www.sciencedirect.com/science/article/pii/S2212420915000229">community wellbeing</a> was taken into account. </p>
<h2>How can natural disasters cause social tipping points?</h2>
<p>Our research brought two dozen researchers from diverse disciplines together to debate what social tipping points are and how we can respond to them.</p>
<p>To understand the issue, we examined a devastating flood in Germany in 2021. Intense rainfall turned the small Ahr River into a torrent with flows rivalling the Rhine. The flooding killed 134 people and destroyed the livelihoods of thousands. </p>
<p>The disaster was made up to nine times <a href="https://www.theguardian.com/environment/2021/aug/23/climate-crisis-made-deadly-german-floods-up-to-nine-times-more-likely">more likely</a> by climate change, because hotter air can hold more moisture to fall as rain. </p>
<p>We found the chaos and damage had led to social tipping points. Local communities <a href="https://www.swr.de/swraktuell/rheinland-pfalz/koblenz/erleichterung-baugesetzgebung-nach-flut-ahrtal-100.html">called for the right</a> to rebuild houses on higher ground, which led to proposed changes to national construction laws. </p>
<p>Australia’s Black Summer bushfires also demonstrate the link between climate-related disasters and social attitudes.</p>
<p>Over the <a href="https://naturaldisaster.royalcommission.gov.au">2019–2020 summer</a>, more than 24 million hectares were burnt, 33 people died, over 3,000 homes were destroyed and an estimated three billion animals were killed. </p>
<p>It triggered shifts in Australian society, both large and small. For the first time, First Nations <a href="https://theconversation.com/australia-you-have-unfinished-business-its-time-to-let-our-fire-people-care-for-this-land-135196">cultural burning practices</a> gained real traction as a way to reduce damage from megafires. </p>
<p><a href="https://csrm.cass.anu.edu.au/sites/default/files/docs/2020/2/Exposure_and_impact_on_attitudes_of_the_2019-20_Australian_Bushfires_publication.pdf">Surveys showed</a> the impact of the fires on public opinion. People were less satisfied with the direction of the country and had less confidence in the federal government. They were more likely to rate climate change as a potential threat, and were less likely to support new coal mines. </p>
<p>More broadly, we can see the response to the ozone hole as an example of a positive social tipping point. In the 1970s and 80s, concern about the growing impacts of the ozone hole on human health and the environment resulted in deliberate intergovernmental action. Thanks to these efforts, we have seen the size of the ozone hole <a href="https://www.eea.europa.eu/en/topics/in-depth/climate-change-mitigation-reducing-emissions/current-state-of-the-ozone-layer#:%7E:text=The%20largest%20historical%20extent%20of,area%20of%2024.5%20million%20km%C2%B2.">stabilise</a> and begin to close. </p>
<p>But social tipping points don’t have to be positive. They can be intensely negative. The Syrian civil war which began in 2011 was triggered, in part, from social tensions emerging from intense and <a href="https://reliefweb.int/report/syrian-arab-republic/climate-change-war-displacement-and-health-impact-syrian-refugee-camps#:%7E:text=Human%2Dinduced%20climate%20change%20was,increasing%20risks%20of%20civil%20strife.">prolonged droughts</a> made more likely by climate change. These tensions – and their climate drivers – <a href="https://www.nytimes.com/2022/02/19/world/middleeast/syria-drought-climate-food.html">haven’t gone away</a>. </p>
<h2>What should we take from this?</h2>
<p>While it’s vitally important to understand climate tipping points, it can be common to focus on them passively – as if it’s something that will simply happen without any human agency. But this isn’t how it will play out. </p>
<p>Our societies and organisations will be forced into change by climate disruption, whether for good or ill. We need to understand whether social tipping points triggered by climate change are desirable or not. If they pose major risks, we need to understand what we can do to avoid them. </p>
<p>We can see this playing out in the Northern Hemisphere. Media coverage tends to focus on the heatwaves and the stark images of tourists trying to <a href="https://theconversation.com/tourists-flock-to-the-mediterranean-as-if-the-climate-crisis-isnt-happening-this-years-heat-and-fire-will-force-change-210282">fight fires</a>. But climate upheaval will bring much larger changes to our societies. </p>
<p>It could be more extreme weather, intensified natural disasters and melting sea ice force us to act ever more quickly to avert the worst outcomes. But we could also see dangerous social tipping points – think flows of climate refugees leading to anti-immigration sentiment and skepticism of global cooperation. The future isn’t set.</p>
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Read more:
<a href="https://theconversation.com/tourists-flock-to-the-mediterranean-as-if-the-climate-crisis-isnt-happening-this-years-heat-and-fire-will-force-change-210282">Tourists flock to the Mediterranean as if the climate crisis isn't happening. This year's heat and fire will force change</a>
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<img src="https://counter.theconversation.com/content/210641/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sonia Graham receives funding from the Australian Research Council (DE200100234) and previously the Spanish Ministry of Science, Innovation and Universities, through the ‘María de Maeztu’ program for Units of Excellence (MDM-2015-0552). She is a member of the Labor party. </span></em></p>Climate change is going to bring social change. Will it drive ever-faster efforts to stave off the worst – or trigger social upheavals making it harder for us to respond?Sonia Graham, DECRA Fellow, University of WollongongLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2079552023-06-22T16:06:19Z2023-06-22T16:06:19ZEcological doom-loops: why ecosystem collapses may occur much sooner than expected – new research<figure><img src="https://images.theconversation.com/files/533528/original/file-20230622-23-zjbjcb.jpg?ixlib=rb-1.1.0&rect=1815%2C7%2C3426%2C2082&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Anna Kucherova / Shutterstock</span></span></figcaption></figure><p>Across the world, rainforests are becoming savanna or farmland, savanna is drying out and turning into desert, and icy tundra is thawing. Indeed, scientific studies have now recorded “regime shifts” like these in <a href="https://www.regimeshifts.org/datasets-resources">more than 20 different types of ecosystem</a> where tipping points have been passed. Across the world, <a href="https://theconversation.com/one-fifth-of-ecosystems-in-danger-of-collapse-heres-what-that-might-look-like-148137">more than 20% of ecosystems</a> are in danger of shifting or collapsing into something different.</p>
<p>These collapses might happen sooner than you’d think. Humans are already putting ecosystems under pressure in <a href="https://www.ipbes.net/global-assessment">many different ways</a> – what we refer to as stresses. And when you combine these stresses with an increase in climate-driven extreme weather, the date these tipping points are crossed could be brought forward by as much as 80%.</p>
<p>This means an ecosystem collapse that we might previously have expected to avoid until late this century could happen as soon as in the next few decades. That’s the gloomy conclusion of our latest research, published in <a href="https://www.nature.com/articles/s41893-023-01157-x">Nature Sustainability</a>.</p>
<p>Human population growth, increased economic demands, and greenhouse gas concentrations put pressures on ecosystems and landscapes to supply food and maintain key services such as clean water. The number of extreme climate events is also increasing and <a href="https://www.ipcc.ch/report/ar6/wg1/">will only get worse</a>.</p>
<p>What really worries us is that climate extremes could hit already stressed ecosystems, which in turn transfer new or heightened stresses to some other ecosystem, and so on. This means one collapsing ecosystem could have a knock-on effect on neighbouring ecosystems through <a href="https://www.science.org/doi/full/10.1126/science.aat7850">successive feedback loops</a>: an “ecological doom-loop” scenario, with catastrophic consequences.</p>
<h2>How long until a collapse?</h2>
<p>In our new research, we wanted to get a sense of the amount of stress that ecosystems can take before collapsing. We did this using models – computer programs that simulate how an ecosystem will work in future, and how it will react to changes in circumstance. </p>
<p>We used two general ecological models representing forests and lake water quality, and two location-specific models representing the Chilika lagoon fishery in the eastern Indian state of Odisha and Easter Island (Rapa Nui) in the Pacific Ocean. These latter two models both explicitly include interactions between human activities and the natural environment. </p>
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<a href="https://images.theconversation.com/files/533532/original/file-20230622-15-8tetyb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="small boats at sunset on a lake" src="https://images.theconversation.com/files/533532/original/file-20230622-15-8tetyb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/533532/original/file-20230622-15-8tetyb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/533532/original/file-20230622-15-8tetyb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/533532/original/file-20230622-15-8tetyb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/533532/original/file-20230622-15-8tetyb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/533532/original/file-20230622-15-8tetyb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/533532/original/file-20230622-15-8tetyb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Fishing in Chilika sustains more than 150,000 people.</span>
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<p>The key characteristic of each model is the presence of feedback mechanisms, which help to keep the system balanced and stable when stresses are sufficiently weak to be absorbed. For example, fishers on Lake Chilika tend to prefer catching adult fish while the fish stock is abundant. So long as enough adults are left to breed, this can be stable. </p>
<p>However, when stresses can no longer be absorbed, the ecosystem abruptly passes a point of no return – the tipping point – and collapses. In Chilika, this might occur when fishers increase the catch of juvenile fish during shortages, which further undermines the renewal of the fish stock. </p>
<p>We used the software to model more than 70,000 different simulations. Across all four models, the combinations of stress and extreme events brought forward the date of a predicted tipping point by between 30% and 80%. </p>
<p>This means an ecosystem predicted to collapse in the 2090s owing to the creeping rise of a single source of stress, such as global temperatures, could, in a worst-case scenario, collapse in the 2030s once we factor in other issues like extreme rainfall, pollution, or a sudden spike in natural resource use.</p>
<p>Importantly, around 15% of ecosystem collapses in our simulations occurred as a result of new stresses or extreme events, while the main stress was kept constant. In other words, even if we believe we are managing ecosystems sustainably by keeping the main stress levels constant – for example, by regulating fish catches – we had better keep an eye out for new stresses and extreme events.</p>
<h2>There are no ecological bailouts</h2>
<p>Previous studies have suggested significant costs from going past tipping points in large ecosystems will kick in from the <a href="https://www.nature.com/articles/nclimate2964">second half of this century onwards</a>. But our findings suggest these costs could occur much sooner. </p>
<p>We found the speed at which stress is applied is vital to understanding system collapse, which is probably relevant to non-ecological systems too. Indeed, the increased speed of both news coverage and mobile banking processes has recently been invoked as raising the risk of bank collapse. As the journalist <a href="https://www.ft.com/content/9bc5e530-ac72-4b4c-9eb1-f5e5c48f34c9">Gillian Tett has observed</a>: </p>
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<p>The collapse of Silicon Valley Bank provided one horrifying lesson in how tech innovation can unexpectedly change finance (in this case by intensifying digital herding). Recent flash crashes offer another. However, these are probably a small foretaste of the future of viral feedback loops.</p>
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<p>But there the comparison between ecological and economic systems runs out. Banks can be saved as long as governments provide sufficient financial capital in bailouts. In contrast, no government can provide the immediate natural capital needed to restore a collapsed ecosystem.</p>
<p>There is no way to restore collapsed ecosystems within any reasonable timeframe. There are no ecological bailouts. In the financial vernacular, we will just have to take the hit.</p>
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<p><strong><em>Don’t have time to read about climate change as much as you’d like?</em></strong>
<br><em><a href="https://theconversation.com/uk/newsletters/imagine-57?utm_source=TCUK&utm_medium=linkback&utm_campaign=Imagine&utm_content=DontHaveTimeTop">Get a weekly roundup in your inbox instead.</a> Every Wednesday, The Conversation’s environment editor writes Imagine, a short email that goes a little deeper into just one climate issue. <a href="https://theconversation.com/uk/newsletters/imagine-57?utm_source=TCUK&utm_medium=linkback&utm_campaign=Imagine&utm_content=DontHaveTimeBottom">Join the 20,000+ readers who’ve subscribed so far.</a></em></p>
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<p class="fine-print"><em><span>John Dearing is a member of the Green Party of England and Wales </span></em></p><p class="fine-print"><em><span>Simon Willcock receives funding from UKRI (NE/W005050/1, NE/T00391X/1, ES/T007877/1, ES/R009279/1,
AH/W003813/1, and BB/X010961/1). He is affiliated with Rothamsted Research and Bangor University. </span></em></p><p class="fine-print"><em><span>Gregory Cooper does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>We ran computer programs that simulate ecosystems 70,000 times and the results are very worrying.John Dearing, Professor of Physical Geography, University of SouthamptonGregory Cooper, Postdoctoral Research Fellow in Social-Ecological Resilience, University of SheffieldSimon Willcock, Professor of Sustainability, Bangor UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2031432023-05-05T00:54:42Z2023-05-05T00:54:42ZHumanity’s tipping point? How the Queen’s death stole a climate warning’s thunder<figure><img src="https://images.theconversation.com/files/524322/original/file-20230504-17-hhnq1y.jpg?ixlib=rb-1.1.0&rect=31%2C25%2C3456%2C2271&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/climate-change-antarctic-melting-glacier-global-324590720">Bernhard Staehli, Shutterstock</a></span></figcaption></figure><p>Think back to September last year. What happened early that month? What news shook the world and reverberated for weeks, if not months?</p>
<p>That’s a question I’ve been asking friends and colleagues lately. </p>
<p>On September 8, 2022, at 6.30pm in Britain, <a href="https://www.royal.uk/announcement-death-queen">Buckingham Palace announced</a> the death of Queen Elizabeth II. The news broke <a href="https://davidarmstrongmckay.com/tag/climate-tipping-points/">just 30 minutes before</a> the press embargo lifted on a major <a href="https://www.science.org/doi/full/10.1126/science.abn7950">review of climate change tipping points</a> in the journal Science.</p>
<p>The paper in Science was truly earth-shattering, as it heralded changes that could threaten the future of civil society on this planet. But it was the other news that captured the world’s attention. </p>
<p>So, in case you missed it, I’d like to alert you to this important paper by British climate researcher David Armstrong MᶜKay and colleagues. </p>
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Read more:
<a href="https://theconversation.com/climate-tipping-points-could-lock-in-unstoppable-changes-to-the-planet-how-close-are-they-191043">Climate tipping points could lock in unstoppable changes to the planet – how close are they?</a>
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<h2>Grappling with tipping points</h2>
<p>The question of when global warming might push elements of the climate system past points of no return has come into focus over last the decade or so. And tipping points <a href="https://climatetippingpoints.info/2022/09/09/climate-tipping-points-reassessment-explainer/">once thought to be far off</a> in the distance have come into sharp relief. </p>
<p>The research examines major features of the global climate system, such as ice sheets, glaciers, rainforests and coral reefs. It asks when melting of ice sheets on Greenland and West Antarctica would become irreversible, ultimately contributing many metres to sea level. Or when thawing of frozen ground in the Arctic might start producing so much methane and carbon dioxide (CO₂) that it blows the global emissions budget.</p>
<p>Amazonian forest die-back is another major part of the Earth’s climate system. Global heating and regional reductions in rainfall could cause trees to die, releasing large amounts of greenhouse gases. Fewer trees <a href="https://www.npr.org/2023/04/02/1167371279/why-deforestation-means-less-rain-in-tropical-forests">ultimately means less rainfall</a> for those that remain, creating a vicious cycle. </p>
<p>The pivotal paper in Science reviewed more than 220 papers published since 2008 to estimate what level of global temperature rise (relative to pre-industrial levels) would trigger each of the global and regional climate tipping points.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/523935/original/file-20230502-24-os2ne3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A bar chart from the original paper in Science showing the likely warming threshold for various tipping points" src="https://images.theconversation.com/files/523935/original/file-20230502-24-os2ne3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/523935/original/file-20230502-24-os2ne3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=365&fit=crop&dpr=1 600w, https://images.theconversation.com/files/523935/original/file-20230502-24-os2ne3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=365&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/523935/original/file-20230502-24-os2ne3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=365&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/523935/original/file-20230502-24-os2ne3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=459&fit=crop&dpr=1 754w, https://images.theconversation.com/files/523935/original/file-20230502-24-os2ne3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=459&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/523935/original/file-20230502-24-os2ne3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=459&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Global warming threshold estimates for climate tipping elements, ranging from the minimum in yellow where tipping is possible, through to maximum in dark red where tipping is very likely, central dotted line is the best estimate. Compare to the Paris Agreement range of 1.5°C to <2°C (green horizontal bar). Future projections are shown in more detail in (B) along with estimated 21st century warming trajectories. In (C), the number of thresholds potentially passed in the coming decades (depending on warming trajectory) is shown per decade (bars) and cumulatively (lines).</span>
<span class="attribution"><a class="source" href="https://www.science.org/stoken/author-tokens/ST-720/full">Reprinted with permission from David I. Armstrong McKay et al., Science 377:eabn7950 (2022). (https://www.science.org/doi/full/10.1126/science.abn7950)</a></span>
</figcaption>
</figure>
<p>The world has already warmed 1.1°C (see the horizontal line “current warming” in the chart above). The 1.5°C and 2°C lines represent the Paris Agreement on climate change targets agreed to internationally in 2016. </p>
<p>Once initiated, irreversible melting of the Greenland Ice Sheet would add about 5m to global sea level. Disturbingly, the threshold for this tipping point may have already been crossed. If not, it is “very likely” to be crossed at 2°C. </p>
<p>Ice sheets in West Antarctica contain about another 3.5m of sea level rise, and again, irreversible melting is likely to begin at around 2°C. </p>
<p>So, that’s about 5m from Greenland and another 3.5m from West Antarctica. Add thermal expansion from warming oceans, and mountain glacier melt, and we have more than 10m of sea level rise to contend with. </p>
<p>While that will unfold over many centuries, it will be irreversible and inexorable. It means children born today will likely see sea levels rise by well over 1m early in the 22nd century. Longer-term, these changes will shape the planet for the next 150,000 years or so, until the next ice age. </p>
<p>Consider how 10m of sea level rise might change the map at <a href="https://coastal.climatecentral.org/map/5/136.0179/-24.1608/?theme=water_level&map_type=water_level_above_mhhw">ClimateCentral</a>. </p>
<iframe allow="fullscreen 'src'" frameborder="0" src="https://coastal.climatecentral.org/embed/map/5/135.0738/-27.9887/?theme=water_level&map_type=water_level_above_mhhw&basemap=roadmap&contiguous=true&elevation_model=best_available&water_level=10.0&water_unit=m" width="100%" height="500" title="Climate Central | Land below 10.0 meters of water"></iframe>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/torrents-of-antarctic-meltwater-are-slowing-the-currents-that-drive-our-vital-ocean-overturning-and-threaten-its-collapse-202108">Torrents of Antarctic meltwater are slowing the currents that drive our vital ocean 'overturning' – and threaten its collapse</a>
</strong>
</em>
</p>
<hr>
<p>Much of the world’s tropical coral reefs will likely die at 1.5°C to 2°C of warming. And thawing of Arctic permafrost would start releasing vast amounts of greenhouse gases, equal to about 10% of human emissions. That would likely push global temperature up by another 0.5°C to 1.0°C (on top of 2°C). </p>
<p>Thankfully, logging and wildfire aside, the Amazon forest looks relatively safe until about 3°C of warming. But the combination of some of those other tipping points might get us there, setting off a further cascade of tipping points. </p>
<h2>Can we avoid disaster?</h2>
<p>After decades of delay, our chances of keeping global warming below 1.5°C are pretty slim. But, clearly, this research shows that limiting warming to 2°C will not keep us safe. </p>
<p>The focus on “<a href="https://www.un.org/en/climatechange/net-zero-coalition">net zero by 2050</a>” has in fact done us a disservice. If we let emissions remain anywhere near current levels for much longer, by 2030 we will have used up the carbon emissions budget that would allow us to stay near 1.5°C. </p>
<p>We need to act quickly and at least halve current emissions by 2030 on the way to net zero before 2050. This research shows that failing to do so will trigger 10m or more of sea level rise. That will gradually displace hundreds of millions of people and many of the world’s major cities.</p>
<p>The Intergovernmental Panel on Climate Change (IPCC) has begun talking about the possible failure of civil society in response to increasing extreme events. We are seeing early indicators of this in Australia, with people living in tents for years after floods made worse by climate change. They face decisions about whether or not to rebuild on that land. </p>
<p>How long will there be money available to provide disaster relief in Australia and around the world? Where will hundreds of millions of people go after being displaced by extreme <a href="https://www.theguardian.com/science/2022/jul/31/why-you-need-to-worry-about-the-wet-bulb-temperature">wet bulb temperature</a>, crop failure, fire, flooding and sea level rise?</p>
<h2>How did we get here?</h2>
<p>Arriving at this juncture in human history feels like a massive failure. A failure of leadership, of decision making, of information dissemination through media, and perhaps our priorities, has left us in this extremely challenging position. </p>
<p>Many factors have conspired against us. These include fossil fuel companies funding misinformation and <a href="https://theconversation.com/capitalising-on-climate-anxiety-what-you-need-to-know-about-climate-washing-202507">climate-related “green washing”</a> – exaggerating or misrepresenting their climate credentials. Elected leaders being influenced by donations from the fossil fuel industry. Earlier low-resolution climate models failing to capture local scale processes, and therefore underestimating climate system sensitivity. Poor media communication of the urgency of the issue. And throw in some good old human “optimism bias” towards positive outcomes. </p>
<p>As a climate scientist, with almost 18 years experience in operations at the Bureau of Meteorology and more recently, in my work on <a href="https://www.environment.sa.gov.au/topics/climate-change/climate-science-knowledge-resources/latest-climate-projections-for-sa">high resolution climate projections</a> for state government, I deeply know the climate grief so eloquently communicated by climate researcher <a href="https://theconversation.com/friday-essay-i-feel-my-heart-breaking-today-a-climate-scientists-path-through-grief-towards-hope-188589">Joelle Gergis</a>. </p>
<p>In response, I have had to draw on tools such as meditation and mindfulness to deal with the awareness the science presents including the likely future suffering of so many. It is challenging to see where we are heading and – with what is at stake – to see life going on as if everything is fine. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/introducing-fear-and-wonder-the-conversations-new-climate-podcast-200066">Introducing Fear and Wonder: The Conversation's new climate podcast</a>
</strong>
</em>
</p>
<hr>
<iframe src="https://embed.acast.com/6306bcc77d4d0a00130bc055/64126e536c268700110de4d7" frameborder="0" width="100%" height="190px"></iframe>
<p><iframe id="tc-infographic-822" class="tc-infographic" height="100" src="https://cdn.theconversation.com/infographics/822/cfe1cb0d01c023aeef001dac6a65f27fcee4c0bb/site/index.html" width="100%" style="border: none" frameborder="0"></iframe></p>
<h2>A turning point</h2>
<p>Future events are going to challenge us in many ways. Humanity faces a choice between retreat into fear and war, or cooperation and collaboration. There is much already happening and a lot we can do, as individuals and communities. We can <a href="https://www.iucn.org/our-work/topic/forests/forest-landscape-restoration">restore landscapes</a>, reward sustainability, create a circular economy and <a href="https://www.rewiringaustralia.org/">electrify everything</a>. But we need to act fast. </p>
<p>So, as King Charles III’s coronation plays across our TV screens and media feeds in coming days, keep the incredibly urgent climate crisis in mind. Ask our leaders to step up. Do not be distracted, as future generations will judge us for the choices we make today.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/it-can-be-done-it-must-be-done-ipcc-delivers-definitive-report-on-climate-change-and-where-to-now-201763">'It can be done. It must be done': IPCC delivers definitive report on climate change, and where to now</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/203143/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Darren Ray receives a Federal Govt RTPS postgraduate scholarship, and is the recipient of funding associated with a SUBAK Australia Fellowship. Darren Ray is a past employee of the Bureau of Meteorology. </span></em></p>When Buckingham Palace announced the death of Queen Elizabeth II in September, the news overshadowed reporting of a critical review of climate tipping points, published in Science. Did you miss it?Darren Ray, PhD candidate | Paleoclimate, University of AdelaideLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1795702022-03-21T07:46:12Z2022-03-21T07:46:12ZAdapt, move, or die: repeated coral bleaching leaves wildlife on the Great Barrier Reef with few options<figure><img src="https://images.theconversation.com/files/453230/original/file-20220321-17-17ioogu.jpg?ixlib=rb-1.1.0&rect=22%2C97%2C3811%2C1965&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Grumpy Turtle Films</span>, <span class="license">Author provided</span></span></figcaption></figure><p>To our horror, another mass coral bleaching event may be striking the Great Barrier Reef, with water temperatures reaching up to <a href="https://www.climatecouncil.org.au/resources/dire-warning-great-barrier-reef-un-inspection-begins-climate-council-briefing/">3°C higher</a> than average in some places. This would be the sixth such event since the late 1990s, and the fourth since 2016. </p>
<p>It comes as a monitoring mission from the United Nations arrives in Queensland today to inspect the reef and <a href="https://theconversation.com/not-declaring-the-great-barrier-reef-as-in-danger-only-postpones-the-inevitable-164867">consider listing</a> the World Heritage site as “in danger”. </p>
<p>As coral reef scientists, we’ve seen firsthand how the Great Barrier Reef is nearing its <a href="https://theconversation.com/what-climate-tipping-points-are-and-how-they-could-suddenly-change-our-planet-49405">tipping point</a>, beyond which the reef will lose its function as a viable ecosystem. This is not only due to climate change exacerbating marine heatwaves, but also higher ocean acidity, loss of oxygen, pollution, and more. </p>
<p>Scientists are at our own tipping points, too. The reef is suffering environmental conditions so extreme, we’re struggling to simulate these scenarios in our laboratories. Even though Australia has <a href="https://www.aims.gov.au/seasim">world-class facilities</a>, we are proverbially beating our heads against the wall each year as conditions worsen. </p>
