tag:theconversation.com,2011:/africa/topics/attribution-study-32737/articlesAttribution study – The Conversation2023-04-20T12:55:46Ztag:theconversation.com,2011:article/2030642023-04-20T12:55:46Z2023-04-20T12:55:46ZClimate change increases the risk of extreme wildfires around Cape Town – but it can be addressed<figure><img src="https://images.theconversation.com/files/519251/original/file-20230404-23-aqpufb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Fire at the University of Cape Town, South Africa.</span> <span class="attribution"><span class="source">Photo by Brenton Geach/Gallo Images via Getty Images</span></span></figcaption></figure><p>Across the globe, <a href="https://www.sciencedirect.com/science/article/pii/S0048969719355871">many recent severe wildfires</a> have moved from wildlands into the urban periphery (the <a href="https://www.frontiersin.org/research-topics/22737/fires-in-the-wildland-urban-interface-wui-an-emerging-global-phenomenon-threatening-modern-society#overview">“wildland urban interface”</a>). In their wake, they’ve left <a href="https://doi.org/10.1016/j.ijdrr.2023.103618">death, destruction and disruption</a>. This has led to questions about the extent to which climate change is to blame.</p>
<p>A field of study called <a href="https://iopscience.iop.org/article/10.1088/2752-5295/ac6e7d?_hsmi=217900917&_hsenc=p2ANqtz--vIRNcML-N5eyhXNbUkFRofJMkOnQu1XYSZ1h_C1qgDnUdoOBCxFrsBkay1X6WZvEJ7egPLQ-Vog5y9mcE8Jm4WSnZZw">extreme event attribution</a> has developed to answer such questions. These studies quantify the links between global climate change, regional extreme weather events, and their effects on people, property and environment. </p>
<p>This branch of attribution science aims to <a href="https://link.springer.com/article/10.1007/s10584-021-03071-7">inform climate change adaptation following extreme events</a>. It also highlights that long-term, global-scale climate change is having real impacts, now, at the scale of human experience. Attribution studies can make the public <a href="https://link.springer.com/article/10.1007/s10584-021-03071-7">more acutely aware</a> of climate change effects and increase support for mitigation measures.</p>
<p>But the rapidly growing body of event attribution analyses shows a strong <a href="https://doi.org/10.1175/BAMS-D-19-0317.1">bias</a> towards extreme events in the global north. <a href="https://link.springer.com/article/10.1007/s10584-015-1432-0">Few attribution studies have considered African events</a>. </p>
<p>One of us, Zhongwei, recently led and Stefaan was involved in <a href="https://doi.org/10.1175/BAMS-D-22-0204.1">the first attribution study</a> to quantify the role of climate change in the risk of extreme fire weather conditions in southern Africa. </p>
<p>Wildfires are <a href="https://esajournals.onlinelibrary.wiley.com/doi/full/10.1002/fee.2359">complex phenomena</a>. They can only be understood fully by considering social, environmental and weather conditions together. We know, however, that extreme wildfire events occur almost exclusively under extreme fire weather conditions. Studying associations between global warming and fire weather can provide evidence for how <a href="https://www.nature.com/articles/s41612-022-00248-4">wildfire potential</a> is changing and help to inform responses. </p>
<p>We analysed the destructive <a href="https://theconversation.com/how-vulnerable-is-the-university-of-cape-town-to-destructive-wildfires-182169">April 2021 wildfire</a> on the slopes of Devil’s Peak in Cape Town, South Africa under extreme fire weather conditions. We concluded that such extreme fire weather has become around 90% more likely in a warmer world.</p>
<h2>The April 2021 Cape Town wildfire</h2>
<p>The wildfire we studied started as a small grass burn. Within a few hours it had destroyed historical buildings and priceless materials in the <a href="https://theconversation.com/significant-archives-are-under-threat-in-cape-towns-fire-why-they-matter-so-much-159299">University of Cape Town African Studies collection</a>. </p>
<p>The event received <a href="https://theconversation.com/why-the-fire-on-cape-towns-iconic-table-mountain-was-particularly-devastating-159390">widespread coverage</a>, documenting the <a href="https://www.news.uct.ac.za/article/-2021-04-23-sad-moment-as-treasured-jagger-reading-room-remembered">resulting losses</a> and the <a href="https://theconversation.com/the-table-mountain-fire-what-we-can-learn-from-the-main-drivers-of-wildfires-159477">factors responsible</a> for its destructiveness. Questions were raised that required <a href="https://www.timeslive.co.za/sunday-times/opinion-and-analysis/2021-05-09-the-fire-at-uct-not-just-the-usual-suspects/">further research</a>. One issue was the role of climate change in the weather conditions during the event.</p>
<p>Shortly after 10 am on that day, 18 April 2021, <a href="https://www.csag.uct.ac.za/2022/04/18/devils-peak-fire-18-19-april-2021-one-year-later/">hot, extremely dry and windy conditions took hold</a>. These extreme conditions resulted in <a href="https://www.news.uct.ac.za/article/-2021-06-23-reflecting-on-the-devastating-uct-fire">highly unusual fire behaviour</a>, which made suppressing the fire exceptionally challenging. Burning embers transported by the wind set vegetation alight at least <a href="https://www.sanparks.org/assets/docs/parks_table_mountain/tmnp-fire-investigation-report.pdf#page=4">350 metres</a> ahead of the main fire. </p>
<p>We found that the observed fire weather conditions were the most extreme in the 1979–2021 autumn (March–May) record. These conditions have become almost twice as likely as a result of climate change. </p>
<h2>How we came to this conclusion</h2>
<p>We used multiple climate model simulations selected from those run for the <a href="https://www.ipcc.ch/report/ar6/wg1/">Intergovernmental Panel on Climate Change</a> assessments. These gave us many years of data to provide a robust risk estimate. This is important because our study area was the smallest over which a wildfire event attribution has been done. Over small domains, local variability makes climate change signals harder to detect. The more data you have, the better the chance of picking up signals.</p>
<p>Using temperature, wind, humidity and rainfall, we calculated the value of an <a href="https://www.nwcg.gov/publications/pms437/cffdrs/fire-weather-index-system">index of fire weather (FWI)</a> over Cape Town on 18 April 2021. Then we compared a past climate before human-driven warming with our current climate to see how often the models output Cape Town autumn FWI values that are at least as extreme.</p>
<p>Our results strongly suggest that the weather conditions under which extreme Cape Town wildfires can occur are happening ever more frequently in this area in a warming world. This adds to a <a href="https://www.nature.com/articles/s43247-022-00344-6">broader body</a> of <a href="https://iopscience.iop.org/article/10.1088/1748-9326/acba33/meta">literature</a> <a href="https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2020RG000726">indicating</a> that climate change is increasing the potential for “megafires” in the world’s dry-summer climates. </p>
<p>Responding to this risk requires interpreting findings in context and engaging across disciplinary boundaries. </p>
<p>In addition to suitable weather conditions, <a href="https://theconversation.com/what-science-tells-us-about-fire-hazards-facing-cape-town-and-its-surrounds-125069">wildfires require</a> a source of ignition and fuel (vegetation that can burn). Cape Town’s mountain slopes are covered by fire-prone indigenous fynbos and alien vegetation that can burn very intensely. Given the <a href="https://theconversation.com/the-table-mountain-fire-what-we-can-learn-from-the-main-drivers-of-wildfires-159477">increasing numbers of people</a> around the mountain, some fires are bound to start. </p>
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Read more:
<a href="https://theconversation.com/the-table-mountain-fire-what-we-can-learn-from-the-main-drivers-of-wildfires-159477">The Table Mountain fire: what we can learn from the main drivers of wildfires</a>
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<p>We outline three avenues for risk mitigation. </p>
<h2>Steps to mitigate risk</h2>
<p><strong>Adopting more holistic <a href="https://iopscience.iop.org/article/10.1088/1748-9326/ab541e/meta">fire management</a> approaches</strong></p>
<p>Focusing exclusively on fire suppression (putting fires out as <a href="https://www.westerncape.gov.za/general-publication/wildfire-season">quickly as possible whenever they occur</a>) can allow very high fuel loads to build up. Experts have warned that this widely used strategy is “<a href="https://iopscience.iop.org/article/10.1088/1748-9326/ab541e/meta">destined to fail</a>”. It can also <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.14861">threaten biodiversity</a> in fire-dependent ecosystems. In the fynbos biome of south-western South Africa, fast-growing <a href="https://theconversation.com/invasive-alien-plants-in-south-africa-pose-huge-risks-but-they-can-be-stopped-94186">alien invasive species</a> and low-density <a href="https://www.iol.co.za/capeargus/news/researchers-warn-the-cape-to-prepare-for-more-disastrous-fires-like-the-2017-knysna-fires-5efb43d9-20e1-4ee4-9ba3-05abc0f73d74">urban expansion</a> into surrounding wildlands enhance the risk of megafires. </p>
<p>Instead, <a href="https://www.frontiersin.org/articles/10.3389/ffgc.2022.848254/full">researchers</a> suggest wildfire risk management should also involve limiting flammable plants and materials immediately around buildings (“defensible space”) in the urban periphery, developing evacuation plans and conducting fire-aware urban planning.</p>
<p><strong>Timely and accurate forecasting and communication of extreme fire weather risk</strong> </p>
<p>This must incorporate understanding of <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.14861">fire pathways that pose the greatest risk locally</a>.</p>
<p>Doing this can aid <a href="http://www.riskreductionafrica.org/assets/files/Knynsa%20Fires%20Report%202019.pdf">short-term preparedness</a> and risk reduction. The <a href="https://www.geonetcastamericas.noaa.gov/products/navigator/details/EO_EUM_DAT_INFO_LFDI.html">fire weather index</a> that’s used in South Africa was developed for the savannah and grasslands of the hot, summer-rain Lowveld in the country’s far north-east. The ecology, climate and fire risk factors in the Lowveld are <a href="https://pta-gis-2-web1.csir.co.za/portal/apps/GBCascade/index.html?appid=a726c58f435141ba80b57fe21d3ec744">very different</a> to those in the fynbos. Consequently, this fire weather index <a href="https://doi.org/10.1186/s42408-018-0001-0">appears</a> not to have been able to identify <a href="https://doi.org/10.1016/j.ijdrr.2023.103618">unprecedented fire weather risk</a> associated with recent <a href="https://www.researchgate.net/publication/333682368_THE_KNYSNA_FIRES_OF_2017_LEARNING_FROM_THIS_DISASTER">extreme wildfires</a> in the fynbos biome.</p>
<p><strong>Further <a href="https://www.news.uct.ac.za/article/-2021-06-23-reflecting-on-the-devastating-uct-fire">research</a> to inform vegetation management</strong> </p>
