tag:theconversation.com,2011:/id/topics/la-nina-3385/articlesLa Nina – The Conversation2024-02-22T18:11:17Ztag:theconversation.com,2011:article/2241332024-02-22T18:11:17Z2024-02-22T18:11:17ZClimate change is fanning the flames of NZ’s wildfire future. Port Hills is only the beginning<p>Last week, <a href="https://www.rnz.co.nz/news/national/509653/police-find-witnesses-to-650-hectare-port-hills-blaze">wildfire burnt through 650 hectares</a> of forest and scrub in Christchurch’s Port Hills. This is not the first time the area has faced a terrifying wildfire event. </p>
<p>The <a href="https://assets.stuff.co.nz/interactives/2017/firestorm/">2017 Port Hills fires</a> burnt through almost 2,000 hectares of land, claiming one life and 11 homes. It took 66 days before the fires were fully extinguished. </p>
<p>It is clear New Zealand stands at a pivotal juncture. The country faces an increasingly severe wildfire climate. And our once relatively “safe” regions are now under threat. </p>
<p>At all levels of government, New Zealand needs to consider whether our current investment to combat fires will be enough in the coming decades. </p>
<p><a href="https://doi.org/10.1029/2022EF002853">Our research</a> integrating detailed climate simulations with daily observations reveals a stark forecast: an uptick in both the frequency and intensity of wildfires, particularly in the inland areas of the South Island. </p>
<p>It is time to consider what this will mean for Fire and Emergency New Zealand (FENZ), and how a strategic calibration of resources, tactics and technologies will help New Zealand confront this emerging threat.</p>
<h2>The climate drivers of wildfires</h2>
<p>Last year was the <a href="https://www.ecmwf.int/en/about/media-centre/news/2024/2023-was-hottest-year-record-copernicus-data-show">warmest year on record</a> by a large margin. And with <a href="https://niwa.co.nz/climate/seasonal-climate-outlook/seasonal-climate-outlook-january-2024-march-2024">El Niño at full throttle into 2024</a>, conditions in late-summer Aotearoa New Zealand are hot and dry. There is also plenty of vegetation fuel from the <a href="https://www.rnz.co.nz/news/national/485129/saying-goodbye-to-la-nina-what-to-expect-from-autumn-s-weather">departing wet La Niña</a>. </p>
<p>The tinder-dry scrub and grass vegetation in the Port Hills – an area that was around 30% above “extreme” drought fire danger thresholds – drove the flammability of the region. And on February 13, when the latest fires started, a strong gusty northwesterly wind was blowing 40-50kph with exceptionally dry relative humidity values.</p>
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Read more:
<a href="https://theconversation.com/human-exposure-to-wildfires-has-more-than-doubled-in-two-decades-who-is-at-risk-might-surprise-you-207903">Human exposure to wildfires has more than doubled in two decades – who is at risk might surprise you</a>
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<p>These conditions resulted in the extreme wildfire behaviour. Only the rapid and coordinated response of FENZ on the ground and in the air prevented this fire from becoming much worse. </p>
<p>While conditions are already bad, our study revealed a concerning trend: the widespread emergence of a new wildfire climate, with regions previously unaffected by “very extreme” wildfire conditions now facing unprecedented threats. </p>
<p>The most severe dangers are projected for areas like the Mackenzie Country, upper Otago and Marlborough, where conditions similar to <a href="https://theconversation.com/200-experts-dissected-the-black-summer-bushfires-in-unprecedented-detail-here-are-6-lessons-to-heed-198989">Australia’s “Black Summer” fires</a> could occur every three to 20 years. </p>
<p>This shift is not merely an environmental concern, it is a socioeconomic one. The increased threat of wildfires will affect communities, the government’s tree-planting initiatives and financial investments in carbon forests.</p>
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<h2>Enhanced resources and agile response</h2>
<p>New Zealand’s firefighting strategy emphases speed and manoeuvrability, especially in the initial attack phase, to prevent wildfires from escalating into large-scale disasters.</p>
<p>Approximately NZ$10 million is allocated annually to general firefighting aviation services, translating into around 11,000 flight hours. The aerial battle over the Port Hills peaked on Thursday and Friday. This effort cost over $1 million, with up to 15 helicopters active over the two days.</p>
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<a href="https://theconversation.com/how-wildfires-affect-climate-change-and-vice-versa-158688">How wildfires affect climate change — and vice versa</a>
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<p>FENZ operations are primarily funded by property insurance levies. However, with the severity and frequency of wildfires on the rise, it may be necessary to review this funding model to match the evolving risk portfolio. </p>
<p>Climate change is already driving insurance retreat – a phenomenon whereby coastal properties are <a href="https://www.climatesigma.com/projects/insurance-retreat">unable to renew their insurance</a> due sea level rise. It is plausible insurance companies could take a similar stance in extremely fire-prone areas.</p>
<p>The agility of FENZ and associated rural fire teams, coupled with the investment and integration of advanced technologies and modelling for better wildfire prediction and management, can significantly enhance the effectiveness of firefighting efforts. </p>
<h2>Policy adjustments and community engagement</h2>
<p>Adjustments in policy and regulatory frameworks are also crucial in mitigating wildfire risks, and should be explored by experts. </p>
<p>To significantly reduce the ignition of new fires, there needs to be greater implementation of restrictions on access, and banning of high-risk activities, when areas are under “extreme fire risk”. </p>
<p>Moreover, community engagement and preparedness initiatives are vital. One successful example is <a href="https://www.scionresearch.com/about-us/about-scion/corporate-publications/scion-connections/past-issues-list/scion-connections-issue-42,-february-2023/accessible-information-vital-in-extending-knowledge-of-wildfire-risk">Mt Iron, Wanaka</a>, where a model was developed after interviews, focus groups and workshops with residents identified wildfire risk awareness and mitigation actions. </p>
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Read more:
<a href="https://theconversation.com/living-with-wildfire-how-to-protect-more-homes-as-fire-risk-rises-in-a-warming-climate-208652">Living with wildfire: How to protect more homes as fire risk rises in a warming climate</a>
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<p>Educating vulnerable communities about their wildfire risks and preparedness strategies can also <a href="https://www.ruralfireresearch.co.nz/__data/assets/pdf_file/0004/78664/RFR_tech_note_45.pdf">enhance community resilience and safety</a>.</p>
<p>The emergence of a more severe wildfire climate in New Zealand calls for a unified response, integrating increased investment in FENZ, strategic planning and community involvement. </p>
<p>By embracing a multifaceted approach that includes technological innovation, enhanced resource, and community empowerment, New Zealand can navigate the complexities of this new era with resilience and foresight.</p><img src="https://counter.theconversation.com/content/224133/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Nathanael is the founding director of Climate Prescience. He has received government funding from MBIE NZ to research the effect of climate change on wildfire risk. The opinions expressed here are his own.</span></em></p>The recent Port Hills fires highlight the increasing wildfire risks caused by climate change. Reducing the threat is going to take a shift in strategy, investment and community engagement.Nathanael Melia, Adjunct Senior Research Fellow – Climate Science, Te Herenga Waka — Victoria University of WellingtonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2230132024-02-08T13:40:00Z2024-02-08T13:40:00ZEl Niño is starting to lose strength after fueling a hot, stormy year, but it’s still powerful − an atmospheric scientist explains what’s ahead for 2024<figure><img src="https://images.theconversation.com/files/574206/original/file-20240207-16-vnmp3w.jpg?ixlib=rb-1.1.0&rect=0%2C23%2C5107%2C3298&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">In California, El Niño helped fuel a wet 2023 and early 2024.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/person-walks-through-flood-waters-as-a-powerful-long-news-photo/1986231877">Mario Tama/Getty Images</a></span></figcaption></figure><p>Wild weather has been <a href="https://theconversation.com/2023s-extreme-storms-heat-and-wildfires-broke-records-a-scientist-explains-how-global-warming-fuels-climate-disasters-217500">roiling North America</a> for the past few months, thanks in part to a strong El Niño that sent temperatures surging in 2023. The climate phenomenon fed <a href="https://theconversation.com/what-is-an-atmospheric-river-with-flooding-and-mudslides-in-california-a-hydrologist-explains-the-good-and-bad-of-these-storms-and-how-theyre-changing-222249">atmospheric rivers</a> drenching the West Coast and contributed to <a href="https://theconversation.com/summer-2023-was-the-hottest-on-record-yes-its-climate-change-but-dont-call-it-the-new-normal-213021">summer’s extreme heat</a> in the South and Midwest and fall’s <a href="https://theconversation.com/2023s-extreme-storms-heat-and-wildfires-broke-records-a-scientist-explains-how-global-warming-fuels-climate-disasters-217500">wet storms across the East</a>.</p>
<p>That strong El Niño is now <a href="https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.shtml">starting to weaken</a> and will likely be gone by late spring 2024.</p>
<p>So, what does that mean for the months ahead – and for the 2024 hurricane season?</p>
<h2>What is El Niño?</h2>
<p>Let’s start with a quick look at what an El Niño is.</p>
<p>El Niño and its opposite, La Niña, are <a href="https://oceanservice.noaa.gov/facts/ninonina.html">climate patterns that influence weather</a> around the world. El Niño tends to raise global temperatures, as we saw in 2023, while La Niña events tend to be slightly cooler. The two result in global temperatures fluctuating above and below the <a href="https://www.climate.gov/news-features/understanding-climate/climate-change-global-temperature">warming trend set by climate change</a>. </p>
<p>El Niño starts as warm water builds up along the equator in the eastern tropical Pacific Ocean, off South America.</p>
<figure class="align-center ">
<img alt="A colored map shows temperature differences with a warm area just west of South America along the equator." src="https://images.theconversation.com/files/574240/original/file-20240207-18-ojnwih.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/574240/original/file-20240207-18-ojnwih.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=325&fit=crop&dpr=1 600w, https://images.theconversation.com/files/574240/original/file-20240207-18-ojnwih.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=325&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/574240/original/file-20240207-18-ojnwih.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=325&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/574240/original/file-20240207-18-ojnwih.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=408&fit=crop&dpr=1 754w, https://images.theconversation.com/files/574240/original/file-20240207-18-ojnwih.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=408&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/574240/original/file-20240207-18-ojnwih.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=408&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Reds and yellows show where Pacific waters were warmer in 2024 than in 2022. The abnormally warmer region along the equator is what we call El Niño. Weak El Niño events occur every few years, with strong events like this averaging once every 10 to 20 years.</span>
<span class="attribution"><span class="source">NOAA</span></span>
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<p>Typically, tropical Pacific winds blow from the east, exposing cold water along the equator and building up warm water in the western Pacific. Every <a href="https://www.noaa.gov/understanding-el-nino">three to seven years or so</a>, however, these winds relax or turn to blow from the west. When that happens, warm water rushes to the east. The warmer-than-normal water drives more rainfall and alters winds around the world. <a href="https://www.youtube.com/watch?v=MPok2G9Fyno">This is El Niño</a>.</p>
<p>The water stays warm for several months until, ultimately, it cools or is driven away from the equator by the return of the trade winds.</p>
<p><iframe id="aOiS8" class="tc-infographic-datawrapper" src="https://datawrapper.dwcdn.net/aOiS8/17/" height="400px" width="100%" style="border: none" frameborder="0"></iframe></p>
<p>When the eastern Pacific region along the equator becomes abnormally cold, La Niña has emerged, and global weather patterns change again.</p>
<h2>What to expect from El Niño in 2024</h2>
<p>While the 2023-24 El Niño event <a href="https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.shtml">likely peaked in December</a>, it is still strong.</p>
<p>For the rest of winter, forecasts suggest that strong El Niño conditions will likely continue to favor unusual warmth in Canada and the northern United States and occasional stormy conditions across the southern states.</p>
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<img alt="Two maps of typical winter conditions under El Nino and La Nina show the Southwest wetter and the Northwest and upper Midwest generally warmer under El Nino." src="https://images.theconversation.com/files/574242/original/file-20240207-24-syjmnk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/574242/original/file-20240207-24-syjmnk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=853&fit=crop&dpr=1 600w, https://images.theconversation.com/files/574242/original/file-20240207-24-syjmnk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=853&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/574242/original/file-20240207-24-syjmnk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=853&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/574242/original/file-20240207-24-syjmnk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1072&fit=crop&dpr=1 754w, https://images.theconversation.com/files/574242/original/file-20240207-24-syjmnk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1072&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/574242/original/file-20240207-24-syjmnk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1072&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Typical winters under El Niño and La Niña show the striking differences between the two patterns. Not all El Niños turn out this way.</span>
<span class="attribution"><a class="source" href="https://www.climate.gov/news-features/understanding-climate/el-ni%C3%B1o-and-la-ni%C3%B1a-frequently-asked-questions">NOAA Climate.gov</a></span>
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<p>El Niño is likely to end in late spring or early summer, shifting briefly to neutral. There’s a good chance we will see La Niña conditions this fall. But forecasting when that happens and what comes next is harder.</p>
<h2>How an El Niño ends</h2>
<p>While it’s easy to tell when an El Niño event reaches its peak, predicting when one will end depends on how the wind blows, and everyday weather affects the winds.</p>
<p>The warm area of surface water that defines El Niño typically becomes more shallow toward spring. In mid-May 1998, at the end of an <a href="https://www.youtube.com/watch?v=9rPqIuXlWuA">even stronger El Niño event</a>, there was a time when people fishing in the warm surface water in the eastern tropical Pacific could have touched the cold water layer a few feet below by just jumping in. At that point, it took only a moderate breeze to pull the cold water to the surface, ending the El Niño event.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/WPA-KpldDVc?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">How El Niño develops in the equatorial Pacific Ocean.</span></figcaption>
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<p>But exactly when a strong El Niño event reverses varies. A <a href="https://www.washingtonpost.com/news/capital-weather-gang/wp/2015/06/12/how-the-super-el-nino-of-1982-83-kept-itself-a-secret/">big 1983 El Niño</a> didn’t end until July. And the <a href="https://doi.org/10.1126/science.241.4862.192">El Niño in 1987</a> retreated into the central Pacific but did not fully reverse until December.</p>
<p>As of early February 2024, strong westerly winds were driving warm water from west to east across the equatorial Pacific.</p>
<p>These winds tend to make El Niño last a little longer. However, they’re also likely to drive what little warm water remains along the equator out of the tropics, up and down the coasts of the Americas. The more warm water that is expelled, the greater the chances of full reversal to La Niña conditions in the fall.</p>
<h2>Summer and the hurricane risk</h2>
<p>Among the more important El Niño effects is its tendency to reduce <a href="https://www.climate.gov/news-features/blogs/enso/impacts-el-ni%C3%B1o-and-la-ni%C3%B1a-hurricane-season">Atlantic hurricane activity</a>.</p>
<p>El Niño’s Pacific Ocean heat affects upper level winds that blow across the Gulf of Mexico and the tropical Atlantic Ocean. That <a href="https://www.accuweather.com/en/weather-news/what-is-wind-shear-and-how-does-it-impact-hurricanes-other-tropical-cyclones/330987">increases wind shear</a> - the change in wind speed and direction with height – which can tear hurricanes apart.</p>
<p>The 2024 hurricane season likely won’t have El Niño around to help weaken storms. But that doesn’t necessarily mean an active season.</p>
<p>During the <a href="https://www.noaa.gov/news-release/2023-atlantic-hurricane-season-ranks-4th-for-most-named-storms-in-year">2023 Atlantic hurricane season</a>, El Niño’s effect on the winds was more than offset by abnormally warm Atlantic waters, which fuel hurricanes. The season ended with more storms than average.</p>
<h2>The strange El Niño of 2023-24</h2>
<p>Although the 2023-24 El Niño event wasn’t the strongest in recent decades, many aspects of it have been unusual.</p>
<p>It followed three years of La Niña conditions, which is unusually long. It also emerged quickly, from March to May 2023. The combination led to weather extremes unseen <a href="https://yaleclimateconnections.org/2020/04/a-horrific-drought-in-the-1870s-offers-a-warning-for-today/">since perhaps the 1870s</a>. </p>
<figure class="align-center ">
<img alt="Two cars are trapped up to their widows in a mudslide that poured through a Los Angeles neighborhood. One car is parked in its driveway," src="https://images.theconversation.com/files/574187/original/file-20240207-30-4e5k3b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/574187/original/file-20240207-30-4e5k3b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/574187/original/file-20240207-30-4e5k3b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/574187/original/file-20240207-30-4e5k3b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/574187/original/file-20240207-30-4e5k3b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/574187/original/file-20240207-30-4e5k3b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/574187/original/file-20240207-30-4e5k3b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Extreme rainfall in early 2024 sent mudslides into dozens of Los Angeles-area neighborhoods.</span>
<span class="attribution"><a class="source" href="https://newsroom.ap.org/detail/APTOPIXCaliforniaStorms/b49e6373657e41f9964a64a6a631e5b6/photo">AP Photo/Marcio Jose Sanchez</a></span>
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<p>La Niña cools the tropics but stores warm water in the western Pacific. It also warms the middle latitude oceans by weakening the winds and allowing more sunshine through. After three years of La Niña, the rapid emergence of El Niño helped make the Earth’s surface <a href="https://www.noaa.gov/news/2023-was-worlds-warmest-year-on-record-by-far">warmer than in any recent year</a>.</p><img src="https://counter.theconversation.com/content/223013/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Paul Roundy receives funding from the National Science Foundation and National Oceanic and Atmospheric Administration. </span></em></p>The strong El Niño that started in 2023 will still have big impacts at least through March. Here’s what to watch for next.Paul Roundy, Professor of Atmospheric and Environmental Sciences, University at Albany, State University of New YorkLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2143072024-01-04T20:01:53Z2024-01-04T20:01:53ZBecome a beach scientist this summer and help monitor changing coastlines<figure><img src="https://images.theconversation.com/files/565647/original/file-20231213-17-zlgqzp.jpg?ixlib=rb-1.1.0&rect=35%2C11%2C3958%2C2257&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">CoastSnap</span></span></figcaption></figure><p>When you arrive at your favourite beach these summer holidays, you may notice something different about the coast. </p>
<p>With the triple-dip La Niña now <a href="https://media.bom.gov.au/releases/1205/the-bureau-forecasts-an-unusually-warm-summer/">making way for El Niño</a>, our beaches have been through a rollercoaster ride. Some beaches have been completely stripped of sand, while others have grown very wide. </p>
<p>In the past, such changes went mostly unrecorded. However, thanks to a project <a href="https://www.coastsnap.com/">known as CoastSnap</a>, coastal data is now being collected like never before. Using designated camera cradles installed at beach viewpoints, CoastSnap uses community snapshots taken on smartphones to track beach change. </p>
<p>Almost <a href="https://www.spotteron.com/coastsnap/">50,000 photos</a> have been collected so far. They have revealed a varying picture in recent years: from <a href="https://www.abc.net.au/news/2020-02-12/tropical-cyclone-uesi-bring-dangerous-conditions-nsw-coast/11955628">dramatic beach loss during La Niña storms three years ago</a>, to <a href="https://www.smh.com.au/environment/climate-change/the-sydney-beach-that-s-grown-by-59-metres-since-last-summer-20230921-p5e6id.html">60 metres of beach growth in recent months</a>. So with smartphones as commonplace as towels and sunscreen in the beach bag, why not add coastal data collection to your list of holiday activities this summer?</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/563079/original/file-20231203-29-n4laod.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="CoastSnap stainless steel camera cradle with smartphone placed in it, overlooking Manly beach" src="https://images.theconversation.com/files/563079/original/file-20231203-29-n4laod.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/563079/original/file-20231203-29-n4laod.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/563079/original/file-20231203-29-n4laod.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/563079/original/file-20231203-29-n4laod.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/563079/original/file-20231203-29-n4laod.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/563079/original/file-20231203-29-n4laod.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/563079/original/file-20231203-29-n4laod.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A CoastSnap community beach monitoring station at Manly Beach in Sydney, Australia.</span>
<span class="attribution"><span class="source">Larry Paice</span></span>
</figcaption>
</figure>
<h2>Turning beach snaps into scientific data</h2>
<p>Through CoastSnap, we installed a network of stainless-steel camera cradles along coastal trails all around the world. These camera cradles are positioned at a perfect vantage point for tracking changes to the coast – whether it be due to rising sea levels, extreme storms or other factors.</p>
<p>All you need to do is place your camera in the cradle, take a photo and upload it using the QR code at the station. Because the position and angle of the photo is always the same, over time these snaps reveal how the beach is changing.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/millions-of-satellite-images-reveal-how-beaches-around-the-pacific-vanish-or-replenish-in-el-nino-and-la-nina-years-198505">Millions of satellite images reveal how beaches around the Pacific vanish or replenish in El Niño and La Niña years</a>
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</em>
</p>
<hr>
<p>As well as being a powerful visual record, <a href="https://www.sciencedirect.com/science/article/pii/S0278434322001492">sophisticated algorithms</a> turn each photo into miniature satellite images that are used to precisely measure shoreline position. This is done using a <a href="https://en.wikipedia.org/wiki/Photogrammetry">process known as photogrammetry</a>, in which pixels in the image are rearranged as though they had been taken from space. </p>
<p>This aerial view enables beach change to be easily measured. Also, since the exact time of photo capture is recorded, the effects of tides as they vary throughout the day can be accounted for.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/563240/original/file-20231204-17-8678xw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="CoastSnap photo of beach (left) and equivalent photo converted to an aerial photo with a red line to mark out the shoreline" src="https://images.theconversation.com/files/563240/original/file-20231204-17-8678xw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/563240/original/file-20231204-17-8678xw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=317&fit=crop&dpr=1 600w, https://images.theconversation.com/files/563240/original/file-20231204-17-8678xw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=317&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/563240/original/file-20231204-17-8678xw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=317&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/563240/original/file-20231204-17-8678xw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=398&fit=crop&dpr=1 754w, https://images.theconversation.com/files/563240/original/file-20231204-17-8678xw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=398&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/563240/original/file-20231204-17-8678xw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=398&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">CoastSnap photos are converted to a miniature satellite image using a process known as photogrammetry.</span>