<p>It’s getting harder for scientists to predict how these conditions will affect individual species, let alone the health and biodiversity of reef ecosystems. But let’s explore what we do know. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/453238/original/file-20220321-17-y02711.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/453238/original/file-20220321-17-y02711.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/453238/original/file-20220321-17-y02711.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=315&fit=crop&dpr=1 600w, https://images.theconversation.com/files/453238/original/file-20220321-17-y02711.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=315&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/453238/original/file-20220321-17-y02711.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=315&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/453238/original/file-20220321-17-y02711.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=396&fit=crop&dpr=1 754w, https://images.theconversation.com/files/453238/original/file-20220321-17-y02711.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=396&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/453238/original/file-20220321-17-y02711.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=396&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Coral bleaching seen due to the current marine heatwave.</span>
<span class="attribution"><span class="source">Grumpy Turtle Films</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>What is coral bleaching and why does it happen?</h2>
<p>Corals are animals that live in a mutually beneficial partnership with tiny single-celled algae called “zooxanthellae” (but scientists call them zooks). </p>
<p>Zooks benefit corals by giving them energy and colour, and in return the coral gives them a home in the coral tissue. Under stress, such as in too-hot water, the algae produce toxins instead of nutrition, and the coral ejects them. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/5-major-heatwaves-in-30-years-have-turned-the-great-barrier-reef-into-a-bleached-checkerboard-170719">5 major heatwaves in 30 years have turned the Great Barrier Reef into a bleached checkerboard</a>
</strong>
</em>
</p>
<hr>
<p>Without the algae, the corals begin to starve. They lose their vibrant colours, revealing the bright white limestone skeleton through the coral tissue. </p>
<p>If stress conditions abate, the algae can return and coral can recover over months. But if stress persists, the corals can die – the skeletons begin to crumble, removing vital habitat for other species. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/453239/original/file-20220321-23-1k97j5m.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/453239/original/file-20220321-23-1k97j5m.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/453239/original/file-20220321-23-1k97j5m.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=313&fit=crop&dpr=1 600w, https://images.theconversation.com/files/453239/original/file-20220321-23-1k97j5m.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=313&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/453239/original/file-20220321-23-1k97j5m.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=313&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/453239/original/file-20220321-23-1k97j5m.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=393&fit=crop&dpr=1 754w, https://images.theconversation.com/files/453239/original/file-20220321-23-1k97j5m.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=393&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/453239/original/file-20220321-23-1k97j5m.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=393&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Water temperatures reaching up to 3°C higher than average in some places.</span>
<span class="attribution"><span class="source">Grumpy Turtle Films</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>We had hoped for a reprieve</h2>
<p>Scientists and managers had hoped for a reprieve this year. Much of the Great Barrier Reef was <a href="https://theconversation.com/5-major-heatwaves-in-30-years-have-turned-the-great-barrier-reef-into-a-bleached-checkerboard-170719">in the early stages of recovery</a> following the 2016, 2017, and 2020 bleaching events.</p>
<p>In the tropical paradise of northern Queensland, we’ve been wishing for cloudy days and cooler temperatures, hoping for rain and even storms (but not big ones). These conditions typically come with La Niña – a natural climate phenomenon associated with cooler, wetter weather, which has now happened <a href="https://theconversation.com/back-so-soon-la-nina-heres-why-were-copping-two-soggy-summers-in-a-row-173684">two years in a row</a>. </p>
<p>But despite these effects of La Niña, climate change meant <a href="https://theconversation.com/2021-was-one-of-the-hottest-years-on-record-and-it-could-also-be-the-coldest-well-ever-see-again-175238%22%22">2021 was one of the hottest years on record</a>. Now, at the tail end of Australia’s summer, the reef is experiencing another marine heatwave and is tipping over the bleaching threshold. </p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1505058856941998086"}"></div></p>
<p>There’s not enough time for coral to recover between events. Even the most robust corals require <a href="https://doi.org/10.1098/rspb.2018.2908">nearly a decade to recover</a>. There is also no clear evidence corals are adapting to the new conditions.</p>
<p>To make matters worse, climate change is supercharging the atmosphere and making even the natural variations of <a href="https://research.noaa.gov/article/ArtMID/587/ArticleID/2685/New-research-volume-explores-future-of-ENSO-under-influence-of-climate-change">La Niña and its counterpart El Niño more variable and less predictable</a>. This means Australia will not only endure more intense heatwaves, but also flooding, droughts and storms. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/453240/original/file-20220321-15-cdocak.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/453240/original/file-20220321-15-cdocak.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/453240/original/file-20220321-15-cdocak.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=314&fit=crop&dpr=1 600w, https://images.theconversation.com/files/453240/original/file-20220321-15-cdocak.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=314&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/453240/original/file-20220321-15-cdocak.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=314&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/453240/original/file-20220321-15-cdocak.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=395&fit=crop&dpr=1 754w, https://images.theconversation.com/files/453240/original/file-20220321-15-cdocak.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=395&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/453240/original/file-20220321-15-cdocak.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=395&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">At least 1,625 species of fishes live in the Great Barrier Reef.</span>
<span class="attribution"><span class="source">Grumpy Turtle Films</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>How will this hurt marine life?</h2>
<p>A healthy Great Barrier Reef <a href="https://www.gbrmpa.gov.au/the-reef/animals#:%7E:text=1625%20species%20of%20fish%2C%20including,3000%20species%20of%20molluscs%20(shells)">is home to</a> at least 1,625 species of fishes, 3,000 species of molluscs, 630 species of echinoderms (such as sea stars and urchins), and the list goes on.</p>
<p>Marine life in coral reefs have three options in warming waters: adapt, move, or die. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/453241/original/file-20220321-15-17tqh2m.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/453241/original/file-20220321-15-17tqh2m.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/453241/original/file-20220321-15-17tqh2m.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=315&fit=crop&dpr=1 600w, https://images.theconversation.com/files/453241/original/file-20220321-15-17tqh2m.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=315&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/453241/original/file-20220321-15-17tqh2m.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=315&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/453241/original/file-20220321-15-17tqh2m.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=396&fit=crop&dpr=1 754w, https://images.theconversation.com/files/453241/original/file-20220321-15-17tqh2m.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=396&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/453241/original/file-20220321-15-17tqh2m.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=396&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Most shark species can’t adapt to warmer waters fast enough to survive.</span>
<span class="attribution"><span class="source">Grumpy Turtle Films</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p><strong>1. Can they adapt?</strong> </p>
<p>Over generations, species can make changes at the molecular level – their DNA – so they’re more suited to or can adapt to new environmental conditions. This evolution may be possible for species with fast generation times, such as <a href="https://doi.org/10.1111/gcb.13419">damselfishes</a>.</p>
<p>But reef species with slower generation times can’t keep pace with the rate we’re changing their habitat conditions. This includes the iconic <a href="https://doi.org/10.2305%2FIUCN.UK.2018-2.RLTS.T132773A100561780.en">potato cod</a> and most sharks, which take a around a decade or longer to reach sexual maturity.</p>
<p><strong>2. Can they move?</strong> </p>
<p><a href="https://doi.org/10.1111/gcb.13488">Some species of reef fishes</a> may start moving to cooler waters before the harmful effects of warming take hold. </p>
<p>But this option isn’t available to all species, such as those that depend on a particular habitat, certain resources, or protection. This includes coral, as well as <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-2486.2004.00839.x">coral-dwelling gobies</a> and <a href="https://besjournals.onlinelibrary.wiley.com/doi/10.1111/j.1365-2656.2007.01341.x">several damselfishes</a>. </p>
<p>A citizen science project called <a href="https://www.redmap.org.au/">Project RedMap</a>, has been documenting <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/faf.12036">the poleward migration of reef fish species</a> due to climate change. <a href="https://doi.org/10.1111/faf.12036">Studies have found</a> that larger, tropical fishes with a high swimming ability are more likely to survive in temperate waters, such as some butterflyfishes.</p>
<p><strong>3. They can die</strong></p>
<p>The third option is one we don’t like to talk about, but is becoming more of a threat. </p>
<p>If marine life can’t adapt or move , we’ll see <a href="https://theconversation.com/almost-60-coral-species-around-lizard-island-are-missing-and-a-great-barrier-reef-extinction-crisis-could-be-next-163714">extinctions at a local scale</a>, total extinction of some species, and dramatic declines in fish populations.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/453242/original/file-20220321-13-wwbv8w.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/453242/original/file-20220321-13-wwbv8w.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/453242/original/file-20220321-13-wwbv8w.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=315&fit=crop&dpr=1 600w, https://images.theconversation.com/files/453242/original/file-20220321-13-wwbv8w.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=315&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/453242/original/file-20220321-13-wwbv8w.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=315&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/453242/original/file-20220321-13-wwbv8w.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=395&fit=crop&dpr=1 754w, https://images.theconversation.com/files/453242/original/file-20220321-13-wwbv8w.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=395&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/453242/original/file-20220321-13-wwbv8w.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=395&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">UNESCO representatives are visiting the reef to assess its World Heritage status.</span>
<span class="attribution"><span class="source">Grumpy Turtle Films</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Listing the reef as ‘in danger’</h2>
<p>While the reef is bleaching, UNESCO delegates have arrived in Queensland to monitor its health, as the World Heritage site is once again being considered for an “<a href="https://whc.unesco.org/en/158/">in danger</a>” listing. </p>
<p>The visit will likely include seeing the bleaching currently occurring, the damage to the reef still apparent from past events, and they’ll hear firsthand from scientists and managers who’ve witnessed these impacts. </p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"926001558747193344"}"></div></p>
<p>Listing the Great Barrier Reef as “in danger” would raise the alert level for the international community and hopefully inspire climate action. </p>
<p>Reducing the major source of stress the reef faces – climate change – will require ongoing collaborations between Australian and international governments, with work on local management issues also involving business owners, reef managers, Traditional Owners, scientists, civil society groups, and other stakeholders.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-1-billion-great-barrier-reef-funding-is-nonsensical-australians-and-their-natural-wonder-deserve-so-much-better-175924">The $1 billion Great Barrier Reef funding is nonsensical. Australians, and their natural wonder, deserve so much better</a>
</strong>
</em>
</p>
<hr>
<p>We’ve known for a long time the most important step to save the reef: cutting emissions to stop global warming. Indeed, <a href="https://www.publish.csiro.au/mf/MF99078">future projections</a> of coral bleaching from the 1990s suggested that frequent and severe events would begin from the late-2010s – and they’ve been alarmingly prescient.</p>
<p>The Great Barrier Reef’s continuing demise is one of the most visible examples of how our inaction as humans has profound and perhaps irreversible consequences. We are rapidly accelerating toward the tipping point.</p><img src="https://counter.theconversation.com/content/179570/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jodie L. Rummer receives funding from the Australian Research Council Centre of Excellence for Coral Reef Studies. </span></em></p><p class="fine-print"><em><span>Scott Heron receives funding from Australian Research Council and NASA ROSES Ecological Forecasting.</span></em></p>The reef is suffering environmental conditions that are so extreme, scientists are struggling to simulate these scenarios in laboratories.Jodie L. Rummer, Associate Professor & Principal Research Fellow, James Cook UniversityScott F. Heron, Associate Professor in Physics, James Cook UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1710302021-11-02T16:43:56Z2021-11-02T16:43:56ZCOP26: what would the world be like at 3°C of warming and how would it be different from 1.5°C?<figure><img src="https://images.theconversation.com/files/429767/original/file-20211102-39236-1pw0zon.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A small increase in average temperature means a much bigger increase in the risk of severe droughts.</span> <span class="attribution"><span class="source">Galyna Andrushko / shutterstock</span></span></figcaption></figure><p>In the Paris Agreement, countries committed to seek to limit the increase in temperature to 1.5°C above pre-industrial levels. However, even if countries fulfilled their current pledges to reduce emissions, we would still see an increase of around 2.7°C. No wonder that nearly two thirds of Intergovernmental Panel on Climate Change (IPCC) authors who responded to a new <a href="https://www.nature.com/articles/d41586-021-02990-w">survey conducted by the journal Nature</a> expect the increase to be 3°C or more. </p>
<p>So how different would the impacts of climate change be at 3°C compared to 1.5°C? </p>
<p>At the outset, it is important to point out that – even if impacts increased in line with temperature – the impacts at 3°C warming would be more than twice those at 1.5°C. This is because we already have an increase of around 1°C above pre-industrial levels, so impacts at 3°C would be four times as great as at 1.5°C (an increase from now of 2°C compared with 0.5°C).</p>
<p>In practice, however, impacts do not necessarily increase linearly with temperature. In some cases the increase accelerates as temperature rises, so the impacts at 3°C may be much more than four times the impacts at 1.5°C. At the most extreme, the climate system may pass some “tipping point” leading to a step change.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/what-climate-tipping-points-are-and-how-they-could-suddenly-change-our-planet-49405">What climate 'tipping points' are – and how they could suddenly change our planet</a>
</strong>
</em>
</p>
<hr>
<p>Two years ago colleagues and I published research looking at <a href="https://link.springer.com/article/10.1007/s10584-019-02464-z">the impacts of climate change at different levels of global temperature increase</a>. We found that, for example, the global average annual chance of having a major heatwave increases from around 5% over the period 1981-2010 to around 30% at 1.5°C but 80% at 3°C. The average chance of a river flood currently expected in 2% of years increases to 2.4% at 1.5°C, and doubles to 4% at 3°C. At 1.5°C, the proportion of time in drought nearly doubles, and at 3°C it more than triples (these are all global averages weighted by the distribution of population or cropland: see the paper <a href="https://link.springer.com/article/10.1007/s10584-019-02464-z">for details</a>). </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/429772/original/file-20211102-28770-s7r2a3.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/429772/original/file-20211102-28770-s7r2a3.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/429772/original/file-20211102-28770-s7r2a3.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=174&fit=crop&dpr=1 600w, https://images.theconversation.com/files/429772/original/file-20211102-28770-s7r2a3.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=174&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/429772/original/file-20211102-28770-s7r2a3.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=174&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/429772/original/file-20211102-28770-s7r2a3.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=219&fit=crop&dpr=1 754w, https://images.theconversation.com/files/429772/original/file-20211102-28770-s7r2a3.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=219&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/429772/original/file-20211102-28770-s7r2a3.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=219&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Change in global average heatwave, river flood and drought risk with increase in global mean temperature. The individual lines represent different climate model projections of regional change in climate, and the horizontal line shows the indicators over the period 1981-2010.</span>
<span class="attribution"><a class="source" href="https://link.springer.com/article/10.1007/s10584-019-02464-z">Arnell et al., 2019</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>There is of course some uncertainty around these figures, as shown in the graphs above where the range of possible outcomes gets wider as temperature increases. There is also variability across the world, and this variability also increases as temperature rises, increasing geographical disparities in impact. River flood risk would increase particularly rapidly in <a href="https://theconversation.com/vanishing-mekong-shifting-tropical-storms-threaten-a-great-river-delta-67342">south Asia</a>, for example, and drought increases at faster than the global rate across <a href="https://theconversation.com/chad-is-the-country-most-vulnerable-to-climate-change-heres-why-78423">much of Africa</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/429760/original/file-20211102-52913-6wpr63.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="People walk through flooded street" src="https://images.theconversation.com/files/429760/original/file-20211102-52913-6wpr63.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/429760/original/file-20211102-52913-6wpr63.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/429760/original/file-20211102-52913-6wpr63.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/429760/original/file-20211102-52913-6wpr63.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/429760/original/file-20211102-52913-6wpr63.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/429760/original/file-20211102-52913-6wpr63.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/429760/original/file-20211102-52913-6wpr63.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Rivers in Asia will become even more flood-prone.</span>
<span class="attribution"><span class="source">Dreame Walker / shutterstock</span></span>
</figcaption>
</figure>
<p>The difference between 1.5°C and 3°C can be stark even in places like the UK where the impacts of climate change will be relatively less severe than elsewhere. In a <a href="https://iopscience.iop.org/article/10.1088/2515-7620/ac24c0/meta">recent study</a>, colleagues and I found that in England the average annual likelihood of a heatwave as defined by the Met Office increases from around 40% now to around 65% at 1.5°C and over 90% at 3°C, and at 3°C the chance of experiencing at least one day in a year with high heat stress is greater than 50%. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/429774/original/file-20211102-17-1wp3qlr.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Lots of graphs" src="https://images.theconversation.com/files/429774/original/file-20211102-17-1wp3qlr.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/429774/original/file-20211102-17-1wp3qlr.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=226&fit=crop&dpr=1 600w, https://images.theconversation.com/files/429774/original/file-20211102-17-1wp3qlr.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=226&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/429774/original/file-20211102-17-1wp3qlr.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=226&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/429774/original/file-20211102-17-1wp3qlr.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=283&fit=crop&dpr=1 754w, https://images.theconversation.com/files/429774/original/file-20211102-17-1wp3qlr.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=283&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/429774/original/file-20211102-17-1wp3qlr.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=283&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Change in heatwaves, heat-stress and river flooding across England at different levels of warming (from Arnell et al., 2021). The two different colours represent different ensembles of climate models and highlight uncertainty.</span>
<span class="attribution"><a class="source" href="https://iopscience.iop.org/article/10.1088/2515-7620/ac24c0/meta#ercac24c0f2">Arnell et al., 2021</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The average proportion of time in drought increases at a similar rate to the global average. The chances of what is currently considered a ten-year flood increases in the north west of England from 10% each year now to 12% at 1.5°C and 16% at 3°C. As at the global scale, there is considerable variability in impact across the UK, with risks related to high temperature extremes and drought increasing most in the south and east, and risks associated with flooding increasing most in the north and west. Again, there is lots of uncertainty around some of these estimates, but the general direction of change and the difference between impacts at different levels of warming is clear.</p>
<p>The graphs in this article show the impact of climate change in terms of changes in the chance or occurrence of specific weather events. The real consequences for people will depend on how these direct physical impacts – the droughts, the heatwaves, the rising seas – affect livelihoods, health and interactions between elements of the economy. </p>
<p>Our experience during COVID-19 tells us that what appear to be relatively modest initial perturbations to a system can lead to major and unanticipated knock-on effects, and we can expect this with climate change too. If the relationship between temperature increases and physical impacts like melting glaciers or extreme weather is often non-linear, then the relationship between temperature increases and the effects on people, societies and economies is likely to be very highly non-linear. All this means a 3°C world will be a lot worse than a 1.5°C world.</p>
<hr>
<figure class="align-right ">
<img alt="COP26: the world's biggest climate talks" src="https://images.theconversation.com/files/424739/original/file-20211005-17-cgrf2z.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/424739/original/file-20211005-17-cgrf2z.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/424739/original/file-20211005-17-cgrf2z.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/424739/original/file-20211005-17-cgrf2z.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/424739/original/file-20211005-17-cgrf2z.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/424739/original/file-20211005-17-cgrf2z.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/424739/original/file-20211005-17-cgrf2z.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p><strong>This story is part of The Conversation’s coverage on COP26, the Glasgow climate conference, by experts from around the world.</strong>
<br><em>Amid a rising tide of climate news and stories, The Conversation is here to clear the air and make sure you get information you can trust. <a href="https://page.theconversation.com/cop26-glasgow-2021-climate-change-summit/"><strong>More.</strong></a></em> </p>
<hr><img src="https://counter.theconversation.com/content/171030/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The work reported here was funded through UKRI (the UK Climate Resilience Programme) and other public funders over the years.</span></em></p>Many scientists now think 3°C of warming is likely.Nigel Arnell, Professor of Climate Change Science, Director of the Walker Institute, University of ReadingLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1651682021-07-28T00:45:35Z2021-07-28T00:45:35ZMore livestock, more carbon dioxide, less ice: the world’s climate change progress since 2019 is (mostly) bad news<p>Back in 2019, more than 11,000 scientists <a href="https://www.sydney.edu.au/news-opinion/news/2019/11/06/world-scientists-declare-climate-emergency.html">declared a global climate emergency</a>. They established a comprehensive set of <a href="https://doi.org/10.1093/biosci/biz088">vital signs</a> that impact or reflect the planet’s health, such as forest loss, fossil fuel subsidies, glacier thickness, ocean acidity and surface temperature. </p>
<p>In a new <a href="https://academic.oup.com/bioscience/article-lookup/doi/10.1093/biosci/biab079">paper</a> published today, we show how these vital signs have changed since the original publication, including through the COVID-19 pandemic. In general, while we’ve seen lots of positive talk and commitments from some governments, our vital signs are mostly not trending in the right direction. </p>
<p>So, let’s look at how things have progressed since 2019, from the growing number of livestock to the meagre influence of the pandemic. </p>
<h2>Is it all bad news?</h2>
<p>No, thankfully. Fossil fuel divestment and fossil fuel subsidies have improved in record-setting ways, potentially signalling an economic shift to a renewable energy future. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/413266/original/file-20210727-16-natj1l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/413266/original/file-20210727-16-natj1l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=327&fit=crop&dpr=1 600w, https://images.theconversation.com/files/413266/original/file-20210727-16-natj1l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=327&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/413266/original/file-20210727-16-natj1l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=327&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/413266/original/file-20210727-16-natj1l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=411&fit=crop&dpr=1 754w, https://images.theconversation.com/files/413266/original/file-20210727-16-natj1l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=411&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/413266/original/file-20210727-16-natj1l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=411&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The graph on the left shows an increase in fossil fuel divestment by 1,117 organisations based on data from 350.org, and the graph on the right shows a decrease in subsidies for fossil fuels based on the International Energy Agency subsidies database. The red lines show changes since our original publication in 2019.</span>
</figcaption>
</figure>
<p>However, most of the other vital signs reflect the consequences of the so far unrelenting “business as usual” approach to climate change policy worldwide. </p>