<p>It’s crucial to understand which <a href="https://www.timeslive.co.za/news/south-africa/2021-04-24-born-to-burn-the-alien-trees-that-turned-cape-town-fire-into-a-disaster/">alien and possibly indigenous vegetation</a> can produce “ember showers”, such as those responsible for setting alight buildings and plants haphazardly on Devil’s Peak. <a href="https://doi.org/10.1016/j.ijdrr.2023.103618">Case studies</a> to assess factors associated with building loss and survival can also inform locally relevant policy.</p><img src="https://counter.theconversation.com/content/203064/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Stefaan Conradie received PhD funding from the South African National Research Foundation (NRF). </span></em></p><p class="fine-print"><em><span>Zhongwei Liu received funding from the Coventry University Trailblazer PhD studentship scheme.</span></em></p>Autumn extreme fire weather around Cape Town in South Africa has become 90% more likely in a warmer world.Stefaan Conradie, PhD student, University of Cape TownZhongwei Liu, PhD researcher, Coventry UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1873682022-07-26T13:47:22Z2022-07-26T13:47:22ZHow likely would Britain’s 40°C heatwave have been without climate change?<figure><img src="https://images.theconversation.com/files/476066/original/file-20220726-22290-y9sdrd.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C5990%2C3232&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A member of the Coldstream Guards succumbs to the heat, June 2022.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/london-uk-june-2022-soldier-uniform-2165811619">Lois GoBe/Shutterstock</a></span></figcaption></figure><p>Every heatwave occurring today is made <a href="https://iopscience.iop.org/article/10.1088/2752-5295/ac6e7d?utm_campaign=Hot%20News&utm_medium=email&_hsmi=217900917&_hsenc=p2ANqtz--vIRNcML-N5eyhXNbUkFRofJMkOnQu1XYSZ1h_C1qgDnUdoOBCxFrsBkay1X6WZvEJ7egPLQ-Vog5y9mcE8Jm4WSnZZw&utm_content=217900917&utm_source=hs_email">more likely and intense</a> by human-caused climate change. Early estimates by the UK Met Office suggest that days over 40°C have become <a href="https://www.metoffice.gov.uk/about-us/press-office/news/weather-and-climate/2022/red-extreme-heat-warning">ten times</a> more likely to happen in the UK as a result of the rising global temperature. </p>
<p>But even this may be a significant underestimate, as models have <a href="https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2021EF002271">underrated</a> increases in the occurrence of extreme heat events before. And we know that <a href="https://iopscience.iop.org/article/10.1088/1748-9326/aaf4cc">climate change</a> has increased the likelihood of new high-temperature records <a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2018EF000813">more than any other</a> extreme weather phenomenon.</p>
<p>July 2022 would have had a few hot days without climate change. But with it, those days were several degrees <a href="https://www.worldweatherattribution.org/human-contribution-to-the-record-breaking-july-2019-heat-wave-in-western-europe/">hotter</a>, which brought 40°C within reach for England for the first time. </p>
<h2>Not-so-great British bake off</h2>
<p>The heatwave was caused by a <a href="https://www.netweather.tv/weather-forecasts/news/11562-july-2022-extreme-uk-heatwave-the-first-signs-how-it-evolved-and-the-records-broken">low pressure system</a> over the North Atlantic that produced a slingshot effect, firing a plume of hot, dry Saharan air northwards. With little moisture to evaporate and no clouds to block the sun’s rays, the land baked.</p>
<p>There is <a href="https://www.nature.com/articles/s41467-022-31432-y">growing evidence</a> to suggest that these hot weather-generating pressure systems are becoming more frequent for Europe. But even if they continued occurring at the same rate, the air itself is certainly getting hotter. </p>
<p>On a warming planet everywhere gets hotter, but not at the same rate. The land heats up <a href="https://climate.mit.edu/ask-mit/which-parts-planet-are-warming-fastest-and-why">faster</a> than the ocean, especially the <a href="https://www.carbonbrief.org/guest-post-why-does-land-warm-up-faster-than-the-oceans/">driest areas</a> such as the Sahara. The approximately 1.2°C of global warming already experienced has added at least 2°C onto the average UK heatwave day, and even more on to <a href="https://theconversation.com/too-hot-to-sleep-nights-are-warming-faster-than-days-as-earth-heats-up-186958">night-time</a> temperatures.</p>
<p>The UK is not prepared for these Mediterranean temperatures. Buildings are poorly insulated and lack air conditioning. Much of the <a href="https://theconversation.com/britain-isnt-built-to-withstand-40-c-here-is-where-infrastructure-is-most-likely-to-fail-187229">infrastructure cannot cope</a>: train lines are built from steel that is only stress-tested to <a href="https://www.networkrail.co.uk/stories/why-rails-buckle-in-britain/">27°C</a>. Beyond that, the lines are prone to buckling. </p>
<p>Extreme heat is a <a href="https://www.ft.com/content/3249dbaa-a4de-4846-bf71-916e848772d4">killer</a>. Heatwaves in Europe in <a href="https://www.sciencedirect.com/science/article/pii/S1631069107003770">2003</a> and in western Russia in <a href="https://www.science.org/doi/full/10.1126/science.1201224?casa_token=w8a7y4TbGuwAAAAA%3AmgLz2uH-3y9evFlRDUuT_9foJn6SGhFyfLdOm3f4p-PBGlarXORNoycUPg6W21NpTt1ShiOUCIqgSw">2010</a> killed around 70,000 and 55,000 people respectively – two of the deadliest weather disasters in history. </p>
<p>Extremely high temperatures are especially dangerous for the elderly, those with chronic medical conditions, people in cities and pets. That’s partly because it takes a heavy toll on the heart and lungs, especially when a <a href="https://www.nature.com/articles/ngeo866">warm night</a> offers little respite. And partly because <a href="https://www.reuters.com/world/europe/air-pollution-surges-heatwave-sweeps-across-europe-2022-07-19/">hot, stagnant air</a> concentrates <a href="https://www.theguardian.com/global-development/2016/jan/16/winter-smog-hits-worlds-cities-air-pollution-soars">dangerous pollution</a> like ozone, especially in <a href="https://ehjournal.biomedcentral.com/articles/10.1186/1476-069X-9-37#Abs1">cities</a>.</p>
<p>Nearly <a href="https://www.independent.co.uk/climate-change/news/spain-portugal-deaths-heatwave-b2128345.html">2,000</a> excess deaths have already been reported from the beginning of the mid-July heatwave in Spain and Portugal, which also experienced this Saharan plume of hot air. For every person killed, several more require <a href="https://www.pnas.org/doi/full/10.1073/pnas.1806393116">hospital treatment</a> for <a href="https://www.sciencedirect.com/science/article/pii/S0749379712008781?casa_token=-GWGrK-MMuoAAAAA:IB2h4TEPTP5SNEd_veHlW85mMLpx-nHME5ZO63wfmZoMWEpeUuYEwa3vji49HtZ_PDPBCe_OvA">heat-related illness</a>. </p>
<h2>Heat on the rise</h2>
<p>An international team of attribution scientists has conducted several studies on recent heatwaves. The March-May 2022 heatwave in <a href="https://www.worldweatherattribution.org/climate-change-made-devastating-early-heat-in-india-and-pakistan-30-times-more-likely/">India and Pakistan</a>, which destroyed much of the wheat harvest and is contributing, alongside the Ukraine conflict, to global <a href="https://www.theguardian.com/world/2022/may/21/india-wheat-farmers-40c-heat-food-security">food price rises</a>, was made 30 times more likely by climate change. <a href="https://www.worldweatherattribution.org/western-north-american-extreme-heat-virtually-impossible-without-human-caused-climate-change/">Canada’s</a> extreme heat in June 2021 and <a href="https://www.worldweatherattribution.org/siberian-heatwave-of-2020-almost-impossible-without-climate-change/">Siberia’s</a> high temperatures in the first half of 2020 each would have been virtually impossible without it.</p>
<p>The recent heatwave was relatively short, but it was also widespread across western Europe, and very intense. We are confident that climate change made it much more likely because the event stands out in bold against natural variation in the climate, which normally averages out to be unremarkable over such a wide area.</p>
<p>Though there aren’t yet estimates, we know that disruption to travel and the slowing down of work during the heatwave <a href="https://www.nytimes.com/2022/07/19/business/dealbook/uk-heatwave-economy.html">cost European economies</a> dearly. Unprecedented water demand put a heavy strain on systems already <a href="https://www.theweek.co.uk/news/uk-news/957386/is-the-uk-facing-a-water-shortage">running dry</a>. A combination of <a href="https://www.wired.com/story/what-is-fire-weather-and-why-is-it-getting-worse/">extreme heat and dryness</a> created <a href="https://www.metoffice.gov.uk/public/weather/fire-severity-index/#?tab=map&fcTime=1658660400&zoom=5&lon=-4.00&lat=55.74">exceptional</a> conditions for wildfires to spread rapidly. </p>
<p>This <a href="https://theconversation.com/how-wildfires-affect-climate-change-and-vice-versa-158688">released carbon</a> held in vegetation, warming the planet further. The resulting smoke is also <a href="https://www.ehn.org/wildfire-smoke-2654940604/far-reaching-impacts-of-wildfires">toxic</a>. As the days and nights were several degrees hotter, the <a href="https://www.nature.com/articles/s41467-019-08745-6">effect of climate change</a> <a href="https://www.nature.com/articles/s41467-021-26050-z">cost society</a> on all of these fronts. </p>
<p>The amount by which previous temperature records were smashed is directly linked to the <a href="https://www.carbonbrief.org/climate-change-will-drive-rise-in-record-shattering-climate-extremes/">rate of greenhouse gas emissions</a>. The faster carbon dioxide (CO₂) is dumped into the atmosphere, the faster the planet warms and the more regularly new records will be exceeded. </p>
<p>While this crisis plays out, the contest to replace Boris Johnson as Conservative Party leader and UK prime minister has <a href="https://www.edie.net/truss-v-sunak-who-is-best-placed-to-lead-the-country-on-climate-and-net-zero/">barely covered</a> climate change, and former contenders even <a href="https://www.theguardian.com/environment/2022/jul/19/kemi-badenoch-moves-away-from-net-zero-by-2050-in-double-climate-u-turn">pledged to scrap</a> the country’s commitment to reach net zero by 2050. </p>
<p>This is the opposite of what is needed to prevent heatwaves becoming ever hotter and deadlier, which can only be achieved by urgently reducing long-lived greenhouse gas emissions such as CO₂ to zero. Economists <a href="https://www.weforum.org/agenda/2021/04/economists-global-action-climate-change-natural-disasters">widely favour</a> action on climate change as a far cheaper alternative to enduring broken weather records year after year.</p>