<span class="attribution"><span class="source">Mitchell Harley</span></span>
</figcaption>
</figure>
<h2>From local to global: a network of community beach monitoring</h2>
<p>From its beginnings on the Northern Beaches of Sydney in 2017, new CoastSnap stations have been rolled out all around the world. We now have more than 350 CoastSnap stations in 31 countries and across five continents. </p>
<p>This makes it the largest coordinated network of coastal monitoring worldwide – and all the data is collected by the community.</p>
<p>In Ghana, West Africa, students from local schools are using CoastSnap to <a href="https://theconversation.com/ghanas-fishing-industry-has-a-golden-seaweed-problem-how-citizen-science-can-help-203007">better understand how the “golden seaweed” sargassum impacts fishing communities</a>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/like-20-tip-trucks-pouring-sand-on-every-metre-wide-strip-how-extreme-storms-can-replenish-beaches-not-just-erode-them-182039">‘Like 20 tip trucks pouring sand on every metre-wide strip’: how extreme storms can replenish beaches, not just erode them</a>
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<p>On Prince Edward Island in Canada, CoastSnap captured the <a href="https://www.cbc.ca/news/canada/prince-edward-island/pei-fiona-coastal-climate-change-1.6599408">damage done by Hurricane Fiona last year</a>. The same stations are now being used to track the post-hurricane dune recovery.</p>
<p>In Australia, there are currently 125 CoastSnap stations around the country. This enables a big-picture assessment of the coastal consequences of large-scale weather events. For example, during <a href="https://theconversation.com/the-east-coast-rain-seems-endless-where-on-earth-is-all-the-water-coming-from-178316">last year’s record rainfall in eastern Australia</a>, extreme erosion was observed at CoastSnap stations from Queensland to southern New South Wales. The images reveal scouring by floodwaters was the main cause of beach erosion in many locations, rather than wave action as is usually the case.</p>
<p><div data-react-class="TiktokEmbed" data-react-props="{"url":"https://www.tiktok.com/@coastsnap/video/7192798251588898049"}"></div></p>
<h2>Monitoring the present to plan for the future</h2>
<p>Data on coastal change is crucial for managing coastlines into the future. This is particularly important as sea levels continue to rise, storm tracks shift, and beaches come under increasing pressure from overdevelopment.</p>
<p>With several CoastSnap stations already operating for over six years now, this growing record is beginning to observe longer-term changes to the coast. This data is being fed into numerical models that help coastal researchers predict what the coastline will be like in the coming decades – and plan accordingly.</p>
<p>Smart coastal planning will help buffer climate change impacts. This will go some way to ensure future generations can enjoy the coast like we do today. </p>
<p>So as you head out to the beach this summer, look out for your nearest CoastSnap station and help monitor the coastline – it really is a “snap”!</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/storms-or-sea-level-rise-what-really-causes-beach-erosion-209213">Storms or sea-level rise – what really causes beach erosion?</a>
</strong>
</em>
</p>
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<img src="https://counter.theconversation.com/content/214307/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mitchell Harley receives funding from the Australian Research Council. He is also the New South Wales Chair of the Australian Coastal Society.</span></em></p><p class="fine-print"><em><span>Fred Chaaya works for the University Of New South Wales Water Research Laboratory, which manages the CoastSnap project and network.</span></em></p>With smartphones as commonplace as towels and sunscreen in the beach bag, why not add coastal data collection to your list of holiday activities this summer? Look for the CoastSnap camera cradles.Mitchell Harley, Scientia Senior Lecturer, UNSW SydneyFred Chaaya, Project Engineer, UNSW Water Research LaboratoryLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2164402023-11-01T19:25:06Z2023-11-01T19:25:06ZExtreme weather is landing more Australians in hospital – and heat is the biggest culprit<figure><img src="https://images.theconversation.com/files/556795/original/file-20231031-23-y5pgcp.jpg?ixlib=rb-1.1.0&rect=34%2C483%2C5725%2C3350&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://unsplash.com/photos/silhouette-of-woman-standing-facing-sunset-LOOKlkcOo5k">Rod Long/Unsplash</a></span></figcaption></figure><p>Hospital admissions for injuries directly attributable to extreme weather events – such as heatwaves, bushfires and storms – have increased in Australia over the past decade.</p>
<p>A new <a href="https://www.aihw.gov.au/reports/injury/extreme-weather-injuries/contents/about">report</a> from the Australian Institute of Health and Welfare (AIHW) shows 9,119 Australians were hospitalised for injuries from extreme weather from 2012-22 and 677 people died from these injuries in the decade up to 2021.</p>
<p>In 2021-22, there were 754 injury hospitalisations directly related to extreme weather, compared to 576 in 2011-12. </p>
<p>Extreme heat is responsible for most weather-related injuries. Exposure to prolonged natural heat can result in physical conditions ranging from mild heat stroke, to organ damage and <a href="https://www.dea.org.au/wp-content/uploads/2021/01/DEA-Fact-Sheet_HeatwavesWEB.pdf">death</a>. </p>
<p>As Australia heads into summer with an El Niño, it’s important to understand and prepare for the health risks associated with extreme weather.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/study-finds-2-billion-people-will-struggle-to-survive-in-a-warming-world-and-these-parts-of-australia-are-most-vulnerable-205927">Study finds 2 billion people will struggle to survive in a warming world – and these parts of Australia are most vulnerable</a>
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</p>
<hr>
<h2>A spike every three years</h2>
<p>Extreme weather-related hospitalisations have spiked at more than 1,000 cases every three years, with the spikes becoming progressively higher. There were:</p>
<ul>
<li>1,027 injury hospitalisations in 2013–14</li>
<li>1,033 in 2016–17 </li>
<li>1,108 in 2019–20. </li>
</ul>
<p><iframe id="vLaas" class="tc-infographic-datawrapper" src="https://datawrapper.dwcdn.net/vLaas/1/" height="400px" width="100%" style="border: none" frameborder="0"></iframe></p>
<p>In each of these three years, extreme heat had the biggest impact on hospital admissions and deaths. </p>
<p><iframe id="P03sm" class="tc-infographic-datawrapper" src="https://datawrapper.dwcdn.net/P03sm/1/" height="400px" width="100%" style="border: none" frameborder="0"></iframe></p>
<p>Extreme heat accounted for 7,104 injury hospitalisations (78% of all injury hospitalisations) and 293 deaths (43% of all injury deaths) in the ten year period analysed. </p>
<p>In 2011-12, there were 354 injury hospitalisations directly related to extreme heat. This rose to 579 by 2021-22. </p>
<h2>El Niño and La Niña</h2>
<p>Over the past three decades, extreme weather events have increased in <a href="https://www.ipcc.ch/report/ar5/syr/">frequency</a> and <a href="http://www.bom.gov.au/state-of-the-climate/">severity</a>.</p>
<p>In Australia, El Niño drives a period of reduced rainfall, warmer temperatures and increased bushfire danger. </p>
<p>La Niña, on the other hand, is associated with above average rainfall, cooler daytime temperatures and increased chance of tropical cyclones and flood events.</p>
<p>Although similar numbers of heatwave-related hospitalisations occurred in El Niño and La Niña years studied, the number of injuries related to bushfires was higher in El Niño years. </p>
<p>During the 2019–20 bushfires, in the week beginning January 5 2020, there were 1,100 more hospitalisations than the previous five-year average, an 11% increase.</p>
<p>Although El Niño hasn’t directly been proved as the cause for these three spikes, according to the Bureau of Meteorology, two of the three years (2016-17 and 2019-20) were El Niño summers. And the other year (2013-14) was the warmest neutral year on record at that time.</p>
<h2>Regional differences</h2>
<p>Exposure to excessive natural heat was the most common cause leading to injury hospitalisation for all the mainland states and territories. From 2019 to 2022, there were 2,143 hospital admissions related to extreme heat, including:</p>
<ul>
<li>717 patients from Queensland</li>
<li>410 from Victoria</li>
<li>348 from NSW</li>
<li>267 from South Australia</li>
<li>266 from Western Australia</li>
<li>73 from the Northern Territory</li>
<li>23 from the ACT </li>
<li>19 from Tasmania. </li>
</ul>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/556987/original/file-20231101-27-3c98xm.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/556987/original/file-20231101-27-3c98xm.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=632&fit=crop&dpr=1 600w, https://images.theconversation.com/files/556987/original/file-20231101-27-3c98xm.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=632&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/556987/original/file-20231101-27-3c98xm.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=632&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/556987/original/file-20231101-27-3c98xm.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=794&fit=crop&dpr=1 754w, https://images.theconversation.com/files/556987/original/file-20231101-27-3c98xm.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=794&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/556987/original/file-20231101-27-3c98xm.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=794&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
<span class="attribution"><a class="source" href="https://www.aihw.gov.au/reports-data/latest-reports">AIHW National Hospital Morbidity Database</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>The report also includes state and territory data on hospitalisations related to extreme cold and storms. </p>
<p>During the ten-year period analysed, there were 773 injury hospitalisations and 242 deaths related to extreme cold. Extreme rain or storms accounted for 348 injury hospitalisations and 77 deaths.</p>
<p>From 2019 to 2022, there were 191 hospitalisations related to extreme cold, with Victoria recording the highest number (51, compared to 40 in next-placed NSW). During the same period there were 111 hospitalisations related to rain and storms, with 52 occurring in NSW and 28 in Queensland.</p>
<h2>What about for bushfires?</h2>
<p>Over the ten-year period studied, there were 894 hospitalisations and 65 deaths related to bushfires. </p>
<p>Bushfire-related injury hospitalisations and deaths peaked in 2019–20, an El Niño year with 174 hospitalisations and 35 deaths. The two most common injuries that result from bushfires are smoke inhalation and burns. </p>
<p>During the 2019–20 bushfires, in the week beginning 5 January 2020 there were 1,100 more respiratory hospitalisations than the previous five-year average, an 11% increase. </p>
<p>The greatest increase in the hospitalisation rate for burns was 30% in the week beginning December 15 2019 — 0.8 per 100,000 persons (about 210 hospitalisations), compared with the previous 5-year average of 0.6 per 100,000 (an average of 155 hospitalisations).</p>
<h2>Some people are particularly vulnerable</h2>
<p>Anyone can be affected by extreme weather-related injuries but some population groups are more at risk than others. This includes older people, children, people with disabilities, those with pre-existing or chronic health conditions, outdoor workers, and those with greater <a href="https://www.mdpi.com/2071-1050/15/1/813">socioeconomic disadvantage</a>. </p>
<p>People in these groups may have reduced capacity to avoid or reduce the health impacts of extreme weather conditions, for example older people taking medication may be less able to regulate their body temperature. “Thermal inequity” includes people living in poor quality housing who have difficulty accessing adequate heating and cooling.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/extreme-heat-is-particularly-hard-on-older-adults-an-aging-population-and-climate-change-put-ever-more-people-at-risk-210049">Extreme heat is particularly hard on older adults – an aging population and climate change put ever more people at risk</a>
</strong>
</em>
</p>
<hr>
<p>For heat-related injuries between 2019–20 and 2021–22, people aged 65 and over were the most commonly admitted to hospital, followed by people aged 25–44. </p>
<p>Across age groups, men had higher numbers of heat related injury hospitalisations than women. This difference was most notable among those aged 25-44 and 45-64 years, where over twice as many men were hospitalised due to extreme heat as women.</p>
<h2>We still don’t have a full picture</h2>
<p>The AIHW data only includes injuries which were serious enough for patients to be admitted to hospital; it doesn’t include cases where patients treated in an emergency department and sent home without being admitted.</p>
<p>It includes injuries that were directly attributable to weather-related events but does not include injuries that were indirectly related. For example, it doesn’t include injuries from road traffic accidents that occur due to wet weather, since the primary cause of injury would be recorded as “transport”. </p>
<p>Improved surveillance of weather-related injuries could help the health system and the community better prepare for responding to extreme weather conditions. For example, better data aids communities in predicting what resources will be needed during periods of extreme weather.</p>
<p>A more complete picture of injuries during weather events could also be used to inform people of actions they can take to protect their own health. Given a predicted hot summer, this could be a matter of life or death. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/drowning-risk-increases-during-heatwaves-in-unexpected-ways-heres-how-to-stay-safe-this-summer-212095">Drowning risk increases during heatwaves in unexpected ways -- here's how to stay safe this summer</a>
</strong>
</em>
</p>
<hr>
<p><em>This article was co-authored by Sarah Ahmed and Heather Swanston from the Injuries and System Surveillance Unit at the Australian Institute of Health and Welfare.</em></p><img src="https://counter.theconversation.com/content/216440/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Amy Peden receives funding from the National Health and Medical Research Council, Meta Inc, Royal Life Saving Society - Australia and Surf Life Saving Australia. She provided expert review for the Australian Institute of Health and Welfare’s Extreme weather-related injuries report. </span></em></p>As Australia heads into summer with an El Niño, it’s important understand and prepare for the health risks associated with extreme weather.Amy Peden, NHMRC Research Fellow, School of Population Health & co-founder UNSW Beach Safety Research Group, UNSW SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2153952023-10-12T12:30:45Z2023-10-12T12:30:45ZWhat is a strong El Niño? Meteorologists anticipate a big impact in winter 2023-2024, but the forecasts don’t all agree<figure><img src="https://images.theconversation.com/files/553361/original/file-20231011-29-363wak.png?ixlib=rb-1.1.0&rect=32%2C873%2C3211%2C2058&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The El Niño pattern stands out in the warm sea surface temperature anomalies in the Pacific in 2023</span> <span class="attribution"><a class="source" href="https://www.climate.gov/maps-data/data-snapshots/data-source/sst-enso-region-monthly-difference-average">NOAA Climate.gov</a></span></figcaption></figure><p><em>Meteorologists have been talking for weeks about <a href="https://www.accuweather.com/en/winter-weather/us-winter-forecast-for-the-2023-2024-season/1583853">a snowy season ahead</a> in the southern Rockies and the Sierra Nevada. They anticipate <a href="https://www.powder.com/trending-news/el-nino-huge-snow-east">more storms</a> in the U.S. South and Northeast, and warmer, drier conditions across the already dry Pacific Northwest and the upper Midwest.</em></p>
<p><em>One phrase comes up repeatedly with these projections: <a href="https://www.wcpo.com/weather/weather-101/a-strong-el-nino-expected-this-winter-heres-what-that-means-for-our-weather">a strong El Niño</a> is coming.</em></p>
<p><em>It sounds ominous. But what does that actually mean? We asked <a href="https://scholar.google.com/citations?user=z7CXcXkAAAAJ&hl=en">Aaron Levine</a>, an atmospheric scientist at the University of Washington whose research focuses on El Niño.</em></p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/wVlfyhs64IY?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">NOAA explains in animations how El Niño forms.</span></figcaption>
</figure>
<h2>What is a strong El Niño?</h2>
<p>During a normal year, the warmest sea surface temperatures are in the western Pacific and the Indian Ocean, in what’s known as the <a href="https://doi.org/10.1186/s40562-016-0054-3">Indo-Western Pacific warm pool</a>.</p>
<p>But every few years, the trade winds that blow from east to west weaken, allowing that warm water to slosh eastward and <a href="https://www.pmel.noaa.gov/elnino/schematic-diagrams">pile up along the equator</a>. The warm water causes the air above it to warm and rise, fueling precipitation in the central Pacific and shifting atmospheric circulation patterns across the basin.</p>
<p>This pattern is <a href="https://www.pmel.noaa.gov/elnino/what-is-el-nino">known as El Niño</a>, and it can <a href="https://www.climate.gov/media/13628">affect weather around the world</a>.</p>
<figure class="align-center ">
<img alt="An animation shows how warm water builds up along the equator off South America. The box where temperatures are measured is south of Hawaii." src="https://images.theconversation.com/files/553048/original/file-20231010-23-c36xip.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/553048/original/file-20231010-23-c36xip.gif?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=272&fit=crop&dpr=1 600w, https://images.theconversation.com/files/553048/original/file-20231010-23-c36xip.gif?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=272&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/553048/original/file-20231010-23-c36xip.gif?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=272&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/553048/original/file-20231010-23-c36xip.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=342&fit=crop&dpr=1 754w, https://images.theconversation.com/files/553048/original/file-20231010-23-c36xip.gif?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=342&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/553048/original/file-20231010-23-c36xip.gif?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=342&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The box shows the Niño 3.4 region as El Niño begins to develop in the tropical Pacific, from January to June 2023.</span>
<span class="attribution"><a class="source" href="https://www.climate.gov/">NOAA Climate.gov</a></span>
</figcaption>
</figure>
<p>A strong El Niño, in the most basic definition, occurs once the average sea surface temperature in the equatorial Pacific is at least 1.5 degrees Celsius (2.7 Fahrenheit) warmer than normal. It’s measured in an imaginary box along the equator, roughly south of Hawaii, known as the <a href="https://svs.gsfc.nasa.gov/4695">Nino 3.4 Index</a>.</p>
<p>But El Niño is a coupled ocean-atmosphere phenomenon, and the atmosphere also plays a crucial role.</p>
<p>What has been surprising about this year’s El Niño – and still is – is that the atmosphere hasn’t responded as much as we would have expected based on the rising sea surface temperatures.</p>
<h2>Is that why El Niño didn’t affect the 2023 hurricane season the way forecasts expected?</h2>
<p>The 2023 Atlantic hurricane season is a good example. Forecasters often use El Niño as a predictor of <a href="https://www.weather.gov/ilx/swop-springtopics">wind shear</a>, which can tear apart Atlantic hurricanes. But with the atmosphere not responding to the warmer water right away, the impact on Atlantic hurricanes was lessened and it turned out to be a <a href="https://www.nytimes.com/article/tropical-storm-sean-hurricane.html">busy season</a>.</p>
<p><a href="https://doi.org/10.1175/JCLI-D-12-00097.1">The atmosphere is what transmits El Niño’s impact</a>. Heat from the warm ocean water causes the air above it to warm and rise, which fuels precipitation. That air sinks again over cooler water. </p>
<p>The rising and sinking creates giant loops in the atmosphere <a href="https://www.climate.gov/news-features/blogs/enso/walker-circulation-ensos-atmospheric-buddy">called the Walker Circulation</a>. When the warm pool’s water shifts eastward, that also shifts where the rising and sinking motions happen. The atmosphere reacts to this change like ripples in a pond when you throw a stone in. These ripples affect the jet stream, which steers weather patterns in the U.S.</p>
<p>This year, in comparison with other large El Niño events – such as <a href="https://www.climate.gov/news-features/blogs/enso/united-states-el-ni%C3%B1o-impacts-0">1982-83, 1997-98</a> and <a href="https://www.climate.gov/news-features/understanding-climate/2015-state-climate-el-ni%C3%B1o-came-saw-and-conquered">2015-16</a> – we’re not seeing the same change in where the precipitation is happening. It’s taking much longer to develop, and it’s not as strong.</p>
<p>Part of that, presumably, is related to the whole tropics being very, very warm. But <a href="https://doi.org/10.1029/2019GL086182">this is still an emerging field of research</a>.</p>
<p>How El Niño will change with global warming is a big and open question. El Niño <a href="https://www.climate.gov/news-features/understanding-climate/climate-variability-oceanic-nino-index">only happens every few years</a>, and there’s a fair amount of variability between events, so just getting a baseline is tough.</p>
<h2>What does a strong El Niño typically mean for US weather?</h2>
<p>During <a href="https://www.climate.gov/enso">a typical El Niño winter</a>, the U.S. South and Southwest are cooler and wetter, and the Northwest is warmer and drier. The upper Midwest tends to be drier, while the Northeast tends to be a little wetter. </p>
<p>The likelihood and the intensity generally scale with the strength of the El Niño event.</p>
<p>El Niño has traditionally been good for the mountain snowpack in California, which the state relies for a large percentage of its water. But it is often not so good for the Pacific Northwest snowpack.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/553424/original/file-20231012-15-3wfvdw.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Two maps showing wetter, cooler weather in the Southeast and drier warmer air in the north during El Nino." src="https://images.theconversation.com/files/553424/original/file-20231012-15-3wfvdw.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/553424/original/file-20231012-15-3wfvdw.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=834&fit=crop&dpr=1 600w, https://images.theconversation.com/files/553424/original/file-20231012-15-3wfvdw.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=834&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/553424/original/file-20231012-15-3wfvdw.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=834&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/553424/original/file-20231012-15-3wfvdw.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1047&fit=crop&dpr=1 754w, https://images.theconversation.com/files/553424/original/file-20231012-15-3wfvdw.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1047&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/553424/original/file-20231012-15-3wfvdw.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1047&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 jet stream takes a very different path in a typical El Niño vs. La Niña winter weather pattern. But these patterns have a great deal of variability. Not every El Niño or La Niña year is the same.</span>
<span class="attribution"><a class="source" href="https://www.climate.gov/media/14484">NOAA Climate.gov</a></span>
</figcaption>
</figure>
<p>The <a href="https://www.climate.gov/news-features/featured-images/how-el-ni%C3%B1o-and-la-ni%C3%B1a-affect-winter-jet-stream-and-us-climate">jet stream plays a role</a> in that shift. When the polar jet stream is either displaced very far northward or southward, storms that would normally move through Washington or British Columbia are steered to California and Oregon instead.</p>
<h2>What do the forecasts show for the months ahead?</h2>
<p>Whether forecasters think a strong El Niño will develop depends on whose forecast model they trust.</p>
<p>This past spring, the <a href="https://www.weather.gov/media/climateservices/NWS%20Climate%20Forecast%20and%20Tools.pdf">dynamical forecast models</a> were <a href="https://iri.columbia.edu/our-expertise/climate/forecasts/enso/current/?enso_tab=enso-sst_table">already very confident</a> about the potential for a strong El Niño developing. These are big models that solve basic physics equations, starting with current oceanic and atmospheric conditions. </p>
<p>However, statistical models, which use statistical predictors of El Niño calculated from historical observations, were less certain.</p>
<p>Even in the <a href="https://iri.columbia.edu/our-expertise/climate/forecasts/enso/current/?enso_tab=enso-sst_table">most recent forecast model outlook</a>, the dynamical forecast models were predicting a stronger El Niño than the statistical models were.</p>
<p>If you go by just a sea surface temperature-based El Niño index, the forecast is for a fairly strong El Niño. </p>
<p>But the indices that incorporate the atmosphere are not responding in the same way. We’ve seen <a href="https://psl.noaa.gov/enso/enso.current.html">atmospheric anomalies</a> – as measured by cloud height monitored by satellites or sea-level pressure at monitoring stations – on and off in the Pacific since May and June, <a href="https://images.theconversation.com/files/553327/original/file-20231011-15-kprvx9.png">but not in a very robust fashion</a>. Even in September, they were nowhere near as large as they were in 1982, in terms of overall magnitude.</p>