<p>Especially troubling is the unprecedented surge in climate-related disasters since 2019. This includes devastating flash floods in the <a href="https://www.greenpeace.org/international/story/47545/climate-emergencies-in-2021/">South Kalimantan province of Indonesia</a>, record heatwaves in the <a href="https://edition.cnn.com/2021/06/16/weather/west-heat-wave-records-drought-climate/index.html">southwestern United States</a>, extraordinary <a href="https://edition.cnn.com/2021/05/18/india/india-cyclone-tauktae-covid-monsoon-intl-hnk/index.html">storms in India</a> and, of course, the <a href="https://www.wwf.org.au/ArticleDocuments/353/WWF_Impacts-of-the-unprecedented-2019-2020-bushfires-on-Australian-animals.pdf">2019-2020 megafires in Australia</a>.</p>
<p>In addition, three main greenhouse gases — carbon dioxide, methane and nitrous oxide — set records for atmospheric concentrations in 2020 and again in 2021. In April this year, carbon dioxide concentration reached <a href="https://gml.noaa.gov/ccgg/trends/">416 parts per million</a>, the highest monthly global average concentration ever recorded.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/413434/original/file-20210727-15-9ycas8.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/413434/original/file-20210727-15-9ycas8.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=240&fit=crop&dpr=1 600w, https://images.theconversation.com/files/413434/original/file-20210727-15-9ycas8.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=240&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/413434/original/file-20210727-15-9ycas8.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=240&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/413434/original/file-20210727-15-9ycas8.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=302&fit=crop&dpr=1 754w, https://images.theconversation.com/files/413434/original/file-20210727-15-9ycas8.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=302&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/413434/original/file-20210727-15-9ycas8.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=302&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Time series of three climate-related responses. The red lines show changes since our original publication in 2019.</span>
</figcaption>
</figure>
<p>Last year was also the <a href="https://www.noaa.gov/news/2020-was-earth-s-2nd-hottest-year-just-behind-2016">second hottest year in recorded history</a>, with the five hottest years on record all occurring since 2015.</p>
<p>Ruminant livestock — cattle, buffalo, sheep, and goats — now number more than <a href="https://wolfkind.neocities.org/livestock/counter.html">4 billion</a>, and their total mass is more than that of all humans and wild mammals combined. This is a problem because these animals are responsible for impacting biodiversity, releasing huge amounts of methane emissions, and land continues to be cleared to make room for them. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/413268/original/file-20210727-21-t2hahd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/413268/original/file-20210727-21-t2hahd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=398&fit=crop&dpr=1 600w, https://images.theconversation.com/files/413268/original/file-20210727-21-t2hahd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=398&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/413268/original/file-20210727-21-t2hahd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=398&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/413268/original/file-20210727-21-t2hahd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=500&fit=crop&dpr=1 754w, https://images.theconversation.com/files/413268/original/file-20210727-21-t2hahd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=500&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/413268/original/file-20210727-21-t2hahd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=500&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">There are now more than 4 billion livestock on Earth.</span>
<span class="attribution"><span class="source">Flickr</span></span>
</figcaption>
</figure>
<p>In better news, recent per capita meat production <a href="http://www.fao.org/news/story/en/item/1287515/icode/">declined</a> by about 5.7% (2.9 kilograms per person) between 2018 and 2020. But this is likely because of an outbreak of African swine fever in China that reduced the pork supply, and possibly also as one of the impacts of the pandemic.</p>
<p>Tragically, Brazilian Amazon annual forest loss rates <a href="https://rainforests.mongabay.com/amazon/deforestation-rate.html">increased in both 2019 and 2020</a>. It reached a 12-year high of 1.11 million hectares deforested in 2020.</p>
<p>Ocean acidification is also near an all-time record. Together with heat stress from warming waters, acidification threatens the coral reefs that more than half a billion people depend on for food, tourism dollars and storm surge protection.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/413265/original/file-20210727-21-u4jrie.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/413265/original/file-20210727-21-u4jrie.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=397&fit=crop&dpr=1 600w, https://images.theconversation.com/files/413265/original/file-20210727-21-u4jrie.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=397&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/413265/original/file-20210727-21-u4jrie.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=397&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/413265/original/file-20210727-21-u4jrie.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=499&fit=crop&dpr=1 754w, https://images.theconversation.com/files/413265/original/file-20210727-21-u4jrie.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=499&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/413265/original/file-20210727-21-u4jrie.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=499&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Map of land-ocean temperature index anomaly in June, relative to the 1951-1980 baseline.</span>
<span class="attribution"><span class="source">Oregon State/NASA</span></span>
</figcaption>
</figure>
<h2>What about the pandemic?</h2>
<p>With its myriad economic interruptions, the COVID-19 pandemic had the side effect of providing some climate relief, but only of the ephemeral variety.</p>
<p>For example, fossil-fuel consumption has gone <a href="https://www.bp.com/content/dam/bp/business-sites/en/global/corporate/pdfs/energy-economics/statistical-review/bp-stats-review-2021-full-report.pdf">down since 2019</a> as did <a href="https://data.worldbank.org/indicator/IS.AIR.PSGR">airline travel levels</a>. </p>
<p>But all of these are expected to significantly rise as the economy reopens. While global gross domestic product dropped by <a href="https://data.worldbank.org/indicator/NY.GDP.MKTP.KD">3.6% in 2020</a>, it is projected to rebound to an all-time high.</p>
<p>So, a major lesson of the pandemic is that even when fossil-fuel consumption and transportation sharply decrease, it’s still insufficient to tackle climate change. </p>
<p>There is growing evidence we’re getting close to or have already gone beyond <a href="https://theconversation.com/failure-is-not-an-option-after-a-lost-decade-on-climate-action-the-2020s-offer-one-last-chance-158913">tipping points</a> associated with important parts of the Earth system, including warm-water coral reefs, the Amazon rainforest and the West Antarctic and Greenland ice sheets.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/413269/original/file-20210727-20-1c0k5wz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/413269/original/file-20210727-20-1c0k5wz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=398&fit=crop&dpr=1 600w, https://images.theconversation.com/files/413269/original/file-20210727-20-1c0k5wz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=398&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/413269/original/file-20210727-20-1c0k5wz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=398&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/413269/original/file-20210727-20-1c0k5wz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=500&fit=crop&dpr=1 754w, https://images.theconversation.com/files/413269/original/file-20210727-20-1c0k5wz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=500&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/413269/original/file-20210727-20-1c0k5wz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=500&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Warming waters are threatening West Antarctic and Greenland ice sheets.</span>
<span class="attribution"><span class="source">Flickr</span></span>
</figcaption>
</figure>
<h2>OK, so what do we do about it?</h2>
<p>In our 2019 paper, we urged six critical and interrelated steps governments — and the rest of humanity — can take to lessen the worst effects of climate change:</p>
<ol>
<li><p>prioritise energy efficiency, and replace fossil fuels with low-carbon renewable energy </p></li>
<li><p>reduce emissions of short-lived pollutants such as methane and soot</p></li>
<li><p>curb land clearing to protect and restore the Earth’s ecosystems </p></li>
<li><p>reduce our <a href="https://theconversation.com/how-to-feed-a-growing-population-healthy-food-without-ruining-the-planet-108994">meat consumption</a></p></li>
<li><p>move away from unsustainable ideas of ever-increasing economic and resource consumption</p></li>
<li><p>stabilise and, ideally, gradually <a href="https://www.economist.com/international/2019/02/02/thanks-to-education-global-fertility-could-fall-faster-than-expected">reduce human populations</a> while improving human well-being especially by educating girls and women globally.</p></li>
</ol>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/ikmI4wx9MRE?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p>These solutions still apply. But in our updated 2021 paper, we go further, highlighting the potential for a three-pronged approach for near-term policy:</p>
<ol>
<li><p>a globally implemented carbon price</p></li>
<li><p>a phase-out and eventual ban of fossil fuels</p></li>
<li><p>strategic environmental reserves to safeguard and restore natural carbon sinks and biodiversity.</p></li>
</ol>
<p>A global price for carbon needs to be high enough to induce decarbonisation across industry. </p>
<p>And our suggestion to create strategic environmental reserves, such as forests and wetlands, reflects the need to stop treating the climate emergency as a stand-alone issue. </p>
<p>By stopping the unsustainable exploitation of natural habitats through, for example, creeping urbanisation, and land degradation for mining, agriculture and forestry, we can reduce animal-borne disease risks, protect carbon stocks and conserve biodiversity — all at the same time.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/413285/original/file-20210727-22-1lzn2dl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A kangaroo in burnt bushland" src="https://images.theconversation.com/files/413285/original/file-20210727-22-1lzn2dl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/413285/original/file-20210727-22-1lzn2dl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/413285/original/file-20210727-22-1lzn2dl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/413285/original/file-20210727-22-1lzn2dl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/413285/original/file-20210727-22-1lzn2dl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/413285/original/file-20210727-22-1lzn2dl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/413285/original/file-20210727-22-1lzn2dl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">There has been a worrying number of disasters since 2019, including Australia’s megafires.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>Is this actually possible?</h2>
<p>Yes, and many opportunities still exist to shift pandemic-related financial support measures into climate friendly activities. Currently, <a href="https://www.oecd.org/coronavirus/en/themes/green-recovery">only 17% of such funds</a> had been allocated that way worldwide, as of early March 2021. This percentage could be lifted with serious coordinated, global commitment.</p>
<p>Greening the economy could also address the longer term need for major transformative change to reduce emissions and, more broadly, the over-exploitation of the planet.</p>
<p>Our planetary vital signs make it clear we need urgent action to address climate change. With new commitments getting made by governments all over the world, we hope to see the curves in our graphs changing in the right directions soon. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/11-000-scientists-warn-climate-change-isnt-just-about-temperature-126261">11,000 scientists warn: climate change isn't just about temperature</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/165168/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Thomas Newsome is a member of the Australian Mammal Society and Ecological Society of Australia, is on the Council of the Royal Zoological Society of NSW, and is acting President of the Australasian Wildlife Management Society. No funding beyond support from The University of Sydney (employer) was provided specifically for this work. </span></em></p><p class="fine-print"><em><span>Christopher Wolf and William Ripple 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>But with new commitments getting made by governments all over the world, we hope to see this progress improve soon.Thomas Newsome, Academic Fellow, University of SydneyChristopher Wolf, Postdoctoral Scholar, Oregon State UniversityWilliam Ripple, Distinguished Professor and Director, Trophic Cascades Program, Oregon State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1589132021-04-14T20:09:54Z2021-04-14T20:09:54Z‘Failure is not an option’: after a lost decade on climate action, the 2020s offer one last chance<figure><img src="https://images.theconversation.com/files/394911/original/file-20210414-21-g0xgpd.jpg?ixlib=rb-1.1.0&rect=8%2C17%2C5742%2C3794&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>In May 2011, almost precisely a decade ago, the government-appointed Climate Commission released its <a href="https://www.climatecouncil.org.au/uploads/34ab075fb66ce1b08976ed1505bec7a3.pdf">inaugural report</a>. Titled The Critical Decade, the report’s final section warned that to keep global temperature rises to 2°C this century, “the decade between now and 2020 is critical”.</p>
<p>As the report noted, if greenhouse gas emissions peaked around 2011, the world’s emissions-reduction trajectory would have been easily manageable: net-zero by around 2060, and a maximum emissions reduction rate of 3.7% each year. Delaying the emissions peak by only a decade would require a trebling of this task – a maximum 9% reduction each year.</p>
<p>But, of course, the decade to 2020 did not mark the beginning of the world’s emissions-reduction journey. Global emissions <a href="https://doi.org/10.5194/essd-12-3269-2020">accelerated</a> before dropping marginally under COVID-19 restrictions, then quickly <a href="https://www.iea.org/news/after-steep-drop-in-early-2020-global-carbon-dioxide-emissions-have-rebounded-strongly">rebounding</a>.</p>
<p>Our new report, <a href="https://www.climatecouncil.org.au/resources/net-zero-emissions-plummet-decade/">released today</a>, shows the immense cost of this inaction. It is now virtually certain Earth will pass the critical 1.5°C temperature rise this century – most likely in the 2030s. Now, without delay, humanity must focus on holding warming to well below 2°C. For Australia, that means tripling its emissions reduction goal this decade to 75%. </p>
<figure class="align-center ">
<img alt="Young girl holds sign at climate protest" src="https://images.theconversation.com/files/394910/original/file-20210414-19-13bqe54.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/394910/original/file-20210414-19-13bqe54.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=337&fit=crop&dpr=1 600w, https://images.theconversation.com/files/394910/original/file-20210414-19-13bqe54.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=337&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/394910/original/file-20210414-19-13bqe54.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=337&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/394910/original/file-20210414-19-13bqe54.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/394910/original/file-20210414-19-13bqe54.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/394910/original/file-20210414-19-13bqe54.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The 2020s offer a last chance to keep warming within 2°C this century, and leave a habitable planet for future generations.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>Aim high, go fast</h2>
<p>The Climate Council report is titled Aim High: Go Fast: Why Emissions Need To Plummet This Decade. It acknowledges the <a href="https://theconversation.com/earth-may-temporarily-pass-dangerous-1-5-warming-limit-by-2024-major-new-report-says-145450">multiple</a> lines of <a href="https://www.carbonbrief.org/analysis-when-might-the-world-exceed-1-5c-and-2c-of-global-warming">evidence</a> showing it will be virtually impossible to keep average global temperature rise to 1.5°C or below this century, without a period of significant overshoot and “drawdown”. (This refers to a hypothetical period in which warming exceeds 1.5°C then cools back down due to the removal of carbon dioxide (CO₂) from the atmosphere.) </p>
<p>The <a href="https://climate.nasa.gov/evidence/">increasing rate</a> of climate change, insights from past climates, and a vanishing <a href="https://climateanalytics.org/publications/2019/zero-in-on-the-remaining-carbon-budget-and-decadal-warming-rates/">carbon budget</a> all suggest the 1.5°C threshold will in fact be crossed very soon, in the 2030s.</p>
<p>There is no safe level of global warming. Already, at a global average temperature rise of <a href="https://www.carbonbrief.org/state-of-the-climate-how-the-world-warmed-in-2019">1.1°C</a>, we’re experiencing more powerful <a href="https://climate.nasa.gov/blog/2956/how-climate-change-may-be-impacting-storms-over-earths-tropical-oceans/">storms</a>, destructive <a href="http://media.bom.gov.au/social/blog/1760/explainer-what-is-a-marine-heatwave/">marine</a> and <a href="https://www.bbc.com/news/world-europe-48756480">land</a> heatwaves, and a new age of <a href="https://www.anu.edu.au/news/all-news/australia%E2%80%99s-black-summer-a-climate-wake-up-call">megafires</a>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/cyclone-seroja-just-demolished-parts-of-wa-and-our-warming-world-will-bring-more-of-the-same-158769">Cyclone Seroja just demolished parts of WA – and our warming world will bring more of the same</a>
</strong>
</em>
</p>
<hr>
<p>As the Intergovernmental Panel on Climate Change <a href="https://www.ipcc.ch/sr15/">has warned</a>, the consequences of breaching 1.5°C warming will be stark. Heatwaves, droughts, bushfires and intense rain events will become even more severe. Sea levels will rise, species will become extinct and crop yields will fall. Coral reefs, including the Great Barrier Reef, will decline by up to 90%.</p>
<p>And perhaps most frighteningly, overshooting 1.5°C runs a greater risk of crossing “<a href="https://www.pnas.org/content/115/33/8252">tipping points</a>”, such as the collapse of ice sheets and the release of natural carbon stores in forests and permafrost. Crossing those thresholds may set off irreversible changes to the global climate system, and destroy critical ecosystems on which life on Earth depends. </p>
<figure class="align-center ">
<img alt="An ice sheet in Greenland" src="https://images.theconversation.com/files/394913/original/file-20210414-13-1htlheb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/394913/original/file-20210414-13-1htlheb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/394913/original/file-20210414-13-1htlheb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/394913/original/file-20210414-13-1htlheb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/394913/original/file-20210414-13-1htlheb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/394913/original/file-20210414-13-1htlheb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/394913/original/file-20210414-13-1htlheb.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">Climate tipping points, such as melting ice sheets, may set off irreversible changes in natural systems.</span>
<span class="attribution"><span class="source">John McConnico/AP</span></span>
</figcaption>
</figure>
<h2>Every fraction of a degree matters</h2>
<p>The outlook may be dire, but every fraction of a degree of avoided warming matters. Its value will be measured in terms of human lives, species and ecosystems saved. We can, and must, limit warming to well below 2°C. The goal is very challenging, but still achievable.</p>
<p>The strategies, technologies and pathways needed to tackle the climate challenge are <a href="https://www.climateworksaustralia.org/resource/decarbonisation-futures-solutions-actions-and-benchmarks-for-a-net-zero-emissions-australia/">now emerging</a> as fast as the risks are escalating. And in the lead-up to the COP26 climate conference in Glasgow later this year, there’s widespread momentum for international cooperation and action.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/seriously-ugly-heres-how-australia-will-look-if-the-world-heats-by-3-c-this-century-157875">Seriously ugly: here's how Australia will look if the world heats by 3°C this century</a>
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</em>
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<p>Many of Australia’s strategic allies and major trading partners – including the <a href="https://theconversation.com/after-bidens-win-australia-needs-to-step-up-and-recommit-to-this-vital-un-climate-change-fund-150444">United States</a>, <a href="https://www.bbc.com/news/world-europe-55273004">Europe</a>, the <a href="https://www.gov.uk/government/news/uk-sets-ambitious-new-climate-target-ahead-of-un-summit">United Kingdom</a> and <a href="https://theconversation.com/china-just-stunned-the-world-with-its-step-up-on-climate-action-and-the-implications-for-australia-may-be-huge-147268">China</a> – are <a href="https://www.climatecouncil.org.au/climate-action-overseas-some-good-news-change/">starting to move</a> on climate change. But Australia is standing still. This is despite our nation being <a href="https://www.ipcc.ch/assessment-report/ar5/">one of the most vulnerable</a> to climate change – and despite us having some of the <a href="https://www.uts.edu.au/sites/default/files/article/downloads/ISF_100%25_Australian_Renewable_Energy_Report.pdf">world’s best</a> renewable energy resources. </p>
<p>We must urgently grab these opportunities. We propose Australia radically scale up its emissions-reduction targets – to a 75% cut by 2030 from 2005 levels (up from the current 26-28% target). Australia should also aim to reach net-zero emissions by 2035. Doing so by 2050 – a goal Prime Minister Scott Morrison says is his <a href="https://theconversation.com/scott-morrison-has-embraced-net-zero-emissions-now-its-time-to-walk-the-talk-154478">preference</a> – is too late.</p>
<figure class="align-center ">
<img alt="A coal plant" src="https://images.theconversation.com/files/394918/original/file-20210414-17-flf6e4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/394918/original/file-20210414-17-flf6e4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/394918/original/file-20210414-17-flf6e4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/394918/original/file-20210414-17-flf6e4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/394918/original/file-20210414-17-flf6e4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/394918/original/file-20210414-17-flf6e4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/394918/original/file-20210414-17-flf6e4.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">Polluting industries such as coal will have to give way to cleaner industries.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>A huge but achievable task</h2>
<p>Such dramatic action is clearly daunting. There are political, technical and other challenges ahead because action has been delayed. But a 75% emissions-reduction target is a fair and achievable contribution to the global effort. </p>
<p>Australia’s unrivalled potential for renewable energy means it can transform the electricity sector and beyond. Electric vehicles can lead to carbon-free transport and renewably generated electricity and green hydrogen can decarbonise industry. </p>
<p>The emerging new economy is <a href="https://www.climatecouncil.org.au/resources/clean-jobs-plan/">bringing jobs</a> to regional Australia and building cleaner cities by reducing fossil fuel pollution. There is staggering potential for a massive new industry built on the export to Asia of clean energy and products made from <a href="https://www.industry.gov.au/data-and-publications/australias-national-hydrogen-strategy">clean hydrogen</a>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/morrison-has-embraced-net-zero-emissions-its-time-to-walk-the-talk-154478">Morrison has embraced net-zero emissions – it's time to walk the talk</a>
</strong>
</em>
</p>
<hr>
<p>State, territory and local governments are <a href="https://www.theguardian.com/environment/2020/dec/02/net-zero-emissions-by-2050-target-climate-summit-president-thanks-australian-states-but-not-morrison-government">leading the way</a> in this transformation. The federal government must now join the effort.</p>
<p>The transition will no doubt be disruptive at times, and involve hard decisions. Industries such as coal will disappear and others will emerge. This will bring economic and social change which must be managed sensitively and carefully. </p>
<p>But the long-term benefits of achieving a stable climate far outweigh the short-term disruptions. As our report concludes:</p>
<blockquote>
<p>The pathway we choose now will either put us on track for a much brighter future for our children, or lock in escalating risks of dangerous climate change. The decision is ours to make. Failure is not an option.</p>
</blockquote>
<hr>
<p><em>Climate Council researcher <a href="https://www.climatecouncil.org.au/author/simon-bradshawclimatecouncil-org-au/">Dr Simon Bradshaw</a> contributed to this article.</em></p><img src="https://counter.theconversation.com/content/158913/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Will Steffen is a Councillor with the Climate Council of Australia.</span></em></p>Australia must treble its emissions reduction targets and reach net-zero emissions by 2035. Without this and other radical global action, the chance to hold warming to well below 2°C will pass us by.Will Steffen, Emeritus Professor, Fenner School of Environment & Society, Australian National UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1352702020-04-02T10:37:58Z2020-04-02T10:37:58ZArctic climate change – it’s recent carbon emissions we should fear, not ancient methane ‘time bombs’<figure><img src="https://images.theconversation.com/files/324682/original/file-20200401-23105-1y1dxys.JPG?ixlib=rb-1.1.0&rect=1092%2C644%2C2968%2C2184&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Joshua Dean</span>, <span class="license">Author provided</span></span></figcaption></figure><p>The Arctic is predicted to warm faster than anywhere else in the world <a href="https://www.nature.com/articles/s41558-020-0694-3">this century</a>, perhaps by as much as 7°C. These rising temperatures threaten one of the largest long-term stores of carbon on land: permafrost.</p>
<p>Permafrost is permanently frozen soil. The generally cold temperatures in the Arctic keep soils there frozen year-on-year. Plants grow in the uppermost soil layers during the short summers and then decay into soil, which freezes when the winter snow arrives. </p>
<p>Over thousands of years, carbon has built up in these frozen soils, and they’re now estimated to contain <a href="https://www.nature.com/articles/d41586-019-01313-4">twice the carbon</a> currently in the atmosphere. Some of this carbon is more than 50,000 years old, which means the plants that decomposed to produce that soil grew over 50,000 years ago. These soil deposits are known as “<a href="https://nsidc.org/cryosphere/glossary/term/yedoma">Yedoma</a>”, which are mainly found in the East Siberian Arctic, but also in parts of Alaska and Canada.</p>
<p>As the region warms, the permafrost is thawing, and this frozen carbon is being released to the atmosphere as carbon dioxide and methane. Methane release is particularly worrying, as it’s a highly potent greenhouse gas.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/324685/original/file-20200401-23100-koiudm.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/324685/original/file-20200401-23100-koiudm.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/324685/original/file-20200401-23100-koiudm.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/324685/original/file-20200401-23100-koiudm.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/324685/original/file-20200401-23100-koiudm.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/324685/original/file-20200401-23100-koiudm.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/324685/original/file-20200401-23100-koiudm.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">Arctic landscapes are changing rapidly as the region warms.</span>
<span class="attribution"><span class="source">Joshua Dean</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>But <a href="https://science.sciencemag.org/content/367/6480/907">a recent study</a> suggested that the release of methane from ancient carbon sources – sometimes referred to as the Arctic methane “bomb” – didn’t contribute much to the warming that occurred during the last deglaciation – the period after the last ice age. This occurred 18,000 to 8,000 years ago, a period that climate scientists study intently, as it’s the last time global temperatures rose by 4°C, which is <a href="https://www.reuters.com/article/us-climate-change-un/global-temperatures-on-track-for-3-5-degree-rise-by-2100-u-n-idUSKCN1NY186">roughly what is predicted</a> for the world by 2100.</p>