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<p class="fine-print"><em><span>Ben Clarke receives funding from the Natural Environment Research Council. </span></em></p><p class="fine-print"><em><span>Friederike Otto works for the Grantham Institute at Imperial College London and leads World Weather Attribution (<a href="https://www.worldweatherattribution.org">https://www.worldweatherattribution.org</a>). She receives funding from the European Climate Foundation, NERC and the European Research Council. </span></em></p><p class="fine-print"><em><span>Luke Harrington receives funding from the Ministry of Business, Innovation and Employment. </span></em></p>Global heating may be making the weather systems behind heatwaves more common in Europe.Ben Clarke, DPhil Candidate in Environmental Research, University of OxfordFriederike Otto, Associate Director, Environmental Change Institute, Imperial College LondonLuke Harrington, Senior Lecturer in Climate Change, University of WaikatoLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1848342022-06-22T20:03:13Z2022-06-22T20:03:13Z4 ways to understand why Australia is so cold right now despite global warming<figure><img src="https://images.theconversation.com/files/470177/original/file-20220622-21-yknk7r.jpg?ixlib=rb-1.1.0&rect=19%2C13%2C4394%2C2918&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>It’s an offhand joke a lot of us make – it’s freezing, can we get a bit more of that global warming right about now? </p>
<p>But how should we really conceive our day-to-day weather in the context of climate change, especially when Australia’s east coast is enduring a <a href="https://theconversation.com/why-is-it-so-cold-right-now-and-how-long-will-it-last-a-climate-scientist-explains-184155">colder-than-normal start to winter</a>? Here are four ways.</p>
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Read more:
<a href="https://theconversation.com/why-is-it-so-cold-right-now-and-how-long-will-it-last-a-climate-scientist-explains-184155">Why is it so cold right now? And how long will it last? A climate scientist explains</a>
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<h2>1. Put the weather in a long-term context</h2>
<p>The recent cold conditions in some parts of Australia haven’t been seen in decades, but they aren’t unprecedented. In Melbourne, <a href="https://www.theguardian.com/australia-news/2022/jun/16/australia-weather-coldest-winter-start-decades-east-coast-cold-snap-power-grid-strain">for instance</a>, the first two weeks of June were coldest since 1949. In Brisbane, they were the coldest since 1990. </p>
<p>Under the global warming trend, cold events such as these are becoming less and less likely. But Australia naturally has a variable climate, which means they, of course, still do occur. </p>
<p>And given Australia’s instrumental records go back only 112 years (a relatively short length of time), it’s actually still possible we’ll see new record cold temperatures, even in a warming climate.</p>
<p>Still, record hot temperatures in Australia are being broken <a href="https://theconversation.com/sure-winter-felt-chilly-but-australia-is-setting-new-heat-records-at-12-times-the-rate-of-cold-ones-35607">12 times more often</a> than cold ones. </p>
<p>The climate would need to be warming incredibly fast for there to be zero cold records broken, and even faster still if we were to see no cold weather at all. No one suggests this is the reality.</p>
<h2>2. Zoom out for a wider view</h2>
<p>Let’s look at an individual day – say, Tuesday June 13 – using <a href="https://climatereanalyzer.org/">Climate Reanalyser</a>, a platform for visualising climate and weather datasets.</p>
<p>That day was certainly colder than the 1979-2000 average in eastern Australia and Tasmania. But it was warmer than average in parts of Western Australia and many places around the world, including large parts of Africa. Meanwhile, parts of the United States and Europe were experiencing major heatwaves. </p>
<p>On this day, the global average was 0.3°C warmer than the 1979-2000 baseline, and this baseline was around 0.6°C warmer than the pre-industrial climate. </p>
<p>This is exactly what you expect from weather variability in a warming climate – variations day to day and place to place, but a consistently warmer climate when you take the wide view.</p>
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Read more:
<a href="https://theconversation.com/after-the-vicious-cold-snap-here-are-our-tips-to-warm-up-while-keeping-your-environmental-footprint-down-143458">After the vicious cold snap, here are our tips to warm up while keeping your environmental footprint down</a>
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<a href="https://images.theconversation.com/files/469712/original/file-20220620-18-ocfpdt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Children and adults cool off in fountain in a park" src="https://images.theconversation.com/files/469712/original/file-20220620-18-ocfpdt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/469712/original/file-20220620-18-ocfpdt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/469712/original/file-20220620-18-ocfpdt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/469712/original/file-20220620-18-ocfpdt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/469712/original/file-20220620-18-ocfpdt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/469712/original/file-20220620-18-ocfpdt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/469712/original/file-20220620-18-ocfpdt.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">Heatwaves from North Africa to Spain brought temperatures over 40°C.</span>
<span class="attribution"><a class="source" href="https://photos.aap.com.au/search/spain%20heatwave%202022">Manu Fernandez/AP</a></span>
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<h2>3. Look at the climate indicators with more ‘memory’</h2>
<p>Looking at the weather day to day is a bit like watching the live share market updates from one stock exchange. To understand the trends and the bigger picture, you need to track it over time and space. </p>
<p>Given instrumental records only go back so far, scientists can use climate indicators found in nature. Glaciers, for example, respond to temperature over time, with almost all glaciers around the world receding in response to a warmer climate.</p>
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<a href="https://images.theconversation.com/files/470176/original/file-20220622-15-950bh6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/470176/original/file-20220622-15-950bh6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/470176/original/file-20220622-15-950bh6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/470176/original/file-20220622-15-950bh6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/470176/original/file-20220622-15-950bh6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/470176/original/file-20220622-15-950bh6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/470176/original/file-20220622-15-950bh6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/470176/original/file-20220622-15-950bh6.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">Climate change is causing the Franz Josef glacier in New Zealand to rapidly retreat.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
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<p>The oceans have longer memories than the atmosphere. Ocean warming is clear in, for instance, the East Australian Current, which now <a href="https://www.abc.net.au/news/2021-05-08/scientists-study-warming-east-australian-current/100124448">extends further south</a>, bringing warmer water down the southeast coast. This, in turn, is driving fish species further south and devastating kelp forests.</p>
<p>Perhaps the most reliable indicator of warming planet is the total “ocean heat content” – the total amount of extra energy stored in our oceans, which can store a lot more than the atmosphere. There has been a rock-steady increase of ocean heat content <a href="https://www.climate.gov/news-features/understanding-climate/climate-change-ocean-heat-content">in recent decades</a>.</p>
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Read more:
<a href="https://theconversation.com/how-climate-change-made-the-melting-of-new-zealands-glaciers-10-times-more-likely-143626">How climate change made the melting of New Zealand's glaciers 10 times more likely</a>
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<h2>4. Consider the concept of attribution</h2>
<p>Determining whether <a href="https://theconversation.com/one-of-the-most-extreme-disasters-in-colonial-australian-history-climate-scientists-on-the-floods-and-our-future-risk-178153">climate change helped</a> make a particular weather <a href="https://ecos.csiro.au/climate-change-attribution/">event more likely or more severe</a> than it would have been – whether a cold snap, a heatwave or flooding rains – requires a formal attribution study, which looks for a climate change “fingerprint”.</p>
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<figcaption><span class="caption">A video explaining climate change attribution | CSIRO.</span></figcaption>
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<p>Overall, the planet has <a href="https://theconversation.com/this-is-the-most-sobering-report-card-yet-on-climate-change-and-earths-future-heres-what-you-need-to-know-165395">warmed 1.09°C</a> since pre-industrial times. And since 2012, the human caused climate change fingerprint <a href="https://www.nature.com/articles/s41558-019-0666-7">has been clear</a> in any single day of <em>global</em> weather. </p>
<p>Thanks to event attribution studies, we can confidently state that cold extremes are now less likely than they would be in a world without climate change, while heatwaves and extreme heat events are far more likely. </p>
<p>For example, climate change made the recent devastating heatwave in India and Pakistan <a href="https://www.worldweatherattribution.org/climate-change-made-devastating-early-heat-in-india-and-pakistan-30-times-more-likely/">30 times more likely</a>. </p>
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<a href="https://images.theconversation.com/files/469691/original/file-20220620-26-7pltnz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A construction worker walks across a mirage on the road in front of a historical building" src="https://images.theconversation.com/files/469691/original/file-20220620-26-7pltnz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/469691/original/file-20220620-26-7pltnz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=384&fit=crop&dpr=1 600w, https://images.theconversation.com/files/469691/original/file-20220620-26-7pltnz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=384&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/469691/original/file-20220620-26-7pltnz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=384&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/469691/original/file-20220620-26-7pltnz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=482&fit=crop&dpr=1 754w, https://images.theconversation.com/files/469691/original/file-20220620-26-7pltnz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=482&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/469691/original/file-20220620-26-7pltnz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=482&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">The severe heatwave in India and Pakistan caused critical electricity and water shortages.</span>
<span class="attribution"><a class="source" href="https://photos.aap.com.au/search/record%20hot%20weather">AP Photo/Manish Swarup</a></span>
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<h2>Our weather intuitions</h2>
<p>Our intuitions and common sense are great tools for navigating our day-to-day life and making decisions. But our first-hand experience is rooted at the scale of centimetres to kilometres, seconds to days. </p>