<p>We’ll see if the atmosphere catches up by wintertime, when El Niño peaks.</p>
<h2>How long do El Niños last?</h2>
<p>Often during El Niño events – particularly strong El Niño events – the sea surface temperature anomalies collapse really quickly during the Northern Hemisphere spring. Almost all end in April or May.</p>
<p>One reason is that El Niño sows the seeds of its own demise. When El Niño happens, it <a href="https://doi.org/10.1175/1520-0469(1997)054%3C0811:AEORPF%3E2.0.CO;2">uses up that warm water</a> and the warm water volume shrinks. <a href="https://doi.org/10.1175/1520-0442(2000)013%3C3551:OOWWVC%3E2.0.CO;2">Eventually, it has eroded its fuel</a>.</p>
<p><iframe id="aOiS8" class="tc-infographic-datawrapper" src="https://datawrapper.dwcdn.net/aOiS8/14/" height="400px" width="100%" style="border: none" frameborder="0"></iframe></p>
<p>The surface can stay warm for a while, but once the heat from the subsurface is gone and the trade winds return, the El Niño event collapses. At the end of past El Niño events, the sea surface anomaly dropped very fast and we saw conditions typically switch to La Niña – El Niño’s cooler opposite.</p><img src="https://counter.theconversation.com/content/215395/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Aaron Levine receives funding from NOAA and has received funding in the past from the National Research Council. He is a member of the American Geophysical Union </span></em></p>An atmospheric scientist explains how El Niño works, this year’s oddities and why this phenomenon doesn’t last long.Aaron Levine, Atmospheric Research Scientist, CICOES, University of WashingtonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2151402023-10-06T01:53:35Z2023-10-06T01:53:35Z6 reasons why global temperatures are spiking right now<figure><img src="https://images.theconversation.com/files/552428/original/file-20231006-27-7ho178.jpg?ixlib=rb-1.1.0&rect=25%2C10%2C3424%2C2286&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://unsplash.com/photos/6gVvfQEnWtY">Jonas Weckschmied/Unsplash</a></span></figcaption></figure><p>The world is very warm right now. We’re not only seeing record temperatures, but the records are being broken by record-wide margins.</p>
<p>Take the preliminary September global-average temperature anomaly of 1.7°C above pre-industrial levels, for example. It’s an incredible 0.5°C above the previous record.</p>
<p>So why is the world so incredibly hot right now? And what does it mean for keeping our Paris Agreement targets? </p>
<p>Here are six contributing factors – with climate change the main reason temperatures are so high.</p>
<h2>1. El Niño</h2>
<p>One reason for the exceptional heat is we are in a <a href="http://www.bom.gov.au/climate/enso/#tabs=Pacific-Ocean">significant El Niño</a> that is still strengthening. During El Niño we see warming of the surface ocean over much of the tropical Pacific. This warming, and the effects of El Niño in other parts of the world, raises global average temperatures by <a href="https://www.realclimate.org/index.php/archives/2023/01/2022-updates-to-the-temperature-records/">about 0.1 to 0.2°C</a>.</p>
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Read more:
<a href="https://theconversation.com/explainer-el-nino-and-la-nina-27719">Explainer: El Niño and La Niña</a>
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<p>Taking into account the fact we’ve just come out of a triple La Niña, which cools global average temperatures slightly, and the fact this is the first major El Niño in eight years, it’s not too surprising we’re seeing unusually high temperatures at the moment.</p>
<p>Still, El Niño alone isn’t enough to explain the crazily high temperatures the world is experiencing.</p>
<h2>2. Falling pollution</h2>
<p>Air pollution from human activities cools the planet and has offset some of the warming caused by humanity’s greenhouse gas emissions. There have been efforts to reduce this pollution – since 2020 there has been an <a href="https://sdg.iisd.org/news/imo-advances-measures-to-reduce-emissions-from-international-shipping/">international agreement</a> to reduce sulphur dioxide emissions from the global shipping industry.</p>
<p>It has been speculated this cleaner air has contributed to the recent heat, particularly over the record-warm <a href="https://climate.copernicus.eu/record-breaking-north-atlantic-ocean-temperatures-contribute-extreme-marine-heatwaves">north Atlantic</a> and Pacific regions with high shipping traffic.</p>
<p>It’s likely this is contributing to the extreme high global temperatures – but only on the order of hundredths of a degree. <a href="https://www.carbonbrief.org/analysis-how-low-sulphur-shipping-rules-are-affecting-global-warming/">Recent analysis</a> suggests the effect of the 2020 shipping agreement is about an extra 0.05°C warming by 2050.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/552429/original/file-20231006-15-4t8dca.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A smog shrouded road with motorcycles, trucks and cars barely visible through the pollution" src="https://images.theconversation.com/files/552429/original/file-20231006-15-4t8dca.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/552429/original/file-20231006-15-4t8dca.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/552429/original/file-20231006-15-4t8dca.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/552429/original/file-20231006-15-4t8dca.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/552429/original/file-20231006-15-4t8dca.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/552429/original/file-20231006-15-4t8dca.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/552429/original/file-20231006-15-4t8dca.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">People pass through the rising pollution on the Delhi-Jaipur Expressway in Gurgaon, Haryana, India, on November 12 2021.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/people-pass-through-rising-pollution-on-2073480677">Shutterstock</a></span>
</figcaption>
</figure>
<h2>3. Increasing solar activity</h2>
<p>While falling pollution levels mean more of the Sun’s energy reaches Earth’s surface, the amount of the energy the Sun emits is itself variable. There are different solar cycles, but an 11-year cycle is the most relevant one to today’s climate.</p>
<p>The Sun is becoming <a href="https://edition.cnn.com/2023/07/14/world/solar-maximum-activity-2024-scn/index.html">more active</a> from a minimum in late 2019. This is also contributing a small amount to the spike in global temperatures. Overall, increasing solar activity is contributing only hundredths of a degree at most to the recent global heat. </p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/this-solar-cycle-the-suns-activity-is-more-powerful-and-surprising-than-predicted-209955">This solar cycle, the sun's activity is more powerful and surprising than predicted</a>
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</p>
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<h2>4. Water vapour from Hunga Tonga eruption</h2>
<p>On January 15 2022 the underwater <a href="https://www.jpl.nasa.gov/images/pia26006-hunga-tonga-hunga-haapai-eruption">Hunga Tonga–Hunga Haʻapai volcano erupted</a> in the South Pacific Ocean, sending large amounts of water vapour high up into the upper atmosphere. Water vapour is a greenhouse gas, so increasing its concentration in the atmosphere in this way does intensify the greenhouse effect.</p>
<p>Even though the eruption happened almost two years ago, it’s still having a small warming effect on the planet. However, as with the reduced pollution and increasing solar activity, we’re talking about hundredths of a degree.</p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/6oANPi-SWN0?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
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<h2>5. Bad luck</h2>
<p>We see variability in global temperatures from one year to the next even without factors like El Niño or major changes in pollution. Part of the reason this September was so extreme was likely due to weather systems being in the right place to heat the land surface.</p>
<p>When we have persistent high-pressure systems over land regions, as seen recently over places like <a href="https://www.theguardian.com/environment/2023/oct/01/autumn-heat-continues-in-europe-after-record-breaking-september">western Europe</a> and <a href="https://www.abc.net.au/news/2023-09-19/australia-weather-september-heat-records-tumble/102870294">Australia</a>, we see local temperatures rise and the conditions for unseasonable heat.</p>
<p>As water requires more energy to warm and the ocean moves around, we don’t see the same quick response in temperatures over the seas when we have high-pressure systems.</p>
<p>The positioning of weather systems warming up many land areas coupled with persistent ocean heat is likely a contributor to the global-average heat too.</p>
<h2>6. Climate change</h2>
<p>By far the biggest contributor to the overall +1.7°C global temperature anomaly is human-caused climate change. Overall, humanity’s effect on the climate has been a global warming of <a href="https://www.globalwarmingindex.org/">about 1.2°C</a>.</p>
<p>The record-high rate of greenhouse gas emissions means we should expect global warming to accelerate too.</p>
<p>While humanity’s greenhouse gas emissions explain the trend seen in September temperatures over many decades, they don’t really explain the big difference from last September (when the greenhouse effect was almost as strong as it is today) and September 2023.</p>
<p>Much of the difference between this year and last comes back to the switch from La Niña to El Niño, and the right weather systems in the right place at the right time.</p>
<h2>The upshot: we need to accelerate climate action</h2>
<p>September 2023 shows that with a combination of climate change and other factors aligning we can see alarmingly high temperatures.</p>
<p>These anomalies may appear to be above the 1.5°C global warming level referred to in the Paris Agreement, but that’s about keeping <a href="https://climateanalytics.org/briefings/understanding-the-paris-agreements-long-term-temperature-goal/">long-term global warming</a> to low levels and not individual months of heat.</p>
<p>But we are seeing the effects of climate change unfolding more and more clearly.</p>
<p>The most vulnerable are suffering the biggest impacts as wealthier nations continue to emit the largest proportion of greenhouse gases. Humanity must accelerate the path to net zero to prevent more record-shattering global temperatures and damaging extreme events.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/net-zero-by-2050-too-late-australia-must-aim-for-2035-213973">Net zero by 2050? Too late. Australia must aim for 2035</a>
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<img src="https://counter.theconversation.com/content/215140/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Andrew King receives funding from the National Environmental Science Program. </span></em></p>The preliminary global-average temperature anomaly for September is a shocking 1.7°C. These are the drivers of current record-breaking heat.Andrew King, Senior Lecturer in Climate Science, The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2108802023-09-29T01:25:27Z2023-09-29T01:25:27ZHere’s how to fix Australia’s approach to soil carbon credits so they really count towards our climate goals<figure><img src="https://images.theconversation.com/files/550802/original/file-20230928-21-n9ydfs.jpg?ixlib=rb-1.1.0&rect=199%2C0%2C9290%2C6331&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/female-farmer-hold-soil-hands-monitoring-2346686237">William Edge, Shutterstock</a></span></figcaption></figure><p>Australia’s plan to achieve <a href="https://www.dcceew.gov.au/climate-change/emissions-reduction/net-zero">net zero</a> greenhouse gas emissions by 2050 relies heavily on carbon credits. </p>
<p>These <a href="https://www.cleanenergyregulator.gov.au/ERF/About-the-Emissions-Reduction-Fund">credits are awarded to projects</a> that avoid the release of greenhouse gases or remove and “sequester” (store) carbon so it’s no longer warming the atmosphere. </p>
<p>Farmers can be awarded credits for <a href="https://www.cleanenergyregulator.gov.au/ERF/Choosing-a-project-type/Opportunities-for-the-land-sector/Agricultural-methods/estimating-soil-organic-carbon-sequestration-using-measurement-and-models-method">increasing soil carbon content</a>. The federal government or companies can then purchase these credits to offset their carbon emissions. </p>
<p>These credits must represent genuine carbon sequestration if they are to mitigate climate change. </p>
<p>As Australian agricultural and soil scientists, we have serious concerns about the way credits are awarded for soil carbon sequestration under the <a href="https://www.cleanenergyregulator.gov.au/OSR/ANREU/types-of-emissions-units/australian-carbon-credit-units">Australian carbon credit unit scheme</a>. There are four main issues with the method that must be addressed as a matter of urgency.</p>
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<figcaption><span class="caption">Soil organic carbon is the treasure beneath our feet (Food and Agriculture Organization of the United Nations)</span></figcaption>
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<p>
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Read more:
<a href="https://theconversation.com/us-scheme-used-by-australian-farmers-reveals-the-dangers-of-trading-soil-carbon-to-tackle-climate-change-161358">US scheme used by Australian farmers reveals the dangers of trading soil carbon to tackle climate change</a>
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<h2>Understanding the carbon cycle</h2>
<p>Much like water, carbon cycles through the environment, moving between plants, the earth and the atmosphere. </p>
<p>Plants take in carbon dioxide from the atmosphere as they grow. The carbon is stored in the plant tissue. When plants die, or drop leaves, this carbon-rich organic matter enters the soil. Then it decomposes, releasing carbon dioxide back into the atmosphere. </p>
<p>When carbon inputs from plants exceed losses from the decomposition of organic matter, the amount of soil carbon increases. That means soil organic carbon is more likely to increase during good seasons when there’s plenty of rainfall available to support plant growth – such as during the recent three-year period of consecutive La Niña events.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/550131/original/file-20230925-15-sf72i6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Graphic illustrating how carbon cycles through agricultural systems" src="https://images.theconversation.com/files/550131/original/file-20230925-15-sf72i6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/550131/original/file-20230925-15-sf72i6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=309&fit=crop&dpr=1 600w, https://images.theconversation.com/files/550131/original/file-20230925-15-sf72i6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=309&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/550131/original/file-20230925-15-sf72i6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=309&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/550131/original/file-20230925-15-sf72i6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=388&fit=crop&dpr=1 754w, https://images.theconversation.com/files/550131/original/file-20230925-15-sf72i6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=388&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/550131/original/file-20230925-15-sf72i6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=388&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 carbon cycle.</span>
<span class="attribution"><span class="source">Richard Eckard, University of Melbourne</span></span>
</figcaption>
</figure>
<h2>Increases need to be due to management</h2>
<p>The recent <a href="https://www.abc.net.au/news/rural/2023-06-24/aus-farmers-to-earn-money-from-soil-carbon-under-new-methods/102213244">tranche</a> of credits awarded to soil carbon projects raises similar concerns to those that have been raised by experts about <a href="https://theconversation.com/australias-central-climate-policy-pays-people-to-grow-trees-that-already-existed-taxpayers-and-the-environment-deserve-better-186900">credits awarded to trees</a>. Namely, carbon credits are being awarded for changes associated with seasonal conditions (changes that would have happened anyway) rather than human actions.</p>
<p>The current soil carbon method awards credits when an increase in soil organic carbon is detected between two points in time. This is problematic because it can award credits to projects that report increases during relatively wet periods. </p>
<p>This is the case for <a href="https://carbonlink.com.au/wp-content/uploads/CarbonLink-ACCUs-Flow-Media-Release-June-2023-1.pdf">projects sampled in 2021</a>, directly after a period where conditions were unusually favourable for plant growth. That means credits were awarded for sequestration that had more to do with the weather than good management. </p>
<p>Where crediting occurs due to seasonal conditions, the scheme is not providing any true (<a href="https://law.anu.edu.au/sites/all/files/what_the_beare_and_chambers_report_really_found_and_a_critique_of_its_method_16_march_2022.pdf">additional</a>) climate change mitigation. </p>
<h2>Soil carbon can be lost</h2>
<p>Where soil carbon losses are greater than inputs, soil carbon stocks decline and sequestered carbon is released back to the atmosphere. The <a href="https://www.sciencedirect.com/science/article/pii/S0301479720301286">emissions can be rapid</a> and considerable. </p>
<p>Furthermore, modelling indicates it’s likely <a href="https://doi.org/10.1016/j.geoderma.2018.09.041">soil carbon could be lost</a> under the warmer and drier conditions of future climates. </p>
<p>Where a project loses soil carbon, the legislation does not require excess credits to be returned. Rather, a scheme-wide <a href="https://www.cleanenergyregulator.gov.au/ERF/Choosing-a-project-type/Opportunities-for-the-land-sector/Risk-of-reversal-buffer">buffer</a> generated from all sequestration projects covers such losses. </p>
<p>This approach is inequitable because all projects share the same burden of maintaining the buffer, irrespective of the risk of reversal of individual projects. </p>
<h2>Overinflated sequestration rates</h2>
<p>Based on a <a href="https://esajournals.onlinelibrary.wiley.com/doi/abs/10.1002/eap.1473?__cf_chl_tk=1zpwtYjrpjjoZAaRpgcOb5o7R5c_fLaqDx0tadA0kWA-1693540306-0-gaNycGzND1A">comprehensive global analysis</a>, the <a href="https://carbonlink.com.au/wp-content/uploads/CarbonLink-ACCUs-Flow-Media-Release-June-2023-1.pdf">number of carbon credits generated</a> by some Australian projects appears unrealistically high. The most likely reason for these large values is high rainfall, but the way the method works makes it impossible to know for sure because the impacts of management are not identified.</p>
<p>This is not the first time a soil carbon project has made <a href="https://theconversation.com/us-scheme-used-by-australian-farmers-reveals-the-dangers-of-trading-soil-carbon-to-tackle-climate-change-161358">unrealistic claims</a>. </p>
<p>In addition, <a href="https://carbonlink.com.au/wp-content/uploads/CarbonLink-ACCUs-Flow-Media-Release-June-2023-1.pdf">one project saw 44%</a> of the increase in soil carbon at depths below 30cm. This is an issue because published studies show soil carbon changes in deeper soil are <a href="https://www.sciencedirect.com/science/article/pii/S0167880923002785">relatively small</a> and happen slowly. We are concerned the reported changes may have more to do with the way they were calculated. </p>
<p>Currently, data used to calculate credits are not released by the scheme regulator so cannot be scientifically verified. The release of data under strict non-disclosure arrangements would allow scientists to assess the implementation of the method. This would provide confidence credits generated represent real climate change mitigation. </p>
<p>Increased transparency was a <a href="https://www.dcceew.gov.au/sites/default/files/documents/independent-review-accu-exec-summary.pdf">key recommendation</a> of the <a href="https://oia.pmc.gov.au/published-impact-analyses-and-reports/chubb-review-australian-carbon-credit-units">Chubb Review</a> of Australian Carbon Credit Units in 2022. </p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/chubb-review-of-australias-carbon-credit-scheme-falls-short-and-problems-will-continue-to-fester-197401">Chubb review of Australia's carbon credit scheme falls short – and problems will continue to fester</a>
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<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1707172133288149265"}"></div></p>
<h2>Contributing to our emissions targets?</h2>
<p>Australia’s emissions are reported annually to the United Nations in the national <a href="https://www.dcceew.gov.au/climate-change/publications/national-inventory-reports">greenhouse gas inventory</a>. These annual inventories show progress towards our declared emissions reduction targets. </p>
<p>The current inventory method used to account for changes in soil carbon uses coarse regional-level statistics. Changes to practices at farm level, such as grazing management, are not detected and will not be reflected in our national greenhouse gas accounts. Further, Australia reports changes in soil carbon for the top 30cm of the soil only whereas carbon credits are also awarded for changes that occur deeper in the soil. </p>
<p>This means some soil carbon credits the Australian government purchases do not count toward our emissions targets. It calls into question the effectiveness of using taxpayer funds to purchase soil carbon credits as a policy tool.</p>
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Read more:
<a href="https://theconversation.com/australia-relies-on-controversial-offsets-to-meet-climate-change-targets-we-might-not-get-away-with-it-in-egypt-193460">Australia relies on controversial offsets to meet climate change targets. We might not get away with it in Egypt</a>
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<h2>Getting it right</h2>
<p>To address the issues we have identified, the measurement-based soil carbon <a href="https://www.cleanenergyregulator.gov.au/ERF/Choosing-a-project-type/Opportunities-for-the-land-sector/Agricultural-methods/estimating-soil-organic-carbon-sequestration-using-measurement-and-models-method">method</a> needs to be revised to only credit increases due to management. For instance, <a href="https://verra.org/methodologies/vm0042-methodology-for-improved-agricultural-land-management-v2-0/">the Verra scheme</a> in the international voluntary carbon market uses a method that minimises crediting for increases associated with rainfall. </p>
<p>To support revision of Australia’s scheme, scientists should be granted access to project data. Data could to be used to improve models in order to distinguish between climate and management effects. This would ensure the method is fit for purpose. </p>
<p>There also needs to be greater focus on monitoring changes in soil carbon. For a start, Australia’s <a href="https://www.tern.org.au/">Terrestrial Ecosystem Research Network</a> should be extended to include agricultural land. This would provide data to increase transparency, independence and rigour of soil carbon estimates. </p>
<p>The revisions we propose would help ensure investment in carbon credits contributes to our national emissions reduction targets and addresses the urgent challenge of climate change.</p>
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Read more:
<a href="https://theconversation.com/a-tonne-of-fossil-carbon-isnt-the-same-as-a-tonne-of-new-trees-why-offsets-cant-save-us-200901">A tonne of fossil carbon isn't the same as a tonne of new trees: why offsets can't save us</a>
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<img src="https://counter.theconversation.com/content/210880/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Aaron Simmons is a Senior Research Scientist with the NSW Department of Primary Industries. Aaron has received funding from the Commonwealth and NSW governments for soil carbon research and policy development. </span></em></p><p class="fine-print"><em><span>Annette Cowie is a Senior Principal Research Scientist in the Climate Branch at the NSW Department of Primary Industries, and Adjunct Professor in the School of Environmental and Rural Science at the University of New England. She has received funding for soil carbon research from NSW and Commonwealth government programs. Annette is a member of Soil Science Australia, a not-for-profit, professional association for soil scientists, and on the Advisory Board of Australia New Zealand Biochar Industry Group. </span></em></p><p class="fine-print"><em><span>Dr Beverley Henry is an Adjunct Associate Professor at Queensland University of Technology. She has previously worked for, and received funding from, the Commonwealth and Queensland Governments, and has, or has previously held, science consulting and advisory roles with Australian and international government and agricultural organisations. </span></em></p><p class="fine-print"><em><span>Brian Wilson is a Professor in Terrestrial Carbon Management at the University of New England. He has received funding from the Commonwealth and State Government and from the Cotton Research and Development Corporation for research relevant to soil carbon.</span></em></p><p class="fine-print"><em><span>David Pannell is a professor in environmental economics and agricultural economics at the University of Western Australia. He has received funding from the Commonwealth Government and from Grains Research and Development Corporation for research relevant to soil carbon. </span></em></p><p class="fine-print"><em><span>David Rowlings is a Professor in Sustainable Agriculture at Queensland University of Technology. He receives funding from Meat and Livestock Australia and Department Agriculture, Forestry and Fisheries for soil carbon research. </span></em></p><p class="fine-print"><em><span>Elaine Mitchell is a Research Fellow at the Queensland University of Technology. She has received funding from the Commonwealth Government for soil carbon research. She is also the founder of Ecometric, which provides advisory services in the natural capital space, including advice to carbon project developers on approaches to stratification, soil sampling and soil carbon modelling.