<p>This study suggested to many that ancient methane emissions are not something we should be worried about <a href="https://science.sciencemag.org/content/367/6480/846">this century</a>. But in <a href="https://www.nature.com/articles/s41467-020-15511-6">new research</a>, we found that this optimism may be misplaced.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-arctic-is-turning-brown-because-of-weird-weather-and-it-could-accelerate-climate-change-107590">The Arctic is turning brown because of weird weather – and it could accelerate climate change</a>
</strong>
</em>
</p>
<hr>
<h2>‘Young’ versus ‘old’ carbon</h2>
<p>We went to the East Siberian Arctic to compare the age of different forms of carbon found in the ponds, rivers and lakes. These waters thaw during the summer and leak greenhouse gases from the surrounding permafrost. We measured the age of the carbon dioxide, methane and organic matter found in these waters using radiocarbon dating and found that most of the carbon released to the atmosphere was overwhelmingly “young”. Where there was intense permafrost thaw, we found that the oldest methane was 4,800 years old, and the oldest carbon dioxide was 6,000 years old. But over this vast Arctic landscape, the carbon released was mainly from young plant organic matter.</p>
<p>This means that the carbon produced by plants growing during each summer growing season is rapidly released over the next few summers. This rapid turnover releases much more carbon than the thaw of older permafrost, even where severe thaw is occurring.</p>
<p>So what does this mean for future climate change? It means that carbon emissions from a warming Arctic may not be driven by the thawing of an ancient frozen carbon bomb, as it’s often described. Instead, most emissions may be relatively new carbon that is produced by plants that grew fairly recently.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/324688/original/file-20200401-23086-glemjl.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/324688/original/file-20200401-23086-glemjl.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/324688/original/file-20200401-23086-glemjl.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/324688/original/file-20200401-23086-glemjl.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/324688/original/file-20200401-23086-glemjl.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/324688/original/file-20200401-23086-glemjl.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/324688/original/file-20200401-23086-glemjl.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">Arctic lakes are growing sources of methane emissions to the atmosphere.</span>
<span class="attribution"><span class="source">Joshua Dean</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>What this shows is that the age of the carbon released from the warming Arctic is less important than the amount and form it takes. Methane is 34 times more potent than carbon dioxide as a greenhouse gas over a <a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2017RG000559">100-year timeframe</a>. The East Siberian Arctic is a generally flat and wet landscape, and these are conditions which produce lots of methane, as there’s less oxygen in soils which might otherwise create carbon dioxide during thaws instead. As a result, potent methane could well dominate the greenhouse gas emissions from the region.</p>
<p>Since most of the emissions from the Arctic this century will likely be from “young” carbon, we may not need to worry about ancient permafrost adding substantially to modern climate change. But the Arctic will still be a huge source of carbon emissions, as carbon that was soil or plant matter only a few hundred years ago leaches to the atmosphere. That will increase as warmer temperatures lengthen growing seasons in the Arctic summer. </p>
<p>The fading spectre of an ancient methane time bomb is cold comfort. The new research should urge the world to act boldly on climate change, to limit how much natural processes in the Arctic can contribute to the problem.</p><img src="https://counter.theconversation.com/content/135270/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Joshua Dean received funding for this work from the Netherlands Earth System Science Centre (NESSC), financially supported by the Ministry of Education, Culture and Science (OCW), grant number: 024.002.001. </span></em></p>The wet and low-lying East Siberian Arctic is likely to be a major methane source in the coming decades.Joshua Dean, Lecturer in Biogeochemical Cycles, University of LiverpoolLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1330082020-03-10T16:03:19Z2020-03-10T16:03:19ZHuge ecosystems could collapse in less than 50 years – new study<figure><img src="https://images.theconversation.com/files/319627/original/file-20200310-61084-1xyqx4q.png?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The Amazon (left) may one day look more like the Serengeti (right). </span> <span class="attribution"><span class="source">worldclassphoto / GTS Productions / shutterstock</span></span></figcaption></figure><p>We know that ecosystems under stress can reach a point where they rapidly collapse into something very different. The clear water of a pristine lake can turn algae-green in a matter of months. In hot summers, a colourful coral reef can soon become bleached and virtually barren. And if a tropical forest has its canopy significantly reduced by deforestation, the loss of humidity can cause a shift to savanna grassland with few trees. </p>
<p>We know this can happen because such changes have already been widely observed. But our research, now published in the journal <a href="https://www.nature.com/articles/s41467-020-15029-x">Nature Communications</a>, shows that the size of the ecosystem is important. Once a “tipping point” is triggered, large ecosystems could collapse much faster than we had thought possible. It’s a finding that has worrying implications for the functioning of our planet.</p>
<p>We started off by wondering how the size of the ecosystem might affect the time taken for these changes (ecologists call them “regime shifts”) to happen. It seems intuitive to expect large ecosystems to shift more slowly than small ones. If so, would the relationship between shift time and size be the same for lakes, corals, fisheries and forests? </p>
<p>We began by analysing data for about 40 regime shifts that had already been observed by scientists. These ranged in size from very small ponds in North America, through to savanna grassland in Botswana, the Newfoundland fishery and the Black Sea aquatic ecosystem. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/319618/original/file-20200310-61148-1yez03x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/319618/original/file-20200310-61148-1yez03x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/319618/original/file-20200310-61148-1yez03x.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/319618/original/file-20200310-61148-1yez03x.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/319618/original/file-20200310-61148-1yez03x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/319618/original/file-20200310-61148-1yez03x.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/319618/original/file-20200310-61148-1yez03x.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">Fish like the beluga once ruled the Black Sea, but their reign ended in an ecological collapse that took just 40 years.</span>
<span class="attribution"><span class="source">alexkoral</span></span>
</figcaption>
</figure>
<p>We found that larger ecosystems do indeed take longer to collapse than small systems, due to the diffusion of stresses across large distances and time-lags. The relationship does seem to hold across different types of ecosystem: lakes take longer than ponds, forests take longer to collapse than a copse, and so on.</p>
<p>But what really stood out was that larger systems shift relatively faster. A forest that is 100 times bigger than another forest will not take 100 times longer to collapse – it actually collapses much more quickly than that. This is quite a profound finding because it means that large ecosystems that have been around for thousands of years could collapse in less than 50 years. Our mean estimates suggest the Caribbean coral reefs could collapse in only 15 years and the whole Amazon rainforest in just 49 years.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/319605/original/file-20200310-61099-1oanczj.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/319605/original/file-20200310-61099-1oanczj.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/319605/original/file-20200310-61099-1oanczj.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=465&fit=crop&dpr=1 600w, https://images.theconversation.com/files/319605/original/file-20200310-61099-1oanczj.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=465&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/319605/original/file-20200310-61099-1oanczj.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=465&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/319605/original/file-20200310-61099-1oanczj.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=584&fit=crop&dpr=1 754w, https://images.theconversation.com/files/319605/original/file-20200310-61099-1oanczj.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=584&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/319605/original/file-20200310-61099-1oanczj.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=584&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Real world observations (solid line) predict large ecosystems will collapse relatively faster than predicted by a simple linear relationship (dashed line).</span>
<span class="attribution"><span class="source">Dearing et al</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>What explains this phenomenon? To find out, we ran five computer models that simulated things like predation and herbivory (think: wolves, sheep and grasslands) or social networks (how accents spread through society). The models support the data in that large systems collapse relatively faster than small ones. </p>
<p>However, the models also provide further insight. For example, large ecosystems often have relatively more species and habitats existing as connected compartments, or sub-systems. This enhanced “modularity” actually makes the system more resilient to stress and collapse, rather like the water-tight compartments in a ship prevent it from sinking if the hull is breached. </p>
<p>But paradoxically, the same modularity seems to allow a highly stressed system to unravel more quickly once a collapse starts. And because large systems are relatively more modular, their collapse is relatively faster.</p>
<p>These unravelling effects should add to concerns about the effects of fires on the long-term resilience of the Amazon to climate change, or the rapid spread of recent bush fires in Australia caused by existing fires igniting further fires. The only upside to our finding concerns ecosystems that have already been managed into alternate regimes, such as human-made agricultural landscapes. These now have much less modularity, and thus may experience relatively slow transitions in the face of climate change or other stresses.</p>
<p>The messages are stark. Humanity now needs to prepare for changes in ecosystems that are faster than we previously envisaged through our traditional linear view of the world. Large iconic ecosystems like the Amazon rainforest or the Caribbean coral reefs are likely to collapse over relatively short “human timescales” of years and decades once a tipping point is triggered. Our findings are yet another reason to halt the environmental damage that is pushing ecosystems to their limits.</p>
<hr>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=140&fit=crop&dpr=1 600w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=140&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=140&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=176&fit=crop&dpr=1 754w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=176&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=176&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p><em><a href="https://theconversation.com/imagine-newsletter-researchers-think-of-a-world-with-climate-action-113443?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=Imagineheader1133008">Click here to subscribe to our climate action newsletter. Climate change is inevitable. Our response to it isn’t.</a></em></p><img src="https://counter.theconversation.com/content/133008/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>John Dearing received funding from the Deltas, Vulnerability and Climate Change: Migration and Adaptation (DECCMA) project under the Collaborative Adaptation Research Initiative in Africa and Asia (CARIAA) program with financial support from the UK Government’s Department for International Development (DFID) and the International Development Research Centre (IDRC), Canada (Grant No. 107642-001). The views expressed in this work are those of the creators and do not necessarily represent those of DFID and IDRC or its Boards of Governors. He is a professor at the University of Southampton. He is also a member of the Green Party of England and Wales and an elected local councillor at Warwick District Council. </span></em></p><p class="fine-print"><em><span>Greg Cooper received a research studentship from the Deltas, Vulnerability and Climate Change: Migration and Adaptation(DECCMA) project under the Collaborative Adaptation Research Initiative in Africa and Asia (CARIAA) program with financial support from the UK Government’s Department for International Development (DFID) and the International Development Research Centre (IDRC), Canada. The views expressed in this work are those of the creators and do not necessarily represent those of DFID and IDRC or its Boards of Governors.</span></em></p><p class="fine-print"><em><span>Simon Willcock receives funding from UK research and innovation (project numbers: NE/L001322/1, NE/T00391X/1, ES/R009279/1 and ES/R006865/1). He is affiliated with Bangor University. </span></em></p>Our findings have worrying implications for the functioning of our planet.John Dearing, Professor of Physical Geography, University of SouthamptonGreg Cooper, Postdoctoral Research Fellow, Centre for Development, Environment and Policy, SOAS, University of LondonSimon Willcock, Senior Lecturer in Environmental Geography, Bangor UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1238172019-09-24T13:31:09Z2019-09-24T13:31:09ZNot convinced on the need for urgent climate action? Here’s what happens to our planet between 1.5°C and 2°C of global warming<p>Many numbers are bandied around in climate emergency discussions. Of them, 1.5°C is perhaps the most important. At the Paris Agreement in 2015, governments agreed to limit global warming to well below 2°C and to aim for 1.5°C. By 2018, the Intergovernmental Panel on Climate Change – the UN body tasked with relaying the science of climate breakdown to the world – had made worryingly clear in a <a href="https://theconversation.com/ipcc-1-5-report-heres-what-the-climate-science-says-104592">special report</a> how much graver the consequences of the higher number would be.</p>
<p>Together with the University of Queensland’s Ove Hoegh-Guldberg and colleagues around the world, we’ve explored in <a href="https://science.sciencemag.org/cgi/doi/10.1126/science.aaw6974">newly published work</a> just how much sticking to 1.5°C matters.</p>
<p>Climate breakdown is already harming livelihoods, cities and ecosystems. From heatwaves and droughts to cyclones and floods, devastating <a href="https://www.ipcc.ch/site/assets/uploads/2018/03/SREX_FD_SPM_final-2.pdf">extreme weather events</a> are more frequent, more intense and more unpredictable than they would be in the absence of global heating. Warming and acidifying oceans are causing severe coral bleaching <a href="https://science.sciencemag.org/content/359/6371/80">to occur twice as often</a> as in 1980, leaving many unable to recover.</p>
<p>Shrinking habitats are increasingly <a href="https://theconversation.com/polar-bear-invasion-how-climate-change-is-making-human-wildlife-conflicts-worse-111654">forcing wildlife into conflict with human settlements</a>. Increasing wildfires are <a href="https://theconversation.com/increasing-wildfires-threaten-to-turn-northern-hemispheres-boreal-forests-from-vital-carbon-stores-into-climate-heaters-122069">damaging vital carbon stores</a> in North America and Siberia, while the <a href="https://www.theguardian.com/environment/2018/mar/02/arctic-spring-is-starting-16-days-earlier-than-a-decade-ago-study-shows">advance of spring</a> is throwing species who depend on each other out of sync. </p>
<p>The more we destabilise our climate, the greater the risk to human societies and ecosystems. Even at 1.5°C of global heating, tough times are in store for the living planet. But the space between 1.5°C and 2°C of heating is a crucial battleground, within which risks to humanity and ecosystems amplify rapidly.</p>
<h2>Climate battleground</h2>
<p>At 1.5°C of warming, about one in twenty insect and vertebrate species will disappear from half of the area they currently inhabit, as will around one in ten plants. At 2°C, this proportion doubles for plants and vertebrates. For insects, it triples.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/293659/original/file-20190923-54813-c74mhk.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/293659/original/file-20190923-54813-c74mhk.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=422&fit=crop&dpr=1 600w, https://images.theconversation.com/files/293659/original/file-20190923-54813-c74mhk.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=422&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/293659/original/file-20190923-54813-c74mhk.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=422&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/293659/original/file-20190923-54813-c74mhk.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=530&fit=crop&dpr=1 754w, https://images.theconversation.com/files/293659/original/file-20190923-54813-c74mhk.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=530&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/293659/original/file-20190923-54813-c74mhk.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=530&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A great many risks amplify between 1.5 and 2 degrees of warming.</span>
<span class="attribution"><a class="source" href="https://www.ipcc.ch/site/assets/uploads/sites/2/2019/06/SR15_Chapter3_Low_Res.pdf">Hoegh-Guldberg, Jacob, Taylor/IPCC</a></span>
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<p>Such high levels of species loss will put many ecosystems across the world at <a href="https://iopscience.iop.org/article/10.1088/1748-9326/8/4/044018/meta">risk of collapse</a>. We rely on healthy ecosystems to pollinate crops, maintain fertile soil, prevent floods, purify water, and much more. Conserving them is essential for human survival and prosperity.</p>
<p>Between 1.5°C and 2°C, the number of extremely hot days <a href="http://pure.iiasa.ac.at/id/eprint/11706/1/ngeo2595-aop.pdf">increases exponentially</a>. Some parts of the world can also expect less rain and more consecutive dry days, while others will receive more extreme floods. Collectively, this will place agriculture, water levels and human health under severe stress – especially in <a href="https://iopscience.iop.org/article/10.1088/1748-9326/aab190">southern African nations</a>, where temperatures will increase faster than the global average. The Mediterranean is another key area at particular risk above 1.5°C of heating, where increased drought will alter flora and fauna in a way <a href="https://science.sciencemag.org/content/354/6311/465.full">without precedent in ten millennia</a>.</p>
<p>At 1.5°C of warming, we could expect to lose between 70% and 90% of our coral reefs. While this would be catastrophic for the millions of ocean creatures and human livelihoods these beautiful ecosystems support, there would still be a chance of recovery in the long term if oceans warm slowly. But at 2°C of warming, we could kill <a href="https://www.ipcc.ch/sr15/chapter/chapter-3/">99% of reefs</a>. To be clear, this is a line that once crossed cannot be easily uncrossed. It could mean the extinction of thousands of species.</p>
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Read more:
<a href="https://theconversation.com/what-climate-tipping-points-are-and-how-they-could-suddenly-change-our-planet-49405">What climate 'tipping points' are – and how they could suddenly change our planet</a>
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<p>Arctic sea ice has been a constant on our planet for hundreds of thousands, perhaps millions of years. If we limit global heating to 1.5°C, there’s a 70% chance of it remaining that way. But at 2°C, <a href="https://www.nature.com/articles/s41558-018-0127-8">some Arctic summers will be ice-free</a>. <a href="https://www.ipcc.ch/site/assets/uploads/2018/02/WGIIAR5-Chap28_FINAL.pdf">Polar bears</a> and other species who depend on frozen sea ice to eat and breed will be left homeless and struggling to survive.</p>
<p>Studies show that at 1.5°C, we could expect <a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2017EF000732">one metre of sea-level rise in 2300, with an extra 26cm at 2°C</a>. However, between these two levels of global heating, the risk of the Greenland and West Antarctic Ice Sheets starting a slow process of decline <a href="https://www.ipcc.ch/site/assets/uploads/sites/2/2019/06/SR15_Chapter3_Low_Res.pdf">dramatically increases</a>. For the Greenland sheet, this is likeliest to happen at <a href="https://www.nature.com/articles/nclimate1449">1.6°C</a>, with the Antarctic ice sheet’s <a href="https://theconversation.com/what-climate-tipping-points-are-and-how-they-could-suddenly-change-our-planet-49405">tipping point</a> hovering <a href="https://www.nature.com/articles/s41558-018-0305-8">not far above</a> this mark.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/293643/original/file-20190923-54790-n9m2yz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/293643/original/file-20190923-54790-n9m2yz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/293643/original/file-20190923-54790-n9m2yz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/293643/original/file-20190923-54790-n9m2yz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/293643/original/file-20190923-54790-n9m2yz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/293643/original/file-20190923-54790-n9m2yz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/293643/original/file-20190923-54790-n9m2yz.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">Polar bears depend on Arctic sea ice.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/high-angle-mother-polar-bear-cub-155217797?src=o0q_shN6p3JsMU5MT1d9qg-1-12">FloridaStock/Shutterstock</a></span>
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<p>If these ice sheets melt, seas could rise by <a href="https://www.ipcc.ch/site/assets/uploads/sites/2/2019/06/SR15_Chapter3_Low_Res.pdf">up to two metres over the next two centuries</a>. These rises could lead to <a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2017EF000738">millions more people being exposed to flooding each year</a>. Many of those living in coastal cities, <a href="https://royalsocietypublishing.org/doi/full/10.1098/rsta.2016.0448">deltas, or small islands</a> will be faced with little option but to build upwards or relocate.</p>
<h2>Way off track</h2>
<p>The impacts of climate breakdown are accelerating. The planet has warmed by <a href="https://www.nature.com/articles/s41598-017-14828-5">1.1°C since 1850-79</a>, but 0.2°C of this warming happened <a href="http://ane4bf-datap1.s3-eu-west-1.amazonaws.com/wmocms/s3fs-public/ckeditor/files/Five_year_report_2015-2019_0.pdf?4M6Z45W4mlGplwRxbJnQrgi08Ssq5LXe">between 2011 and 2015 alone</a>. The last four years <a href="https://gallery.mailchimp.com/daf3c1527c528609c379f3c08/files/82234023-0318-408a-9905-5f84bbb04eee/Climate_Statement_2018.pdf">were the warmest in the global temperature record</a>.</p>
<p>Despite knowing all the above, many country-level commitments and action are <a href="https://climateactiontracker.org/">nowhere near enough</a> to limit warming to 2°C, let alone 1.5°C. We’re heading for <a href="https://www.theguardian.com/environment/2019/sep/23/countries-must-triple-climate-emissions-targets-to-limit-global-heating-to-2c">2.9°C to 3.4°C of warming</a>. By this point, many dangerous <a href="https://theconversation.com/what-climate-tipping-points-are-and-how-they-could-suddenly-change-our-planet-49405">tipping points</a> could be crossed, leading to <a href="https://www.ipcc.ch/site/assets/uploads/sites/2/2019/06/SR15_Chapter3_Low_Res.pdf">rainforest die-back, deadly heatwaves, and significant sea-level rise</a>. Half of all insect and plant species are projected to disappear from <a href="https://science.sciencemag.org/content/360/6390/791.full">more than half of the area they currently inhabit</a>, potentially causing widespread ecosystem collapse and threatening organised human civilisation itself.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/five-things-every-government-needs-to-do-right-now-to-tackle-the-climate-emergency-123344">Five things every government needs to do right now to tackle the climate emergency</a>
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</p>
<hr>
<p>Limiting warming to 1.5°C will <a href="https://www.ipcc.ch/sr15/chapter/chapter-3/">save the global economy trillions of dollars</a> in the long run, even accounting for the <a href="https://www.ipcc.ch/sr15/chapter/chapter-2/">seemingly gargantuan cost</a> of transitioning our energy systems. But this is more than just an economic or academic issue – its a matter of life and death for millions of humans and animal species, and a severe threat to the well-being of billions.</p>
<p>Tackling climate breakdown is perhaps the tallest order humanity has ever faced, and there is no simple solution. The only way forward is accepting that we must fundamentally change the way we live our lives. It won’t be an easy transition, but there is no alternative if we are to preserve the well-being of humans, wildlife, and ecosystems. The coming year is vital, and there’s too much at stake not to act now.</p>
<hr>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=140&fit=crop&dpr=1 600w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=140&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=140&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=176&fit=crop&dpr=1 754w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=176&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=176&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p><em><a href="https://theconversation.com/imagine-newsletter-researchers-think-of-a-world-with-climate-action-113443?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=Imagineheader1123817">Click here to subscribe to our climate action newsletter. Climate change is inevitable. Our response to it isn’t.</a></em></p><img src="https://counter.theconversation.com/content/123817/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Rachel Warren receives funding from Natural Environment Research Council, the European Commission, and the UK Department of Business and Industrial Strategy. She was a lead author in the IPCC Special Report on 1.5°C.</span></em></p><p class="fine-print"><em><span>Sally Brown presently receives funding from funding from the Natural Environment Research Council (NE/S016651/1). She previously received relevant funding (on the impacts of a rise in 1.5°C in temperatures) from Natural Environment Research Council (NE/P01495X/1) and similar research projects, and was a lead author in the IPCC Special Report on 1.5°C.</span></em></p>Nations are signed up to limit global heating to well below 2°C, and to aim for 1.5°C. Limiting warming to the latter matters - the future of humanity and the living world is at stake.Rachel Warren, Professor of Global Change, University of East AngliaSally Brown, Senior Research Fellow, University of SouthamptonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1177962019-06-06T21:26:41Z2019-06-06T21:26:41ZLanguage matters when the Earth is in the midst of a climate crisis<figure><img src="https://images.theconversation.com/files/277418/original/file-20190531-69091-1xr1pyh.jpg?ixlib=rb-1.1.0&rect=142%2C123%2C3982%2C2622&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Tens of thousands of students march in Sydney, Australia in March 2019 to demand action on climate change.</span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><p><a href="https://medium.com/matter/it-s-not-climate-change-it-s-everything-change-8fd9aa671804">In a 2015 essay</a>, poet and novelist Margaret Atwood wrote, “It’s not climate change, it’s everything change.” </p>
<p>Atwood asked us back then to reconsider the term “climate change” because there is not a system — human or non-human — that will remain untouched by the impacts of climate change. Everything will be affected, and so, likely, everything (as we know it) will have to change.</p>
<p>The writing impressed me, and I agreed with her thesis, but somehow it wasn’t this essay that shook me up as much as another recent reading on climate change did. </p>
<p>The recent scientific <a href="https://www.ipcc.ch/sr15/">Special Report on the impacts of 1.5C of global warming</a> of the Intergovernmental Panel on Climate Change (IPCC) concluded: “Limiting global warming to 1.5C would require rapid, far-reaching and unprecedented changes in all aspects of society.” </p>
<p>That’s what gave me pause: Rapid. Far-reaching. Unprecedented. All aspects of society.</p>
<p>Everything screamed “emergency,” even though the word wasn’t used. </p>
<p>I know how cautious scientists can be in their communications — I am one myself. That is precisely why those words were sufficient to evoke an emotional response. </p>
<p>It was this shift in language (and not the countless graphs, reports, books and scientific articles I’d read — and indeed created myself — as a global-change ecologist) that finally elicited a tipping point in my own behaviour towards mitigating climate change. </p>
<h2>Between “cliffhanger” and “climbdown”</h2>