<p>Our brains are not perfect data loggers over decades, and our memories are subjective. Vivid childhood memories of hot asphalt on our young feet, cars with hot vinyl seats and houses with no air conditioners affect how we compare the past to today. And we aren’t exposed to all weather, especially us city dwellers who spend a lot of time indoors.</p>
<p>Pulling at our intuitions about cold weather to comment about climate change can be compelling. United States senator James Inhofe famously brought a snowball into the senate in 2015 to claim that if there’s cold weather then the climate can’t be warming. </p>
<p>While this was widely mocked at the time, these appeals do tug at our instincts to turn to our experiences to understand the world. </p>
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<figcaption><span class="caption">James Inhofe bringing a snowball into the US Senate.</span></figcaption>
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<p>To get out of these local scales, we need to feed our intuitions some more input. So, data are important. </p>
<p>With data, we can inform and guide our intuitions and overcome our natural focus on the local scale. To be convinced the climate is warming, we need to watch the long-term trends and expect the wiggles.</p>
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<p>And just like in places such as southern Australia where the climate is drying, we <a href="https://theconversation.com/climate-change-is-likely-driving-a-drier-southern-australia-so-why-are-we-having-such-a-wet-year-172409">still expect some wet years</a>, we still expect cold spells in a warming climate.</p>
<p>It is instinctual to downplay or doubt the idea the climate is getting warmer when you’re feeling cold right now. But next time, consider these four points.</p>
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<p>
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<strong>
Read more:
<a href="https://theconversation.com/if-youre-renting-chances-are-your-home-is-cold-with-power-prices-soaring-heres-what-you-can-do-to-keep-warm-184472">If you're renting, chances are your home is cold. With power prices soaring, here's what you can do to keep warm</a>
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<img src="https://counter.theconversation.com/content/184834/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.</span></em></p>Cold snaps are becoming less and less likely as the world warms. But that doesn’t mean they don’t happen. An expert helps you put the colder-than-normal start to winter in context.Michael Grose, Climate projections scientist, CSIROLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1637152021-07-06T15:00:08Z2021-07-06T15:00:08ZGlobal evidence links rise in extreme precipitation to human-driven climate change<figure><img src="https://images.theconversation.com/files/409546/original/file-20210703-17-ttg7th.jpg?ixlib=rb-1.1.0&rect=0%2C29%2C2821%2C1851&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Hurricane Harvey dumped an unheard-of 60 inches of rain in parts of Texas in 2017.</span> <span class="attribution"><a class="source" href="https://newsroom.ap.org/detail/HarveyYearLaterNumbers/be30963c08954226857ee87c4045adb5/photo">AP Photo/David J. Phillip</a></span></figcaption></figure><p><em>The <a href="https://theconversation.com/us/topics/research-brief-83231">Research Brief</a> is a short take about interesting academic work.</em></p>
<h2>The big idea</h2>
<p>Human activities, such as burning fossil fuels for transportation and electricity, have worsened the intensity of extreme rainfall and snowfall over land in recent decades, not just in a few areas but on a global scale, <a href="https://www.nature.com/articles/s41467-021-24262-x">new research</a> shows.</p>
<p>Past studies were able to <a href="https://www.worldweatherattribution.org/analysis/rainfall/">attribute individual extreme events</a> and <a href="https://doi.org/10.1073/pnas.1921628117">long-term changes in some regions</a> to climate change, but global assessments have been more difficult. We used a new technique to analyze precipitation records from around the world and found conclusive evidence of human influence on extreme precipitation in every region. </p>
<p>Scientists have been warning that <a href="https://doi.org/10.1073/pnas.0907610106">rising global temperatures</a> will lead to more extreme precipitation in the future, mainly because warm air “holds” more <a href="https://doi.org/10.1175/BAMS-84-9-1205">water vapor</a> in the atmosphere, fueling storms. </p>
<p>With Earth already <a href="http://berkeleyearth.org/2019-temperatures/">about 1 degree Celsius (1.8 F) warmer</a> since the start of the industrial era, we wanted to find out if that change had already started.</p>
<p>Past attempts to detect the human influence in historical precipitation records typically <a href="https://doi.org/10.1016/j.wace.2016.01.001">required long time series with many consecutive years of data</a>. But precipitation is difficult to monitor over long periods from land or space, so those records are rare. We found another way.</p>
<p>We used artificial neural networks, a type of machine learning, to find patterns of extreme precipitation in weather records. Once those neural networks understood what to look for, we could analyze shorter and more disparate observational records.</p>
<p>The result is multiple lines of evidence that human activity has intensified extreme precipitation during recent decades. Even when the <a href="https://doi.org/10.1088/1748-9326/ab6a22">data sets were widely different</a>, we were able to see the human influence.</p>
<p><a href="https://www.nature.com/articles/s41467-021-24262-x">The findings</a> were published July 6, 2021, in the journal Nature Communications. </p>
<h2>Why it matters</h2>
<p>Understanding how humans influence extreme precipitation is important for interpreting climate events today and for preparing cities and <a href="https://theconversation.com/how-to-make-sure-bidens-infrastructure-plan-can-hold-up-to-climate-change-and-save-money-153869">protective infrastructure</a> for the changing world ahead. </p>
<p>In recent years, devastating flooding has made headlines after extraordinary rainfall that historically would have been extremely rare. The <a href="https://www.usatoday.com/story/weather/2018/01/30/2017-s-three-monster-hurricanes-harvey-irma-and-maria-among-five-costliest-ever/1078930001/">2017 hurricane season in Texas, Florida and Puerto Rico</a> and the <a href="https://www.theguardian.com/world/2017/aug/30/mumbai-paralysed-by-floods-as-india-and-region-hit-by-worst-monsoon-rains-in-years">extreme monsoon rains over India and Bangladesh in 2017</a> are two examples. Our results indicate that, as a general rule, precipitation has become more extreme around the world in recent decades.</p>
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<p>Perhaps more importantly, our results indicate that further warming of the planet through the 21st century is likely to continue to intensify the most extreme precipitation events. <a href="https://doi.org/10.1002/jgrd.50188">Climate models project such an intensification</a> will happen this century, and they suggest that a similar but <a href="https://doi.org/10.1002/jgrd.50203">less-rapid intensification occurred in the 20th Century</a>, based on how much the planet has already warmed. Our results validate that finding.</p>
<p>With greenhouse gas levels in the atmosphere still increasing, the planet is projected to continue <a href="https://www.ipcc.ch/report/ar5/syr/">warming through the 21st century</a>. How much it warms will depend on choices made today about fossil fuel use and other major contributors to climate change. That 1 degree of warming could be <a href="https://www.nature.com/articles/d41586-020-00177-3">4 degrees</a> by the end of the century if emissions continue at a high rate.</p>
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<h2>What’s next</h2>
<p>While we clearly identified the influence of humans on extreme precipitation in the past, we haven’t yet isolated how much each type of human activity has contributed. Greenhouse gas emissions, aerosols and changes in land use can all have an influence. We plan to modify our machine learning method in the future to home in on those sources.</p>
<p>The machine learning method we used is also currently learning from data alone. We can take this up a notch by bringing <a href="https://doi.org/10.1109/TKDE.2017.2720168">climate physics into the algorithm</a>. By doing that, the machine would learn the <a href="https://doi.org/10.1073/pnas.0907610106">physical processes</a> that lead to intensifying extreme precipitation. Other climate variables could be included, such as winds, clouds and radiation, helping to answer not just whether extreme precipitation is intensifying, but why.</p><img src="https://counter.theconversation.com/content/163715/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Gavin D. Madakumbura receives funding from the US Department of Energy.</span></em></p><p class="fine-print"><em><span>Alex Hall receives research funding from the National Science Foundation and the US Department of Energy. </span></em></p><p class="fine-print"><em><span>Chad Thackeray receives funding from the National Science Foundation and the US Department of Energy. </span></em></p><p class="fine-print"><em><span>Jesse Norris receives funding from the US Department of Energy.</span></em></p>Scientists used artificial neural networks to analyze precipitation records. They found evidence of human activities influencing extreme rainfall or snowfall around the world.Gavin D. Madakumbura, Ph.D. candidate in Atmospheric and Oceanic Sciences, University of California, Los AngelesAlex Hall, Professor and Director, UCLA Center for Climate Science, University of California, Los AngelesChad Thackeray, Assistant Researcher, UCLA Center for Climate Science, University of California, Los AngelesJesse Norris, Project Scientist, Atmospheric and Oceanic Sciences, University of California, Los AngelesLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1360032020-04-20T15:19:12Z2020-04-20T15:19:12ZYes, climate change can affect extreme weather – but there is still a lot to learn<figure><img src="https://images.theconversation.com/files/329129/original/file-20200420-152571-kw3te8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Vadven / shutterstock</span></span></figcaption></figure><p>The fact that the climate has warmed is hard for humans to actually experience first hand, and we certainly can’t see carbon in the air with our own eyes. For most of us, climate change manifests itself and affects our lives through heatwaves, storms, wildfires, floods and droughts.</p>
<p>However, this does not mean that all extreme weather events are being made stronger or more frequent. The role played by climate change compared to other drivers of extremes – whether natural variability in weather systems, or man-made drivers such as deforestation – strongly depends on the type of extreme event and the part of the world and season they are happening in.</p>
<p>Attribution scientists like me aim to quantify whether and to what extent human-induced climate change alters the likelihood and intensity of extreme weather events. In some cases, like heat waves in <a href="https://journals.ametsoc.org/doi/pdf/10.1175/BAMS-D-19-0170.1">European summers</a>, it’s a real game-changer. The European heatwave in July 2019, for example, was made up to 100 times more likely due to climate change. In other cases, analysis shows that the role of climate change was very small – for example recent droughts in Brazil were mainly driven by <a href="https://journals.ametsoc.org/doi/pdf/10.1175/BAMS-D-15-00120.1">other factors</a>. </p>