</span></em></p><p class="fine-print"><em><span>Matthew Tom Harrison is an Associate Professor at the University of Tasmania. He has been awarded funding from State and Commonwealth Governments, as well as Research Development Corporations to research practices, skills and technologies for improving soil organic carbon sequestration.</span></em></p><p class="fine-print"><em><span>Peter Grace is Professor Global Change at Queensland University of Technology. He currently receives funding from the Grains Research and Development Corporation, Meat and Livestock Australia, the Dept of Climate Change Energy Environment and Water, National Collaborative Research Infrastructure Scheme - Terrestrial Ecosystem Research Network, AgriFutures, and AgriMix. He has previously received funding from the Clean Energy Regulator, the Dept of Agriculture Fisheries and Forestry, and Cotton Research and Development Corporation.</span></em></p><p class="fine-print"><em><span>Raphael Viscarra Rossel is a Professor of Soil and Landscape Science at Curtin University. Previously, he was a Senior Principal Research Scientist at CSIRO, where he received funding from the Commonwealth Government for developing innovative soil carbon measurement methods that aided the formulation of the soil carbon methodology.</span></em></p><p class="fine-print"><em><span>Richard Eckard receives funding from Meat and Livestock Australia and the Commonwealth of Australia on greenhouse gas emissions from agriculture and carbon farming. His science contributed to six Australian carbon credit methods. </span></em></p><p class="fine-print"><em><span>Warwick Badgery is a Research Leader with the NSW Department of Primary Industries and is an Honorary Senior Fellow at Melbourne University. He receives funding from Meat and Livestock Australia, the NSW and Federal Governments for research on climate mitigation and soil carbon. </span></em></p>A group of agricultural and soil scientists has serious concerns about the way credits are awarded for soil carbon sequestration in Australia.Aaron Simmons, Adjunct Senior Research Fellow, University of New EnglandAnnette Cowie, Adjunct Professor, University of New EnglandBeverley Henry, Adjunct Associate Professor, Queensland University of TechnologyBrian Wilson, Professor, University of New EnglandDavid Pannell, Director, Centre for Environmental Economics and Policy, The University of Western AustraliaDavid Rowlings, Professor, Queensland University of TechnologyElaine Mitchell, Research Fellow, Queensland University of TechnologyMatthew Tom Harrison, Associate Professor of Sustainable Agriculture, University of TasmaniaPeter Grace, Professor of Global Change, Queensland University of TechnologyRaphael Viscarra Rossel, Professor of Soil & Landscape Science, Curtin UniversityRichard Eckard, Professor & Director, Primary Industries Climate Challenges Centre, The University of MelbourneWarwick Badgery, Research Leader Pastures an Rangelands, The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2110292023-08-23T20:09:51Z2023-08-23T20:09:51ZGreenhouse gases are changing air flow over the Pacific Ocean – raising Australia’s risks of extreme weather<figure><img src="https://images.theconversation.com/files/543865/original/file-20230822-15-u5fe58.jpg?ixlib=rb-1.1.0&rect=64%2C16%2C5327%2C3573&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/clouds-gather-over-seascape-near-new-1339682141">Shutterstock</a></span></figcaption></figure><p>After a <a href="https://theconversation.com/la-nina-3-years-in-a-row-a-climate-scientist-on-what-flood-weary-australians-can-expect-this-summer-190542">rare three-year La Niña event</a> brought heavy rain and flooding to eastern Australia in 2020-22, we’re now bracing for the heat and drought of El Niño at the opposite end of the spectrum. </p>
<p>But while the World Meteorological Organisation <a href="https://public.wmo.int/en/media/press-release/world-meteorological-organization-declares-onset-of-el-ni%C3%B1o-conditions">has declared</a> an El Niño event is underway, Australia’s Bureau of Meteorology is <a href="http://www.bom.gov.au/climate/enso/outlook/">yet to make a similar declaration</a>. Instead, the Bureau remains on “El Niño alert”. </p>
<p>The reason for this discrepancy is what’s called the <a href="https://climateextremes.org.au/what-is-the-pacific-walker-circulation/">Pacific Walker Circulation</a>. The pattern and strength of air flows over the Pacific Ocean, combined with sea surface temperatures, determines whether Australia experiences El Niño or La Niña events.</p>
<p>In our new research, published today in the journal <a href="https://doi.org/10.1038/s41586-023-06447-0">Nature</a>, we asked whether the buildup of greenhouse gases in the atmosphere had affected the Walker Circulation. We found the overall strength hasn’t changed yet, but instead, the year-to-year behaviour is different.</p>
<p>Switching between El Niño and La Niña conditions has slowed over the industrial era. That means in the future we could see more of these multi-year La Niña or El Niño type events. So we need to prepare for greater risks of floods, drought and fire. </p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/ydMP4kG3SXs?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">What is the Pacific Walker Circulation? An explainer.</span></figcaption>
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Read more:
<a href="https://theconversation.com/la-nina-is-finishing-an-extremely-unusual-three-year-cycle-heres-how-it-affected-weather-around-the-world-196561">La Niña is finishing an extremely unusual three-year cycle – here's how it affected weather around the world</a>
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<h2>An ocean-atmosphere climate system</h2>
<p>La Niña and its counterpart El Niño are the two extremes of the El Niño Southern Oscillation — a coupled ocean-atmosphere system that plays a major role in global climate variability.</p>
<p>The Walker Circulation is the atmospheric part. Air rises over <a href="https://geoscienceletters.springeropen.com/articles/10.1186/s40562-016-0054-3">the Indo-Pacific Warm Pool</a> (a region of the ocean that stays warm year-round) and flows eastward high in the atmosphere. Then it sinks back to the surface over the eastern equatorial Pacific and flows back to the west along the surface, forming the Pacific trade winds. In short, it loops in an east-west direction across the equatorial Pacific Ocean.</p>
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Read more:
<a href="https://theconversation.com/curious-kids-where-does-wind-actually-come-from-198404">Curious Kids: where does wind actually come from?</a>
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<p>But the Walker Circulation doesn’t always flow with the same intensity — sometimes it is stronger, and sometimes it is weaker. </p>
<p>Periods of stronger or weaker Walker Circulation have <a href="https://climateextremes.org.au/what-is-the-pacific-walker-circulation/">major impacts on Australian climate</a>. A stronger Walker Circulation means stronger-than-average trade winds, and generally La Niña-like ocean conditions. This often brings wetter weather to eastern Australia. </p>
<p>On the flip side, a weaker Walker Circulation brings weaker-than-average trade winds, and El Niño-like ocean conditions. A weak Walker Circulation is often associated with drier weather across northern and eastern Australia. </p>
<p>So far, the Walker Circulation is what’s missing from the current El Niño event developing in the Pacific Ocean: it has not weakened enough for the Bureau to declare an El Niño event. </p>
<figure class="align-center ">
<img alt="Animated GIF illustrating the Pacific Walker Circulation" src="https://images.theconversation.com/files/543868/original/file-20230822-15-hqqzna.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/543868/original/file-20230822-15-hqqzna.gif?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/543868/original/file-20230822-15-hqqzna.gif?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/543868/original/file-20230822-15-hqqzna.gif?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/543868/original/file-20230822-15-hqqzna.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/543868/original/file-20230822-15-hqqzna.gif?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/543868/original/file-20230822-15-hqqzna.gif?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">In the Pacific Walker Circulation, warm air rises above the western Pacific Ocean, cools down and sinks over the east of the Pacific Ocean, circling back and continuing an important atmospheric cycle for the entire planet.</span>
<span class="attribution"><a class="source" href="https://climateextremes.org.au/what-is-the-pacific-walker-circulation/">The ARC Centre of Excellence for Climate Extremes via Canva.com</a></span>
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<h2>What’s happening to the Walker Circulation?</h2>
<p>The Walker Circulation is a <a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018RG000596">major influence</a> on weather and climate in many places around the world, not just Australia.</p>
<p>A stronger-than-usual Walker Circulation even contributed to the “<a href="https://www.nature.com/articles/nclimate2106">global warming slowdown</a>” of the early 2000s. This is because a stronger Walker Circulation is often associated with slightly cooler global temperature. </p>
<p>So we need to know how it is going to behave in the future. To do that, we first need to know if — and if so, how — the Walker Circulation’s behaviour has changed due to human activities. And to do that, we need information about how the Walker Circulation behaved <em>before</em> humans started affecting the climate system. </p>
<p>We reconstructed Walker Circulation variability over the past millennium. We used global data from ice cores, trees, lakes, corals and caves to build a picture of how the Walker Circulation changed over time.</p>
<p>We found that on average, there has not yet been any industrial-era change in the strength of the Walker Circulation. This was surprising, because <a href="https://climateextremes.org.au/climate-modelling/">computer simulations of Earth’s climate</a> generally suggest global warming will <a href="https://www.nature.com/articles/nature04744">ultimately cause a weaker</a>, or more El Niño-like, Walker Circulation. </p>
<p>There are a few possible reasons for this. One is that <a href="https://www.nature.com/articles/s41558-021-01101-x">a buildup of fine particles in the air</a>, such as smoke or industrial pollution, may be driving a stronger Walker Circulation, hence “cancelling out” the weakening effect of global warming.</p>
<p>Another is there may have been <em>some</em> weakening, but so far it is too small to be detectable among the Walker Circulation’s large year-to-year variability. </p>
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Read more:
<a href="https://theconversation.com/smoke-from-the-black-summer-fires-could-have-made-the-triple-la-nina-more-likely-205292">Smoke from the Black Summer fires could have made the triple La Niña more likely</a>
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<p>Our research also does not rule out the possibility that with future increases in global temperature, the Walker Circulation will indeed weaken, in a trend to more El Niño-like conditions. In that scenario, Australians might expect <a href="https://climateextremes.org.au/understanding-australias-rainfall/">decreased rainfall in the north and east</a>, as well as warmer temperatures across the continent, and <a href="http://www.bom.gov.au/climate/updates/articles/a008-el-nino-and-australia.shtml">less snow in the Australian Alps</a>. </p>
<p>Even though the average strength of the Walker Circulation has not changed in the industrial era, there has been a subtle change in the length of time taken for the Walker Circulation to switch from one state to the next. </p>
<p>The Walker Circulation now switches more <em>slowly</em> between weak and strong phases, and we suspect this is influenced by climate change. This has potentially important implications for climate extremes, as El Niño and La Niña conditions could hang around for longer. </p>
<p>Our research also found that major explosive volcanic eruptions — at least as big as the 1982 eruption of El Chichón — can trigger an El Niño-like weakening of the Walker Circulation one to three years after the eruption. Unfortunately, volcanic eruptions remain <a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018JB016974">extremely difficult</a> to predict, so this doesn’t help our long-term climate predictions.</p>
<h2>What is the message for Australians?</h2>
<p>In terms of predicting how the Walker Circulation will change in the future, we can now focus attention on the particular climate models whose outputs <a href="https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2022GL100011">most closely match</a> what we discovered from our reconstruction.</p>
<p>That is, models that show no industrial-era weakening trend. This approach might help us get more accurate predictions of future Walker Circulation change. </p>
<p>The other thing we can do is to be prepared for more consecutive-year El Niño and La Niña events, and the sustained wet or dry spells they could bring to Australia.</p>
<p>And if there is a major volcanic eruption? Be prepared for a couple of years of weak Walker Circulation, and the warm, dry weather that can bring. </p>
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Read more:
<a href="https://theconversation.com/new-study-helps-solve-a-30-year-old-puzzle-how-is-climate-change-affecting-el-nino-and-la-nina-205128">New study helps solve a 30-year-old puzzle: how is climate change affecting El Niño and La Niña?</a>
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<img src="https://counter.theconversation.com/content/211029/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Georgina Falster receives funding from the Australian Research Council Centre of Excellence for Climate Extremes. This research was funded by the US National Science Foundation.</span></em></p>It’s not just ocean temperatures that determine whether we have El Niño or La Niña. Air circulation also plays a role, and it’s changing in unexpected ways.Georgina Falster, Postdoctoral Fellow, Australian National UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2084122023-06-29T11:15:17Z2023-06-29T11:15:17ZEl Niño could push global warming past 1.5°C – but what is it and how does it affect the weather in Europe?<figure><img src="https://images.theconversation.com/files/534592/original/file-20230628-29-3vggu2.jpg?ixlib=rb-1.1.0&rect=27%2C0%2C3072%2C2046&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A natural weather event known as El Niño is underway in the Pacific Ocean.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/el-nino-san-diego-788564623">jon sullivan/Shutterstock</a></span></figcaption></figure><p>Scientists have warned that 2024 could mark the year when global warming <a href="https://www.bbc.co.uk/news/science-environment-65839060">exceeds 1.5°C above pre-industrial levels</a>. They attribute these predictions, at least in part, to the emergence of an El Niño event.</p>
<p>An El Niño <a href="https://www.climate.gov/news-features/blogs/june-2023-enso-update-el-ni%C3%B1o-here">is declared</a> when the sea surface temperature in large parts of the central or eastern equatorial regions of the Pacific Ocean warms significantly – sometimes by as much as 2°C. This additional heat in turn warms the atmosphere. During El Niño years, this warming contributes to a temporary rise in the global temperature by a fraction of a degree. </p>
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<p>El Niño primarily affects weather in the tropics. Intense downpours that would usually fall on parts of south-east Asia or eastern Australia instead fall on the west coast of South America. This change can cause major drought and <a href="https://www.pnas.org/doi/10.1073/pnas.1409822111">flooding</a> on different continents, affecting <a href="https://www.fao.org/el-nino/en/">food production</a> and even weather-dependent sports like <a href="https://rmets.onlinelibrary.wiley.com/doi/10.1002/wea.403">cricket</a>.</p>
<p>But changes to the weather in these regions can have knock-on effects all over the world. Even thousands of kilometres away in northern Europe, El Niño tends to cause colder and drier winter weather. </p>
<p>Yet many factors affect European weather, especially during winter. So care is needed when linking unusual weather events in Europe to El Niño.</p>
<figure class="align-center ">
<img alt="Storm clouds over the Andaman Sea." src="https://images.theconversation.com/files/534591/original/file-20230628-15-yriir7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/534591/original/file-20230628-15-yriir7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/534591/original/file-20230628-15-yriir7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/534591/original/file-20230628-15-yriir7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/534591/original/file-20230628-15-yriir7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/534591/original/file-20230628-15-yriir7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/534591/original/file-20230628-15-yriir7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Storm clouds over the Andaman Sea, Thailand.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/severe-storm-clouds-torrential-rain-shaft-1303569019">Ian Murdoch/Shutterstock</a></span>
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<h2>What is El Niño?</h2>
<p>The Pacific Ocean spans over 13,000 kilometres from its eastern edge on the South American coast to its western margins near Indonesia. The sea surface temperature changes considerably over this vast distance. </p>
<p>Normally, the eastern edge of the Pacific Ocean is more than 5°C colder on average than the western Pacific. This is primarily due to the <a href="https://www.youtube.com/watch?v=WPA-KpldDVc">upwelling of cold water near South America</a>, a process in which colder water is pulled up from deeper down in the ocean.</p>
<p>However, this temperature contrast flattens or steepens every few years in a natural cycle called the <a href="https://www.climate.gov/news-features/blogs/enso/what-el-ni%C3%B1o%E2%80%93southern-oscillation-enso-nutshell">El Niño southern oscillation</a> (Enso). During this cycle, the strength of trade winds that blow westwards across the Pacific can strengthen or weaken, causing more or less cold water to upwell and flow along the equator. </p>
<p>We’re currently entering a period where the eastern Pacific will be warmer than it usually is – an El Niño event. Forecasts suggest that a part of the equatorial Pacific, regarded as a key indicator of Enso, has a <a href="https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.shtml">50% chance of warming by over 1.5°C</a> by the start of 2024.</p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/69N494UIlS8?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">How Pacific Ocean temperatures change during an El Niño event.</span></figcaption>
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<p>La Niña is the opposite phase of the cycle. It is instead characterised by cooler sea surface temperatures in these waters. This year brought an end to three successive La Niña years.</p>
<p>The western tropical Pacific region has some of the warmest ocean temperatures on Earth. Humid air tends to converge here, creating unstable conditions characterised by turbulent rising air known as <a href="https://www.metoffice.gov.uk/weather/learn-about/weather/how-weather-works/what-is-convection">convection</a> by meteorologists. The result of this is towering clouds and intense rainfall. </p>
<p>The region with the highest ocean temperature tends to experience the greatest amount of rainfall. As the warmest ocean temperatures shift eastward during El Niño, so too does the location of maximum cloud cover and rainfall.</p>
<p>Each El Niño event is different. Some mainly warm the eastern Pacific Ocean, such as the <a href="https://en.wikipedia.org/wiki/1997%E2%80%9398_El_Ni%C3%B1o_event">1997-98 event</a>. Others cause more warming in the central Pacific, <a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2011GL048521">like in 2009-10</a>.</p>
<h2>How does it affect Europe’s climate?</h2>
<p>Towering clouds and intense rains in the western Pacific create atmospheric waves known as <a href="https://oceanservice.noaa.gov/facts/rossby-wave.html">Rossby waves</a>. These waves extend over thousands of kilometres and travel into and along the eastward-flowing <a href="https://www.metoffice.gov.uk/weather/learn-about/weather/types-of-weather/wind/what-is-the-jet-stream">jet streams</a> that encircle the planet’s mid-latitude regions. When the Rossby waves interact with the jet streams, they cause them to undulate.</p>
<p>As unsettled weather in the Pacific moves eastwards during an El Niño event, it influences the location of the peaks and troughs of these Rossby waves. This results in subtle changes in the positions of the jet streams. These alterations in the jet streams, which play a significant role in shaping weather patterns, can have notable <a href="https://www.climate.gov/news-features/featured-images/how-el-ni%C3%B1o-and-la-ni%C3%B1a-affect-winter-jet-stream-and-us-climate">effects on weather conditions</a> worldwide.</p>
<p>Depending on the specific movement of the jet stream in a particular area, the effect can either lead to warmer or cooler weather, despite El Niño warming the global climate as a whole. El Niño tends to slightly warm Europe in summer and <a href="https://www.metoffice.gov.uk/research/climate/seasonal-to-decadal/gpc-outlooks/el-nino-la-nina">slightly cool</a> northern Europe in winter.</p>
<h2>External noise</h2>
<p>However, a colder-than-average winter in Europe is not guaranteed during an El Niño event. Europe’s winter climate is <a href="https://www.metoffice.gov.uk/weather/learn-about/weather/seasons/winter/factors-that-influence-uk-winters">affected by various factors</a> beyond El Niño, including <a href="https://journals.ametsoc.org/view/journals/mwre/142/2/mwr-d-13-00104.1.xml?tab_body=abstract-display">conditions in the Atlantic</a>, the amount of Arctic sea ice and the state of the stratosphere 15-40km above us (which is <a href="https://journals.ametsoc.org/view/journals/clim/22/15/2009jcli2717.1.xml">itself affected by El Niño</a>). </p>
<p>For instance, the <a href="https://www.metoffice.gov.uk/weather/learn-about/weather/atmosphere/quasi-biennial-oscillation">quasi-biennial oscillation</a> – a regular reversal of winds that blow high above the equator – can alter wind patterns in the stratosphere. This can subsequently affect the position of the North Atlantic storm track, which influences Europe’s winter weather.</p>
<p>But even then, the underlying warming trend caused by climate change is making higher temperatures more probable in all seasons. Together, these other factors make any climatic signals from El Niño harder to detect and forecast. Caution must therefore be exercised before <a href="https://www.metoffice.gov.uk/research/climate/understanding-climate/attributing-extreme-weather-to-climate-change">attributing anomalies</a> in European winter weather to El Niño alone.</p>
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<img alt="Imagine weekly climate newsletter" src="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p class="fine-print"><em><span>Manoj Joshi receives funding from the UK Natural Environment Research Council (NERC)</span></em></p>An El Niño weather-warming phase is underway in the Pacific – but what does this mean for the weather in Europe?Manoj Joshi, Professor of Climate Dynamics, University of East AngliaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2079022023-06-21T12:30:01Z2023-06-21T12:30:01ZOcean heat is off the charts – here’s what that means for humans and ecosystems around the world<figure><img src="https://images.theconversation.com/files/532300/original/file-20230615-15-tk80ew.png?ixlib=rb-1.1.0&rect=717%2C150%2C1160%2C710&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The Indian Ocean's heat is having effects on land, too.</span> <span class="attribution"><a class="source" href="https://coralreefwatch.noaa.gov/product/5km/index_5km_sst.php">NOAA Coral Reef Watch</a></span></figcaption></figure><p>Ocean temperatures have been <a href="https://climatereanalyzer.org/clim/sst_daily/">off the charts since mid-March 2023</a>, with the highest average levels in 40 years of satellite monitoring, and the impact is breaking through in disruptive ways around the world.</p>
<p>The sea of Japan is <a href="https://www.energyconnects.com/news/renewables/2023/may/early-heat-wave-gives-tokyo-a-glimpse-of-a-sweltering-summer/">more than 7 degrees</a> Fahrenheit (4 degrees Celsius) warmer than average. The Indian monsoon, closely tied to conditions in the warm Indian Ocean, has been <a href="https://mausam.imd.gov.in/responsive/rainfallinformation.php">well below its expected strength</a>.</p>
<p>Spain, France, England and the whole Scandinavian Peninsula <a href="https://joint-research-centre.ec.europa.eu/jrc-news-and-updates/severe-drought-western-mediterranean-faces-low-river-flows-and-crop-yields-earlier-ever-2023-06-13_en">are also seeing rainfall far below normal</a>, likely connected to an extraordinary marine heat wave in the eastern North Atlantic. Sea surface temperatures there have been 1.8 to 5 F (1 to 3 C) above average from the coast of Africa all the way to Iceland.</p>
<p>So, what’s going on?</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/533018/original/file-20230620-27-zj3g9.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Chart shows 22 years of sea surface temperature, with 2023 well above that of previous years" src="https://images.theconversation.com/files/533018/original/file-20230620-27-zj3g9.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/533018/original/file-20230620-27-zj3g9.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=382&fit=crop&dpr=1 600w, https://images.theconversation.com/files/533018/original/file-20230620-27-zj3g9.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=382&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/533018/original/file-20230620-27-zj3g9.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=382&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/533018/original/file-20230620-27-zj3g9.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=480&fit=crop&dpr=1 754w, https://images.theconversation.com/files/533018/original/file-20230620-27-zj3g9.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=480&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/533018/original/file-20230620-27-zj3g9.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=480&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Sea surface temperatures are running well above the average since satellite monitoring began. The thick black line is 2023. The orange line is 2022. The 1982-2011 average is the middle dashed line.</span>
<span class="attribution"><a class="source" href="https://climatereanalyzer.org/clim/sst_daily/">ClimateReanalyzer.org/NOAA OISST v2.1</a></span>
</figcaption>
</figure>
<p>El Niño is partly to blame. <a href="https://theconversation.com/el-nino-is-back-thats-good-news-or-bad-news-depending-on-where-you-live-205974">This climate phenomenon</a>, now developing in the equatorial Pacific Ocean, is characterized by warm waters in the central and eastern Pacific, which generally weakens the trade winds in the tropics. This weakening of those winds can affect oceans and land around the world.</p>
<p>But there are other forces at work on ocean temperatures.</p>