<p>Recently, the <em>Guardian</em> updated its <a href="https://www.theguardian.com/guardian-observer-style-guide-a">style guide</a> to revise its use of the term “climate change.” The move both echoes the tones of Atwood’s essay and the seriousness of the latest IPCC report. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/277510/original/file-20190602-69059-1j59yc8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/277510/original/file-20190602-69059-1j59yc8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/277510/original/file-20190602-69059-1j59yc8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/277510/original/file-20190602-69059-1j59yc8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/277510/original/file-20190602-69059-1j59yc8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/277510/original/file-20190602-69059-1j59yc8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/277510/original/file-20190602-69059-1j59yc8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/277510/original/file-20190602-69059-1j59yc8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Climate change or climate emergency?</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
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<p>The newly defined climate change terms appear in the guide, right between “cliffhanger” and “climbdown.” </p>
<blockquote>
<p>Climate change … is no longer considered to accurately reflect the seriousness of the situation; use climate emergency, crisis or breakdown instead.</p>
</blockquote>
<p>The IPCC reports with high confidence that global warming reached approximately 1C above pre-industrial levels in 2017, and several catastrophes, indeed we could say “emergencies,” including floods, forest fires, drought and storms <a href="https://www.nap.edu/catalog/21852/attribution-of-extreme-weather-events-in-the-context-of-climate-change">have been linked</a> to this change.</p>
<p><a href="https://sciencepolicy.colorado.edu/admin/publication_files/2017.04.pdf">Researchers have determined</a> that media can influence policy and public understanding of the environment. Both of these things can also affect human behaviour. So the language they use is indeed important. </p>
<p>The <em>Guardian</em> wants to <a href="https://www.theguardian.com/environment/2019/may/17/why-the-guardian-is-changing-the-language-it-uses-about-the-environment">tell it like it is</a>, but where did the term “climate change” come from in the first place?</p>
<h2>New terms now old?</h2>
<p>The study of anthropogenic climate change is quite old. Svante Arrhenius proposed the <a href="https://www.acs.org/content/acs/en/education/whatischemistry/landmarks/keeling-curve.html">connection between fossil fuel combustion and increases in global temperature</a> in 1896. In the late 1950s, Charles David Keeling’s measurements of atmospheric CO2 from the Mauna Koa Observatory determined the effect of human activities on the chemical composition of the global atmosphere. But widespread adoption of the term climate change is relatively new. </p>
<p>I was a student in the very first cohort of the Environmental Sciences Graduate Program at Western University more than 20 years ago. We learned about global warming and the greenhouse effect, both of which had become well-established facts decades earlier. But I don’t recall the term climate change ever being used in my courses and neither do some of my classmates.</p>
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Read more:
<a href="https://theconversation.com/the-meaning-of-environmental-words-matters-in-the-age-of-fake-news-106050">The meaning of environmental words matters in the age of 'fake news'</a>
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<p><a href="https://pmm.nasa.gov/education/articles/whats-name-global-warming-vs-climate-change">NASA claims the term</a> climate change <a href="https://science.sciencemag.org/content/189/4201/460">was introduced in 1975</a>, in an article titled “Climatic Change: Are We on the Brink of Pronounced Global Warming?” published in <em>Science</em>. </p>
<p>The article communicates the difference between the two commonly used terms: “Global warming: the increase in Earth’s average surface temperature due to rising levels of greenhouse gases. Climate change: a long-term change in the Earth’s climate, or of a region on Earth.” </p>
<p>Yet when my colleagues and I published our textbook <em><a href="https://www.cabi.org/bookshop/book/9781845937485">Climate Change Biology</a></em> in 2011, it was, to our surprise, one of the first with the term in its title in our field. With several climate change terms already in existence, it does merit some consideration as to what might be the impact of the new terms the <em>Guardian</em> wants to use. </p>
<h2>Climate change poetics</h2>
<p>Poets, who have been famously dubbed “the unacknowledged legislators of the world” by <a href="https://www.poetryfoundation.org/articles/69388/a-defence-of-poetry">Percy Bysshe Shelley</a>, know the power of language is not only about accuracy but also metaphorical potential. </p>
<p>Many poets, some of whom are discussed in the book <em><a href="https://www.npr.org/templates/story/story.php?storyId=102795472">Can Poetry Save the Earth?</a></em> have been working to use language to foster change. In my 2015 found poem based on one of my climate change scientific articles, “<a href="https://howapoemmoves.wordpress.com/2017/07/20/madhur-anand-especially-in-a-time/">Especially in a Time</a>,” I refer to a need for a new word for “change” when I write: “a prolonged change is also under scrutiny.” </p>
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<img alt="" src="https://images.theconversation.com/files/277511/original/file-20190602-69091-1rao9t9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/277511/original/file-20190602-69091-1rao9t9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/277511/original/file-20190602-69091-1rao9t9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/277511/original/file-20190602-69091-1rao9t9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/277511/original/file-20190602-69091-1rao9t9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/277511/original/file-20190602-69091-1rao9t9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/277511/original/file-20190602-69091-1rao9t9.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">Projections suggest that a recent trend towards heavy rainfall and flooding will continue in parts of the United States, Canada, Europe and elsewhere.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
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<p>But poetry alone, by definition, overshoots the aim to serve as specific propaganda, even for good causes, and thus we must also look to the language of other discourses to create the change we want. Certainly, <a href="https://www.wnycstudios.org/story/91728-words-that-change-the-world">politicians know the power of language when they prepare speeches</a>. </p>
<h2>What might emergency mean?</h2>
<p>The past few years there has been a dramatic <a href="https://www.doi.org/10.1038/539140a">change in the language</a> scientists use to communicate their science. This isn’t unusual; science could not progress without the invention of terms to communicate new discoveries precisely. </p>
<p>And to be fair, scientists have long referred to different kinds of change related to climate and weather in scientific papers. There’s “abrupt climate change,” “extreme events,” “acceleration” (the rate of change of change) and even “regime shifts,” which all have specific scientific definitions. </p>
<p>But generally speaking, scientists often refrain from using emotion-inducing language. As such, you will rarely find the term “emergency” in a scientific article about some new impact of climate change. </p>
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Read more:
<a href="https://theconversation.com/the-impact-of-climate-change-on-language-loss-105475">The impact of climate change on language loss</a>
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<p>Consider another example of language change from the <em>Guardian Style Guide</em>: The term “child abuse images” is recommended over “child pornography,” “child porn” and “kiddy porn,” to avoid “a misleading and potentially trivializing impression of what is a very serious crime.” Reporters and editors are also urged to add a footnote with details about support services to stories about child sexual abuse.</p>
<p>And the United Nations rarely uses the term genocide, but when it does, it demands attention. This includes “<a href="https://theconversation.com/un-report-documents-genocide-against-rohingya-what-now-102555">naming and shaming the persecutors</a>,” something others have said should be done for the climate crisis. </p>
<p>Not everyone is on board with changing “climate change” to “climate emergency.” Just this past week, my own city council <a href="https://globalnews.ca/news/5325462/guelph-city-council-climate-crisis-emergency-vote/">voted against it</a> in favour of the term “crisis.” Words do carry weight. <a href="https://www.guelphmercury.com/news-story/9394243-guelph-council-narrowly-votes-against-declaring-climate-emergency/">One of the councillors feared</a> that “to knowingly say emergency today, knowing that that will kick 20, 30, 40 per cent of the people in our city out of that conversation because they will not engage any more.” This councillor worried that if the general public heard this, some of them might disengage, thinking it was for the radicals, not them. </p>
<p>Arundhati Roy, one of my <a href="https://www.theguardian.com/commentisfree/2019/may/13/arundhati-roy-literature-shelter-pen-america">favourite writers</a>, is wary, and indeed prescient, of how the term “emergency” may get used by those in power. She finds, especially in India and the Global South, that “increasingly the vocabulary around it is being militarized. And no doubt very soon its victims will become the ‘enemies’ in the new war without end.” </p>
<p>Still, as a global citizen, as a scientist and as a poet, I commend the <em>Guardian</em> for its change in style. The IPCC report language led me to make personal lifestyle changes (diet, car, air plane use and divestment), but the word “emergency” adopted by governments and media would certainly make me more hopeful for the kind of rapid and far-reaching and unprecedented change we need. I wonder if in the future the style guide will include a footnote with details about support services for readers to be added to future climate emergency stories.</p><img src="https://counter.theconversation.com/content/117796/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Madhur Anand receives funding from the Natural Sciences and Engineering Council of Canada, the Canada First Research Excellence Fund & the James S. MacDonnell Foundation.</span></em></p>Can new language change the way the public and politicians perceive the hazards of the Earth’s changing climate?Madhur Anand, Professor & Director, Global Ecological Change & Sustainability Laboratory, University of GuelphLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1152442019-04-12T15:24:46Z2019-04-12T15:24:46ZTip the planet: tackling climate change with small, sensitive interventions<figure><img src="https://images.theconversation.com/files/269002/original/file-20190412-76856-129sc0d.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C4928%2C3253&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/man-working-solar-power-station-529456828">Sonpichit Salangsing/Shutterstock</a></span></figcaption></figure><p>Search online for “climate change” and “tipping points” and you’ll find some scary results. <a href="https://www.pnas.org/content/105/6/1786">Melting ice sheets</a>, the collapse of the <a href="https://www.pnas.org/content/105/6/1786#ref-1">Atlantic thermohaline circulation </a>, <a href="https://www.nature.com/articles/climate.2009.24">the permafrost methane “time bomb”</a> and the <a href="https://link.springer.com/content/pdf/10.1007/s00704-004-0049-4.pdf">die-back of the Amazon rainforest</a> threaten to <a href="https://www.theguardian.com/environment/2018/oct/09/tipping-points-could-exacerbate-climate-crisis-scientists-fear">exacerbate the climate crisis</a> and send global warming <a href="https://www.businessinsider.com/hothouse-earth-climate-change-tipping-point-2018-8?r=US&IR=T">spiralling out of control</a>.</p>
<p>But what if we could leverage similar tipping point dynamics to solve the climate problem? Like physical or environmental systems, socioeconomic and political systems can also exhibit nonlinear dynamics. Memes on the internet can go viral, loan defaults can cascade into financial crises, and public opinion can shift in rapid and radical ways.</p>
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Read more:
<a href="https://theconversation.com/what-climate-tipping-points-are-and-how-they-could-suddenly-change-our-planet-49405">What climate 'tipping points' are – and how they could suddenly change our planet</a>
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<p>In an article just out in <a href="https://science.sciencemag.org/cgi/doi/10.1126/science.aaw7287">Science</a>, we outline a new approach to climate change that tries to find areas in socioeconomic and political systems that are “sensitive” – where modest but well-timed interventions could generate outsized impacts and accelerate progress towards a post-carbon world.</p>
<h2>Sensitive Intervention Points (SIPs)</h2>
<p>These “Sensitive Intervention Points” – or SIPs – could trigger self-reinforcing feedback loops, which can amplify small changes to produce outsized effects. Take, for example, solar photovoltaics. As more solar panels are produced and deployed, costs fall through “learning-by-doing” as practice, market testing and incremental innovation make the whole process cheaper. </p>
<p>Cost reductions lead to greater demand, further deployment, more learning-by-doing, more cost reductions and so on. However, the spread of renewables isn’t just dependent on technology and cost improvements. Social dynamics can also play a major role. As people observe their neighbours installing rooftop solar panels they might be more inclined to do so themselves. This effect could cause a shift in cultural and social norms.</p>
<p>Financial markets are another key area where SIPs could help accelerate the transition to post-carbon societies. Many companies are currently failing to disclose and account for climate risks associated with assets on their balance sheet. Climate risk can entail physical risks, caused by extreme weather or flooding. They can also entail the risk of assets such as fossil fuel reserves becoming stranded as economies transition to limit warming to 1.5°C or 2°C, when such resources are no longer valuable.</p>
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<img alt="" src="https://images.theconversation.com/files/269003/original/file-20190412-76840-gzu9iz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/269003/original/file-20190412-76840-gzu9iz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/269003/original/file-20190412-76840-gzu9iz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/269003/original/file-20190412-76840-gzu9iz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/269003/original/file-20190412-76840-gzu9iz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/269003/original/file-20190412-76840-gzu9iz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/269003/original/file-20190412-76840-gzu9iz.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">Oil and other fossil fuel reserves could become stranded assets.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/oil-barrels-341071466?src=bX8agwRF21u5Wh92iHSTkw-1-2">The Sun photo/Shutterstock</a></span>
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<p>Most of the world’s current fossil fuel reserves <a href="https://www.theguardian.com/environment/2013/apr/17/why-cant-we-give-up-fossil-fuels">can’t be used</a> if the world is to limit warming and they become <a href="https://www.theguardian.com/environment/2018/jun/04/carbon-bubble-could-spark-global-financial-crisis-study-warns">effectively worthless</a> once this is acknowledged. By not accounting for these risks to fossil fuel assets, high-emission industries are effectively given an advantage over low-carbon alternatives that shouldn’t exist. Relatively modest changes to accounting and disclosure guidelines could make a significant difference.</p>
<p>If companies are required to disclose information about the climate risks associated with their assets – and if such disclosure is <a href="https://www.fsb-tcfd.org">consistent and comparable across companies</a> – investors can make more informed decisions and the implicit subsidy enjoyed by high-emission industries is likely to rapidly disappear.</p>
<p>Opportunities for triggering SIPs in a given system can also change over time. Sometimes “windows of opportunity” open up, where very unlikely changes become possible. A key example in the UK was the political climate in 2007-2008 which enabled the 2008 UK Climate Change Act to pass with near unanimous support. This national legislation was the first of its kind and committed the UK to reducing greenhouse gas emissions by 80% relative to 1990 levels by 2050.</p>
<p>The act also created a regular ratcheting cycle which encourages more ambitious future climate action. Since 2008, emissions in the UK have <a href="https://voxeu.org/article/driving-uks-capita-carbon-dioxide-emissions-below-1860-levels">fallen dramatically</a>. However, the UK Climate Change Act’s influence beyond the UK is also significant as it encouraged similar legislation in other countries, including the Paris Agreement, which contains the same self-reinforcing ratcheting mechanism.</p>
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<h2>Using SIPs for rapid change</h2>
<p>Thinking about SIPs in policy and business could accelerate the post-carbon transition – but much work lies ahead. The first step is to systematically identify potential SIPs and the mechanisms by which they can be amplified. </p>
<p>Unfortunately, traditional economic models commonly used to evaluate climate policy are <a href="https://www.nature.com/news/economics-current-climate-models-are-grossly-misleading-1.19416">poorly equipped to do this</a>, but new analytical methods are <a href="https://www.sciencedirect.com/science/article/pii/S157400211830011X">increasingly being used</a> in <a href="https://www.bankofengland.co.uk/-/media/boe/files/quarterly-bulletin/2016/agent-based-models-understanding-the-economy-from-the-bottom-up.pdf?la=en&hash=66A41463EC6EBCDD4B040AA27A8DF7929387A5B6">policy</a>. </p>
<p>These new methods could provide more accurate insights into the costs, benefits and possibilities of SIPs for addressing climate change. As SIPs could be present in all spheres of life, experts in social and natural sciences will need to work together.</p>
<p>The window to avert catastrophic climate change is closing fast, but with intelligent interventions at sensitive points in the system, we believe success is still possible. Since the stakes are so high – and the time frame so limited – it is not possible to chase every seemingly promising idea. But with a smart, strategic approach to unleashing feedback mechanisms and exploiting critical windows of opportunity in systems that are ripe for change, we may just be able to tip the planet onto a post-carbon trajectory.</p>
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<img alt="" src="https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=140&fit=crop&dpr=1 600w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=140&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=140&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=176&fit=crop&dpr=1 754w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=176&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=176&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p><em><a href="https://theconversation.com/imagine-newsletter-researchers-think-of-a-world-with-climate-action-113443?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=Imagineheader1115244">Click here to subscribe to our climate action newsletter. Climate change is inevitable. Our response to it isn’t.</a></em></p><img src="https://counter.theconversation.com/content/115244/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Matthew Carl Ives receives funding from the Oxford Martin School Post-carbon Transition Programme and a member of the UK University and College Union.</span></em></p><p class="fine-print"><em><span>Penny Mealy receives funding from the Oxford Martin School Post-carbon Transition Programme</span></em></p><p class="fine-print"><em><span>Thom Wetzer receives funding from the UK Economic and Social Research Council and the Oxford Clarendon Fund. </span></em></p>A rapid transition from fossil fuels is possible by targeting the ‘tipping points’ in our political and economic systems.Matthew Carl Ives, Senior Researcher in Economics, University of OxfordPenny Mealy, Research Fellow in Complexity Economics, University of OxfordThom Wetzer, DPhil (PhD) Candidate in Law and Finance, University of OxfordLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1017222018-08-22T22:38:56Z2018-08-22T22:38:56ZPolicies on petroleum and pipelines move us closer to a ‘Hothouse Canada’<figure><img src="https://images.theconversation.com/files/232967/original/file-20180821-149493-1abz1hf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Record-shattering heatwaves and exceptional wildfires have occurred throughout the northern hemisphere this summer. </span> <span class="attribution"><span class="source">U.S. Department of Agriculture</span></span></figcaption></figure><p>It is another hot, hot summer in the Northern Hemisphere. </p>
<p>Sweden is having trouble <a href="https://www.theguardian.com/world/2018/jul/30/the-swedish-town-on-the-frontline-of-the-arctic-wildfires">fighting wildfires north of the Arctic Circle</a>. <a href="https://www.bbc.com/news/world-europe-45030082">Greece has seen its worst wildfires in years</a>, and <a href="https://www.theguardian.com/news/2018/jul/02/weatherwatch-wildfires-uk-peatland-carbon-moors-moorland">even Britain has been scorched</a>. </p>
<p>In Canada, British Columbia has, once again, <a href="https://www.cbc.ca/news/canada/british-columbia/b-c-declares-state-of-emergency-as-hundreds-of-wildfires-burn-across-province-1.4785983">declared a state of emergency</a>, and <a href="https://calgaryherald.com/news/local-news/air-quality-deemed-high-risk-in-calgary-as-wildfires-burn">Calgary has air quality problems</a> because of the smoke. As researchers who watch these things know, all of this is <a href="https://thenarwhal.ca/how-climate-change-is-making-b-c-s-wildfire-season-hotter-longer-dryer/">being made worse by climate change</a>.</p>
<p>The remarkably hot summer and surge of wildfires coincides with the publication of a <a href="http://www.pnas.org/content/115/33/8252">recent essay about “Hothouse Earth” by Will Steffen, Johan Rockström</a> and their colleagues. The essay bluntly asks whether the Earth is heading towards a state it last experienced many million years ago when global temperatures were much higher and the world didn’t have polar icecaps. </p>
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Read more:
<a href="https://theconversation.com/hothouse-earth-our-planet-has-been-here-before-heres-what-it-looked-like-101413">Hothouse Earth: our planet has been here before – here's what it looked like</a>
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<p>Much of the media coverage of the paper says that we are, in fact, heading towards a hothouse Earth. But <a href="https://theconversation.com/hothouse-earth-heres-what-the-science-actually-does-and-doesnt-say-101341">the research points to a much more important conclusion</a>: if we take the risks seriously there is room for a more benign future. </p>
<p>Having worked on matters of security, political economy and environment for the past three decades, it’s clear to me that human actions — and how we use <a href="https://www.e-ir.info/2018/03/01/firepower-and-environmental-security-in-the-anthropocene/">combustion as a tool in particular</a> — are shaping the future of the planet. </p>
<h2>‘The Human Planet’</h2>
<p><em>The Human Planet</em>, a new book by scientists Simon Lewis and Mark Maslin, provides <a href="https://www.penguin.co.uk/books/298037/the-human-planet/">the background for the hothouse Earth research</a>. Their title says it all. Earth system science has documented the case that human actions — or at least those of the rich and powerful among us — are profoundly changing how the world works. </p>
<p>There are enough of us now, using all sorts of technologies and living in ways that use huge amounts of resources, to dramatically alter how the Earth works. We are part of the world, not a separate species who just happens to be on Earth. Our actions are now shaping the planet’s future. </p>
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Read more:
<a href="https://theconversation.com/hothouse-earth-heres-what-the-science-actually-does-and-doesnt-say-101341">Hothouse Earth: here's what the science actually does – and doesn't – say</a>
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<p>It may become the hothouse Earth that Steffen, Rockström and their colleagues warn is a dangerous possibility. Or, it may not, if sensible policies such as reducing greenhouse gas emissions and protecting and enhancing ecosystems that remove carbon dioxide from the atmosphere prevail, and economies move rapidly beyond the use of fossil fuels. </p>
<p>But if we are to avert a hothouse Earth, policies, like the sciences, need to connect things that are often considered separately. </p>
<h2>Energy policy</h2>
<p>Through much of the twentieth century Western governments have thought of energy security in terms of guaranteeing fossil fuel supplies at reasonable prices. Environmental matters were unrelated, or at best an after-thought, a matter of local pollution, <a href="https://global.oup.com/academic/product/the-energy-security-paradox-9780198820444?cc=gb&lang=en&#">not an Earth-changing matter</a>. </p>
<p>That mode of thought persists and as Earth system science has demonstrated, dangerously wrong. </p>
<p>In <em>The Human Planet</em>, Lewis and Maslin quote Prime Minister Justin Trudeau in his remarks at a <a href="https://www.cbc.ca/news/world/trudeau-no-country-would-find-173-billion-barrels-of-oil-in-the-ground-and-leave-them-there-1.4019321">Houston petroleum conference in 2017</a>: </p>
<blockquote>
<p>“No country would find 173 billion barrels of oil in the ground and just leave them there.”</p>
</blockquote>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/232970/original/file-20180821-149481-15b4ppt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/232970/original/file-20180821-149481-15b4ppt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/232970/original/file-20180821-149481-15b4ppt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/232970/original/file-20180821-149481-15b4ppt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/232970/original/file-20180821-149481-15b4ppt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/232970/original/file-20180821-149481-15b4ppt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/232970/original/file-20180821-149481-15b4ppt.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">Protesters opposed to the Kinder Morgan Trans Mountain pipeline extension demonstrate outside Justice Minister Jody Wilson-Raybould’s constituency office, in Vancouver, on June 4, 2018.</span>
<span class="attribution"><span class="source">(THE CANADIAN PRESS/Darryl Dyck)</span></span>
</figcaption>
</figure>
<p>Earth system science has shown precisely the opposite: most of those reserves must stay in the ground if we are to avoid a hothouse Earth. </p>
<p>If large supplies of petroleum continue to be made easily available, carbon taxes, cap and trade schemes and innovations with electric cars, batteries and storage systems, are very unlikely to be enough to tackle climate change. Turning off the tap and <a href="https://www.vox.com/energy-and-environment/2018/4/3/17187606/fossil-fuel-supply">keeping expensive, difficult-to-extract fossil fuels in the ground is an essential, “supply side” complement to the “demand side” of taxes and fees</a>.</p>
<p>Adding to the infrastructure that supplies the world’s markets with more petroleum, as the twinned Kinder Morgan pipeline would do, makes constraining fossil fuel use more difficult down the line. And using taxpayer’s dollars to do all this, if in fact the <a href="https://www.theglobeandmail.com/politics/article-study-predicts-trans-mountain-pipeline-buy-will-add-to-federal-deficit/">purchase of Kinder Morgan’s Trans Mountain pipeline goes ahead</a> in coming months, adds insult to injury. The political pressures to use the pipeline and hence get a return on the investment would be intense and distract attention from building a post-fossil fuel economy. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/canadas-paris-pipeline-paradox-97636">Canada's Paris-pipeline paradox</a>
</strong>
</em>
</p>
<hr>
<h2>Investing in the future</h2>
<p>The future configuration of the Earth’s climate is dependent on such investment decisions because they shape what is made in coming decades: solar panels or pipelines, carbon-neutral buildings or gas-guzzling automobiles. </p>
<p>This recognition is key to what needs to be done, and to the larger conversation we need to be having about how to live well together without burning large quantities of stuff to do so. We need to stop burning fossil fuels so that we can reduce the likelihood of burning even more forests, bogs and grasslands. </p>
<p>Joining up the dots is now ever more necessary. If we don’t start investing wisely in the new economy rather than propping up the old one, then the likelihood of a hothouse Earth looms large.</p><img src="https://counter.theconversation.com/content/101722/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Simon Dalby receives funding from the Social Sciences and Humanities Research Council of Canada.