<p>And in some cases we do not know, either because the data and tools we currently have are not sophisticated enough to quantify the role of climate change – as was the case for <a href="https://theconversation.com/droughts-in-east-africa-some-headway-in-unpacking-whats-causing-them-75476">droughts in East Africa</a> – or because no study has been undertaken. This is the case for many extreme weather events occurring around the world, because attribution studies are still relatively rare and heavily skewed towards events happening in the developed world.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1252013114134011904"}"></div></p>
<p>The website Carbon Brief has just published an update of its map of all the attribution studies that have looked at the <a href="https://www.carbonbrief.org/mapped-how-climate-change-affects-extreme-weather-around-the-world">impact of climate change on extreme weather events around the world</a>. For now, the map still shows a heavy bias towards events in Europe, North America and Australia, and also towards heatwaves. However, with every update it is becoming more and more comprehensive as the science evolves and includes a more diverse set of events. </p>
<h2>Science within the news cycle</h2>
<p>The latest update includes, for the first time, rapid attribution studies – those that are done during or immediately after an extreme weather event. In December 2015, I was involved in one of the first such studies which found that climate change had made large-scale flooding after <a href="https://www.worldweatherattribution.org/uks-storm-desmond-december-2015/">Storm Desmond</a> about 40% more likely. A more recent study looked at <a href="https://www.worldweatherattribution.org/rapid-attribution-of-the-extreme-rainfall-in-texas-from-tropical-storm-imelda/">tropical storm Imelda</a> which drenched Texas in September 2019, and found that the rainfall was increased almost three times by climate change.</p>
<p>These sorts of studies are important, as they provide scientific evidence while the event is still in the news and everyone is still paying attention – not months later after the academic peer-review process. </p>
<p>But this has also made these studies somewhat controversial, because they do not go through peer-review before publication. To help address this, rapid attribution studies use peer-reviewed methods, make data publicly available, and regularly submit to peer-review journals after the fact. Such subsequent academic studies demonstrated that the rapid studies on <a href="https://iopscience.iop.org/article/10.1088/1748-9326/aa9663">Desmond</a>, <a href="https://journals.ametsoc.org/doi/10.1175/JHM-D-18-0074.1">floods in Paris</a> and the <a href="http://www.ametsoc.net/eee/2017a/ch11_EEEof2017_Kew.pdf">Mediterranean heatwave of 2017</a> stood the test of time. The inclusion of rapid attribution studies in the Carbon Brief map reflects a growing acceptance of these methods.</p>
<h2>Attribution studies can be too conservative</h2>
<p>This branch of science remains relatively new, and far from perfect. Attribution studies, rapid and traditional alike, have been criticised by some scientists for both being <a href="https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2017EF000665@10.1002/(ISSN)1944-9208.COMOC1">too conservative</a> and underestimating the role of climate change. They also get accused of not being cautious enough in communicating uncertainty and therefore <a href="https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2015GL067189">overstating</a> the impact of burning fossil fuels on extreme weather events. </p>
<p>Underlying both arguments is the fact that the climate models needed for attribution studies are often not as good as one would like. In fact, in recent studies colleagues and I found that climate models underestimated the increase in heat extremes <a href="https://www.worldweatherattribution.org/human-contribution-to-record-breaking-june-2019-heatwave-in-france/">in Europe</a> and <a href="https://www.worldweatherattribution.org/bushfires-in-australia-2019-2020/">Australia</a>. The observed temperatures – that is, what was happening in the real world – increased twice as much as the temperatures predicted by the models. </p>
<p>If models do not represent the full warming seen in the real world, then attribution studies can only give conservative, and arguably too conservative, estimates of the role of climate change.</p>
<p>Overall, while climate models are very good at representing how increases in greenhouse gases affect <a href="https://www.carbonbrief.org/qa-how-do-climate-models-work">average temperatures</a>, they are less good at representing more local extreme events. Attribution studies remain our best (and only) tool for understanding the impact of climate change on extreme weather and on our daily lives. They play a key role in helping <a href="https://www.climatecentre.org/news/1253/climate-attribution-work-in-mit-review-ten-a-breakthrough-technologiesa-for-2020">decision makers plan for, or avoid, a future where extreme weather events</a> are more likely and intense due to global warming. This is particularly true if the role of climate change is assessed rapidly and alongside factors influencing vulnerability and exposure.</p>
<p>Attribution studies are also really important within climate science as they bridge the gap between observations and model projections. They test climate models in a real-world context, allowing scientists to understand better where they can have more confidence in their projections and where model improvements are needed before projections can be used for decision making. </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=Imagineheader1136003">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/136003/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Friederike Otto receives funding from UKIERI, CIFF, BNP Paribas climate foundation. </span></em></p>It is not the case that all extreme weather events are being made stronger or more frequent.Friederike Otto, Acting Director, Environmental Change Institute, University of OxfordLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/706482016-12-21T19:03:16Z2016-12-21T19:03:16ZYes, the Arctic’s freakishly warm winter is due to humans’ climate influence<figure><img src="https://images.theconversation.com/files/151164/original/image-20161221-14203-1ksx4bd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">An Arctic iceberg, pictured in 2015. This year, ice coverage has reached record lows for the early northern winter.</span> <span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File%3AIceberg_in_the_Arctic_with_its_underside_exposed.jpg">AWeith/Wikimedia Commons</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>For the Arctic, <a href="https://theconversation.com/2016-is-likely-to-be-the-worlds-hottest-year-heres-why-59378">like the globe as a whole</a>, 2016 has been exceptionally warm. For much of the year, Arctic temperatures have been much higher than normal, and sea ice concentrations have been at <a href="https://theconversation.com/climate-shenanigans-at-the-ends-of-the-earth-why-has-sea-ice-gone-haywire-69485">record low levels</a>.</p>
<p>The Arctic’s seasonal cycle means that the lowest sea ice concentrations occur in September each year. But while September 2012 had less ice than September 2016, this year the ice coverage has not increased as expected as we moved into the northern winter. As a result, since late October, Arctic sea ice extent has been at <a href="http://nsidc.org/arcticseaicenews/2016/12/arctic-and-antarctic-at-record-low-levels/">record low levels for the time of year</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/151155/original/image-20161221-13147-yynqko.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/151155/original/image-20161221-13147-yynqko.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/151155/original/image-20161221-13147-yynqko.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=468&fit=crop&dpr=1 600w, https://images.theconversation.com/files/151155/original/image-20161221-13147-yynqko.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=468&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/151155/original/image-20161221-13147-yynqko.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=468&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/151155/original/image-20161221-13147-yynqko.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=588&fit=crop&dpr=1 754w, https://images.theconversation.com/files/151155/original/image-20161221-13147-yynqko.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=588&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/151155/original/image-20161221-13147-yynqko.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=588&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Late 2016 has produced new record lows for Arctic ice.</span>
<span class="attribution"><span class="source">NSIDC</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>These record low sea ice levels have been associated with exceptionally high temperatures for the Arctic region. November and December (so far) have seen record warm temperatures. At the same time Siberia, and <a href="http://www.usatoday.com/story/news/2016/12/16/bitter-cold-grips-us-plains-new-england/95511250/">very recently North America</a>, have experienced conditions that are slightly cooler than normal.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/151158/original/image-20161221-14216-p6zlsy.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/151158/original/image-20161221-14216-p6zlsy.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/151158/original/image-20161221-14216-p6zlsy.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=497&fit=crop&dpr=1 600w, https://images.theconversation.com/files/151158/original/image-20161221-14216-p6zlsy.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=497&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/151158/original/image-20161221-14216-p6zlsy.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=497&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/151158/original/image-20161221-14216-p6zlsy.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=624&fit=crop&dpr=1 754w, https://images.theconversation.com/files/151158/original/image-20161221-14216-p6zlsy.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=624&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/151158/original/image-20161221-14216-p6zlsy.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=624&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Temperatures have been far above normal over vast areas of the Arctic this November and December.</span>
<span class="attribution"><span class="source">Geert Jan van Oldenborgh/KNMI/ERA-Interim</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Extreme Arctic warmth and low ice coverage affect the <a href="http://rsbl.royalsocietypublishing.org/content/12/8/20160198">migration patterns of marine mammals</a> and have been linked with <a href="https://www.newscientist.com/article/2112958-80000-reindeer-have-starved-to-death-as-arctic-sea-ice-retreats/">mass starvation and deaths among reindeer</a>, as well as affecting <a href="https://www.carbonbrief.org/polar-bears-and-climate-change-what-does-the-science-say">polar bear habitats</a>.</p>