<p>Underlying everything is global warming – the <a href="https://climate.nasa.gov/">continuing rising trend</a> of <a href="https://images.theconversation.com/files/533088/original/file-20230621-16119-v4sxij.png">sea surface and land temperatures</a> for the past several decades as human activities have increased greenhouse gas concentrations in the atmosphere.</p>
<p>The world just came off <a href="https://earthobservatory.nasa.gov/images/150691/la-nina-times-three" title=""">three straight years</a> of La Niña – El Niño’s opposite, characterized by cooler waters rising in the equatorial Pacific. La Niña has a <a href="https://oceanservice.noaa.gov/facts/ninonina.html">cooling effect</a> globally that helps keep global sea surface temperatures in check but can also mask global warming. With that cooling effect turned off, the heat is increasingly evident.</p>
<p>Arctic sea ice was also <a href="https://nsidc.org/arcticseaicenews/">unusually low</a> in May and early June, and it may play a role. Losing ice cover <a href="https://oceanservice.noaa.gov/facts/sea-ice-climate.html">can increase water temperatures</a>, because dark open water absorbs solar radiation that white ice had reflected back into space.</p>
<p>These influences are playing out in various ways around the world. </p>
<h2>The effects of extraordinary Atlantic heat</h2>
<p>In early June 2023, <a href="https://scholar.google.com/citations?user=6jEKlrQAAAAJ&hl=en">I visited</a> the <a href="https://www.norceresearch.no/en">NORCE climate center</a> in Bergen, Norway, for two weeks to meet with other ocean scientists. The warm waters and mild winds across the eastern North Atlantic brought a long stretch of sunny, warm weather in a month when more than 70% of days normally would have been downpours. </p>
<p>The whole agricultural sector of Norway is now bracing for a drought as bad as the one in 2018, when <a href="https://bg.copernicus.org/articles/17/1655/2020/">yield was 40% below normal</a>. Our train from Bergen to Oslo had a two-hour delay because the brakes of one car overheated and the 90 F (32 C) temperatures approaching the capital were too high to allow them to cool down. </p>
<p>Many scientists have speculated on the causes of the eastern North Atlantic’s unusually high temperatures, and several studies are underway.</p>
<p>Weakened winds caused the <a href="https://www.weatheronline.co.uk/reports/wxfacts/The-Azores-High.htm">Azores high</a>, a semi-permanent high pressure system over the Atlantic that affects Europe’s weather, to be especially weak and brought less <a href="https://atmosphere.copernicus.eu/what-saharan-dust-and-how-does-it-change-atmosphere-and-air-we-breathe">dust from the Sahara</a> over the ocean during the spring, which may have increased the amount of solar radiation reaching the water. A decrease in human-produced aerosol emissions in Europe and in the United States over the past few years – which has succeeded in improving air quality – <a href="https://doi.org/10.1002/2017GL076079">may also have reduced the cooling effect</a> such aerosols have.</p>
<h2>A weakened monsoon in South Asia</h2>
<p>In the Indian Ocean, El Niño tends to cause a warming of the water in April and May that <a href="https://www.climate.gov/news-features/blogs/enso/enso-and-indian-monsoon%E2%80%A6-not-straightforward-you%E2%80%99d-think">can dampen the crucial Indian monsoon</a>.</p>
<p>That may be happening – the monsoon <a href="https://www.reuters.com/world/india/indias-stalled-monsoon-gain-momentum-3-4-days-weather-officials-2023-06-20/">was much weaker than normal</a> from mid-May to mid-June 2023. That can be a problem for a large part of South Asia, where most of the agriculture is still rain-fed and depends heavily on the summer monsoon.</p>
<figure class="align-center ">
<img alt="Three adults walk under umbrellas sheltering them from the sun. A woman without an umbrella shades her eyes with her hands on a hot day, and a boy wears a cap." src="https://images.theconversation.com/files/532987/original/file-20230620-19276-e74oss.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/532987/original/file-20230620-19276-e74oss.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=387&fit=crop&dpr=1 600w, https://images.theconversation.com/files/532987/original/file-20230620-19276-e74oss.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=387&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/532987/original/file-20230620-19276-e74oss.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=387&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/532987/original/file-20230620-19276-e74oss.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=487&fit=crop&dpr=1 754w, https://images.theconversation.com/files/532987/original/file-20230620-19276-e74oss.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=487&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/532987/original/file-20230620-19276-e74oss.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=487&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">India saw sweltering temperatures in May and June 2023.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/people-out-at-india-gate-on-hot-afternoon-on-may-21-2023-in-news-photo/1256969460">Sanjeev Verma/Hindustan Times via Getty Images</a></span>
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<p>The Indian Ocean also saw an intense, <a href="https://www.reuters.com/graphics/ASIA-WEATHER/byvrlywymve/index.html">slow-moving cyclone</a> in the Arabian Sea this year that deprived land of moisture and rainfall for weeks. Studies suggest storms can sit for <a href="https://theconversation.com/what-makes-hurricanes-stall-and-why-is-that-so-hard-to-forecast-146804">longer over warmer waters</a>, gaining strength and pulling moisture to their core, and that can deprive surrounding land masses of water, increasing the risk of droughts, wildfires and marine heat waves.</p>
<h2>North American hurricane season up in the air</h2>
<p>In the Atlantic, the weakening trade winds with El Niño tend to <a href="https://theconversation.com/atlantic-hurricane-season-2023-el-nino-and-extreme-atlantic-ocean-heat-are-about-to-clash-204670">tamp down hurricane activity</a>, but warm Atlantic temperatures can supercharge those storms. Whether the ocean heat, if it persists into fall, will override El Niño’s effects remains to be seen.</p>
<p><iframe id="hzENA" class="tc-infographic-datawrapper" src="https://datawrapper.dwcdn.net/hzENA/4/" height="400px" width="100%" style="border: none" frameborder="0"></iframe></p>
<h2>Risk of marine heat waves in South America</h2>
<p><a href="https://theconversation.com/el-nino-is-coming-and-ocean-temps-are-already-at-record-highs-that-can-spell-disaster-for-fish-and-corals-202424">Marine heat waves</a> can also have huge impacts on marine ecosystems, <a href="https://theconversation.com/coral-reefs-are-dying-as-climate-change-decimates-ocean-ecosystems-vital-to-fish-and-humans-164743">bleaching coral reefs</a> and causing the death or movement of entire species. Coral-based ecosystems are nurseries for fish that provide food for 1 billion people around the world.</p>
<p>The reefs of the Galapagos Islands and those along the coastlines of Colombia, Panama and Ecuador are already at risk of <a href="https://coralreefwatch.noaa.gov/">severe bleaching and mortality from this year’s El Nino</a>. Meanwhile, the Japan Sea and the eastern Mediterranean Sea are both losing their biodiversity to invasive species – <a href="https://doi.org/10.1007/s10750-014-2046-7">giant jellyfish in Asia</a> and <a href="https://doi.org/10.12681/mms.21845">lionfish in the Mediterranean</a> – that can thrive in warmer waters.</p>
<h2>These kinds of risks are increasing</h2>
<p>Spring 2023 was exceptional, with several chaotic weather events accompanying the formation of El Niño and the exceptionally warmer temperatures in many parts of the world. At the same time, the warming of the oceans and atmosphere increase the chances for this kind of ocean warming.</p>
<p>To lower the risk, the world needs to reduce baseline warming by limiting excess greenhouse gas emissions, like fossil fuels, and <a href="https://www.ipcc.ch/report/ar6/syr/">move to a carbon-neutral planet</a>. People will have to <a href="https://www.un.org/en/climatechange/climate-adaptation">adapt to a warming climate</a> in which extreme events are more likely and learn how to mitigate their impact.</p><img src="https://counter.theconversation.com/content/207902/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Annalisa Bracco receives funding from NSF, NOAA, DOE. </span></em></p>Drought in Europe, dwindling Arctic sea ice, a slow start to the Indian monsoon – unusually hot ocean temperatures can disrupt climate patterns around the world, as an ocean scientist explains.Annalisa Bracco, Professor of Ocean and Climate Dynamics, Georgia Institute of TechnologyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2074932023-06-12T22:37:26Z2023-06-12T22:37:26ZEl Niño combined with global warming means big changes for New Zealand’s weather<figure><img src="https://images.theconversation.com/files/531272/original/file-20230612-84194-6x3bxx.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C6720%2C4466&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Getty Images</span></span></figcaption></figure><p>El Niño is officially here, according to the US National Oceanic and Atmospheric Administration, and with it comes a change from the La Niña weather patterns New Zealand has experienced for the past three years.</p>
<p>In particular, a switch from prevailing northeasterlies to southwesterlies means New Zealand is one of the few countries where cooler conditions are felt during El Niño. But what “flavour” will this El Niño be?</p>
<p>Time will tell, but El Niño has been looming for some time. Evidence of its imminent arrival could be seen last year in subsurface ocean temperatures, with a buildup of warm water in the Coral Sea and western tropical Pacific.</p>
<p>Moreover, it was overdue. When La Niña finally gave up the ghost in March this year, global sea surface temperatures were suddenly the highest on record (Figure 1 below), as the tropical Pacific abruptly began to warm. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/531270/original/file-20230612-29-braw6w.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/531270/original/file-20230612-29-braw6w.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/531270/original/file-20230612-29-braw6w.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=342&fit=crop&dpr=1 600w, https://images.theconversation.com/files/531270/original/file-20230612-29-braw6w.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=342&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/531270/original/file-20230612-29-braw6w.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=342&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/531270/original/file-20230612-29-braw6w.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=430&fit=crop&dpr=1 754w, https://images.theconversation.com/files/531270/original/file-20230612-29-braw6w.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=430&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/531270/original/file-20230612-29-braw6w.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=430&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Figure 1. Global mean sea surface temperatures (with other calendar years in grey), showing 2023’s record highs.</span>
<span class="attribution"><a class="source" href="https://climatereanalyzer.org/clim/sst_daily/">University of Maine</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Meanwhile, record high sea surface temperatures in the extratropical North and South Pacific were partly a signature from La Niña and partly a sign of global warming. The resulting “atmospheric rivers” delivered torrential rains to California in the north and New Zealand in the south.</p>
<p>These sea surface temperature changes can be readily seen by comparing variations from mean temperatures for December 2022 versus May 2023 (Figure 2 below). We can see a startling transformation throughout the central tropical Pacific, with a coastal El Niño off Peru and Ecuador strongly evident. </p>
<p>Modest cooling in the eastern North Pacific is associated with the train of storms that barrelled into the West Coast of the US and in northwest Australia from Cyclone Ilsa.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/531271/original/file-20230612-151713-wk6u4j.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/531271/original/file-20230612-151713-wk6u4j.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/531271/original/file-20230612-151713-wk6u4j.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=643&fit=crop&dpr=1 600w, https://images.theconversation.com/files/531271/original/file-20230612-151713-wk6u4j.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=643&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/531271/original/file-20230612-151713-wk6u4j.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=643&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/531271/original/file-20230612-151713-wk6u4j.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=808&fit=crop&dpr=1 754w, https://images.theconversation.com/files/531271/original/file-20230612-151713-wk6u4j.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=808&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/531271/original/file-20230612-151713-wk6u4j.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=808&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Fig 2. Sea surface temperature changes (measured by departure from the mean), comparing December 2022 and May 2023.</span>
<span class="attribution"><a class="source" href="https://www.climate.gov/maps-data/data-snapshots/data-source/sst-global-monthly-difference-average">National Oceanic and Atmospheric Administration</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>El Niño and New Zealand</h2>
<p>The weather in the tropics is seldom average, however. It tends to fluctuate more like a roller coaster. In the atmosphere, this is referred to as the Southern Oscillation. The combined atmosphere and ocean phenomenon is often referred to as the El Niño-Southern Oscillation (ENSO). </p>
<p>The bottom of the roller coaster is the cold phase: a basin-wide cooling of the tropical Pacific, named La Niña, while the top of the roller coaster is El Niño, which occurs every three to seven years or so. The most intense phase of each event typically lasts half a year.</p>
<p>But El Niños can be very strong, and hence highly anomalous. La Niñas, by comparison, are usually moderate in strength and occur more often. </p>
<p>El Niños tend to peak in December, although their biggest atmospheric impacts may not be until February. The last major El Niño was in 2016-17, while a weak El Niño occurred in 2019-20. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/el-nino-is-back-thats-good-news-or-bad-news-depending-on-where-you-live-205974">El Niño is back – that's good news or bad news, depending on where you live</a>
</strong>
</em>
</p>
<hr>
<h2>Coupled oceans and atmosphere</h2>
<p>In the tropical Pacific Ocean, the atmosphere and ocean are strongly coupled. Surface winds drive surface ocean currents, and largely determine the sea surface temperature distribution, the differential sea levels, and the <a href="https://doi.org/10.1175/JCLI-D-18-0607.1">heat content of the upper ocean</a>. In turn, the sea surface temperatures determine the winds. </p>
<p>Cool waters limit atmospheric convection and storm activity, while high sea surface temperatures attract convection, clusters of thunderstorms, and tropical cyclones (off the equator, where Earth’s rotation comes into play). </p>
<p>Heat that was stored up in the tropical western Pacific during La Niña is moved around and into the atmosphere during El Niño, mainly through evaporation. This cools the ocean and moistens the atmosphere. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/2023-hurricane-forecast-get-ready-for-a-busy-pacific-storm-season-quieter-atlantic-than-recent-years-thanks-to-el-nino-204526">2023 hurricane forecast: Get ready for a busy Pacific storm season, quieter Atlantic than recent years thanks to El Niño</a>
</strong>
</em>
</p>
<hr>
<p>This alters where the main rainfall occurs. In turn, it changes the latent heating of the atmosphere that sets up “<a href="https://www.climate.gov/news-features/blogs/what-are-teleconnections-connecting-earths-climate-patterns-global-information">teleconnections</a>” (links between weather phenomena in different parts of the globe) and major changes in the jet streams and extratropical storm tracks in both hemispheres – including across New Zealand, especially in winter. </p>
<p>Because most action occurs over the tropical Pacific Ocean, more settled weather and dry spells often occur over land. </p>
<p>The warmest years in terms of global mean surface temperature are the latter stages of El Niño events. 2016 is the world’s warmest year on record, in part because of the very strong El Niño event. But 2023 could beat that record – and odds are that 2024 will beat it by a lot. </p>
<p>So far, there is little evidence that climate change has altered ENSO events themselves. But all impacts of El Niño are exacerbated by global warming, including extremes of the hydrological cycle involving floods and droughts, which are already common with ENSO. </p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1667351422592241669"}"></div></p>
<h2>Impacts of El Niño</h2>
<p>Of course, major events related to El Niño have serious social and economic impacts, too. Droughts, floods, heatwaves and other changes can severely disrupt agriculture, fisheries, health, energy demand and air quality (mainly from wildfires).</p>
<p><a href="https://doi.org/10.1126/science.adf2983">Research shows</a> El Niño “persistently reduces country-level economic growth”, with damage now estimated in the trillions of US dollars.</p>
<p>Globally, El Niño is the <a href="https://doi.org/10.1002/9781119548164.ch2">largest cause of droughts</a>; they are more intense, set in quicker and increase the risk of wildfires, especially in Australia, Indonesia and Brazil. In the weak 2019-20 El Niño, smoke from fires in eastern Australia affected the southern hemisphere to the extent that it blocked the sun and may have <a href="https://doi.org/10.1126/sciadv.adg1213">exacerbated</a> the subsequent La Niña conditions. </p>
<p>Meanwhile, torrential rains are heavier, with greater risk of flooding, especially in Peru and Ecuador. Very wet conditions can also (though not always) occur in California and the southeast US. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/new-study-helps-solve-a-30-year-old-puzzle-how-is-climate-change-affecting-el-nino-and-la-nina-205128">New study helps solve a 30-year-old puzzle: how is climate change affecting El Niño and La Niña?</a>
</strong>
</em>
</p>
<hr>
<h2>Another ‘super’ El Niño?</h2>
<p>New Zealand had its <a href="https://www.rnz.co.nz/news/national/482221/2022-confirmed-as-country-s-warmest-year-on-record">highest annual mean surface temperature</a> on record in 2022. In the past year the preponderance of northeasterlies due to La Niña has seen an unprecedented number of tropical and subtropical storms bombarding the country. </p>
<p>The record rain event in Auckland on January 27, and Cyclone Gabrielle just three weeks later, were just two among many such events. </p>
<p>By contrast, New Zealand tends to experience stronger and more frequent winds from the southwest in winter and from the west in summer during El Niño. This can encourage dryness in eastern areas and more rain on the West Coast, with generally cooler conditions overall.</p>
<p>But <a href="https://doi.org/10.1002/9781119548164.ch2">El Niño varies</a>, and there have been three “super” El Niños: 1982-83, 1997-98 and 2015-16. It remains to be seen whether the latest will join them. But together with the augmenting effects of global warming, any El Niño can be very disruptive. We need to be vigilant.</p><img src="https://counter.theconversation.com/content/207493/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kevin Trenberth does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>2016 was the world’s warmest year on record, due in part to a very strong El Niño event. But 2023 (and 2024) could beat that record – what should we expect?Kevin Trenberth, Distinguished Scholar, NCAR; Affiliate Faculty, University of Auckland, Waipapa Taumata RauLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2058472023-05-25T05:24:14Z2023-05-25T05:24:14ZWhat was behind Australia’s potato shortage? Wet weather and hard-to-control diseases<figure><img src="https://images.theconversation.com/files/528181/original/file-20230525-15-h10y1q.jpg?ixlib=rb-1.1.0&rect=14%2C36%2C4908%2C3233&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>If you’ve been into a fish and chip shop in the last 12 months, you may well have seen a notice tacked to the wall about the impact of the potato shortage. Supermarkets, too, slapped <a href="https://www.abc.net.au/news/2023-01-16/potato-shortage-incredibly-challenging-for-farmers/101858424">temporary limits</a> on frozen chip purchases. </p>
<p>What was behind it? Wet weather, floods – and highly persistent fungal diseases. Growers in Tasmania were worst hit, with mainland growers in New South Wales and Victoria also hit. </p>
<p>Even 175 years after Ireland’s devastating famine caused by an <a href="https://www.pnas.org/doi/10.1073/pnas.1401884111#:%7E:text=The%20potato%20late%20blight%20pathogen,potato%20famine%20and%20subsequent%20diaspora.">introduced potato</a> blight, we’re still struggling to combat these diseases. That’s a problem, because potatoes are vital. More than a billion of us <a href="https://thegoodcarb.com.au/good-for-the-planet/#:%7E:text=More%20than%20a%20billion%20people,exceeds%20300%20million%20metric%20tons">eat them</a> regularly. They’re the <a href="https://www.sciencedirect.com/science/article/pii/S2095311917617362">fourth most important</a> staple food after rice, wheat and corn, and the largest non-cereal crop. </p>
<p>Diseases such as pink rot and powdery scab can live in the soil for years. They’re almost impossible to eradicate down there. When there’s a sudden pulse of water, they spread and can destroy entire fields of potatoes. </p>
<p>What we can do is be better prepared. Our research team is monitoring soil moisture and temperature levels to help us predict whether we’re likely to see an outbreak. This knowledge could let growers respond quickly with fungicide or stopping irrigation to slow or prevent a severe outbreak. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/528180/original/file-20230525-17-gsgzbt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="powdery scab potato" src="https://images.theconversation.com/files/528180/original/file-20230525-17-gsgzbt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/528180/original/file-20230525-17-gsgzbt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/528180/original/file-20230525-17-gsgzbt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/528180/original/file-20230525-17-gsgzbt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/528180/original/file-20230525-17-gsgzbt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/528180/original/file-20230525-17-gsgzbt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/528180/original/file-20230525-17-gsgzbt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Powdery scab disease makes potatoes look distinctly unappetising.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>So what caused the shortage?</h2>
<p>In the lead-up to Christmas last year, Australia had a major <a href="https://www.potatonewstoday.com/2022/11/02/potato-supply-in-tasmania-impacted-by-wet-harvesting-conditions-growers-worried-about-planting-season">potato shortage</a>. </p>
<p>Our main growing regions in Tasmania, Victoria and South Australia were hard hit by <a href="https://www.smh.com.au/environment/climate-change/it-s-official-2022-was-wet-very-wet-20230208-p5ciwd.html">flooding and heavy rain</a> due to La Niña, which created conditions ripe for potato diseases to spread. Waterlogged or diseased potatoes cannot be sold.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1612660062744633344"}"></div></p>
<p>Other issues included delays to harvesting and planting due to the weather. And the <a href="https://www.ruralbank.com.au/news/production-costs-to-bite-as-farmers-look-to-improving-conditions-in-2023/">skyrocketing costs</a> of fuel and fertiliser have forced some growers not to plant potatoes. Potatoes need a lot of fertiliser and water. </p>
<p>While you might associate these tubers with snack foods, in reality they’re <a href="https://www.hutton.ac.uk/webfm_send/743">highly nutritious</a> and an important source of complex carbohydrates. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/potatoes-deserve-to-be-a-part-of-the-super-food-family-59625">Potatoes deserve to be a part of the super-food family</a>
</strong>
</em>
</p>
<hr>
<p>The way we grow them is <a href="https://cgspace.cgiar.org/bitstream/handle/10568/87958/CIP-Why-are-potatoes-important-English-2017.pdf?sequence=1&isAllowed=y">very efficient</a>. The amount of food energy we get per hectare of potatoes is many times greater than other staples like rice and wheat.</p>
<p>Stored properly, potatoes <a href="https://extension.oregonstate.edu/news/tips-keeping-harvested-potatoes-fresh#:%7E:text=%22With%20proper%20storage%2C%20well%2D,sprouting%20and%20shriveling%20may%20occur">can last</a> up to eight months. </p>
<p>Many growers find them to be one of the most profitable crops they can grow – as long as they’re prepared to face risks such as disease. </p>
<h2>What’s next for our potato sector?</h2>
<p>With the major rains at an end for now, potatoes are returning to the shelves and frozen food section. </p>
<p>But potato lovers aren’t out of the woods yet. For producers, there are still many worries. The increasing costs of production in fertiliser and other inputs. The chance of renewed heavy rainfall. And the continual battle against soil-borne disease. </p>
<p>Take Tasmania’s growers, who produce <a href="https://www.horticulture.com.au/globalassets/hort-innovation/australian-horticulture-statistics-handbook/ahsh-2021-22-vegetables-r.pdf">almost a third</a> (31%) of Australia’s potatoes. </p>
<p>Unexpectedly wet soil conditions in spring last year forced many growers to <a href="https://www.abc.net.au/news/rural/2021-11-17/tasmanian-potato-season-delayed-by-wet-weather/100620382">delay planting</a> until after mid-November. </p>
<p>Planting after this date comes with a cost. It means that by the time the plants mature, Tasmania will be through summer and into cooler months, reducing available sunlight and growing temperatures. That can mean a lower yield. </p>
<p>Facing delays like this, growers often simply don’t plant a crop at all. But because of the shortages, Tasmania’s major processing companies <a href="https://www.theadvocate.com.au/story/7394520/coasts-spud-supply-secured-as-farmers-cut-deal-with-simplot/">offered a bonus</a> to encourage a late crop to ensure factories could keep running. </p>
<h2>The eternal fight against disease</h2>
<p>Ever since potatoes emerged from the Andes to become a global crop, growers have battled the threat of soil-borne fungal and bacterial diseases. </p>
<p>Backyard gardeners may well be familiar with some of these. If you’ve ever pulled up a potato plant only to find a half-rotten tater, you’ll know the disappointment. </p>
<p>What keeps Australian growers up at night are diseases like powdery scab, as well as rot diseases like black leg, soft rot and pink rot. </p>
<p>Powdery scab is mainly a cosmetic issue, turning nice-looking potatoes into unappetising, lesion-covered blobs. </p>