I am a Senior Fellow of the Centre for International Governance Innovation.</span></em></p>The Earth is on the edge of being pushed over a planetary threshold that could lead to a “Hothouse Earth.” But if we take the risks seriously there is room for a more benign future.Simon Dalby, CIGI Chair in the Political Economy of Climate Change, Wilfrid Laurier UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/837762017-09-12T19:41:44Z2017-09-12T19:41:44ZHow Antarctic ice melt can be a tipping point for the whole planet’s climate<figure><img src="https://images.theconversation.com/files/185599/original/file-20170912-26996-15apq9m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Melting Antarctic ice can trigger effects on the other side of the globe.</span> <span class="attribution"><span class="source">NASA/Jane Peterson</span></span></figcaption></figure><p>Melting of Antarctica’s ice can trigger rapid warming on the other side of the planet, according to our <a href="https://www.nature.com/articles/s41467-017-00577-6">new research</a> which details how just such an abrupt climate event happened 30,000 years ago, in which the North Atlantic region warmed dramatically.</p>
<p>This idea of “tipping points” in Earth’s system has had something of a bad rap ever since the 2004 blockbuster <a href="http://www.imdb.com/title/tt0319262/">The Day After Tomorrow</a> purportedly showed how melting polar ice can trigger all manner of global changes.</p>
<p>But while the movie certainly exaggerated the speed and severity of abrupt climate change, we do know that many natural systems are vulnerable to being pushed into different modes of operation. The melting of Greenland’s ice sheet, the retreat of Arctic summer sea ice, and the collapse of the global ocean circulation are all examples of potential vulnerability in a future, warmer world.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/chasing-ice-how-ice-cores-shape-our-understanding-of-ancient-climate-55235">Chasing ice: how ice cores shape our understanding of ancient climate</a>
</strong>
</em>
</p>
<hr>
<p>Of course it is notoriously hard to predict when and where elements of Earth’s system will abruptly tip into a different state. A key limitation is that historical climate records are often too short to test the skill of our computer models used to predict future environmental change, hampering our ability to plan for potential abrupt changes. </p>
<p>Fortunately, however, <a href="http://www.sciencedirect.com/science/article/pii/S0277379116303766">nature preserves a wealth of evidence in the landscape that allows us to understand how longer time-scale shifts can happen</a>.</p>
<h2>Core values</h2>
<p>One of the most important sources of information on past climate tipping points are the kilometre-long cores of ice drilled from the Greenland and Antarctic ice sheets, which preserve exquisitely detailed information <a href="https://theconversation.com/the-three-minute-story-of-800-000-years-of-climate-change-with-a-sting-in-the-tail-73368">stretching back up to 800,000 years</a>. </p>
<p>The Greenland ice cores record <a href="http://onlinelibrary.wiley.com/doi/10.1002/2015GL066344/full">massive, millennial-scale swings in temperature</a> that have occurred across the North Atlantic region over the past 90,000 years. The scale of these swings is staggering: in some cases temperatures rose by 16°C in just a few decades or even years.</p>
<p>Twenty-five of these major so-called <a href="https://www.ncdc.noaa.gov/abrupt-climate-change/Heinrich%20and%20Dansgaard%E2%80%93Oeschger%20Events">Dansgaard–Oeschger (D-O) warming events</a> have been identified. These abrupt swings in temperature happened too quickly to have been caused by Earth’s slowly changing orbit around the Sun. Fascinatingly, when ice cores from Antarctica are compared with those from Greenland, we see a “seesaw” relationship: when it warms in the north, the south cools, and vice versa.</p>
<p>Attempts to explain the cause of this bipolar seesaw have traditionally focused on the North Atlantic region, and include melting ice sheets, changes in ocean circulation or wind patterns.</p>
<p>But as our new research shows, these might not be the only cause of D-O events.</p>
<p>Our new paper, <a href="https://www.nature.com/articles/s41467-017-00577-6">published today in Nature Communications</a>, suggests that another mechanism, with its origins in Antarctica, has also contributed to these rapid seesaws in global temperature.</p>
<h2>Tree of knowledge</h2>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/185597/original/file-20170912-28358-gzsv1v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/185597/original/file-20170912-28358-gzsv1v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/185597/original/file-20170912-28358-gzsv1v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=900&fit=crop&dpr=1 600w, https://images.theconversation.com/files/185597/original/file-20170912-28358-gzsv1v.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=900&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/185597/original/file-20170912-28358-gzsv1v.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=900&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/185597/original/file-20170912-28358-gzsv1v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1131&fit=crop&dpr=1 754w, https://images.theconversation.com/files/185597/original/file-20170912-28358-gzsv1v.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1131&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/185597/original/file-20170912-28358-gzsv1v.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">The 30,000-year-old key to climate secrets.</span>
<span class="attribution"><span class="source">Chris Turney</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>We know that there have been <a href="http://science.sciencemag.org/content/sci/288/5472/1815.full.pdf?ck=nck">major collapses of the Antarctic ice sheet in the past</a>, raising the possibility that these may have tipped one or more parts of the Earth system into a different state. To investigate this idea, we analysed an ancient New Zealand kauri tree that was extracted from a peat swamp near Dargaville, Northland, and which lived between 29,000 and 31,000 years ago. </p>
<p>Through accurate dating, we know that this tree lived through a short D-O event, during which (as explained above) temperatures in the Northern Hemisphere would have risen. Importantly, the unique pattern of atmospheric radioactive carbon (or carbon-14) found in the tree rings allowed us to identify similar changes preserved in climate records from ocean and ice cores (the latter using beryllium-10, an isotope formed by similar processes to carbon-14). This tree thus allows us to compare directly what the climate was doing during a D-O event beyond the polar regions, providing a global picture.</p>
<p>The extraordinary thing we discovered is that the warm D-O event coincided with a 400-year period of surface cooling in the south and <a href="http://science.sciencemag.org/content/sci/288/5472/1815.full.pdf?ck=nck">a major retreat of Antarctic ice</a>. </p>
<p>When we searched through other climate records for more information about what was happening at the time, we found no evidence of a change in ocean circulation. Instead we found a collapse in the rain-bearing Pacific trade winds over tropical northeast Australia that was coincident with the 400-year southern cooling. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/two-centuries-of-continuous-volcanic-eruption-may-have-triggered-the-end-of-the-ice-age-83420">Two centuries of continuous volcanic eruption may have triggered the end of the ice age</a>
</strong>
</em>
</p>
<hr>
<p>To explore how melting Antarctic ice might cause such dramatic change in the global climate, we used a climate model to simulate the release of large volumes of freshwater into the Southern Ocean. The model simulations all showed the same response, in agreement with our climate reconstructions: regardless of the amount of freshwater released into the Southern Ocean, the surface waters of the tropical Pacific nevertheless warmed, causing changes to wind patterns that in turn triggered the North Atlantic to warm too. </p>
<p>Future work is now focusing on what caused the Antarctic ice sheets to retreat so dramatically. Regardless of how it happened, it looks like melting ice in the south can drive abrupt global change, something of which we should be aware in a future warmer world.</p><img src="https://counter.theconversation.com/content/83776/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Chris Turney receives funding from the Australian Research Council.</span></em></p><p class="fine-print"><em><span>Jonathan Palmer receives funding from the Australian Research Council (ARC). </span></em></p><p class="fine-print"><em><span>Peter Kershaw has received fundng from the Australian Research Council.</span></em></p><p class="fine-print"><em><span>Steven Phipps receives funding from the Australian Antarctic Science Program, the Australian Research Council, the International Union for Quaternary Research, the National Computational Infrastructure Merit Allocation Scheme, the New Zealand Marsden Fund, the University of Tasmania and UNSW Australia.</span></em></p><p class="fine-print"><em><span>Zoe Thomas receives funding from the Australian Research Council. </span></em></p>The climate secrets contained in an ancient tree that lived through abrupt global change reveal how Antarctica can trigger rapid warming in the north by dumping cold water into the Southern Ocean.Christian Turney, Professor of Earth Sciences and Climate Change, UNSW SydneyJonathan Palmer, Research Fellow, School of Biological, Earth and Environmental Sciences., UNSW SydneyPeter Kershaw, Emeritus Professor, Earth, Atmosphere and Environment, Monash UniversitySteven Phipps, Palaeo Ice Sheet Modeller, University of TasmaniaZoë Thomas, Research Associate, UNSW SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/820512017-09-01T14:32:46Z2017-09-01T14:32:46ZWhat the Industrial Revolution really tells us about the future of automation and work<figure><img src="https://images.theconversation.com/files/184260/original/file-20170831-2020-1l0nrf9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Where are all the people in this factory?</span> <span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/California-Economy/6bff05f67d36408ea7f7a752472224e1/23/0">AP Photo/Jeff Chiu</a></span></figcaption></figure><p>As automation and artificial intelligence technologies improve, many people worry about the future of work. If millions of human workers no longer have jobs, <a href="https://www.theguardian.com/technology/2017/jan/11/robots-jobs-employees-artificial-intelligence">the worriers ask</a>, what will people do, how will they provide for themselves and their families, and what <a href="https://theconversation.com/basic-income-after-automation-thats-not-how-capitalism-works-65023">changes might occur</a> (or be needed) in order for society to adjust? </p>
<p>Many economists say there is <a href="https://qz.com/932417/robots-wont-take-your-job-theyll-help-make-room-for-meaningful-work-instead/">no need to worry</a>. They point to how past major transformations in work tasks and labor markets – specifically the Industrial Revolution during the 18th and 19th centuries – did not lead to <a href="https://www.fastcompany.com/3049079/robots-might-take-your-job-but-heres-why-you-shouldnt-worry">major social upheaval or widespread suffering</a>. These economists say that when technology destroys jobs, people find other jobs. As <a href="https://www.project-syndicate.org/commentary/technology-unemployment-jobs-internet-by-kenneth-rogoff">one economist argued</a>:</p>
<blockquote>
<p>“Since the dawn of the industrial age, a recurrent fear has been that technological change will spawn mass unemployment. Neoclassical economists predicted that this would not happen, because people would find other jobs, albeit possibly after a long period of painful adjustment. By and large, that prediction has proven to be correct.” </p>
</blockquote>
<p>They are definitely right about the long period of painful adjustment! The aftermath of the Industrial Revolution involved <a href="https://www.independent.co.uk/arts-entertainment/books/news/maos-great-leap-forward-killed-45-million-in-four-years-2081630.html">two major</a> <a href="http://www.nytimes.com/1989/02/04/world/major-soviet-paper-says-20-million-died-as-victims-of-stalin.html">Communist revolutions</a>, whose <a href="http://necrometrics.com/20c5m.htm">death toll approaches 100 million</a>. The stabilizing influence of the <a href="http://americanhistory.oxfordre.com/view/10.1093/acrefore/9780199329175.001.0001/acrefore-9780199329175-e-276">modern social welfare state</a> emerged only <a href="https://www.theguardian.com/politics/2001/mar/14/past.education">after World War II</a>, nearly 200 years on from the 18th-century beginnings of the Industrial Revolution. </p>
<p>Today, as <a href="https://theconversation.com/are-robots-taking-our-jobs-56537">globalization and automation</a> dramatically boost corporate productivity, many workers have seen their wages stagnate. The increasing power of automation and artificial intelligence technology means more pain may follow. Are these economists minimizing the historical record when projecting the future, essentially telling us not to worry because <a href="https://www.economist.com/news/finance-and-economics/21723403-recent-rise-earnings-skilled-workers-rare-phenomenon-what-history">in a century or two things will get better</a>?</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/184255/original/file-20170831-32045-18h9aci.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/184255/original/file-20170831-32045-18h9aci.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/184255/original/file-20170831-32045-18h9aci.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=391&fit=crop&dpr=1 600w, https://images.theconversation.com/files/184255/original/file-20170831-32045-18h9aci.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=391&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/184255/original/file-20170831-32045-18h9aci.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=391&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/184255/original/file-20170831-32045-18h9aci.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=491&fit=crop&dpr=1 754w, https://images.theconversation.com/files/184255/original/file-20170831-32045-18h9aci.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=491&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/184255/original/file-20170831-32045-18h9aci.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=491&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Upheaval more than a century into the Industrial Revolution, and more than 100 years ago: An International Workers of the World union demonstration in New York City in 1914.</span>
<span class="attribution"><a class="source" href="https://loc.gov/pictures/resource/cph.3a31188/">Library of Congress</a></span>
</figcaption>
</figure>
<h2>Reaching a tipping point</h2>
<p>To learn from the Industrial Revolution, we must put it in the proper historical context. The Industrial Revolution was
<a href="https://www.hachettebookgroup.com/titles/malcolm-gladwell/tipping-point-the/9780316316965/">a tipping point</a>. For many thousands of years before it, economic growth was practically negligible, generally tracking with population growth: Farmers grew a bit more food and blacksmiths made a few more tools, but people from the early agrarian societies of Mesopotamia, Egypt, China and India would have recognized the world of 17th-century Europe.</p>
<p>But when steam power and industrial machinery came along in the 18th century, <a href="https://www.theatlantic.com/business/archive/2012/06/the-economic-history-of-the-last-2-000-years-in-1-little-graph/258676/">economic activity took off</a>. The growth that happened in just a couple hundred years was on a vastly different scale than anything that had happened before. We may be at a similar tipping point now, referred to by some as the “<a href="https://www.weforum.org/about/the-fourth-industrial-revolution-by-klaus-schwab">Fourth Industrial Revolution</a>,” where all that has happened in the past may appear minor compared to the productivity and profitability potential of the future.</p>
<h2>Getting predictions wrong</h2>
<p>It is easy to underestimate in advance the impact of globalization and automation – I have done it myself. In March 2000, the <a href="https://www.cnbc.com/15-years-after-nasdaqs-peak-look-how-its-changed/">NASDAQ Composite Index peaked</a> and then <a href="https://fred.stlouisfed.org/series/NASDAQCOM">crashed</a>, wiping out <a href="https://www.newyorker.com/magazine/2002/11/11/the-next-crash">US$8 trillion in market valuations</a> over the next two years. At the same time, the global spread of the internet enabled <a href="http://www.sfgate.com/business/article/Techies-see-jobs-go-overseas-Opposition-to-2571861.php">offshore outsourcing</a> of software production, leading to <a href="http://www.cnn.com/2004/ALLPOLITICS/02/23/timep.jobs.tm/">fears of information technology jobs</a> <a href="http://archive.boston.com/business/articles/2004/05/25/at_the_center_of_a_culture_shift/">disappearing en masse</a>.</p>
<p>The <a href="http://www.acm.org">Association for Computing Machinery</a> worried what these factors might mean for computer education and employment in the future. Its study group, which I co-chaired, reported in 2006 that there was <a href="http://www.acm.org/globalizationreport">no real reason to believe</a> that computer industry jobs were migrating away from developed countries. The last decade has <a href="https://www.bls.gov/ooh/computer-and-information-technology/software-developers.htm#tab-6">vindicated that conclusion</a>.</p>
<p>Our report conceded, however, that “trade gains may be distributed differentially,” meaning some individuals and regions would gain and others would lose. And it was focused narrowly on the information technology industry. Had we looked at the broader impact of globalization and automation on the economy, we might have seen the much bigger changes that even then were taking hold.</p>
<h2>Spreading to manufacturing</h2>
<p>In both the first Industrial Revolution and today’s, the first effects were in manufacturing in the developed world. By substituting technology for workers, U.S. <a href="https://www.aei.org/publication/phenomenal-gains-in-manufacturing-productivity/print/">manufacturing productivity roughly doubled</a> between 1995 and 2015. As a result, while U.S. manufacturing output today is <a href="https://fred.stlouisfed.org/series/OUTMS">essentially at an all-time high</a>, employment peaked around 1980, and has been <a href="https://fred.stlouisfed.org/series/MANEMP">declining precipitously since 1995</a>.</p>
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<p>Unlike in the 19th century, though, the effects of globalization and automation are spreading across the developing world. Economist Branko Milanovic’s “<a href="http://prospect.org/article/worlds-inequality">Elephant Curve</a>” shows how people around the globe, ranked by their income in 1998, saw their incomes increase by 2008. While the income of the very poor was stagnant, <a href="http://www.resolutionfoundation.org/app/uploads/2016/09/Examining-an-elephant.pdf">rising incomes in emerging economies</a> lifted hundreds of millions of people <a href="http://www.gc.cuny.edu/CUNY_GC/media/CUNY-Graduate-Center/LIS%20Center/elephant_debate-4,-reformatted.pdf">out of poverty</a>. People at the very top of the income scale also benefited from globalization and automation. </p>
<p>But the income of working- and middle-class people in the developed world has stagnated. In the U.S., for example, income of production workers today, adjusted for inflation, is essentially <a href="https://fred.stlouisfed.org/graph/?g=eUHS">at the level it was around 1970</a>.</p>
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<p>Now automation is also coming to developing-world economies. A recent report from the International Labor Organization found that more than two-thirds of Southeast Asia’s 9.2 million <a href="http://www.ilo.org/public/english/dialogue/actemp/whatwedo/aseanpubs/report2016_r1_techn.htm">textile and footwear jobs are threatened</a> by automation.</p>
<h2>Waking up to the problems</h2>
<p>In addition to spreading across the world, automation and artificial intelligence are beginning to pervade entire economies. <a href="https://www.fastcompany.com/3067279/you-didnt-see-this-coming-10-jobs-that-will-be-replaced-by-robots">Accountants, lawyers, truckers and even construction workers</a> – whose jobs were largely unchanged by the first Industrial Revolution – are about to find their work changing substantially, if not entirely taken over by computers.</p>
<p>Until very recently, the global educated professional class <a href="https://www.psychologytoday.com/blog/theory-knowledge/201406/cultural-bubbles-in-the-era-globalization">didn’t recognize what was happening</a> to working- and middle-class people in developed countries. But now it is about to happen to them.</p>
<p>The results will be startling, disruptive and potentially long-lasting. <a href="http://www.newsweek.com/index-economic-inequality-trump-alt-right-marine-le-pen-populism-542358">Political developments of the past year</a> make it clear that the issue of shared prosperity cannot be ignored. It is now evident that the Brexit vote in the U.K. and the election of President Donald Trump in the U.S. were driven to a major extent by <a href="http://blogs.lse.ac.uk/politicsandpolicy/the-brexit-trump-syndrome/">economic grievances</a>.</p>
<p>Our current economy and society will transform in significant ways, with no simple fixes or adaptations to lessen their effects. But when trying to make economic predictions based on the past, it is worth remembering – and exercising – the caution provided by the distinguished Israeli economist Ariel Rubinstein in his 2012 book, “<a href="https://www.openbookpublishers.com/product/136/economic-fables">Economic Fables</a>”:</p>
<blockquote>
<p>“I am obsessively occupied with denying any interpretation contending that economic models produce conclusions of real value.” </p>
</blockquote>
<p>Rubinstein’s basic assertion, which is that economic theory tells us more about economic models than it tells us about economic reality, is a warning: We should listen not only to economists when it comes to predicting the future of work; we should listen also to <a href="https://www.theguardian.com/technology/2017/may/08/virtual-reality-religion-robots-sapiens-book">historians</a>, who often bring a deeper historical perspective to their predictions. Automation will significantly change many people’s lives in ways that may be painful and enduring.</p><img src="https://counter.theconversation.com/content/82051/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Moshe Y. Vardi does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The Industrial Revolution led to centuries of social and economic upheaval. Are economists telling us not to worry about workplace automation because things will be better in a couple hundred years?Moshe Y. Vardi, Professor of Computer Science, Rice UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/820582017-08-23T02:04:47Z2017-08-23T02:04:47ZWhy is climate change’s 2 degrees Celsius of warming limit so important?<figure><img src="https://images.theconversation.com/files/183051/original/file-20170822-13672-1btyqh6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Who set the guardrails on global temperature rise? </span> <span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Drought_land_dry_mud_BOUHANIFIA_Algeria.jpg">Hydrosami</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>If you read or listen to almost any article about climate change, it’s likely the story refers in some way to the <a href="http://www.pbs.org/newshour/bb/why-2-degrees-celsius-is-climate-changes-magic-number/">“2 degrees Celsius limit</a>.” The story often mentions greatly increased risks if the climate exceeds 2°C and even “<a href="https://www.nytimes.com/2017/08/07/climate/climate-change-drastic-warming-trump.html">catastrophic</a>” impacts to our world if we warm more than the target. </p>
<p>Recently a series of scientific papers have come out and stated that we <a href="http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate3352.html?foxtrotcallback=true">have a 5 percent chance of limiting warming to 2°C</a>, and only one chance in a hundred of keeping man-made global warming to 1.5°C, the aspirational goal of the <a href="http://unfccc.int/paris_agreement/items/9485.php">2015 Paris United Nations Framework Convention on Climate Change</a> conference. Additionally, recent research shows that <a href="https://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate3357.html">we may have already locked in 1.5°C of warming</a> even if we magically reduced our carbon footprint to zero today. </p>
<p>And there’s an additional wrinkle: What is the correct baseline we should use? The Intergovernmental Panel on Climate Change (IPCC) frequently references temperature increases relative to the second half of the 19th century, but the Paris Agreement states the temperature increases should be measured from “preindustrial” levels, or before 1850. <a href="http://www.nature.com/nclimate/journal/v7/n8/full/nclimate3345.html">Scientists have shown</a> such a baseline effectively pushes us another 0.2°C closer to the upper limits.</p>
<p>That’s a lot of numbers and data – so much that it could make even the most climate-literate head spin. How did the climate, and climate policy community, come to agree that 2°C is the safe limit? What does it mean? And if we can’t meet that target, should we even try and limit climate change?</p>
<h2>Fear of ‘tipping points’</h2>
<p>The <a href="https://link.springer.com/article/10.1007/s10113-010-0190-9">academic literature</a>, <a href="https://www.economist.com/blogs/economist-explains/2015/12/economist-explains-4">popular press</a> and <a href="https://www.carbonbrief.org/two-degrees-the-history-of-climate-changes-speed-limit">blog sites</a> have all traced out the history of the 2°C limit. Its origin stems not from the climate science community, but from a Yale economist, William Nordhaus. </p>
<p>In his 1975 paper “<a href="http://pure.iiasa.ac.at/365/1/WP-75-063.pdf">Can We Control Carbon Dioxide?</a>,” Nordhaus, “thinks out loud” as to what a reasonable limit on CO2 might be. He believed it would be reasonable to keep climatic variations within the “normal range of climatic variation.” He also asserted that science alone cannot set a limit; importantly, it must account for both society’s values and available technologies. He concluded that a reasonable upper limit would be the temperature increase one would observe from a doubling of preindustrial CO2 levels, which he believed equated to a temperature increase of about 2°C. </p>