<p>Given these severe ecological impacts and the <a href="https://www.theguardian.com/environment/2015/jun/01/rapid-arctic-ice-loss-linked-to-extreme-weather-changes-in-europe-and-us">potential influence of the Arctic on the climates of North America and Europe</a>, it is important that we try to understand whether and how human-induced climate change has played a role in this event.</p>
<h2>Arctic attribution</h2>
<p>Our <a href="https://wwa.climatecentral.org/">World Weather Attribution group</a>, led by <a href="https://www.climatecentral.org/">Climate Central</a> and including researchers at the <a href="http://earthsci.unimelb.edu.au/">University of Melbourne</a>, the <a href="http://www.eci.ox.ac.uk/">University of Oxford</a> and the Dutch Meteorological Service (<a href="https://www.knmi.nl/over-het-knmi/about">KNMI</a>), used three different methods to assess the role of the human climate influence on record Arctic warmth over November and December. </p>
<p>We used forecast temperatures and heat persistence models to predict what will happen for the rest of December. But even with 10 days still to go, it is clear that November-December 2016 will certainly be record-breakingly warm for the Arctic.</p>
<p>Next, I investigated whether human-caused climate change has altered the likelihood of extremely warm Arctic temperatures, using state-of-the-art climate models. By comparing climate model simulations that include human influences, such as increased greenhouse gas concentrations, with ones without these human effects, we can estimate the role of climate change in this event. </p>
<p>This technique is similar to that used in previous analyses of <a href="https://theconversation.com/the-human-role-in-our-angry-hot-summer-15596">Australian record heat</a> and the sea temperatures associated with the <a href="https://theconversation.com/great-barrier-reef-bleaching-would-be-almost-impossible-without-climate-change-58408">Great Barrier Reef coral bleaching event</a>.</p>
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<a href="https://images.theconversation.com/files/151160/original/image-20161221-14185-4yy2jo.gif?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/151160/original/image-20161221-14185-4yy2jo.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/151160/original/image-20161221-14185-4yy2jo.gif?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=424&fit=crop&dpr=1 600w, https://images.theconversation.com/files/151160/original/image-20161221-14185-4yy2jo.gif?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=424&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/151160/original/image-20161221-14185-4yy2jo.gif?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=424&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/151160/original/image-20161221-14185-4yy2jo.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=533&fit=crop&dpr=1 754w, https://images.theconversation.com/files/151160/original/image-20161221-14185-4yy2jo.gif?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=533&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/151160/original/image-20161221-14185-4yy2jo.gif?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=533&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The November-December temperatures of 2016 are record-breaking but will be commonplace in a few decades’ time.</span>
<span class="attribution"><span class="source">Andrew King</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>To put it simply, the record November-December temperatures in the Arctic do not happen in the simulations that leave out human-driven climate factors. In fact, even with human effects included, the models suggest that this Arctic hot spell is a 1-in-200-year event. So this is a freak event even by the standards of today’s world, which humans have warmed by roughly 1°C on average since pre-industrial times.</p>
<p>But in the future, as we continue to emit greenhouse gases and further warm the planet, events like this won’t be freaks any more. If we do not reduce our greenhouse gas emissions, we estimate that by the late 2040s this event will occur on average once every two years.</p>
<h2>Watching the trend</h2>
<p>The group at KNMI used observational data (not a straightforward task in an area where very few observations are taken) to examine whether the probability of extreme warmth in the Arctic has changed over the past 100 years. To do this, temperatures slightly further south of the North Pole were incorporated into the analysis (to make up for the lack of data around the North Pole), and these indicated that the current Arctic heat is unprecedented in more than a century.</p>
<p>The observational analysis reached a similar conclusion to the model study: that a century ago this event would be extremely unlikely to occur, and now it is somewhat more likely (the observational analysis puts it at about a 1-in-50-year event).</p>
<p>The Oxford group used the very large ensemble of <a href="http://www.climateprediction.net/weatherathome/">Weather@Home</a> climate model simulations to compare Arctic heat like 2016 in the world of today with a year like 2016 without human influences. They also found a substantial human influence in this event.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/151193/original/image-20161221-14208-2uqgdn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/151193/original/image-20161221-14208-2uqgdn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/151193/original/image-20161221-14208-2uqgdn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=844&fit=crop&dpr=1 600w, https://images.theconversation.com/files/151193/original/image-20161221-14208-2uqgdn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=844&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/151193/original/image-20161221-14208-2uqgdn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=844&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/151193/original/image-20161221-14208-2uqgdn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1060&fit=crop&dpr=1 754w, https://images.theconversation.com/files/151193/original/image-20161221-14208-2uqgdn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1060&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/151193/original/image-20161221-14208-2uqgdn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1060&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Santa struggles with the heat. Climate change is warming the North Pole and increasing the chance of extreme warm events.</span>
<span class="attribution"><span class="source">Climate Central</span></span>
</figcaption>
</figure>
<p>All of our analysis points the finger at human-induced climate change for this event. Without it, Arctic warmth like this is extremely unlikely to occur. And while it’s still an extreme event in today’s climate, in the future it won’t be that unusual, unless we drastically curtail our greenhouse gas emissions. </p>
<p>As we have already seen, the consequences of more frequent extreme warmth in the future could be devastating for the animals and other species that call the Arctic home.</p>
<p><em>Geert Jan van Oldenborgh, Marc Macias-Fauria, Peter Uhe, Sjoukje Philip, Sarah Kew, David Karoly, Friederike Otto, Myles Allen and Heidi Cullen all contributed to the research on which this article is based.</em></p>
<p><em>You can find more details on all the analysis techniques <a href="https://wwa.climatecentral.org/analyses/">here</a>. Each of the methods used has been peer-reviewed, although as with the Great Barrier Reef bleaching study, we will submit a research manuscript for peer review and publication in 2017.</em></p><img src="https://counter.theconversation.com/content/70648/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Andrew King receives funding from the ARC Centre of Excellence for Climate System Science.</span></em></p>The end of 2016 has brought balmy Arctic temperatures and record low ice extent for the time of year. It’s a freak event even by modern standards, and climate models point the finger firmly at humans.Andrew King, Climate Extremes Research Fellow, The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/682292016-11-09T19:06:14Z2016-11-09T19:06:14ZIgnore the doubters: here’s why Christopher Marlowe co-wrote Shakespeare’s Henry VI<figure><img src="https://images.theconversation.com/files/145111/original/image-20161108-16702-a4r84z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">An artwork by James C. Christensen, which represents Shakespeare with characters from all of his plays.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/tracyleephoto/3186046746/">Tracy Lee/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span></figcaption></figure><p>A new edition of Shakespeare’s works has identified Christopher Marlowe <a href="https://www.theguardian.com/culture/2016/oct/23/christopher-marlowe-credited-as-one-of-shakespeares-co-writers">as a co-author</a>. The editors of the New Oxford Shakespeare believe that Marlowe collaborated in Parts 1, 2 and 3 of Henry VI. The conclusion was reached on the advice of an “Attribution Board” of three specialists in the field of literary authorship.</p>
<p>I was one of the members of this board. I first used computers in the late 1980s for attribution and have worked in this area ever since. Still, as I have discovered, a new Shakespeare attribution (or indeed a de-attribution – when a work by a noted author turns out to be written by someone else) – meets an interesting range of responses.</p>
<h2>The sceptics</h2>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/145112/original/image-20161108-20183-wtocyi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/145112/original/image-20161108-20183-wtocyi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/145112/original/image-20161108-20183-wtocyi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=740&fit=crop&dpr=1 600w, https://images.theconversation.com/files/145112/original/image-20161108-20183-wtocyi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=740&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/145112/original/image-20161108-20183-wtocyi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=740&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/145112/original/image-20161108-20183-wtocyi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=929&fit=crop&dpr=1 754w, https://images.theconversation.com/files/145112/original/image-20161108-20183-wtocyi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=929&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/145112/original/image-20161108-20183-wtocyi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=929&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Portrait of a supposedly 21-year-old Christopher Marlowe in 1585.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Marlowe-Portrait-1585.jpg">Wikimedia Commons</a></span>
</figcaption>
</figure>
<p>First, there are those who think that attribution – the process of finding an author for anonymous or disputed works – is itself misguided, because it doesn’t matter who wrote a play or an act or a scene. The work is interesting, or not, regardless of author. </p>