<p>But rot is real trouble. These bacteria and fungi can destroy entire fields. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/528183/original/file-20230525-28-44uwq8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="black foot rot potato" src="https://images.theconversation.com/files/528183/original/file-20230525-28-44uwq8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/528183/original/file-20230525-28-44uwq8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=402&fit=crop&dpr=1 600w, https://images.theconversation.com/files/528183/original/file-20230525-28-44uwq8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=402&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/528183/original/file-20230525-28-44uwq8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=402&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/528183/original/file-20230525-28-44uwq8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=505&fit=crop&dpr=1 754w, https://images.theconversation.com/files/528183/original/file-20230525-28-44uwq8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=505&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/528183/original/file-20230525-28-44uwq8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=505&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Fungal rot diseases like black foot can devastate potato crops.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
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</figure>
<p>Pink rot is heavily influenced by free water in the soil. Heavy rainfalls just before an autumn harvest have triggered <a href="https://northeasternadvertiser.com/featured-articles/potato-yield-suffers-due-to-pink-rot">major rot epidemics</a> with significant losses to growers in three of Tasmania’s last five growing seasons.</p>
<p>In severe cases, growers have to abandon fields with the tubers left to rot away, while in less severe cases there’s still substantial <a href="https://www.examiner.com.au/story/6861997/research-to-help-more-potatoes-end-up-on-plates/">loss of crop</a> and lower product quality. </p>
<p>If we see these levels of unprecedented rainfall again – as is likely with climate changes warping weather patterns – we’re like to see more potato shortages.</p>
<p>So what can growers do? For pink rot and powdery scab disease, we don’t have good options. There are a few disease-resistant varieties, but their resistance comes at the cost of desirable properties like crop yield and how well they cook. Chemical controls are limited, and if we overuse them, we risk these fungi developing resistance just as bacteria do with antibiotics. </p>
<p>Fungi and bacteria can lie dormant for many years or stay alive on other plant species between crops. That limits how effective crop rotation is as a tool. </p>
<p>Cropping land proven to be pathogen free is in very short supply. Food industries which rely on potatoes are compensating for these expected losses by contracting a greater number of growers and over-planting. </p>
<p>But it’s not a hopeless case. We and other researchers are working on it. Recently, we made a <a href="https://www.utas.edu.au/tia/news-events/news-items/2021/new-tool-provides-rapid-screening-for-powdery-scab-in-potatoes">new tool</a> to help rapidly spot powdery scab disease in new potato varieties. </p>
<p>Now we’re <a href="http://www.utas.edu.au/tia/news-events/news-items/2022/agricultural-innovation-funds-to-help-deliver-benefits-to-critical-industries">working on ways</a> to track changes in soil moisture and temperature against rot and powdery scab outbreaks. This, we hope, will let us predict outbreaks before they occur. </p>
<p>Sometimes, you don’t have to defeat a disease outright. Better prediction and containment may be enough to keep us supplied with hot chips. </p>
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Read more:
<a href="https://theconversation.com/whats-driving-the-potato-chip-shortage-and-when-will-it-pass-198667">What's driving the potato chip shortage and when will it pass?</a>
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<img src="https://counter.theconversation.com/content/205847/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ronika Thapa receives a postgraduate scholarship award from the University of Tasmania </span></em></p><p class="fine-print"><em><span>Calum Wilson receives funding from Hort Innovation Pty Ltd, Simplot Australia Pty Ltd and Potatoes New Zealand.</span></em></p><p class="fine-print"><em><span>Robert Tegg receives funding from the University of Tasmania, Tasmanian government, Hort Innovation and private potato companies. </span></em></p>Potatoes are profitable and in demand. But wet weather and hard-to-control diseases have caused havoc for our growers.Ronika Thapa, PhD Student, University of TasmaniaCalum Wilson, Professor, University of TasmaniaRobert Tegg, Research Fellow, University of TasmaniaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2051282023-05-18T09:05:21Z2023-05-18T09:05:21ZNew study helps solve a 30-year-old puzzle: how is climate change affecting El Niño and La Niña?<p>Human-caused greenhouse gas emissions mean strong El Niño and La Niña events are occurring more often, according to our <a href="https://www.nature.com/articles/s43017-023-00427-8.epdf?sharing_token=F5jUWk6n2pNs6r4Q_fB-adRgN0jAjWel9jnR3ZoTv0Pte_xqACNGqtGKpHCToNiPWiuQhld4EzePttPmt4VYL7eOZiV2HFGOgK7IgGtTuVAwQWWw-47LrakAroi0Wb2ex5WSf1srrLocjHXZORLfsvgBdO7_eSRBO47xtzUYeFk%3D">new research</a>, which provides important new evidence of the human fingerprint on Earth’s climate.</p>
<p>For more than 30 years, climate researchers have puzzled over the link between human-caused climate change and El Niño and La Niña events. We set out to bridge this knowledge gap. </p>
<p>Climate scientists have long observed a correlation between climate change impacts on our oceans and atmosphere, and the increase in greenhouse gas emissions from human activity.</p>
<p>Our research examined when this activity may have started to make El Niño and La Niña events more extreme. Our deep analysis found a relationship between human-caused greenhouse gas activity and changes to El Niño and La Niña. </p>
<p>Our findings were five years in the making. They help us understand how El Niño and La Niña will change as the world warms in the future.</p>
<h2>What are El Niño and La Niña?</h2>
<p>La Niña typically brings wet, cooler conditions to much of Australia. Every few years it alternates with an El Niño, which typically brings drier, hotter conditions. Together, the two phases are known as the El Niño-Southern Oscillation. </p>
<p>The events are driven by changes in sea-surface temperature in the tropical Pacific Ocean. During an El Niño, the surface temperature is warmer than usual. During a La Niña, it’s colder than usual. </p>
<p>Small changes in sea-surface temperature can lead to big changes in the atmosphere. That’s how El Niño and La Niña events can so dramatically affect weather patterns around the world.</p>
<p>The El Niño-Southern Oscillation is naturally occurring. But over the last 50 years or so, strong El Niño and La Niña events have occurred more often. Was climate change playing a role? Our <a href="https://www.nature.com/articles/s43017-023-00427-8.epdf?sharing_token=F5jUWk6n2pNs6r4Q_fB-adRgN0jAjWel9jnR3ZoTv0Pte_xqACNGqtGKpHCToNiPWiuQhld4EzePttPmt4VYL7eOZiV2HFGOgK7IgGtTuVAwQWWw-47LrakAroi0Wb2ex5WSf1srrLocjHXZORLfsvgBdO7_eSRBO47xtzUYeFk%3D">research</a> set out to answer this question. </p>
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<strong>
Read more:
<a href="https://theconversation.com/fear-and-wonder-podcast-how-climate-action-can-create-a-more-liveable-future-for-all-205563">Fear and Wonder podcast: how climate action can create a more liveable future for all</a>
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<h2>Unpicking climate ‘variability’</h2>
<p>So how might climate change affect the development of El Niño and La Niña?</p>
<p>Decades of observations of climate change show sea surface temperatures are warming. In many oceans across the world, including the Pacific, this has caused the sea surface to warm faster than the water below.</p>
<p>We wanted to understand what impact this warming had on the El Niño-Southern Oscillation in the past century.</p>
<p>Our research analysed several simulations produced by 43 “climate models”, or <a href="https://ncas.ac.uk/learn/what-is-a-climate-model/">computer simulations</a> of Earth’s climate system. </p>
<p>First, we compared simulations from between 1901-1960 with those from 1961-2020.
Most results showed an increase in the “variability” of the El Niño-Southern Oscillation since 1960. </p>
<p>Variability refers to a departure from the average. In this case, our results show strong El Niño and La Niña events have occurred more frequently than average since 1960. This finding is consistent with observations over the same periods. </p>
<p>We then examined climate simulations over hundreds of years before humans started ramping up greenhouse gas emissions, and compared these to the simulations after 1960. </p>
<p>This analysis showed even more clearly the very strong variability in the El Niño-Southern Oscillation after 1960. This reinforces the finding that human-caused greenhouse gas emissions are the culprit.</p>
<p>The strong variability has contributed to more extreme and frequent droughts, floods, heatwaves, bushfires and storms around the world.</p>
<h2>So what’s next?</h2>
<p><a href="http://dx.doi.org/10.1038/s43017-021-00199-z">Previous research</a> suggests the El Niño-Southern Oscillation will continue to change this century. In particular, we can expect more intense and frequent El Niño and La Niña events. </p>
<p>We can also expect more frequent swings from a strong El Niño to a strong La Niña the following year. </p>
<p>These predictions apply to <a href="http://dx.doi.org/10.1038/s41558-022-01282-z">various emission scenarios</a>. Even if greenhouse gas emissions were slashed and global warming was kept to 1.5°C, as per the goal of the Paris Agreement, we can expect more frequent strong El Nino events for <a href="http://dx.doi.org/10.1038/NCLIMATE3351">another century</a>. That’s because the Pacific Ocean holds a lot of heat, which will take several decades to dissipate. </p>
<p>Of course, variability in the El Niño-Southern Oscillation is already making itself felt. Think back to the <a href="http://www.bom.gov.au/climate/updates/articles/a018.shtml">extreme El Niño of 2015</a>, which led to drought across much of Australia. And of course, a rare “triple” La-Nina from 2020 to 2022 led to severe flooding in eastern Australia. </p>
<p>An El Niño <a href="https://www.theguardian.com/australia-news/2023/may/14/extremely-high-likelihood-forecast-el-nino-will-impact-australian-summer-us-scientists-predict">may develop</a> later this year. As climate change worsens, we must prepare for many more of these potentially damaging climate events.</p>
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Read more:
<a href="https://theconversation.com/la-nina-3-years-in-a-row-a-climate-scientist-on-what-flood-weary-australians-can-expect-this-summer-190542">La Niña, 3 years in a row: a climate scientist on what flood-weary Australians can expect this summer</a>
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<img src="https://counter.theconversation.com/content/205128/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Agus Santoso receives funding from CSIRO and NESP. </span></em></p><p class="fine-print"><em><span>Wenju Cai does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The research help us understand how El Niño and La Niña will change as the world warms in the future.Wenju Cai, Chief Research Scientist, Oceans and Atmosphere, CSIRO, CSIROAgus Santoso, Senior Research Associate, UNSW SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2057582023-05-17T10:01:48Z2023-05-17T10:01:48ZGlobal warming to bring record hot year by 2028 – probably our first above 1.5°C limit<p>One year in the next five will almost certainly be the hottest on record and there’s a two-in-three chance a single year will cross the crucial 1.5°C global warming threshold, an alarming <a href="https://public.wmo.int/en/our-mandate/climate/global-annual-decadal-climate-update">new report</a> by the World Meteorological Organization predicts.</p>
<p>The report, known as the <a href="https://public.wmo.int/en/our-mandate/climate/global-annual-decadal-climate-update">Global Annual to Decadal Climate Update</a>, warns if humanity fails to reduce greenhouse gas emissions to net zero, increasingly worse heat records will tumble beyond this decade.</p>
<p>So what is driving the bleak outlook for the next five years? An expected El Niño, on top of the overall global warming trend, will likely push the global temperature to record levels.</p>
<p>Has the Paris Agreement already failed if the global average temperature exceeds the 1.5°C threshold in one of the next five years? No, but it will be a stark warning of what’s in store if we don’t quickly reduce emissions to net zero.</p>
<figure class="align-center ">
<img alt="boy plays in fountain during heatwave" src="https://images.theconversation.com/files/526731/original/file-20230517-15-fhpzvb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/526731/original/file-20230517-15-fhpzvb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=409&fit=crop&dpr=1 600w, https://images.theconversation.com/files/526731/original/file-20230517-15-fhpzvb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=409&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/526731/original/file-20230517-15-fhpzvb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=409&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/526731/original/file-20230517-15-fhpzvb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=514&fit=crop&dpr=1 754w, https://images.theconversation.com/files/526731/original/file-20230517-15-fhpzvb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=514&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/526731/original/file-20230517-15-fhpzvb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=514&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">One year in the next five will almost certainly be the hottest on record, bringing more heatwaves like this boy experienced in Britain around the time the last record was set.</span>
<span class="attribution"><span class="source">Andy Rain/EPA</span></span>
</figcaption>
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Read more:
<a href="https://theconversation.com/two-trillion-tonnes-of-greenhouse-gases-25-billion-nukes-of-heat-are-we-pushing-earth-out-of-the-goldilocks-zone-202619">Two trillion tonnes of greenhouse gases, 25 billion nukes of heat: are we pushing Earth out of the Goldilocks zone?</a>
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<h2>Warming makes record heat inevitable</h2>
<p>The World Meteorological Organization update says there is a 98% chance at least one of the next five years will be the hottest on record. And there’s a 66% chance of at least one year over the 1.5°C threshold.</p>
<p>There’s also a 32% chance the average temperature over the next five years will exceed the 1.5°C threshold. The chance of temporarily exceeding 1.5°C has risen steadily since 2015, when it was close to zero. For the years between 2017 and 2021, it was a 10% chance. </p>
<p>Human-caused greenhouse gas emissions have already driven up global average temperatures by more than 1°C since the late 19th century. The update notes the 2022 average global temperature was about 1.15°C above the 1850-1900 average, despite the <a href="http://www.bom.gov.au/climate/updates/articles/a020.shtml">cooling influence of La Niña</a> conditions. Temperatures are now rising by <a href="https://climate.metoffice.cloud/temperature.html">about 0.2°C per decade</a>.</p>
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<span class="caption">Global average surface temperatures relative to 1850-1900 from major datasets. The temperature is increasing by about 0.2°C per decade.</span>
<span class="attribution"><a class="source" href="https://climate.metoffice.cloud/temperature.html">UK Met Office</a></span>
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<p>We now have more than a century of global mean temperature data. That means it should be getting harder, not easier, to achieve new records. If there was no trend, we would expect to see fewer records as time passes and the data we’ve collected better captures the full range of natural climate variability. </p>
<p>Instead, because we are warming the world so quickly, more heat records are being set globally and <a href="https://interactive.carbonbrief.org/half-global-population-saw-all-time-record-temperatures-over-past-decade/">at the local level</a>. The human influence on the climate is pushing temperatures to unprecedented highs with alarming frequency.</p>
<h2>Add El Niño, then extreme highs are likely</h2>
<p>The current record global average temperature <a href="https://theconversation.com/2016-crowned-hottest-year-on-record-australia-needs-to-get-heat-smart-70994">dates back to 2016</a>. A major <a href="http://www.bom.gov.au/climate/updates/articles/a008-el-nino-and-australia.shtml">El Niño event</a> early that year pushed up the global average temperature. </p>
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Read more:
<a href="https://theconversation.com/2016-crowned-hottest-year-on-record-australia-needs-to-get-heat-smart-70994">2016 crowned hottest year on record: Australia needs to get heat smart</a>
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<p>El Niño events are associated with warmer-than-normal seas over much of the central and eastern Pacific. This helps warm the lower atmosphere and raise global temperatures <a href="https://www.realclimate.org/index.php/archives/2023/01/2022-updates-to-the-temperature-records/">by about 0.1°C</a>. This might not sound like much, but with rapid background warming it’s often enough to break the previous record.</p>
<p>In the seven years since the current global temperature record, humanity has continued to intensify the greenhouse effect. This is making a new record ever more likely.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1655840754135097346"}"></div></p>
<p><a href="http://www.bom.gov.au/climate/enso/">El Niño conditions are starting to form</a> in the Pacific and are looking increasingly likely to take hold in June and July. This could be the first significant El Niño since 2016. An El Niño would greatly increase the chance of breaking that year’s record high global average temperature, particularly in 2024. </p>
<h2>Does this mean the Paris Agreement has already failed?</h2>
<p>Almost all nations around the world have signed the <a href="https://unfccc.int/process-and-meetings/the-paris-agreement">Paris Agreement</a>. The aim is to limit global warming to well below 2°C and preferably below 1.5°C above pre-industrial levels. </p>
<p>The prediction that an individual year above 1.5°C global warming is more likely than not is alarming. But it doesn’t mean we have failed to achieve the Paris Agreement’s goals. The agreement aims to limit long-term global warming to a level that avoids major climate impacts, including ecosystem loss. One or two years that pop over the 1.5°C level don’t constitute failure.</p>
<p>However, the world is getting closer to the 1.5°C global warming level due to our <a href="https://theconversation.com/global-carbon-emissions-at-record-levels-with-no-signs-of-shrinking-new-data-shows-humanity-has-a-monumental-task-ahead-193108">continuing high greenhouse gas emissions</a>. The forecast of a probable year that exceeds that level should serve as a warning. </p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/global-carbon-emissions-at-record-levels-with-no-signs-of-shrinking-new-data-shows-humanity-has-a-monumental-task-ahead-193108">Global carbon emissions at record levels with no signs of shrinking, new data shows. Humanity has a monumental task ahead</a>
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<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1656736097081098242"}"></div></p>
<h2>Yet another sign of humanity’s damage to the climate</h2>
<p>Past inaction on reducing emissions and tackling climate change means we have already <a href="https://globalwarmingindex.org/">warmed the world by more than 1.2°C</a>. Global emissions remain at <a href="https://theconversation.com/global-carbon-emissions-at-record-levels-with-no-signs-of-shrinking-new-data-shows-humanity-has-a-monumental-task-ahead-193108">near-record high levels</a>, so we are continuing to <a href="https://theconversation.com/two-trillion-tonnes-of-greenhouse-gases-25-billion-nukes-of-heat-are-we-pushing-earth-out-of-the-goldilocks-zone-202619">intensify the greenhouse effect</a> and warm the planet. </p>
<p>If we are to limit global warming to well below 2°C, then we must act so future generations don’t suffer a much less hospitable planet.</p>
<p>We have understood the solution for decades. We <a href="https://www.carbonbrief.org/explainer-will-global-warming-stop-as-soon-as-net-zero-emissions-are-reached/">must reduce emissions to net zero</a> to stop warming Earth. Countries such as Australia, with high historical emissions, have a leading role to play by decarbonising electricity supply and ramping down coal, oil and gas production <a href="https://theconversation.com/australias-116-new-coal-oil-and-gas-projects-equate-to-215-new-coal-power-stations-202135">in line with goals laid out by the United Nations</a>.</p>
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Read more:
<a href="https://theconversation.com/australias-116-new-coal-oil-and-gas-projects-equate-to-215-new-coal-power-stations-202135">Australia's 116 new coal, oil and gas projects equate to 215 new coal power stations</a>
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<p>Failure to act should not be considered an option. Otherwise we are locking in more record hot years and <a href="https://theconversation.com/theres-no-end-to-the-damage-humans-can-wreak-on-the-climate-this-is-how-bad-its-likely-to-get-166031">much worse climate change impacts</a> for decades and centuries to come.</p><img src="https://counter.theconversation.com/content/205758/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Andrew King receives funding from the National Environmental Science Program. </span></em></p>There’s a 98% chance of a record hot year by 2028, and a 66% chance of exceeding the 1.5°C threshold for at least that year, according to the latest World Meteorological Organization update.Andrew King, Senior Lecturer in Climate Science, The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2052922023-05-10T20:01:28Z2023-05-10T20:01:28ZSmoke from the Black Summer fires could have made the triple La Niña more likely<p>The 2019-2020 bushfire season was devastating. Vast areas of pristine forest burned, many for the first time in memory. By some estimates, a billion native animals died up and down Australia’s east coast. Dozens of people died. </p>
<p>While Sydney’s skies are blue again, Australia’s Black Summer has kept scientists around the globe busy. The sheer size of these megafires produced startling effects. Recently, researchers found the huge volumes of smoke <a href="https://www.abc.net.au/news/2023-03-10/how-the-black-summer-bushfires-depleted-the-ozone-layer/102076136">ate away</a> at our protective ozone layer. </p>
<p>Now, <a href="https://dx.doi.org/10.1126/sciadv.adg1213">new research</a> by American scientists suggests the Black Summer fires were massive enough to influence the <a href="https://cosmosmagazine.com/earth/enso-iod-weather-patterns-explainer/#:%7E:text=El%20Ni%C3%B1o%20and%20La%20Ni%C3%B1a%2C%20also%20called%20El%20Ni%C3%B1o%20Southern,to%20the%20north%20of%20Australia.">El Niño Southern Oscillation cycle</a>. It’s one of the most important drivers of unusual weather over the entire globe – and one which Australians know intimately.</p>
<p>The <a href="https://theconversation.com/la-nina-is-finishing-an-extremely-unusual-three-year-cycle-heres-how-it-affected-weather-around-the-world-196561">three successive years</a> of La Niña we just had? They could have been made more likely by the Black Summer fires. The reason, strangely enough, is the smoke. </p>
<p>But it’s important not to say the link is proven. While groundbreaking, this research relies on a single model. It’s too early to clearly say bushfire smoke can trigger La Niña. </p>
<h2>Where there’s fire, there’s smoke</h2>
<p>We’ve long known that the huge volume of ash blown high into the upper atmosphere by a big volcanic eruption can cool Earth’s surface for many months, or <a href="https://www.ipcc.ch/report/sixth-assessment-report-working-group-i/">even years</a>. </p>
<p>We also know volcanoes <a href="https://doi.org/10.1007/s41748-022-00331-z">can influence</a> the tropical Pacific, and thus affect whether an El Niño or a La Niña phase develops. </p>
<p>How? By blocking light. Particles of ash reduce how much light gets to the surface. </p>
<p>Volcanic ash gets blown high into the stratosphere, the part of the atmosphere just above the clouds where long-haul airplanes fly. Then, sunlight gets reflected before it reaches the ground, thus cooling the surface much like an umbrella can. </p>
<h2>Is bushfire smoke the same as volcanic ash?</h2>
<p>It’s tempting to equate smoke with ash, and assume a large enough bushfire would have similar effects to a volcano. </p>
<p>But there are important differences. Most obviously, a bushfire does not smell of rotten eggs.</p>
<p>That might sound unimportant, but the rotten egg smell – which comes from sulfur – indicates major differences in the composition of volcanic ash and bushfire smoke. </p>
<p>Different chemicals could mean very different responses to sunlight once in the atmosphere, which in turn could affect how much light is reflected. </p>
<p>Second, bushfires don’t explode.</p>
<p>A decent volcano erupts with enough force to blast smoke high into the stratosphere. Bushfires don’t have the same propulsive force.</p>
<p>Bushfire smoke is hot, though, and hot smoke rises well. Some of the smoke from the Black Summer fires <a href="https://www.science.org/doi/abs/10.1126/science.abe1415">reached the stratosphere</a>, although after a much longer interval than for volcanic eruptions. </p>
<p>So, does a large bushfire have the same effect on climate as a volcano?</p>
<p>The American researchers begin by checking the similarities using climate model simulations. They found bushfire smoke does indeed shade the surface from sunlight in these simulations. </p>
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Read more:
<a href="https://theconversation.com/australias-black-summer-of-fire-was-not-normal-and-we-can-prove-it-172506">Australia's Black Summer of fire was not normal – and we can prove it</a>
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<p>How much? Over a region of the south-eastern Pacific, about 150 terawatts of sunlight bounced back to space – the equivalent of about 100,000 coal power plants. </p>
<h2>Clouds matter</h2>
<p>The surprising finding is how it happens. In contrast to eruptions, bushfire smoke didn’t reflect the sunlight directly. Instead, clouds were responsible. </p>