<p>Nordaus himself stressed how “deeply unsatisfactory” this thought process was. It’s ironic that a back-of-the-envelope, rough guess ultimately became a cornerstone of international climate policy.</p>
<p>The climate science community subsequently attempted to quantify the impacts and recommend limits to climate change, as seen in the <a href="https://www.sei-international.org/mediamanager/documents/Publications/SEI-Report-TargetsAndIndicatorsOfClimaticChange-1990.pdf">1990 report issued by the Stockholm Environmental Institute</a>. This report argued that limiting climate change to 1°C would be the safest option but recognized even then that 1°C was probably unrealistic, so 2°C would be the next best limit. </p>
<p>During the late 1990s and early 21st century, there was increasing concern that the climate system might encounter catastrophic and nonlinear changes, popularized by Malcolm Gladwell’s “Tipping Points” book. For example, continued carbon emissions could lead to a <a href="http://www.whoi.edu/page.do?pid=83339&tid=3622&cid=9986">shutdown of the large ocean circulation</a> systems or <a href="http://scholars.unh.edu/cgi/viewcontent.cgi?article=1485&context=earthsci_facpub">massive permafrost melting</a>. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/182690/original/file-20170820-7944-1jqxvwa.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/182690/original/file-20170820-7944-1jqxvwa.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/182690/original/file-20170820-7944-1jqxvwa.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=433&fit=crop&dpr=1 600w, https://images.theconversation.com/files/182690/original/file-20170820-7944-1jqxvwa.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=433&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/182690/original/file-20170820-7944-1jqxvwa.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=433&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/182690/original/file-20170820-7944-1jqxvwa.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=544&fit=crop&dpr=1 754w, https://images.theconversation.com/files/182690/original/file-20170820-7944-1jqxvwa.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=544&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/182690/original/file-20170820-7944-1jqxvwa.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=544&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">It’s all about risk: Chart from 2014 IPCC report shows how higher temperatures lead to higher risk of problems.</span>
<span class="attribution"><a class="source" href="http://www.ipcc.ch/report/graphics/index.php?t=Assessment%20Reports&r=AR5%20-%20Synthesis%20Report&f=Topic%202">UN IPCC</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span>
</figcaption>
</figure>
<p>This fear of abrupt climate change also drove the political acceptance of a defined temperature limit. The 2°C limit moved into the policy and political world when it was adopted by the European Union’s Council of Ministers in 1996, the G8 in 2008 and the UN in 2010. In 2015 in Paris, negotiators adopted 2°C as the upper limit, with a desire to limit warming to 1.5°C.</p>
<p>This short history makes it clear that the goal evolved from the qualitative but reasonable desire to keep changes to the climate within certain bounds: namely, within what the world had experienced in the relatively recent geological past to avoid catastrophically disrupting both human civilization and natural ecosystems. </p>
<p>Climate scientists subsequently began supporting the idea of a limit of 1°C or 2°C starting over three decades ago. They showed the likely risks increase with temperatures over 1°C, and those <a href="https://www.ncbi.nlm.nih.gov/pubmed/17731712">risks grow substantially with additional warming</a>. </p>
<h2>And if we miss the target?</h2>
<p>Perhaps the most powerful aspect about the 2°C threshold is not its scientific veracity, but its simplicity as an organizing principle. </p>
<p>The climate system is vast and has more dynamics, parameters and variations in space and time than is possible to quickly and simply convey. What the 2°C threshold lacks in nuance and depth, it more than makes up as a goal that is understandable, measurable and may still be achievable, although our actions will need to change quickly. Goals and goal-setting are very <a href="http://hilt.harvard.edu/files/hilt/files/settinggoals.pdf">powerful instruments in effecting change.</a> </p>
<p>While the 2°C threshold is a blunt instrument that has many faults, similar to attempting to <a href="http://www.slate.com/articles/news_and_politics/explainer/2001/08/how_does_the_nfls_quarterback_rating_system_work.html">judge a quarterback’s value to his team solely by his rating</a>, its ability to rally 195 countries to sign an agreement should not be discounted.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/183052/original/file-20170822-13668-1atybt6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/183052/original/file-20170822-13668-1atybt6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/183052/original/file-20170822-13668-1atybt6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/183052/original/file-20170822-13668-1atybt6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/183052/original/file-20170822-13668-1atybt6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/183052/original/file-20170822-13668-1atybt6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/183052/original/file-20170822-13668-1atybt6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/183052/original/file-20170822-13668-1atybt6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The 2°C threshold is a lot like trying to stop a truck going downhill: The quicker you hit the brakes (on emissions), the easier it will to lower the risk of problems later.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/132466470@N05/35699905915/in/photolist-WoFmge-jPJZ3x-nZ3Fmj-rX9nrM-morwHp-e4Rn6x-5B652D-cd2GQo-jCguY-adTgWK-m97ap4-EhFnjr-8xaBqW-3hEzVS-ohsp6H-HrPtAa-qAzZTF-irfDAH-71K73-2ntkug-8Y9FLh-8RvPy-386ESs-2aq1Q9-hiri4-4wVNvv-aBobLg-aBqRiA-66cEPs-4z5AkF-eRNZ6P-7FYW3H-8qFEpn-6r8dFp-cznVM9-4TxAyj-71K3H-p9iM7J-7PRpCF-tSvZY-cznKPW-2ntkvD-aRVMne-6yva91-aFu99c-5EfUrx-czocNE-4sxmvE-aRVRGz-6FTwx4">Bruno Vanbesien</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span>
</figcaption>
</figure>
<p>Ultimately, what should we do if we cannot make the 1.5°C or 2°C limit? The <a href="http://www.ipcc.ch/pdf/assessment-report/ar5/wg2/ar5_wgII_spm_en.pdf">most current IPCC report shows the risks</a>, parsed by continent, of a 2°C world, and how they are part of a continuum of risk extending from today’s climate to a 4°C. </p>
<p>Most of these risks are assessed by the IPCC to increase in steady fashion. That is, for most aspects of climate impacts we do not “fall off a cliff” at 2°C, although considerable damage to <a href="http://www.nature.com/nclimate/journal/v3/n2/full/nclimate1674.html">coral reefs</a> and even agriculture may increase significantly around this threshold.</p>
<p>Like any goal, the 2°C limit should be ambitious but achievable. However, if it is not met, we should do everything we can to meet a 2¼°C or 2.5°C goal. </p>
<p>These goals can be compared to the speed limits for trucks we see on a mountain descent. The speed limit (say 30 mph) will allow trucks of any type to descend with a safety margin to spare. We know that coming down the hill at 70 mph likely results in a crash at the bottom. </p>
<p>In between those two numbers? The risk increases – and that’s where we are with climate change. If we can’t come down the hill at 30 mph, let’s try for 35 or 40 mph. Because we know that at 70 mph – or business as usual – we will have a very bad outcome, and nobody wants that.</p><img src="https://counter.theconversation.com/content/82058/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>David Titley is a member of the CNA Military Advisory Board, He is an advisory board member of Citizens' Climate Lobby, the Bulletin of the Atomic Scientists, the Center for Climate and Security, and is a member of the National Academy of Science's Board of Atmospheric Science and Climate. </span></em></p>More and more research shows that we are likely to pass the 2 degree Celsius temperature limit much of the world has agreed on. Where did that limit come from, and what if we miss it?David Titley, Professor of Practice in Meteorology, Professor of International Affairs & Director Center for Solutions to Weather and Climate Risk, Penn StateLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/797432017-06-26T07:03:43Z2017-06-26T07:03:43ZLogically, how is it possible to use more resources than Earth can replenish?<figure><img src="https://images.theconversation.com/files/175551/original/file-20170626-321-10j0hzy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">According to the WWF, we're living off 1.6 Earths' worth of resources.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/kevinmgill/32553367763/">Kevin Gill/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>Since the 1970s, humans have used more resources than the planet can regenerate. This is known as overshoot. The <a href="http://wwf.panda.org/about_our_earth/all_publications/living_planet_report_timeline">WWF Living Planet Report</a> has reported overshoot every two years since 2000.</p>
<p>However, this fact can inspire some confusion. How can it logically be possible for us to use more resources than Earth can produce, for decades on end? </p>
<p>There are two basic concepts at work here. One is our <a href="http://www.footprintnetwork.org/our-work/ecological-footprint/">ecological footprint</a>, which can be very loosely understood as a way of tallying up the resources we use from nature. The other is the planet’s ability to provide or renew those resources every year: its “biocapacity”. </p>
<p>When our ecological footprint exceeds Earth’s biocapacity, that’s unsustainable resource use. Unsustainable resource use can occur for some time. The environmental thinker <a href="http://donellameadows.org/donella-meadows-legacy/donella-dana-meadows/">Donella Meadows</a> used a <a href="https://www.climateinteractive.org/tools/climate-bathtub-simulation/">bathtub</a> analogy to explain how. </p>
<p>Imagine a bathtub full of water, with the tap running and the plug out at the same time. It is possible for more water to flow out of the bath than into it for some time without the water in the tub running out. This is because the significant store of water in the bath acts like a buffer. The same goes for nature. </p>
<p>Because nature has accumulated resources – for example, in a forest – it’s possible for us to harvest nature at a greater rate than it can replenish itself for a certain amount of time.</p>
<p>But this leads to the question: if humanity’s ecological footprint exceeds Earth’s biocapacity, how long can we keep going without crossing a tipping point? Our <a href="https://doi.org/10.1016/j.gloplacha.2017.06.002">recent research</a> investigates this question. </p>
<h2>Explaining the feedback system</h2>
<p>It’s important to make the point that nature provides us with literally everything we need, through processes known as <a href="http://www.environment.gov.au/biodiversity/publications/ecosystem-services-key-concepts-and-applications">ecosystem services</a>. Much of this is obvious because we buy and sell it, as food, shelter and clothing. </p>
<p>Other services go largely unnoticed. Forests provide protection from flooding by slowing down surface water runoff, for example, while mangroves absorb carbon dioxide from the air and store it. Until relatively recently, nature has continued to provide, despite our rapidly increasing ecological footprint. </p>
<p>In part this resilience comes from being able to buffer disturbance with the existing store of resources. But there’s an important mechanism that helps natural systems adjust – to a certain extent – to disruption. This is called a feedback mechanism, and if we take the bathtub analogy one step further we can see how it works. </p>
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<p>Say we set up our bathtub so that the tap and the plughole communicate with one another. If more water suddenly starts flowing down the plug, then the tap increases the flow of water into the bath to compensate, thus maintaining the water level. This is an example of a “positive” feedback (more water exiting the bath) being moderated by a “negative” feedback (more water entering from the tap), thus maintaining the state of the system (water in the bath).</p>
<p>Let’s pick a real-world example. Clearing trees from a forest might mean that seeds from the soil have the chance to germinate. If they germinate before the landscape gets too degraded, they can potentially balance out the disturbance.</p>
<p>But harvesting forest also exposes the ground, causing soil loss. In turn, vegetation might find it more difficult to regrow – resulting in yet more soil loss, and so on. This is a “positive” feedback – one that reinforces and exacerbates the original problem. </p>
<p>Negative feedbacks can only adapt to a certain level of disruption. Once the disturbance is too large, they break down. Positive feedback loops can then prevail and the ecosystem is likely to cross a tipping point, resulting in permanent, dramatic and sudden transformation. </p>
<h2>Crossing planetary boundaries</h2>
<p>In our research, my colleagues and I compared future ecological footprints with <a href="http://www.stockholmresilience.org/research/planetary-boundaries.html">research about planetary boundaries</a> (points at which the risks to humanity of crossing a tipping point become unacceptably high). <a href="http://www.sciencedirect.com/science/article/pii/S0921818116302314">We found</a> the discrepancy between the ecological footprint and biocapacity is likely to continue until at least 2050. We also found that our global cropping footprint is likely to exceed the planetary boundary for land clearing between 2025 and 2035. </p>
<p>This occurs in the context of atmospheric carbon dioxide concentrations that have already crossed the <a href="https://theconversation.com/humanity-is-in-the-existential-danger-zone-study-confirms-36307">planetary boundary of 350 ppm</a>. (As I write, the carbon dioxide concentration is <a href="https://www.co2.earth/">over 400 ppm</a>.)</p>
<p>By itself, both these points are serious enough. More seriously, we have no idea what happens when two planetary boundaries are approached simultaneously, or two tipping points interact.</p>
<p>We face the <a href="https://www.ecologyandsociety.org/vol11/iss1/art20/main.html">permanent loss</a> of essential natural processes, putting, for example, our <a href="http://www.sciencedirect.com/science/article/pii/S0959378003000827">global food security</a> at risk. Our research shows we need to address gradual, cumulative change, as the global resource buffer shrinks and stabilising feedback mechanisms are overwhelmed. </p>
<p>But there’s good news too. Ecological footprints decrease in response to human decisions. Our current trajectory towards tipping points is not <em>fait accompli</em> at all, but can be influenced by the choices we make now.</p><img src="https://counter.theconversation.com/content/79743/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Bonnie McBain received ARC funding for this research.</span></em></p>You may have seen reports that humans use more resources than the Earth can produce – but, logically, how is that possible? A bathtub can help explain.Bonnie McBain, Tutor in Sustainability Science, University of NewcastleLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/553902016-02-28T19:01:55Z2016-02-28T19:01:55ZSix burning questions for climate science to answer post-Paris<figure><img src="https://images.theconversation.com/files/112879/original/image-20160225-15174-17iutg9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">We still don't know enough about questions such as where the tipping points are for Arctic ice melt.</span> <span class="attribution"><span class="source">Christine Zenino/Wikimedia Commons</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>Much has been written about the challenge of achieving the targets set out in the <a href="https://theconversation.com/the-paris-climate-agreement-at-a-glance-50465">Paris climate agreement</a>, which calls for global warming to be held well below 2°C and ideally within 1.5°C of pre-industrial temperatures. </p>
<p>That’s the headline goal, but the Paris agreement also calls for a strong focus on climate science as well as on curbing greenhouse emissions. Article 7.7c of the <a href="https://unfccc.int/resource/docs/2015/cop21/eng/l09r01.pdf">agreement</a> specifically calls for:</p>
<blockquote>
<p>Strengthening scientific knowledge on climate, including research, systematic observation of the climate system and early warning systems, in a manner that informs climate services and supports decision-making. </p>
</blockquote>
<p>The next paragraph also calls on countries to help poorer nations, which have less scientific capability, to do the same.</p>
<p>But what are the many elements of climate science that need strengthening to achieve the aims of the Paris agreement? Here are six questions that need answers.</p>
<p><strong>What do the targets mean?</strong></p>
<p>What do the 2°C and 1.5°C targets imply for our climate and adaptation responses? Even warming of 2°C will have significant impacts for humans and natural systems, albeit much less than would occur if we allowed warming to continue unchecked. Still, climate science needs to clarify what is gained by meeting the 1.5°C and 2°C targets, and the consequences of missing them. </p>
<p><strong>Are we on track?</strong></p>
<p>It will be essential to monitor the climate system over the coming years and decades to see whether our efforts at curbing warming are delivering the expected benefits, or if more measures are needed.</p>
<p>The path to these ambitious temperature targets will not be smooth – there will be periods of rapid warming interspersed with periods of slower warming. We will not meet the targets if the world relaxes on mitigation efforts because of a short-term slowing in the rate of warming as a result of natural variability, such as we saw <a href="https://theconversation.com/the-climate-hiatus-doesnt-take-the-heat-off-global-warming-40686">between 1998 and 2013</a>. </p>
<p>Greenhouse gas concentrations, global temperatures, rainfall and water balance changes, extreme weather events, ocean heat content, sea level and terrestrial and marine carbon sinks are all vitally important elements to track. A focus on surface temperature alone is not sufficient. </p>
<p><strong>What are the tipping points in the climate system?</strong></p>
<p>Tipping points are thresholds beyond which there will be large, rapid and possibly irreversible changes in the climate system. The Greenland and Antarctic ice sheets are one example – beyond a certain level, warming will cause large and irreversible loss of ice, and sea level rise of many metres over the ensuing centuries. Thresholds also exist for ecosystems, such as the Great Barrier Reef, and the services they provide, including food production and water supply. </p>
<p>We need to know what these thresholds are, the consequences of crossing them, and how much and how fast we will have to reduce emissions in order to avoid this. </p>
<p><strong>How will climate and extreme events change?</strong></p>
<p>Many places already experience weather extremes such as heatwaves, droughts, fire, floods, storm surges and cyclones, all with damaging consequences. Many of the negative impacts of climate change will occur through changes in the magnitude, duration and frequency of these extreme events. </p>
<p>To adapt to these changes and manage the risks, more detailed information is needed on local and regional scales. It is important to recognise that 2°C of globally averaged warming does not imply 2°C everywhere (many regions, particularly on land, will have larger temperature rises). Extremes may increase faster than averages. </p>
<p>We also need to understand the short-term (decades) and long-term (centuries) implications of choices made today.</p>
<p><strong>What are the appropriate adaptation pathways?</strong></p>
<p>Even if the Paris targets are achieved, some adaptation will be essential. So how do we reduce vulnerability, minimise costs and maximise opportunities? Given the changes already observed with the roughly 1°C of global warming so far, it’s fair to say that more severe impacts will occur during this century.</p>
<p>Keeping warming within 2°C and moving to a lower-carbon world presents many challenges. Considerable work will be needed to help identify climate-resilient pathways and allow humans to adapt to the changes. </p>
<p>Successful adaptation will require an ability to foresee and prepare for inevitable changes in the likelihoods of extreme climate events from year to year. Development of climate forecasts on timescales of a year to decades may provide opportunities to reduce losses in critical sectors such as water, agriculture, infrastructure, tourism, fisheries, energy and natural resources.</p>
<p><strong>Can we take greenhouse gases back out of the atmosphere?</strong></p>
<p>Most scenarios for future emissions that keep warming below the agreed Paris target require not just a reduction in emissions, but also the ability to reduce greenhouse gas concentrations in the atmosphere – so-called “negative emissions”.</p>
<p>One proposed method of partially meeting our energy needs and reducing CO₂ concentrations is called <a href="http://www.globalccsinstitute.com/insights/authors/ErwinJackson/2014/04/17/bioenergy-carbon-capture-and-storage-%E2%80%93-why-all-fuss">BioEnergy Carbon Capture and Storage</a>. It would involve growing biofuels for energy, then capturing and burying the carbon dioxide released by these fuels. While potentially important, its large-scale deployment poses important questions regarding its costs and benefits and how the large amount of agricultural land required would compete with food production to feed the world’s growing population. </p>
<p>To keep climate change below 2°C, some have proposed a need for more radical geoengineering options if emissions are not phased out quickly enough. These include schemes to cool the Earth by reducing solar radiation. But these proposals fail to address other knock-on issues of carbon dioxide emissions, such as ocean acidification. They also pose large risks, are beset with ethical issues and beg the question of who is going to take responsibility for such schemes. </p>
<p>The Paris agreement proves that the world’s nations know we need strong climate action. But society faces tough choices as we seek to find economically, socially and environmentally feasible ways to meet the targets. Informed decisions will depend on robust science at both local and global scales, which means that far from being done, climate science is now more important than ever.</p><img src="https://counter.theconversation.com/content/55390/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>John Church works for CSIRO and is partly funded by the Australian Climate Change Science Program. </span></em></p><p class="fine-print"><em><span>Alistair Hobday works for CSIRO, and his projects include development of climate adaptation solutions for fisheries, aquaculture, and biodiversity. He currently receives funding from the FRDC, AFMA, DoE and Belmont Foundation. </span></em></p><p class="fine-print"><em><span>Andrew Lenton works for CSIRO and is partly funded by the Australian Climate Change Science Program.</span></em></p><p class="fine-print"><em><span>Steve Rintoul works for CSIRO. He receives funding from the Australian Climate Change Science Program and the Antarctic Climate and Ecosystems Cooperative Research Centre.</span></em></p>The Paris agreement has given us some solid targets to aim for in terms of limiting global warming. But that in turn begs a whole range of new scientific questions.John Church, CSIRO Fellow, CSIROAlistair Hobday, Senior Principal Research Scientist - Oceans and Atmosphere, CSIROAndrew Lenton, Senior Research Scientist, Oceans and Atmosphere, CSIROSteve Rintoul, Research Team Leader, Marine & Atmospheric Research, CSIROLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/494052015-12-09T13:09:55Z2015-12-09T13:09:55ZWhat climate ‘tipping points’ are – and how they could suddenly change our planet<p>As recently as <a href="http://www.technologyreview.com/article/515436/a-green-sahara/">6,000 years ago</a> the Sahara was green and fertile. We’ve found evidence of large rivers crossing the region, lined by flourishing settlements. Then suddenly things changed. Trees died and the land dried up. Soil blew away or turned into sand and those rivers were no more. In just a few centuries, the Sahara was transformed from a region similar to modern South Africa into the desert we know today.</p>
<p>This is an example of a “tipping point”. Just think of the climate like a chair. It takes a strong push to tip over a chair stood on four legs, but when it’s leaning on only two legs the required push becomes smaller. Indeed, if the inclination becomes large enough, it will tip over by itself. </p>
<p>Today, climate change inclination is increasing – and we know it could suddenly tip over, as our planet has previously witnessed several abrupt switches between different states. Along with what happened to the Sahara, there are also the flip-flops between ice ages and moderate conditions which happened every 1,000 years, before things settled down 10,000 years ago. </p>
<p>The idea that global warming might destabilise many climate systems and give rise to abrupt transitions was explored in the movie <a href="http://www.imdb.com/title/tt0319262/">The Day After Tomorrow</a>, in which melting ice shelves caused a sudden reversal in Atlantic currents – and a worldwide catastrophe.</p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/104473/original/image-20151204-4710-1avbmly.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/104473/original/image-20151204-4710-1avbmly.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=894&fit=crop&dpr=1 600w, https://images.theconversation.com/files/104473/original/image-20151204-4710-1avbmly.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=894&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/104473/original/image-20151204-4710-1avbmly.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=894&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/104473/original/image-20151204-4710-1avbmly.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1123&fit=crop&dpr=1 754w, https://images.theconversation.com/files/104473/original/image-20151204-4710-1avbmly.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1123&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/104473/original/image-20151204-4710-1avbmly.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1123&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Don’t mess with Atlantic currents.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/File:The_Day_After_Tomorrow_movie.jpg">20th Century Fox</a></span>