<p>Then there is the view that authors aren’t the most important creators of literary works. All authors borrow from a common stock of language, the genre of writing is all-important, and everyone in a given era or group shares so much in attitudes and expressions. In the case of Shakespeare, there is the added point that authors don’t seem to have mattered much then – plays were often printed with no author mentioned, or just mysterious initials.</p>
<p>Others think attribution, though important, is impossible. There is so much mutual influence, imitation, and even plagiarism that we can’t distinguish one author’s voice among all the noise of others.</p>
<p>A second often cited obstacle to reliable attribution is the fact that authors change their styles over their careers. There is early Shakespeare and late Shakespeare.</p>
<p>Plus the nature of drama is that the author doesn’t speak and creates all sorts of different voices, inevitably disguising his or her own style. Added to this are the problems of transmission. What happened between the author’s first hand-written version and the frail printed book that happens to have survived from the 1590s?</p>
<p>Last in this group of attribution sceptics are those who think “Shakespeare” is a fraud anyway – the plays were really written by a committee, or the Earl of Oxford, or Sir Henry Neville, or indeed Marlowe. </p>
<p>A second group is those who think that authorship attribution is important, and possible, but this particular one is wrong. There is a better candidate, they say, or the case is not properly conducted, so we must remain in doubt.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/145113/original/image-20161109-16712-ql44hv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/145113/original/image-20161109-16712-ql44hv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/145113/original/image-20161109-16712-ql44hv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=397&fit=crop&dpr=1 600w, https://images.theconversation.com/files/145113/original/image-20161109-16712-ql44hv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=397&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/145113/original/image-20161109-16712-ql44hv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=397&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/145113/original/image-20161109-16712-ql44hv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=499&fit=crop&dpr=1 754w, https://images.theconversation.com/files/145113/original/image-20161109-16712-ql44hv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=499&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/145113/original/image-20161109-16712-ql44hv.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"></a>
<figcaption>
<span class="caption">A modern reconstruction of Shakespeare’s Globe Theatre, approximately 230m from the original site.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/marcusmeissner/9842586713/">Marcus Meissner</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>Two new plays credited to the Bard</h2>
<p>Strange as it may seem after that litany of objections, Shakespeare attribution powers ahead and is now, with the new Oxford edition, changing how Shakespeare is read. </p>
<p>The edition includes 40 plays. Two new ones originally published anonymously, <a href="http://www.encyclopedia.com/arts/educational-magazines/arden-faversham">Arden of Faversham</a> and<a href="http://www.shakespeare-online.com/plays/edwardIII.html"> Edward III</a>, have been added to the usual tally of 38. New research in the Authorship Companion, which is to be published alongside the edition, strengthens the case that Shakespeare wrote parts of these two plays. </p>
<p>Of these 40, 12 are listed as collaborations between Shakespeare and other writers. The edition also includes two sets of scenes Shakespeare added to existing plays, <a href="https://en.wikipedia.org/wiki/The_Spanish_Tragedy">The Spanish Tragedy</a> and <a href="https://www.playshakespeare.com/sir-thomas-more">Sir Thomas More</a>.</p>
<p>My view is that it does matter who wrote what. If we now know more about Shakespeare’s early collaborations, for instance, we can stop regarding unexpected styles in the plays as “apprentice work” and see them as simply a mixture of another writer.</p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/145110/original/image-20161108-16721-2roc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/145110/original/image-20161108-16721-2roc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/145110/original/image-20161108-16721-2roc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=423&fit=crop&dpr=1 600w, https://images.theconversation.com/files/145110/original/image-20161108-16721-2roc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=423&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/145110/original/image-20161108-16721-2roc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=423&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/145110/original/image-20161108-16721-2roc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=532&fit=crop&dpr=1 754w, https://images.theconversation.com/files/145110/original/image-20161108-16721-2roc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=532&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/145110/original/image-20161108-16721-2roc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=532&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 first page from Henry VI, Part 1.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/File:First-page-first-folio-1henry6.jpg">Folger Shakespeare Library Digital Image Collection/Wikimedia Commons</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>When we thought the poem A Funerall Elegie was Shakespeare’s, it was not only of intense interest in itself, but changed what “Shakespeare” is. Now that we know it is by Shakespeare’s fellow playwright <a href="https://www.jstor.org/stable/3070371?seq=1#page_scan_tab_contents">John Ford</a>, there will be fewer people reading it, inevitably, and “Shakespeare” changes again. </p>
<p>On the question of internal variation cutting across the authorial voice, there are ways of testing this as a factor. We can set up an experiment to see whether with a given classifying system – a set of data, variables and procedures – we can tell Shakespeare’s writing from others despite the obstacles put in the way by the nature of drama, the influence of genres, and authors changing styles over their career. This testing generally shows that while the other factors do matter, they don’t drown out the voice of the author.</p>
<p>This self-testing aspect is the most reassuring part of attributing (say) parts of the three Henry VI plays to <a href="http://www.biography.com/people/christopher-marlowe-9399572">Marlowe</a>, the author of Tamburlaine, Doctor Faustus and Edward II, who died at just 29. Using the same method, we can see whether when we treat parts of known Shakespeare and known Marlowe as anonymous we get a reliable attribution.</p>
<h2>How were the Henry VI plays written?</h2>
<p>There is a long tradition of authorship work on Shakespeare, going back to the 18th century, and many people around the world, in universities and outside them, involved. What has happened with the Henry VI plays is that older ideas that Shakespeare was influenced by Marlowe and closely imitated him gave way to suggestions that Marlowe wrote parts of the plays.</p>
<p>Probably the two playwrights were commissioned by a theatre company to write designated separate sections within a plot that was given them. In the first two parts, for instance, Marlowe’s work seems to have focused on the characters Joan la Pucelle (Joan of Arc) and the rebel Jack Cade.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/145109/original/image-20161108-16727-uh9d2i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/145109/original/image-20161108-16727-uh9d2i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/145109/original/image-20161108-16727-uh9d2i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=724&fit=crop&dpr=1 600w, https://images.theconversation.com/files/145109/original/image-20161108-16727-uh9d2i.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=724&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/145109/original/image-20161108-16727-uh9d2i.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=724&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/145109/original/image-20161108-16727-uh9d2i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=910&fit=crop&dpr=1 754w, https://images.theconversation.com/files/145109/original/image-20161108-16727-uh9d2i.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=910&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/145109/original/image-20161108-16727-uh9d2i.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=910&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A portrait of King Henry VI.</span>
<span class="attribution"><span class="source">National Portrait Gallery/Wikimedia Commons</span></span>
</figcaption>
</figure>
<p>An independent scholar, Tom Merriam, first argued this on the basis of Marlowe-like phrases in the first part of the play. My own work in a 2009 book supported this and added sections of the second part. Newer work on very rare phrases by John V Nance and Gary Taylor, and tests using networks of words by Gabriel Egan and others, have confirmed it. John Burrows, the doyen of computational stylistics, and I have a chapter in the Authorship Companion adding sections of Henry VI, Part 3, to the tally of Marlowe contributions. </p>
<p>Thus there is now a body of work published and forthcoming from the New Oxford Shakespeare team, which we believe is state of the art and as rigorous as we can make it. Nevertheless not everyone will be persuaded, and that is their right. </p>
<h2>But what about Thomas Kyd?</h2>
<p>For instance, <a href="https://theconversation.com/those-who-think-marlowe-co-wrote-plays-with-shakespeare-may-kyd-themselves-67622">a recent article</a> by Darren Freebury-Jones argues that it was Marlowe’s fellow dramatist Kyd who collaborated with Shakespeare on the first part of Henry VI, and Shakespeare alone who wrote the other two.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/145114/original/image-20161109-16724-1tgxhqd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/145114/original/image-20161109-16724-1tgxhqd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/145114/original/image-20161109-16724-1tgxhqd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=769&fit=crop&dpr=1 600w, https://images.theconversation.com/files/145114/original/image-20161109-16724-1tgxhqd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=769&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/145114/original/image-20161109-16724-1tgxhqd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=769&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/145114/original/image-20161109-16724-1tgxhqd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=966&fit=crop&dpr=1 754w, https://images.theconversation.com/files/145114/original/image-20161109-16724-1tgxhqd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=966&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/145114/original/image-20161109-16724-1tgxhqd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=966&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A portrait of William Shakespeare, believed to be painted by John Taylor.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/William_Shakespeare#/media/File:Shakespeare.jpg">Wikimedia Commons</a></span>