<p>How does that work? This is where the magic of the climate system kicks in. Our atmosphere, oceans and lands are constantly interacting with each other.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/525315/original/file-20230510-17-634wtl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Clouds over ocean" src="https://images.theconversation.com/files/525315/original/file-20230510-17-634wtl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/525315/original/file-20230510-17-634wtl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/525315/original/file-20230510-17-634wtl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/525315/original/file-20230510-17-634wtl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/525315/original/file-20230510-17-634wtl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=504&fit=crop&dpr=1 754w, https://images.theconversation.com/files/525315/original/file-20230510-17-634wtl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=504&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/525315/original/file-20230510-17-634wtl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=504&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">Whiter, thicker clouds make the surface of the ocean cooler.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
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<p>In their simulations, Black Summer smoke was first blown eastward by strong winds in the atmosphere. Under specific conditions, some smoke particles can interact with droplets in clouds and make clouds thicker and brighter. One region where this can happen is the subtropical south-eastern Pacific. </p>
<p>The researchers were able to show the brightness of the clouds over this area increased considerably just around the time when the smoke particles arrived. </p>
<p>These brighter, whiter clouds reflected more sunlight back into space and shaded the surface underneath. The net effect: cooler seawater. </p>
<p>The effect was particularly important because of the timing. Smoke-whitened clouds emerged around our summer solstice in late December, which is the same time of year when the strength of the incoming sunlight peaks in the southern hemisphere.</p>
<p>How is this linked to La Niña? </p>
<p>Follow the chain: huge volumes of smoke blow east where they whiten clouds, cool the seawater, and cause less water to evaporate.</p>
<p>Surface winds carried this cooler, drier air over the tropical Pacific, where it cooled the ocean surface again, and made it harder for tropical storms to form.</p>
<p>A cooler sea surface in the tropical Pacific is a hallmark of La Niña, the cold phase of the El Niño Southern Oscillation cycle. </p>
<p>That’s how this research was able to trace a link between Black Summer smoke and the rare back-to-back La Niña events in 2019-20 and 2020-21. As you know, we ended up having an even rarer triple La Niña in 2021-22, though the research period ends before this. </p>
<h2>Is the link now proven? Not quite</h2>
<p>This study offers a consistent physical explanation for how bushfires might influence the El Niño cycle. </p>
<p>It’s yet another example of how complex climate science can be, and how much we can still be surprised and challenged by what mother nature presents us. </p>
<p>But there are a few caveats to keep in mind.</p>
<p>For one, the ENSO cycle in the simulation was heading for a double La Niña even without the impact of the smoke. The simulation stops in the winter of 2021, which is before the real-world ENSO tipped into a third La Niña. </p>
<p>What does that mean? In short, we can’t know for sure if the effect of the bushfire smoke really did cause the triple La Niña. </p>
<p>Another caveat is the fact the study relied on a single climate model, and relies heavily on the representation of clouds in that model.</p>
<p>That’s a potential problem, because we know clouds – and especially their interactions with aerosols like smoke – are still the largest source of uncertainties and model errors. </p>
<p>To prove or disprove the link, we’ll have to simulate the impact of ballooning Black Summer smoke plumes across many different models. </p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/smoke-from-the-black-summer-fires-created-an-algal-bloom-bigger-than-australia-in-the-southern-ocean-164564">Smoke from the Black Summer fires created an algal bloom bigger than Australia in the Southern Ocean</a>
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<img src="https://counter.theconversation.com/content/205292/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Martin Jucker does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Where there’s fire, there’s smoke – could plumes from the Black Summer of fire have cooled regions of the Pacific and triggered a La Niña? New research suggests it’s possible.Martin Jucker, Lecturer in Atmospheric Dynamics, UNSW SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2024242023-04-18T12:44:48Z2023-04-18T12:44:48ZEl Niño is coming, and ocean temps are already at record highs – that can spell disaster for fish and corals<figure><img src="https://images.theconversation.com/files/521111/original/file-20230414-14-kbsx6w.jpg?ixlib=rb-1.1.0&rect=10%2C3%2C2385%2C1591&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Marine heat waves can reach the ocean floor as well as surface waters.</span> <span class="attribution"><a class="source" href="https://unsplash.com/photos/YV593oyMKmo">Sebastian Pena Lambarri via Unsplash</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>It’s coming. Winds are weakening along the equatorial Pacific Ocean. Heat is building beneath the ocean surface. By July, <a href="https://iri.columbia.edu/our-expertise/climate/forecasts/enso/current/">most forecast models agree</a> that the climate system’s biggest player – El Niño – will return for the first time in nearly four years.</p>
<p>El Niño is one side of the climatic coin called the <a href="https://www.climate.gov/news-features/understanding-climate/el-ni%C3%B1o-and-la-ni%C3%B1a-frequently-asked-questions">El Niño-Southern Oscillation, or ENSO</a>. It’s the heads to La Niña’s tails.</p>
<p>During El Niño, a swath of ocean stretching 6,000 miles (about 10,000 kilometers) westward off the coast of Ecuador warms for months on end, typically by 2 to 4 degrees Fahrenheit (about 1 to 2 degrees Celsius). A few degrees may not seem like much, but in that part of the world, it’s more than enough to completely reorganize wind, rainfall and temperature patterns all over the planet.</p>
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<img alt="White corals indicate bleaching from heat stress." src="https://images.theconversation.com/files/521376/original/file-20230417-26-ukagro.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/521376/original/file-20230417-26-ukagro.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/521376/original/file-20230417-26-ukagro.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/521376/original/file-20230417-26-ukagro.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/521376/original/file-20230417-26-ukagro.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/521376/original/file-20230417-26-ukagro.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/521376/original/file-20230417-26-ukagro.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Marine heat waves can trigger coral bleaching.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/view-of-major-bleaching-on-the-coral-reefs-of-the-society-news-photo/1148857683">Alexis Rosenfeld/Getty Images</a></span>
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<p>I’m a climate scientist who studies the oceans. After <a href="https://earthobservatory.nasa.gov/images/150691/la-nina-times-three">three years</a> of <a href="https://oceanservice.noaa.gov/facts/ninonina.html">La Niña</a>, it’s time to start preparing for what El Niño may have in store.</p>
<h2>How El Niño affects the planet</h2>
<p>No two El Niño events are exactly alike, though we’ve seen enough of them that forecasters have a pretty good idea of <a href="https://www.weather.gov/images/fwd/climate/enso/ElNino.png">what’s likely to happen</a>.</p>
<p>People tend to focus on El Niño’s impact on land, justifiably. The warm water affects air currents that leave areas wetter or drier than usual. It can ramp up storms in some areas, like the southern U.S., while <a href="https://tropical.colostate.edu/Forecast/2023-04.pdf">tending to tamp down Atlantic hurricane activity</a>.</p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/wVlfyhs64IY?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">How El Niño forms. NOAA.</span></figcaption>
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<p>El Niño can also wreak havoc on the many marine ecosystems that support the world’s fishing industries, including <a href="https://theconversation.com/watching-a-coral-reef-die-as-climate-change-devastates-one-of-the-most-pristine-tropical-island-areas-on-earth-159792">coral reefs</a> and <a href="https://theconversation.com/restoring-seagrasses-can-bring-coastal-bays-back-to-life-147798">seagrass meadows</a>.</p>
<p>Specifically, El Niño tends to trigger intense and widespread periods of extreme ocean warming known as marine heat waves.</p>
<p><a href="https://www.theguardian.com/environment/2023/apr/08/headed-off-the-charts-worlds-ocean-surface-temperature-hits-record-high?CMP=share_btn_tw">Global ocean temperatures</a> are already <a href="https://climatereanalyzer.org/clim/sst_daily/">at record highs</a>, so El Niño-induced marine heat waves could push many sensitive fisheries to a breaking point.</p>
<h2>The problem with marine heat waves</h2>
<p>A marine heat wave is just that: a “wave” of extreme heat in the ocean, not dissimilar to an atmospheric heat wave on land. </p>
<p>At their smallest, marine heat waves can inundate <a href="https://doi.org/10.1029/2019JC015673">local bays and coves</a> with hotter-than-normal water for a few days or weeks. At their largest, marine heat waves like the <a href="https://doi.org/10.1002/2015GL063306">Northeast Pacific Warm Blob</a> of 2013-2014 can grow to gargantuan proportions, with regions <a href="https://indd.adobe.com/view/ffe33cde-3628-42e8-adc2-eaf85d8312e4">three times the size of Texas</a> experiencing ocean temperatures 4 to 6 F (about 2 to 3 C) above average for months or even years.</p>
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<img alt="An example of a marine heat wave showing intense heat." src="https://images.theconversation.com/files/521094/original/file-20230414-24-5gh4an.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/521094/original/file-20230414-24-5gh4an.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=363&fit=crop&dpr=1 600w, https://images.theconversation.com/files/521094/original/file-20230414-24-5gh4an.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=363&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/521094/original/file-20230414-24-5gh4an.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=363&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/521094/original/file-20230414-24-5gh4an.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=456&fit=crop&dpr=1 754w, https://images.theconversation.com/files/521094/original/file-20230414-24-5gh4an.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=456&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/521094/original/file-20230414-24-5gh4an.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=456&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Fierce marine heat waves like this one in 2019 can wreak havoc on sea life off the North American Pacific Coast with temperatures about 4 to 6 F (2 to 3 C) above normal.</span>
<span class="attribution"><span class="source">Dillon Amaya</span></span>
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<p>Warm water might not seem like a big deal, especially to surfers hoping to leave their wetsuits at home. But for many marine organisms that are highly adapted to specific water temperatures, <a href="https://doi.org/10.1146/annurev-marine-032122-121437">marine heat waves can make living in the ocean feel like running a marathon</a>.</p>
<p>For example, some fish increase their metabolism in warm waters by so much that they burn energy faster than they can eat, and they can die. Pacific cod declined by 70% in the Gulf of Alaska in response to a marine heat wave. <a href="https://doi.org/10.1038/s41558-019-0412-1">Other impacts</a> include bleached corals, widespread harmful algal blooms, decimated seaweeds and increased marine mammal strandings. All told, <a href="https://www.annualreviews.org/doi/10.1146/annurev-marine-032122-121437">billions of U.S. dollars are lost</a> to marine heat waves each year.</p>
<p>Marine heat waves flare up for a <a href="https://doi.org/10.1038/s41467-019-10206-z">variety of reasons</a>. Sometimes ocean currents shift warm water around. Sometimes surface winds are weaker than normal, leading to less evaporation over the ocean and warmer waters. Sometimes cloudy places just aren’t as cloudy for a few months, which lets more sunlight in and heats up the ocean. Sometimes both weaker winds and fewer clouds happen at the same time, producing <a href="https://doi.org/10.1038/s41467-020-15820-w">record-breaking marine heat waves</a>.</p>
<h2>Where El Niño fits in</h2>
<p>In the climate system, El Niño is king. When it dons its fiery crown, the entire planet takes notice, and the oceans are no exception. But the likelihood of increased marine heat wave activity during El Niño depends on where you are.</p>
<p>Along the U.S. West Coast during El Niño, surface winds that normally blow from the north tend to subside. This weakens evaporation and <a href="https://oceanservice.noaa.gov/education/tutorial_currents/03coastal4.html">slows upwelling</a> of colder, deeper water. That increases the chances of coastal marine heat waves.</p>
<p><iframe id="17ZbA" class="tc-infographic-datawrapper" src="https://datawrapper.dwcdn.net/17ZbA/4/" height="400px" width="100%" style="border: none" frameborder="0"></iframe></p>
<p>Peruvian fishers have for centuries weathered periods of extreme ocean warming that drive fish away. <a href="https://earthobservatory.nasa.gov/features/ElNino/page3.php">It wasn’t until the 1920s</a> that scientists realized that these South American marine heat waves were related to the Pacificwide ENSO.</p>
<p>In the Bay of Bengal east of India, interactions between El Niño and a tropical air flow pattern known as the <a href="https://www.climate.gov/news-features/blogs/enso/walker-circulation-ensos-atmospheric-buddy">Walker Circulation</a> elevate the risk for marine heat waves.</p>
<h2>Seafloor heat waves are another risk</h2>
<p>Even if marine heat waves aren’t more obvious at the ocean surface this year, it doesn’t mean all is well down below.</p>
<p>In a <a href="https://doi.org/10.1038/s41467-023-36567-0">recent study</a>, my colleagues and I showed that marine heat waves also unfold along the seafloor of coastal regions. In fact, these “bottom marine heat waves” are sometimes more intense than their surface counterparts. They can also persist much longer. For example, a 1997-1998 bottom marine heat wave off the U.S. West Coast lasted an extra four to five months after surface ocean temperatures had already cooled.</p>
<p>Events like this can be related to El Niño and put a lot of stress on bottom-dwelling species. Bering Sea snow crab landings were down 84% in 2018 after a marine heat wave reached the seafloor.</p>
<h2>We’re in (for) hot water</h2>
<p>With El Niño on the horizon, what can we expect for this year?</p>
<p>The good news is <a href="https://doi.org/10.1038/s41586-022-04573-9">seasonal forecast models can skillfully predict marine heat waves</a> three to six months in advance, depending on the region. And forecasts tend to be most accurate during El Niño years.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/521512/original/file-20230418-28-f96w6.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Map showing where marine heat waves are forecast in October 2023." src="https://images.theconversation.com/files/521512/original/file-20230418-28-f96w6.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/521512/original/file-20230418-28-f96w6.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=292&fit=crop&dpr=1 600w, https://images.theconversation.com/files/521512/original/file-20230418-28-f96w6.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=292&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/521512/original/file-20230418-28-f96w6.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=292&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/521512/original/file-20230418-28-f96w6.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=367&fit=crop&dpr=1 754w, https://images.theconversation.com/files/521512/original/file-20230418-28-f96w6.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=367&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/521512/original/file-20230418-28-f96w6.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=367&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">NOAA’s marine heat wave forecast issued in early April predicting October 2023.</span>
<span class="attribution"><a class="source" href="https://psl.noaa.gov/marine-heatwaves/">NOAA/Jacox, et al. 2022</a></span>
</figcaption>
</figure>
<p><a href="https://psl.noaa.gov/marine-heatwaves/">The latest forecast</a> predicts several active marine heat waves to persist into June-August, including in the North Pacific, off the coast of Peru, southeast of New Zealand and in the tropical North Atlantic.</p>
<p>The same forecasts predict El Niño to ramp up over the next six to nine months, increasing marine heat wave risk in January to March of 2024 for the U.S. West Coast, the western Indian Ocean, the Bay of Bengal, and the tropical North Atlantic. </p>
<p>That said, these predictions are far enough out that things could change. Time will tell whether they hold (hot) water, but we would do well to prepare. El Niño is coming.</p><img src="https://counter.theconversation.com/content/202424/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Dillon Amaya does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>El Niño can trigger intense and widespread periods of extreme ocean warming known as marine heat waves. They can devastate marine life.Dillon Amaya, Climate Research Scientist, National Oceanic and Atmospheric AdministrationLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2017782023-03-27T19:01:49Z2023-03-27T19:01:49Z2022 was a good year for nature in Australia – but three nasty problems remain<figure><img src="https://images.theconversation.com/files/517575/original/file-20230327-16-flxve.jpg?ixlib=rb-1.1.0&rect=6%2C0%2C4594%2C3456&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>A new <a href="https://www.ausenv.online">report card</a> on Australia’s environment reveals 2022 was a bumper year for our rivers and vegetation – but it wasn’t enough to reverse the long-term decline in plant and animal species.</p>
<p>The analysis was drawn from many millions of measurements of weather, biodiversity, water availability, river flows and the condition of soil and vegetation. The data is gathered from satellites and field stations and processed by a supercomputer. </p>
<p>From the data, we calculate a score between 0 and 10 to determine the overall condition of Australia’s environment. </p>
<p>In 2022, a third and very wet La Niña year brought a strong improvement in several key indicators, leading to a national score of 8.7 out of 10. This is the best score since 2011. But unfortunately, three wicked problems remain.</p>
<figure class="align-center ">
<img alt="scientist kneels in water and takes observation" src="https://images.theconversation.com/files/517574/original/file-20230327-14-t3yn8b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/517574/original/file-20230327-14-t3yn8b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/517574/original/file-20230327-14-t3yn8b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/517574/original/file-20230327-14-t3yn8b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/517574/original/file-20230327-14-t3yn8b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/517574/original/file-20230327-14-t3yn8b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/517574/original/file-20230327-14-t3yn8b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A vast number of datasets are combined to generate the environmental scorecard.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>First, the good news</h2>
<p>By some measures, 2022 was the best year for water availability and plant growth since our national score system began 23 years ago. </p>
<p>New South Wales, Victoria and the ACT enjoyed the highest environmental scores since before 2000. South Australia and Queensland also improved.</p>
<p>Scores for rainfall, river flows and the extent of floodplain inundation were the highest since before 2000 in many parts of eastern Australia. The water supplies of all eastern capital cities all rose and several reached capacity. </p>
<p>Wetland area and waterbird breeding were well above the long-term average. Vegetation density, growth rates and tree cover in NSW and Queensland were the best since before 2000.</p>
<p>It was a bumper year for dryland farmers. Average national growth rates in dryland cropping were a massive 49% better than average conditions. The many full or filling reservoirs are also good news for irrigators.</p>
<h2>What about the losers?</h2>
<p>Some regions missed out on the rainfall bonanza, and many environmental indicators declined. They include the Top End in the Northern Territory, southern inland Western Australia and western Tasmania. </p>
<p>Across the NT, low rainfall and high temperatures meant environmental scores once more declined to the low values seen before 2021. </p>
<p>And in areas where rainfall was high, not everyone benefited. Many homes and businesses flooded, and some farmers lost crops or stock.</p>
<p>At the end of 2022, <a href="https://www.theguardian.com/australia-news/2023/jan/01/river-murray-fish-kill-concerns-grow-as-flood-waters-peak-in-south-australia">reports emerged</a> that floodwaters were causing so-called “blackwater events” and fish kills in the Murray River. Murky floodwaters also ran into the ocean and smothered seagrass meadows, leading <a href="https://theconversation.com/dugongs-and-turtles-are-starving-to-death-in-queensland-seas-and-la-ninas-floods-are-to-blame-190663">dugongs and sea turtles</a> to starve.</p>
<p>The ocean around Australia was the warmest on record in 2022. The Great Barrier Reef suffered the <a href="https://www.aims.gov.au/research-topics/environmental-issues/coral-bleaching/coral-bleaching-events">fourth mass bleaching</a> event in seven years – and alarmingly, the first to occur during a La Niña year, which is usually cooler. </p>
<p>Fortunately, conditions for the remainder of the year favoured coral recovery. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/new-report-shows-alarming-changes-in-the-entire-global-water-cycle-197535">New report shows alarming changes in the entire global water cycle</a>
</strong>
</em>
</p>
<hr>
<figure class="align-center ">
<img alt="flood-damaged doll and other items with house in background" src="https://images.theconversation.com/files/517588/original/file-20230327-14-49f0b0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/517588/original/file-20230327-14-49f0b0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/517588/original/file-20230327-14-49f0b0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/517588/original/file-20230327-14-49f0b0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/517588/original/file-20230327-14-49f0b0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/517588/original/file-20230327-14-49f0b0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/517588/original/file-20230327-14-49f0b0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Floodwaters severely damaged homes and businesses last year.</span>
<span class="attribution"><span class="source">Darren England/AAP</span></span>
</figcaption>
</figure>
<h2>Chronic ailments</h2>
<p>Despite many positive indicators, three severe, chronic and untreated problems continue to weaken our environment: habitat destruction, invasive species and climate change.</p>
<p>The rate of habitat destruction shows little sign of improvement. Much vegetation continues to be removed for new housing, mining and agriculture. Fire activity in 2022 was low, but climate change means bushfires will be back soon, and become more frequent and severe over time. </p>
<p>La Niña is already on the way out, although it will probably take more than one hot and dry year before we experience <a href="https://theconversation.com/a-major-scorecard-gives-the-health-of-australias-environment-less-than-1-out-of-10-133444">megafires</a> such as those in the Black Summer of 2019-20.</p>
<p>The scorecard also shows Australia is still struggling to combat pest species. They include fungi, invasive weeds, carp, cane toads, rats, rabbits, goats, pigs, foxes and cats. Every year, about eight million feral cats and foxes <a href="https://theconversation.com/1-7-million-foxes-300-million-native-animals-killed-every-year-now-we-know-the-damage-foxes-wreak-177832">kill</a> 1.5 billion native reptiles, birds and mammals. </p>
<p>Climate change remains a huge problem. La Niña normally brings cool conditions and the average temperature last year in Australia was the coolest since 2012. But it was still relatively warm, at 0.5°C above the long-term average. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/fear-and-wonder-podcast-how-scientists-know-the-climate-is-changing-202237">Fear and Wonder podcast: how scientists know the climate is changing</a>
</strong>
</em>
</p>
<hr>
<p>The combination of habitat destruction, invasive species and climate change has already decimated many Australian species. In 2022, 30 plants and animals were added to the official list of threatened species. </p>
<p>That’s a 43% increase since 2000, bringing the total number to 1,973. Most species added last year were affected by the Black Summer fires.</p>
<p>Our analysis drew on the <a href="https://tsx.org.au">Threatened Species Index</a>, which reports with a three-year time lag. In 2019 the index showed a steady decline of about 3% in the abundance of threatened species each year. This is an overall decline of 62% since 2000. </p>
<p>Threatened plants showed the worst decline (72%), followed by birds (62%) and mammals (33%).</p>
<h2>We can avoid the worst</h2>
<p>Amid the gloom, there are glimmers of hope. Many species feared impacted by the fires proved resilient. Some large new national park areas have been added. Active management is recovering – or at least slowing – the decline of some threatened species, albeit sometimes within the narrow confines of reserves.</p>
<p>Also in 2022, humpback whales were one of the few species in Australian history to be taken off the threatened species list due to a population increase. The species has staged a remarkable recovery since the global moratorium on whaling. </p>
<p>Sadly, there is no fast solution to climate change. Greenhouse gases will linger in the atmosphere for decades to come and further warming is unavoidable. But we can still prevent worse outcomes, by dramatically curbing global emissions.</p>
<p>Australia’s emissions are not falling anywhere near fast enough. They were almost the same in 2022 as in the previous year. And our national emissions remain among the <a href="https://www.sbs.com.au/news/article/interactive-how-australia-compares-to-the-rest-of-the-world-on-co2-emissions/7oooxwnnm">highest</a> in the world per person.</p>