</figcaption>
</figure>
<p>The idea of climate tipping points was explored more rigorously by a team of scientists led by myself for a study recently published in <a href="http://www.pnas.org/content/112/43/E5777.abstract?tab=author-info">the journal PNAS</a>. We looked at all the simulations performed by 37 climate models that had been used to inform the Intergovernmental Panel of Climate Change (IPCC) – together with their historical and pre-industrial simulations. That gave us a gigantic amount of data: around 10<sup>15</sup> bytes divided over several computer servers around the world. </p>
<p>We detected 37 cases of abrupt change, distributed over three different climate change scenarios. These include the Arctic becoming ice-free even in winter, the Amazon rainforest dying off and the total disappearance of snow and ice cover on the Tibetan Plateau.</p>
<p>There’s a 30% chance that at least one of these tipping points will be crossed over the next 200 years. This increases to 50% in the most aggressive warming scenario. However, the likelihood of crossing any individual tipping point is much lower, only a few percentage points. So the Himalayas will probably still retain at least some of their glaciers. You should still be able to stand on the North Pole in January. But, taken together, there’s a decent chance that something major will happen.</p>
<p>One of the most important findings is that 18 out of 37 abrupt changes are likely to occur when global temperature rises are 2°C or less, often presented as an upper level of “safe” global warming. Our results imply that there is no window of “safe” global warming and no threshold separating safe and dangerous climate change. Every 0.5°C temperature increase is similarly dangerous.</p>
<h2>Tipping points we might reach</h2>
<p>Many of the tipping points we found apply to sea ice and ocean circulation. Because seawater reflects less sunlight than ice – and absorbs more heat – disappearing sea ice means further local warming, which in turn means more melting sea ice. This process may quickly amplify the effect of global warming. Most climate models simulate an abrupt disappearance of all summer sea-ice in the Arctic at <a href="http://www.carbonbrief.org/why-isnt-the-arctic-sea-ice-free-already">some point this century</a>.</p>
<p>Sometimes models predict the reverse process will occur, with sea-ice forming in regions that were previously open water. For instance, water draining from the Greenland and Antarctic ice sheets, combined with increased precipitation and melting sea ice may lead to ocean surface waters becoming fresher and lighter than usual. In the far north Atlantic, this would prevent the mixing between colder surface water and <a href="https://theconversation.com/heat-accumulating-deep-in-the-atlantic-has-put-global-warming-on-hiatus-30805">heat from the deep ocean</a> that usually takes place in the region. With heat remaining deep in the ocean, the resulting cooling would be more widespread – one model predicted that by 2060 the Baltic Sea could almost entirely freeze over every winter.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/104484/original/image-20151204-29724-1p269nt.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/104484/original/image-20151204-29724-1p269nt.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/104484/original/image-20151204-29724-1p269nt.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=446&fit=crop&dpr=1 600w, https://images.theconversation.com/files/104484/original/image-20151204-29724-1p269nt.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=446&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/104484/original/image-20151204-29724-1p269nt.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=446&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/104484/original/image-20151204-29724-1p269nt.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=561&fit=crop&dpr=1 754w, https://images.theconversation.com/files/104484/original/image-20151204-29724-1p269nt.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=561&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/104484/original/image-20151204-29724-1p269nt.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=561&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Atlantic current collapse would make northern Europe very chilly. Map shows potential temperature difference between 2080-2100 and 1850-1900 average as simulated by the FIO-ESM model.</span>
<span class="attribution"><span class="source">Sybren Drijfhout</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>In two scenarios this process is associated with a collapse of the Atlantic circulation that brings warm water from the Southern Hemisphere to cold seas around Greenland where it sinks. A collapse of all sinking shuts this circulation down. </p>
<p>This is The Day After Tomorrow scenario. I recently wrote a separate paper analysing the possible effects of such a <a href="http://www.nature.com/articles/srep14877">collapse in oceanic currents</a> – it’s more plausible than you might think and it really would lead to global cooling. In fact, depending on continued emissions levels, the effects could even outweigh global warming for decades to a century, especially in the Northern Hemisphere.</p>
<p>Such sudden transitions are more rare on land, but some models predict that a 2.5°C warming could cause the Amazon rainforest to disappear within 200 years. Forests contain a lot of moisture, and evaporation keeps the local climate cool. If trees start dying the region will grow warmer and drier, which will kill more trees. </p>
<p>Most climate models still don’t even factor in how vegetation will respond to changes in climate – and improvements in this respect would probably lead to more predictions of land-based “tipping points”. Likewise, ice sheet collapses and carbon and methane release from thawing permafrost could also lead to abrupt transitions but aren’t yet included in climate models.</p>
<p>For these reasons my colleagues and I believe that the catalogue of abrupt shifts we found is actually at the lower end of what might occur in reality. Dangerous climate change isn’t restricted to 2°C global warming or more – to avoid unpleasant surprises we should limit it as much as possible.</p><img src="https://counter.theconversation.com/content/49405/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sybren Drijfhout receives funding from the National Environment Research Council of the UK..</span></em></p>Things can change disturbingly quickly – just ask the people who once farmed the Sahara.Sybren Drijfhout, Professor in Physical Oceanography and Climate Physics, University of SouthamptonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/380762015-03-17T09:47:07Z2015-03-17T09:47:07ZAre you a stingy tipper? You may have unresolved trust issues<figure><img src="https://images.theconversation.com/files/74836/original/image-20150313-7048-z300io.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Don't you trust me? Give me a tip!</span> <span class="attribution"><span class="source">Tip jar from www.shutterstock.com</span></span></figcaption></figure><p><em>Editor’s note: this article is part of <a href="https://theconversation.com/us/topics/tipped-off">an occasional series</a> exploring the custom of tipping.</em></p>
<p>A purely rational economic analysis of human behavior seems unable to explain why some societies tip waiters, busboys or taxi drivers and others don’t. Why are some known for being generous and others for being stingy? </p>
<p>That’s because there isn’t anything rational about it. We tip so that we get better service and food. It’s an incentive. But since we do it after finishing our meal, we lose the ability to incentivize the staff to improve the experience. So why tip if there is no reason it would change your (already consumed) service experience? </p>
<p>But then, whoever said we behave rationally? Well, at least not all the time. So maybe we can explain tipping in some other manner. Is it just a human thing to do, perhaps? That is, more emotional than rational? </p>
<p>An investigation of correlations between typical tipping rates in restaurants across dozens of countries and other metrics suggests exactly that. A key human trait linked to gratuity generosity is whether or not we tend to trust others. Countries that score higher in terms of “<a href="http://www.jdsurvey.net/jds/jdsurveyActualidad.jsp?Idioma=I&SeccionTexto=0404&NOID=104">interpersonal trust</a>” tend to be better tippers. Those that score lowest, tend to be stingier. </p>
<p>Of course, many factors can come into play in determining when we choose to tip, such as custom, how well paid service-sector employees are and how recognized the services in question are as professions. </p>
<p>But based on my research, trust does seem to be a factor. </p>
<h2>The cost of experience</h2>
<p>So even though rational analysis may be of little use, the field of economics does offer some other insights, since eating in a restaurant is essentially an economic transaction. And every transaction has a cost attached to it, whether monetary or non-monetary. An obvious cost of going to a restaurant is the actual price of the food. But what about the “experience” of eating in the restaurant? Does that come with a potential cost?</p>
<p>Restaurants typically don’t offer their customers a guarantee at the entrance or elsewhere that if the food or service doesn’t achieve a certain quality they don’t have to pay for their meals. But still when we step into a restaurant, we assume it will. </p>
<p>In other words, we <em><a href="http://www.forbes.com/2006/09/22/trust-economy-markets-tech_cx_th_06trust_0925harford.html">trust</a></em> the restaurant to provide a good experience during our meal. That is, trust helps us manage this other cost of the transaction of eating in the restaurant – that we might suffer a “bad experience” since how well it turns out is outside of our control. Will they use quality ingredients? Will the chef prepare our food with interest? Will our waiter be pleasant and helpful or rushed and cold? </p>
<p>When we feel that this trust has been acknowledged (in the form of good food, good service or both), we tip!</p>
<h2>Trust and generosity</h2>
<p>So how do we know this really happens? </p>
<p>I looked at <a href="http://usatoday30.usatoday.com/travel/world/2007-09-10-tipchart_N.htm">tipping statistics</a> on 77 countries and compared this data with a measure of interpersonal trust derived from various surveys. The so-called <a href="http://www.jdsurvey.net/jds/jdsurveyActualidad.jsp?Idioma=I&SeccionTexto=0404&NOID=104">Trust Index</a> is based on the percentage of respondents who say most people can be trusted minus the share who say “you never can be too careful,” plus 100 to create the final figure. For example, a Trust Index score of exactly 100 would mean half of those surveyed tend to trust others, and half interact with caution. </p>
<p>The preliminary results were interesting. Some of the countries that had a higher score on the trust index also tended to offer higher tips. On the other hand, there were countries that had a higher Trust Index but also had lower tipping rates. (A caveat, in only nine countries did more than half of those surveyed agree that most people can be trusted, suggesting the world has some “trust issues” – but that’s for another column.)</p>
<p>When I conducted a simple statistical analysis of whether the Trust Index can predict tipping rates, I found the analysis to provide some support to this hypothesis. Tipping rates were positively related to the Trust Index values, and in research terms, these results were “<a href="http://www.investopedia.com/terms/s/statistically_significant.asp">statistically significant</a>” – a statistician’s way of saying they mean something. </p>
<p>Americans, for example, are the best tippers, with gratuities of about 17.5% of the bill. The US also ranked relatively high on the Trust Index, or 17th among 66 countries listed, with a score of 79 (meaning about 40% trust most people, while 60% don’t, assuming everyone agreed with one or the other statement). The average tipping rate in restaurants in these 77 countries was about 7.7%.</p>
<p>Quite a few countries can share the title for the least generous diners, who generally don’t seem to tip at all, and most score poorly in terms of trust. Turkey, Malaysia and Morocco, for example, rank at or near the bottom of both lists. </p>
<p>Additional analysis confirmed this observation – the relationship between trust and tipping is <a href="https://explorable.com/non-linear-relationship">not all that straight forward</a>. In fact, its quite “non-linear” in statistical jargon. So just because America’s Trust Index is about twice that of South Africa, it does not mean that tipping rates in the US is double those in the African country. </p>
<p>Brazil and Portugal, for example, had very low trust scores (17 and 21), yet residents tend to tip around 12.5%, above the 7.7% average for the 77 countries in all that I looked at. Meanwhile, Switzerland and Denmark are among the few countries ranked among the highest in terms of trust yet in both countries people don’t tip much. (Herein lies the complexity of the relationship, something that I intend to analyze further in the future.) </p>
<p>Apart from trust, I also tried to look at other factors to find correlations and help explain why we tip. Another one I thought worth investigating was the purchasing power of consumers in a given country – or essentially how wealthy they are. Are richer countries more generous? </p>
<p>An international measure of this idea is the <a href="http://www.economist.com/content/big-mac-index">Big Mac index</a>. When I compared the Big Mac Index data with the figures on tipping, I found very little correlation. Trust was statistically more convincingly related to tipping levels than purchasing power. </p>
<h2>Acknowledging trust</h2>
<p>So what should we make of this? </p>
<p>Have you ever had a great experience in a restaurant and walked away without giving a “proper” tip or any tip at all (for some reason or another)? I have done it a few times. Not intentionally, but sometimes because I miscalculated my tip or other times when I didn’t have enough cash and the restaurant did not accept a credit card. </p>
<p>How did I feel? Embarrassed, and if I might add, slightly guilty. On the other hand, when I do tip in a manner I feel is appropriate for the experience I received, I felt good about it. </p>
<p>But how might servers feel in such situations? Incidentally, I am also a professional in the food service industry, and I trained in my early life to work in restaurants. When I kept that trust of the customer, I felt good about it. On the other hand, when for some reason I broke that trust by providing poor service, it made me feel bad. Receiving a tip was always a moment of acknowledgment that I did a good job – though I must admit it wasn’t always because I did. </p>
<p>So what does this tell us about the custom of tipping? That tips might be an economic manifestation of acknowledging trust between the server and the customer. Removing tips without replacing them with “something else” that embodies this trust may lead to some unintended consequences. Would removing tips make servers feel less appreciated? Or would it make consumers feel relieved and over time adjust their service expectations? </p>
<p>This analysis doesn’t lend much support to whether or not we should abolish tipping and perhaps move to a system more common in Europe in which a service charge is automatically included. But my analysis does suggest that tipping represents this acknowledgment of trust. By itself then, trust is not a bad thing. If anything, it shows that we are more human than we sometimes give ourselves credit for.</p><img src="https://counter.theconversation.com/content/38076/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Amit Sharma receives funding from the US Department of Agriculture.</span></em></p>Citizens of countries that rank higher on the so-called Trust Index tend to be more generous when it comes to tipping waiters.Amit Sharma, Associate Professor of Hospitality Finance, Penn StateLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/271082014-07-14T06:04:30Z2014-07-14T06:04:30ZWhat climate tipping points should we be looking out for?<figure><img src="https://images.theconversation.com/files/50678/original/dm99pjqw-1402381905.jpg?ixlib=rb-1.1.0&rect=5%2C8%2C942%2C698&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Melt pond on the Greenland ice sheet.</span> <span class="attribution"><span class="source">NASA / Michael Studinger</span></span></figcaption></figure><p>The concept of a “tipping point” – a threshold beyond which a system shifts to a new state – is becoming a familiar one in discussions of the climate.</p>
<p>Examples of tipping points are everywhere: a glass falling off a table upon tilting; a bacterial population hitting a level where it pushes your body into fever; the boiling point of water, or a cube of ice being thrown into warm water, where it rapidly melts.</p>
<p>The ice cube is a poignant example, because scientists now fear that <a href="https://theconversation.com/we-can-now-only-watch-as-west-antarcticas-ice-sheets-collapse-26957">West Antarctica’s ice sheets are also heading towards irreversible melting</a>. </p>
<p>Likewise, the recent discovery of deep canyons <a href="http://www.nasa.gov/press/2014/may/hidden-greenland-canyons-mean-more-sea-level-rise/">beneath the Greenland ice sheet</a> raises concerns regarding its stability. </p>
<p>The <a href="http://pubs.giss.nasa.gov/abs/ha02210k.html">history</a> of the atmosphere, oceans and ice caps indicates that, once changes in the energy level which drive either warming or cooling reach a critical threshold, irreversible <a href="http://www.pnas.org/content/105/6/1786.abstract">tipping points ensue</a>.</p>
<p>An example is a process called “<a href="http://en.wikipedia.org/wiki/Future_sea_level">albedo flip</a>”, where a small amount of melting creates a film of water on top of the ice. The water absorbs infrared radiation and melts more ice, leading to runaway melting of ice sheet. The opposite process occurs where the freezing of water results in reflection of radiation to space, leading to cooling and freezing of more water. </p>
<p>Other examples are abrupt warming episodes during glacial states, termed “<a href="http://www.springerreference.com/docs/html/chapterdbid/77379.html">interstadials</a>”, for example the “<a href="http://www.climatepedia.org/terms.php?term_id=205">Dansgaard-Oeschger</a>” warming cycles which occurred during the last glacial period between about 100,000 and 20,000 thousand years ago, which caused large parts of the North Atlantic Ocean to <a href="http://www.pik-potsdam.de/%7Estefan/Publications/Journals/rahmstorf_grl_2003.pdf">undergo temperature changes of several degrees Celsius within short periods</a>. Other examples are points at which a glacial state ends abruptly to be replaced <a href="http://www.pnas.org/content/105/38/14308">by rapid glacial termination</a>.</p>
<h2>Over the threshold</h2>
<p>An increase in global temperatures can lead to a threshold representing the culmination and synergy of <a href="http://www.sciencemag.org/content/324/5926/481">multiple processes</a>, such as release of methane from permafrost or polar ocean sediments, retreating sea ice and ice sheets, warming oceans, collapse of ocean current systems such as the North Atlantic Thermohaline Current and – not least – large scale fires. </p>
<p>A major consequence of warming of ice sheets is the increase in supply of cold fresh melt water to adjacent oceans, such as the abrupt cooling of the North Atlantic Ocean inducing rapid freezing events (stadials), as represented by the <a href="http://www.ncbi.nlm.nih.gov/pubmed/18566247">“Younger dryas” event (12,900-11,700 years ago)</a>, or the rapid melting of <a href="http://www.jstor.org/discover/10.2307/1550356?uid=3737536&uid=2129&uid=2&uid=70&uid=4&sid=21104279148323">Laurentian ice cap about 8500 years ago</a> and related abrupt cooling events in Europe and North America.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/50679/original/8zbdwwkg-1402382110.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/50679/original/8zbdwwkg-1402382110.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/50679/original/8zbdwwkg-1402382110.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=546&fit=crop&dpr=1 600w, https://images.theconversation.com/files/50679/original/8zbdwwkg-1402382110.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=546&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/50679/original/8zbdwwkg-1402382110.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=546&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/50679/original/8zbdwwkg-1402382110.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=686&fit=crop&dpr=1 754w, https://images.theconversation.com/files/50679/original/8zbdwwkg-1402382110.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=686&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/50679/original/8zbdwwkg-1402382110.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=686&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Satellite images of Greenland, July 8 and July 12, 2012. White shows remaining ice; red shows melt; pink shows probable melt; grey shows ice-free; dark grey means no data.</span>
<span class="attribution"><a class="source" href="http://www.nasa.gov/topics/earth/features/greenland-melt.html">NASA</a></span>
</figcaption>
</figure>
<p>The question is whether the post-18th century global warming trend may culminate in a major tipping point or, alternatively, is represented by an increase in disparate extreme weather events, as are currently occurring around the world. </p>
<p>A potential indicator of such tipping point may be represented by a collapse of the North Atlantic Thermal Circulation, which would lead to a sharp, albeit transient, temperature drop in the North Atlantic Ocean, North America and Western Europe. Evidence for a weakening of the North Atlantic deep water circulation by about 30% between 1957 and 2004 has been reported <a href="http://www.nature.com/nature/journal/v438/n7068/abs/nature04385.html">in Nature</a> as well as by other researchers.</p>
<p>The question of tipping points is of critical importance since it affects future climate projections and adaptation plans. In this regard <a href="http://www.europeanclimate.org/documents/IPCCWebGuide.pdf">the latest Intergovernmental Panel on Climate Change report</a> leaves the question of tipping points open.</p>
<h2>The crucial question</h2>
<p>So how likely is the current climate change trend to reach a tipping point, and if so of what magnitude and on what time scale?</p>
<p>General circulation climate models which attempt to delineate overall future climate trends are limited in their capacity to predict the precise timing, location and magnitude of abrupt climate and weather events with confidence. </p>
<p>Since the 19th century <a href="http://www.europeanclimate.org/documents/IPCCWebGuide.pdf">the rise in the energy level of the atmosphere</a> has reached a level of more than 3 degrees Celsius when the masking effects of sulphur aerosols are discounted. This degree of temperature rise is just under the energy rise level associated with the last glacial termination between <a href="http://www.atmos-chem-phys.net/11/13421/2011/acp-11-13421-2011.pdf">about 16,000 and 10,000 years ago</a>. </p>
<p>The atmosphere-ocean system continued to warm following the peak El-Nino event of 1998. Most of the warming occurred in the oceans, whose mean temperature has risen by about <a href="http://www.nodc.noaa.gov/OC5/3M_HEAT_CONTENT/index3.html">0.3C since 1950</a>. </p>
<p>The current rise in atmospheric CO<sub>2</sub> of about 2 parts per million CO2/year, reaching <a href="http://climate.nasa.gov/400ppmquotes/">401.85 parts per million at the Mauna Loa Observatory in Hawaii in May 2014</a>, exceeds rates observed in the geological record of the <a href="http://www.springer.com/earth+sciences+and+geography/earth+system+sciences/book/978-94-007-7331-8">last 65 million years</a>.</p>
<p>An atmospheric CO<sub>2</sub> level of 400 parts per million is estimated for the Miocene, about 16 million years ago, when mean temperatures have reached 3 to 4 degrees Celsius above those of pre-industrial temperatures. <a href="http://www.foreign.senate.gov/imo/media/doc/Hansen_Testimony.pdf">Economically available fossil fuel reserves</a>, if used, are capable of returning the atmosphere to tropical state such as existed during the early to mid-Eocene prior to the formation of the Antarctic ice sheet about 32 million years ago.</p>
<p>The evidence indicates that, since the mid-1980s, the Earth is shifting from a climate state that favoured land cultivation since about 7000 years ago to a climate state characterised by mean global temperatures about 2-3 degrees Celsius above pre-industrial levels. </p>
<p>At this level, extreme weather events would render large parts of the continents unsuitable for agriculture. The <a href="http://www.nasa.gov/press/2014/may/hidden-greenland-canyons-mean-more-sea-level-rise/">accelerated melting of the Greenland</a> and <a href="https://theconversation.com/we-can-now-only-watch-as-west-antarcticas-ice-sheets-collapse-26957">west Antarctic ice sheets</a> could lead to conditions akin to those of the Pliocene, before 2.6 million years ago, when sea level were between 5 and 40 metres higher than at present, as <a href="http://geology.er.usgs.gov/eespteam/prism/products/Raymo_et_al_2009.pdf">estimated by the US Geological Survey</a>.</p>
<p>The evidence indicates the climate may be tracking toward – or is already crossing – tipping points whose precise nature and timing remain undefined, depending on the extent to which ice sheet melting is retarded due to hysteresis. The increase in frequency and intensity of extreme weather events around the globe may represent a shift in state of the atmosphere-ocean system. There is no alternative to a global effort at deep cuts of carbon emissions coupled with fast-tracked CO<sub>2</sub> sequestration. </p>
<p>As Professor Joachim Schellnhuber, Germany’s climate advisor and Director of the Potsdam Climate Impacts Institute, <a href="http://www.reuters.com/article/2009/09/28/us-climate-science-idUSTRE58R3UI20090928">has said</a>:</p>
<blockquote>
<p>We’re simply talking about the very life support system of this planet.</p>
</blockquote><img src="https://counter.theconversation.com/content/27108/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Andrew Glikson does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The concept of a “tipping point” – a threshold beyond which a system shifts to a new state – is becoming a familiar one in discussions of the climate. Examples of tipping points are everywhere: a glass…Andrew Glikson, Earth and paleo-climate scientist, Australian National UniversityLicensed as Creative Commons – attribution, no derivatives.