</figcaption>
</figure>
<p>In specific criticisms of the Marlowe attribution work, Freebury-Jones wonders if individual words taken out of context are reliable for attribution, whether shared phrases need to be vetted to see if they are really evidence of a single mind at work, and whether the numbers of words and phrases can ever distinguish between other writers. </p>
<p>My answer would be that all these questions can be tested, and indeed have been, and that while there will never be complete certainty, we can show that there is a high degree of reliability. And of course, these doubts about reliability also apply to the work Freebury-Jones cites in favour of his alternative attributions. </p>
<p>Ultimately we have to return to the detailed work presented in published articles and books. By my count, Freebury-Jones mentions three experts other than himself who support his views on the authorship of the Henry VI plays. None of them has published their work on this topic in an article or a book as far as I am aware. </p>
<p>It’s a risk going out there with a Shakespeare attribution, but we do think that it matters who wrote what, that it’s possible to be pretty sure in some cases, and that we have done our due diligence in what we are proposing in the edition.</p><img src="https://counter.theconversation.com/content/68229/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Hugh Craig receives funding from the Australian Research Council which has supported the work mentioned in the article.</span></em></p>Attributing a Shakespeare work to another writer attracts plenty of critics. But an attribution specialist says his team’s decision to name Christopher Marlowe as a co-author is based on state of the art research.Hugh Craig, Professor of English, University of NewcastleLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/676952016-10-31T05:35:55Z2016-10-31T05:35:55ZUnnatural disasters: how we can spot climate’s role in specific extreme events<p>These days, after an extreme weather event like a cyclone, bushfire, or major storm, it’s common to find people asking: was it climate change? </p>
<p>We also often hear people saying it is impossible to attribute any single weather event to climate change, as former prime minister Tony Abbott and the then environment minister Greg Hunt said after the <a href="http://www.smh.com.au/federal-politics/political-news/bureau-warned-greg-hunt-about-climate-change-before-he-cited-wikipedia-20141006-10qyg0.html">bushfires in New South Wales in 2013</a>. </p>
<p>While this may have been true in the 1990s, the science of <a href="https://www.ametsoc.org/ams/index.cfm/publications/bulletin-of-the-american-meteorological-society-bams/explaining-extreme-events-from-a-climate-perspective/">attributing individual extreme events</a> to global warming has advanced significantly since then. It is now possible to link aspects of extreme events to climate change. </p>
<p>However, as I describe in an article co-written by Susan Hassol, Simon Torok and Patrick Luganda and published today in the World Meteorologcal Organization’s <a href="http://library.wmo.int/opac/doc_num.php?explnum_id=3093">Bulletin</a>, how we communicate these findings has not kept pace with the rapidly evolving science. As a result, there is widespread confusion about the links between climate change and extreme weather. </p>
<h2>Evolving science</h2>
<p>The science of attributing individual extreme weather events to climate change dates back to 2003, when a <a href="http://www.nature.com/nature/journal/v421/n6926/full/421891a.html">discussion article in Nature</a> raised the question of liability for damages from extreme events. The idea was that if you could attribute a specific event to rising greenhouse gas emissions, you could potentially hold someone to account. </p>
<p>This was soon followed by a <a href="http://www.nature.com/nature/journal/v432/n7017/full/nature03089.html">2004 study</a> of the 2003 European heatwave, which caused more than 35,000 deaths. This analysis found that climate change had more than doubled the risk of such extreme heat.</p>
<p>These early studies laid the foundations for using climate models to analyse the links between specific extreme weather events and human-induced climate change. Many studies since then have focused on putting numbers to the risks and likelihoods of various extremes.</p>
<p>Attribution science has now evolved to the point where it is possible to analyse extreme events almost as they happen. The <a href="https://wwa.climatecentral.org/">World Weather Attribution project</a> is an example of an international effort to sharpen and accelerate our ability to analyse and communicate the influence of climate change on extreme weather events.</p>
<p>This project <a href="https://wwa.climatecentral.org/analyses/european-rainstorms-may-2016/">examined the major flooding in France</a> and nearby countries in 2016. The floods – which forced thousands of people to evacuate their homes and caused damage estimated at more than a billion euros in France alone – were made about 80% more likely by climate change.</p>
<h2>Lost in translation</h2>
<p>The communication of this science outside the research community has, with a few <a href="https://theconversation.com/great-barrier-reef-bleaching-would-be-almost-impossible-without-climate-change-58408">notable exceptions</a>, not fully reflected these scientific advances. This confusion about the state of the science comes from many sources.</p>
<p>The media, politicians and some scientists outside this area of research still often claim that we can’t attribute any individual event to climate change. In some countries – including Australia – the causes of specific extremes can be seen as a politically charged issue.</p>
<p>In the aftermath of an extreme event such as a fire or flood, it can be seen as insensitive or overly political to discuss the human-induced causes of loss of life or property. The views of political and media leaders can be influential in shaping public opinions about extreme climate events. </p>
<p>It doesn’t help that <a href="https://theconversation.com/lost-in-translation-confidence-and-certainty-in-climate-science-17181">confidence</a> and <a href="https://theconversation.com/in-science-the-only-certainty-is-uncertainty-17180">uncertainty</a> are widely misunderstood concepts outside the scientific community. </p>
<p>Another part of the problem is that for a long time, many scientists themselves repeated this message because of the complexity of the climate system. All extremes take place in a naturally variable and chaotic climate system, which complicates event attribution. </p>
<p>Attribution scientists have the greatest clarity and confidence in attributing heat events that occur over large areas and extended time periods. For example, <a href="http://journals.ametsoc.org/doi/pdf/10.1175/BAMS-ExplainingExtremeEvents2014.1">two separate studies</a> found that the 2013 extreme heat in Australia would have been virtually impossible without human-caused climate change. </p>
<p><a href="http://link.springer.com/article/10.1007/s00382-014-2283-5">Rainfall events</a> are trickier. This complexity can create confusion about the extreme events that are better understood, and lead to missed communication opportunities.</p>
<h2>The need for better communication</h2>
<p>Understanding the precise causes of recent extreme weather and climate events isn’t just an academic pursuit.</p>
<p>Extreme event attribution has become a research avenue with important benefits to the public. Society’s beliefs about which events are caused by climate change will influence decisions about how to adapt to those changes. Poor decisions in this area can jeopardise infrastructure and human health.</p>
<p>For example, if we dismissed the link between climate change and the 2003 European heatwave without scientific analysis, we would be poorly prepared for protecting vulnerable people from heat stress in the future under further global warming.</p>
<p>Any assessment of future climate risk and preparedness requires a scientific basis. It should not be based on opinions formed from personal perceptions, media reports, or politicians’ comments.</p>
<h2>A community responsibility</h2>
<p>Changes in extreme weather and climate events are the primary way that most people experience climate change. While scientific discussions around global average temperatures are useful for understanding the wider issue, you don’t experience “global average temperature”. Yet we all have some direct experience of extremes.</p>
<p>We argue that scientists need to communicate accurately the scientific links between extremes and global warming, so that people can make informed decisions about actions to limit the risks posed by these events.</p>
<p>We propose several simple guidelines for clear communication around extremes:</p>
<ul>
<li><p>Lead with what the science does understand and save the caveats and uncertainties for later. For example, start by explaining the impact of global warming on heatwaves and then discuss the specifics of an individual event.</p></li>
<li><p>Use metaphors to explain risk and probabilities. For instance, discussion of global warming as “loading the dice toward more rolls of extreme events”, or
“stacking the deck” in favour of extremes, are examples of accessible language. </p></li>
<li><p>Avoid loaded language like “blame” and “fault”.</p></li>
<li><p>Use accessible language for conveying uncertainty and confidence. For example, scientists often use the word “uncertainty” to discuss the envelope
of future climate scenarios, but to the public, “uncertainty” means we just don’t know. Instead, use the word “range”.</p></li>
<li><p>Try to avoid language that creates a sense of hopelessness. For example, rather than calling further increases in some extreme weather “inevitable”, we can discuss the choice we face between a future with increases in extreme weather, and one with less.</p></li>
</ul>
<p>These guidelines may also help the public evaluate the accuracy of reporting about weather extremes. If the link between an extreme event and climate change is rejected outright without an attribution analysis, it probably doesn’t represent the evolving science. </p>
<p>Conversely, if an extreme is presented as evidence of climate change, without discussion of nuance and complexity, it is equally unlikely to reflect up-to-date attribution science. </p>
<p>If scientists get better at communicating their work, and readers get better at assessing what’s accurate and what’s not, we will all be better informed to make choices that can hopefully stave off a future with more extreme weather.</p>
<hr>
<p><em>This article is based on an analysis published today in the World Meteorological Organization (WMO) <a href="http://library.wmo.int/opac/doc_num.php?explnum_id=3093">Bulletin</a>, led by Susan Hassol and Simon Torok.</em></p><img src="https://counter.theconversation.com/content/67695/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sophie Lewis receives funding from the Australian Research Council.</span></em></p>The science of attributing extreme weather events to human-induced climate change has evolved rapidly in recent years. But how we communicate it to the public has not kept pace with this advance.Sophie Lewis, Research fellow, Australian National UniversityLicensed as Creative Commons – attribution, no derivatives.