<p>Decisive action is needed. Slowing down habitat destruction, invasive species and climate change is key to preserving our natural resources and species for future generations. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/we-found-29-threatened-species-are-back-from-the-brink-in-australia-heres-how-200057">We found 29 threatened species are back from the brink in Australia. Here's how</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/201778/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Australia’s Environment is produced by the ANU Fenner School for Environment & Society and the Terrestrial Ecosystem Research Network (TERN), an NCRIS-enabled National Research Infrastructure. Albert Van Dijk receives or has previously received funding from several government-funded agencies, grant schemes and programmes.</span></em></p><p class="fine-print"><em><span>Geoff Heard is a current employee of the Terrestrial Ecosystem Research Network (TERN), funded by the National Collaborative Research Infrastructure Strategy. Geoff has previously received funding from several government agencies in Australia for the study and monitoring of threatened species.</span></em></p><p class="fine-print"><em><span>Mark Grant is a current employee of the Terrestrial Ecosystem Research Network (TERN).</span></em></p><p class="fine-print"><em><span>Shoshana Rapley does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Last year was great for plant growth and river flows. But Australia is still on the brink of losing a slew of plant and animal species.Albert Van Dijk, Professor, Water and Landscape Dynamics, Fenner School of Environment & Society, Australian National UniversityGeoffrey Heard, The University of QueenslandMark Grant, Ecosystem Science Programs Lead, Terrestrial Ecosystem Research Network, The University of QueenslandShoshana Rapley, Research assistant, Australian National UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1985102023-03-22T02:36:01Z2023-03-22T02:36:01ZWhat to expect when you’re expecting an El Niño (the answer might surprise you)<figure><img src="https://images.theconversation.com/files/509327/original/file-20230210-16-w2n1zt.jpg?ixlib=rb-1.1.0&rect=4%2C0%2C3281%2C2069&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Dean Lewins/AAP</span></span></figcaption></figure><p><a href="http://www.bom.gov.au/climate/about/australian-climate-influences.shtml?bookmark=enso">La Niña and El Niño</a> are well-known terms in Australia these days. Linked to them are certain expectations: we expect wet conditions in La Niña and dry conditions in El Niño.</p>
<p>These expectations have certainly been met over the past couple of years, when regions across Australia experienced <a href="https://www.abc.net.au/news/2022-12-31/australian-weather-rain-2022-records-broken-flooding/101789262">record-breaking</a> rains and severe floods during consecutive La Niña events.</p>
<p>It might surprise you to learn, however, that not all La Niñas have been wet, nor El Niños dry. Step back to spring 2020, for example, and Australia was relatively <a href="https://www.theguardian.com/australia-news/2020/dec/01/australia-endures-hottest-spring-ever-with-average-temperatures-more-than-2c-above-average">dry and warm</a>, despite a La Niña.</p>
<p>Officials have declared the recent La Niña as over, and now we’re on an <a href="https://www.abc.net.au/news/2023-03-14/bureau-of-meteorology-declares-el-nino-watch/102093892">El Niño watch</a>. You might therefore be wondering: how often can we expect it to be dry in Australia during El Niño? Our <a href="https://doi.org/10.1071/ES22034">new research</a> sought to answer this question, and the converse for La Niña.</p>
<p>We found La Niña and El Niño are good indicators of wet and dry conditions in eastern Australia as a whole. But at some locations, including Sydney, they do little to shift the normal odds of wet and dry conditions.</p>
<figure class="align-center ">
<img alt="dry grass and basketball court with palms" src="https://images.theconversation.com/files/509328/original/file-20230210-28-l7t62z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/509328/original/file-20230210-28-l7t62z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/509328/original/file-20230210-28-l7t62z.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/509328/original/file-20230210-28-l7t62z.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/509328/original/file-20230210-28-l7t62z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/509328/original/file-20230210-28-l7t62z.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/509328/original/file-20230210-28-l7t62z.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">We expect El Niños to be dry - but that’s not always the case.</span>
<span class="attribution"><span class="source">Eugene Tan/AAP</span></span>
</figcaption>
</figure>
<h2>What we did</h2>
<p>We focused on the spring season because spring rainfall has the strongest historical relationship with La Niña/El Niño. We used a simple approach known as “tercile analysis”. </p>
<p>First, we ordered the past 72 years of rainfall data from the wettest spring to the driest. We then split the data into thirds. Springs with rainfall totals in the bottom third are considered “dry”; springs in the middle third are considered “average”; and springs with rainfall totals in the top third are “wet”. </p>
<p>Splitting the data in this way means we can say that any spring normally has a 33% chance of being dry, 33% chance of being average and 33% chance of being wet. Our aim was to see if these “normal” odds change during El Niño and La Niña events.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-flap-of-a-butterflys-wings-why-autumn-is-not-a-good-time-to-predict-if-el-nino-is-coming-201940">The flap of a butterfly's wings: why autumn is not a good time to predict if El Niño is coming</a>
</strong>
</em>
</p>
<hr>
<h2>Do La Niña and El Niño change rainfall odds in eastern Australia?</h2>
<p>For rainfall averaged across eastern Australian states, the short answer is yes. </p>
<p>The figure below shows the rainfall data split into wet, average and dry boxes and also La Niña, neutral and El Niño boxes. If La Niña and El Niño did not change the rainfall odds, we would expect to see an even number of dots spread across all the boxes. However, this is not the case. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/507264/original/file-20230131-16-ht3mvi.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/507264/original/file-20230131-16-ht3mvi.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=375&fit=crop&dpr=1 600w, https://images.theconversation.com/files/507264/original/file-20230131-16-ht3mvi.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=375&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/507264/original/file-20230131-16-ht3mvi.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=375&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/507264/original/file-20230131-16-ht3mvi.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=471&fit=crop&dpr=1 754w, https://images.theconversation.com/files/507264/original/file-20230131-16-ht3mvi.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=471&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/507264/original/file-20230131-16-ht3mvi.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=471&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Dry conditions during La Niña or wet conditions during El Niño are rare across eastern Australia as a whole.</span>
</figcaption>
</figure>
<p>The almost empty “dry” box in La Niña and “wet” box in El Niño show very low odds in eastern Australia of experiencing dry conditions in La Niña or wet conditions in El Niño. On the other hand, La Niña approximately doubles the normal 33% chance of experiencing wet conditions and El Niño doubles the chance of dry conditions.</p>
<p>This result is helpful in setting broad expectations across eastern Australia. But it doesn’t necessarily apply in all locations, as we discuss below.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/why-el-nino-doesnt-mean-certain-drought-197678">Why El Niño doesn't mean certain drought</a>
</strong>
</em>
</p>
<hr>
<h2>What about individual locations?</h2>
<p>We applied the analysis approach described above to 5km grids across Australia. </p>
<p>For parts of northern and southeastern Australia, including the Murray-Darling Basin, La Niña and El Niño significantly increase the normal odds of wet and dry springs respectively (orange and red areas). </p>
<p>But in some places, La Niña and El Niño do not markedly change the normal odds of wet or dry conditions. These locations include large parts of Western Australia, southwestern Tasmania, and southern and eastern coasts of mainland Australia, including the eastern seaboard (yellow and white areas). </p>
<p>The eastern seaboard is the easternmost part of Australia, <a href="https://www.researchgate.net/figure/The-eastern-seaboard-of-Australia-ESA-shown-on-the-left-is-roughly-the-area-between_fig5_311092024">between</a> the east coast and the Great Dividing Range. The seemingly weak relationship between La Niña and El Niño and the eastern seaboard might seem surprising. After all, just consider the large amount of rain that’s fallen on the east coast over the past couple of years during La Niña, including <a href="https://www.abc.net.au/news/2022-10-06/sydney-breaks-annual-rainfall-record/101506452">Sydney’s record-breaking 2022</a>. </p>
<p>Historically, though, rainfall on the eastern seaboard has had a <a href="https://rmets.onlinelibrary.wiley.com/doi/10.1002/joc.3741">weak relationship with La Niña and El Niño</a>. Why? Because the rainfall in this region is particularly sensitive to the frequency with which the local winds blow from the east to west. But that wind flow is not necessarily strongly linked to La Niña. </p>
<p>In 2022 there were more of these <a href="https://www.abc.net.au/news/2022-10-22/sydney-record-wet-weather-2022-due-to-shift-in-wind-direction/101562826">east-to-west wind-flow events</a> than usual, resulting in high rainfall in Sydney.</p>
<p>In the Sydney region, the normal chance of experiencing a wet spring is 33% – and this increases only slightly in a La Niña to 38%. It suggests La Niña is not a strong indicator for wet conditions in this region.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/millions-of-satellite-images-reveal-how-beaches-around-the-pacific-vanish-or-replenish-in-el-nino-and-la-nina-years-198505">Millions of satellite images reveal how beaches around the Pacific vanish or replenish in El Niño and La Niña years</a>
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</em>
</p>
<hr>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/510226/original/file-20230214-18-7rdtdm.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Map showing odds of experiencing wet conditions in La Niña or dry in El Niño across Australia" src="https://images.theconversation.com/files/510226/original/file-20230214-18-7rdtdm.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/510226/original/file-20230214-18-7rdtdm.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=282&fit=crop&dpr=1 600w, https://images.theconversation.com/files/510226/original/file-20230214-18-7rdtdm.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=282&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/510226/original/file-20230214-18-7rdtdm.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=282&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/510226/original/file-20230214-18-7rdtdm.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=355&fit=crop&dpr=1 754w, https://images.theconversation.com/files/510226/original/file-20230214-18-7rdtdm.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=355&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/510226/original/file-20230214-18-7rdtdm.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=355&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 odds of experiencing wet conditions in La Niña or dry in El Niño change depending on where you’re located in Australia.</span>
<span class="attribution"><span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>When you’re expecting an El Niño, location matters</h2>
<p>The declaration of an El Niño watch this early in the year carries <a href="https://theconversation.com/the-flap-of-a-butterflys-wings-why-autumn-is-not-a-good-time-to-predict-if-el-nino-is-coming-201940">considerable uncertainty</a>. But it’s still got people thinking about the possibility of dry conditions. </p>
<p>The odds of experiencing dry conditions in El Niño, however, change according to where you’re located in Australia. </p>
<p>In the above-right map, regions in orange and red could expect an increased chance of dry conditions. Regions in red are very likely to be dry, based on historical relationships. The chance of a dry spring is around normal (33%) in other regions. </p>
<p>Of course, while El Niño plays a large role in moderating Australia’s climate, it is <a href="https://theconversation.com/why-el-nino-doesnt-mean-certain-drought-197678?utm_source=linkedin&utm_medium=bylinelinkedinbutton">not the only driver</a> of dry conditions in Australia. Processes including the <a href="https://theconversation.com/a-rare-natural-phenomenon-brings-severe-drought-to-australia-climate-change-is-making-it-more-common-133058">Indian Ocean Dipole</a>, <a href="http://www.bom.gov.au/watl/about-weather-and-climate/australian-climate-influences.shtml?bookmark=sam">Southern Annular Mode</a> and other related or unrelated weather systems all contribute to Australia’s climate variability. </p>
<p>So it’s important to consider these factors, as well as your specific location in Australia, when interpreting what an El Niño forecast means for you. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/on-our-wettest-days-stormclouds-can-dump-30-trillion-litres-of-water-across-australia-191949">On our wettest days, stormclouds can dump 30 trillion litres of water across Australia</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/198510/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Nandini Ramesh has previously received funding from the Australian Research Council, the US Department of Energy, and NASA. She is a Research Affiliate at the The University of Sydney. </span></em></p><p class="fine-print"><em><span>Carly Tozer does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Not all La Niñas are wet, nor El Niños dry – especially if you live in Sydney. So here’s how to interpret what an El Niño forecast means for you.Carly Tozer, Senior Research Scientist, CSIRONandini Ramesh, Senior Research Scientist, Data61, CSIROLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2019402023-03-16T19:12:05Z2023-03-16T19:12:05ZThe flap of a butterfly’s wings: why autumn is not a good time to predict if El Niño is coming<figure><img src="https://images.theconversation.com/files/515674/original/file-20230316-26-allg6u.jpg?ixlib=rb-1.1.0&rect=49%2C0%2C5472%2C3645&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>Remember the butterfly effect? It was a popular summary of chaos theory suggesting a butterfly flapping its wings in the Amazon could cause a tornado in Texas. </p>
<p>Right now, a version of this is making it hard for us to predict whether an <a href="https://oceanservice.noaa.gov/facts/ninonina.html">El Niño event</a> is coming. </p>
<p>After three consecutive La Niña years, that part of the cycle is <a href="http://www.bom.gov.au/climate/enso/#:%7E:text=Pacific%20Ocean,-Forecast&text=El%20Ni%C3%B1o%20typically%20produces%20drier,been%20declared%20in%20September%202022.">officially over</a>. But it’s not certain an El Niño will replace it. Australia’s Bureau of Meteorology this week announced an <a href="http://www.bom.gov.au/climate/enso/outlook/">El Niño watch</a> – a “wait and see” forecast giving us a 50% chance of an El Niño forming later this year. Other climate forecasting agencies around the world are sending a <a href="https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.shtml">similar message</a> to the Bureau of Meteorology’s, that we are on an El Niño watch. </p>
<p>While the conditions seem right for El Niño to form and likely bring hotter, drier weather to Australia, the world’s chaotic climate system is in a very unpredictable state. Fast forward three months, and our models will be much more certain about whether El Niño really is coming – or whether the system will remain in a neutral, or near-normal, state. </p>
<h2>Why can’t we predict what’s going to happen?</h2>
<p>At this time of year, the El Niño-Southern Oscillation (ENSO) cycle is at its most susceptible to change. Right now, the subsurface waters of the equatorial western Pacific are warmer than usual. If this water rises from deeper down to the surface of the ocean, it will interact with the atmosphere. This usually leads to more rain and floods for Chile, drier, hotter weather for Australia, and a variety of other effects worldwide. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/why-el-nino-doesnt-mean-certain-drought-197678">Why El Niño doesn't mean certain drought</a>
</strong>
</em>
</p>
<hr>
<p>But this isn’t inevitable. Let’s say a sudden burst of wind strikes, forcing warmer water to stay down deeper. This can disturb the whole cycle. Unexpected windbursts at this time of year can even tip the system into a different mode, ending up neutral or as a La Niña event. </p>
<p>Among climate scientists, this is known as the <a href="https://www.climate.gov/news-features/blogs/enso/spring-predictability-barrier-we%E2%80%99d-rather-be-spring-break">predictability barrier</a> – and it’s why we can’t say for certain an El Niño is coming until later in the year. </p>
<h2>Have we seen unexpected swings in the cycle before?</h2>
<p>Yes, most recently in 2014. Early that year, climate models were predicting a truly enormous El Niño was set to begin. </p>
<p>But the monster El Niño <a href="https://www.nature.com/articles/nclimate2775">didn’t happen</a>. Cooler water flowed into the south-eastern Pacific at a critical time of year, while the unusual timing of westerly windbursts kept the warmer water down deeper. </p>
<p>The end result was that the whole system was nudged into a different configuration of a weak El Niño. It took another year for a full El Niño to develop. This time, it was <a href="https://www.nature.com/articles/s41598-018-29130-1">very strong</a>. </p>
<p>Could we really see a fourth La Niña? It could happen but it would be very unusual, given we’ve never seen four years of successive La Niña conditions. At present, the heat build-up under the surface of the equatorial Pacific suggests an El Niño is coming, but it’s not a given. </p>
<h2>Why do we get these cycles anyway?</h2>
<p>We believe the El Niño-La Niña cycle has a very long history, dating back to <a href="https://www.nature.com/articles/nature.2016.20334#:%7E:text=The%20Pacific%20Ocean%20was%20born,lava%20welled%20up%20from%20below.">the formation</a> of the Pacific Ocean about 190 million years ago. </p>
<p>That’s because this ocean basin is the largest on Earth – and has a lot of seawater sitting along the equator. In our models, we can see the El Niño cycle forming out of the fluid dynamics, as <a href="https://theconversation.com/explainer-el-nino-and-la-nina-27719">warmer or cooler water moves</a> across the ocean. </p>
<p>The Atlantic has a smaller version, named the Atlantic Niño. Why is it smaller? Because there’s much less water along the equator in the Atlantic. As a result, the Atlantic Niño has much less of an effect on weather globally. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/515673/original/file-20230316-14-sqwy47.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Pacific ocean atlantic ocean centred maps" src="https://images.theconversation.com/files/515673/original/file-20230316-14-sqwy47.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/515673/original/file-20230316-14-sqwy47.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=304&fit=crop&dpr=1 600w, https://images.theconversation.com/files/515673/original/file-20230316-14-sqwy47.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=304&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/515673/original/file-20230316-14-sqwy47.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=304&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/515673/original/file-20230316-14-sqwy47.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=382&fit=crop&dpr=1 754w, https://images.theconversation.com/files/515673/original/file-20230316-14-sqwy47.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=382&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/515673/original/file-20230316-14-sqwy47.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=382&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 El Nino cycle’s significance is due to the sheer size of the Pacific – and the amount of water along the equator. By contrast, the Atlantic’s equatorial waters are more limited.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>So when will we know for sure?</h2>
<p>El Niño and La Niña are at their strongest over December and January, though the effects and their timing can differ in Australia depending on where in the country you are. These cycles usually end some time between February and May. </p>
<p>The popular understanding of the butterfly effect and chaos science often gets one thing wrong. Chaotic systems like the world’s weather are not always unpredictable, but can be more or less sensitive to small changes at different times. Between March and May, it can take just a small nudge to flip the system. Later in the year, as either an El Niño, neutral phase or La Niña gathers pace, it is much harder to change course. </p>
<p>It’s like a ball poised on top of a high hill. A very tiny push is enough to send the ball rolling down either one side of the hill or another. The push might even be so tiny you can’t measure it accurately. </p>
<p>That’s why it’s so difficult to predict what’s going to happen, even though we understand the physics behind these events fairly well. The Pacific Ocean and the air overhead are extremely sensitive to “pushes” in any direction from March to May. </p>
<p>But once the ball rolls down one side rather than another, it’s much easier to predict which way it will keep rolling. By June or July, the ball is already rolling down the hill on whichever side it’s going to go, and there’s a lot more confidence and clarity in our predictions. Stay tuned. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/la-nina-is-finishing-an-extremely-unusual-three-year-cycle-heres-how-it-affected-weather-around-the-world-196561">La Niña is finishing an extremely unusual three-year cycle – here's how it affected weather around the world</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/201940/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Nandini Ramesh has previously received funding from the Australian Research Council, NASA, and the US Department of Energy. She is a Research Affiliate at the University of Sydney. </span></em></p>After three long years of rainy weather, La Niña is over. But that doesn’t mean El Niño is a certainty. Here’s why.Nandini Ramesh, Senior Research Scientist, Data61, CSIROLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1965612023-02-28T06:12:35Z2023-02-28T06:12:35ZLa Niña is finishing an extremely unusual three-year cycle – here’s how it affected weather around the world<figure><img src="https://images.theconversation.com/files/511814/original/file-20230222-16-zc2v88.jpg?ixlib=rb-1.1.0&rect=1288%2C0%2C4184%2C1813&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">El Niño was given its name by Peruvian fishermen.</span> <span class="attribution"><span class="source">Christian Vinces / shutterstock</span></span></figcaption></figure><p>It was anchovy fishermen in Peru who first noticed and named El Niño events in the tropical Pacific <a href="https://baynature.org/article/whys-it-called-el-nino-and-how-did-scientists-figure-out-what-it-is/">hundreds of years ago</a>. Their catches would fluctuate and the largest declines were seen near Christmas when the ocean was at its warmest – they called it <em>El Niño de Navidad</em>, the boy of Christmas. </p>
<p>With a larger network of observations and some <a href="https://www.rmets.org/sites/default/files/classicindia2.pdf">inspired statistical analysis</a>, it became apparent that this decline in fish stocks was part of a Pacific-wide phenomenon including changes in the ocean and atmosphere. This was ENSO, the El Niño-Southern Oscillation. </p>
<p>As part of this analysis it became clear that during El Niño events the Pacific was typically warmer than usual in the east, colder in the west, and the trade winds blowing from east to west were weaker. What also became clear was that there were other times when the winds were stronger and the east was colder and the west was warmer. These periods were named La Niña – the girl – in a nod to their opposite characteristics to El Niño. </p>
<p>El Niño or La Niña conditions typically last for around nine months, beginning in June, peaking in December, before dissipating by April. Historically, La Niña events have been smaller and less noted – the change in the anchovy catches is not as notable as the collapse seen in El Niños so was never remarkable to the Peruvian fishermen. However, for a number of reasons, La Niña is becoming a more noted phenomenon. </p>
<p>During La Niña events, global temperatures tend to be colder and this can explain some of the downward bumps on the otherwise inexorable rise of global temperatures. Last year, 2022, was the third consecutive La Niña year, which is highly unusual and has only occurred <a href="https://earthobservatory.nasa.gov/images/150691/la-nina-times-three">three times</a> since reliable records began in the 1950s. Outside of the tropical Pacific, the effects of La Niña can be just as marked and just as devastating as those of El Niño, which is likely to return in <a href="https://theconversation.com/four-possible-consequences-of-el-nino-returning-in-2023-198105">late 2023</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/511810/original/file-20230222-18-lndbr1.gif?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/511810/original/file-20230222-18-lndbr1.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/511810/original/file-20230222-18-lndbr1.gif?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=300&fit=crop&dpr=1 600w, https://images.theconversation.com/files/511810/original/file-20230222-18-lndbr1.gif?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=300&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/511810/original/file-20230222-18-lndbr1.gif?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=300&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/511810/original/file-20230222-18-lndbr1.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=377&fit=crop&dpr=1 754w, https://images.theconversation.com/files/511810/original/file-20230222-18-lndbr1.gif?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=377&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/511810/original/file-20230222-18-lndbr1.gif?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=377&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">In general, the warmest year of any decade will be an El Niño year, the coldest a La Niña one.</span>
<span class="attribution"><a class="source" href="https://www.climate.gov/media/10685">NOAA / climate.gov</a></span>
</figcaption>
</figure>
<h2>How changes in the tropical Pacific affect the rest of the world</h2>
<p>Climate scientists have been aware of how changes in the atmosphere in one location can be linked to another for many years. These links are termed “teleconnections”. Perhaps the first example of a teleconnection was described <a href="https://www.rmets.org/sites/default/files/classicindia2.pdf">in the 1920s</a> by the physicist Gilbert Walker who noticed that changes in atmospheric pressure in Darwin, on the north coast of Australia, and Tahiti, 8,000kms away in the middle of the Pacific, were linked through, what he termed, the Southern Oscillation. This observation ultimately led to the description of the El Niño/La Niña phenomenon. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/511989/original/file-20230223-658-i6d7r5.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Two annotated maps of the Pacific Ocean" src="https://images.theconversation.com/files/511989/original/file-20230223-658-i6d7r5.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/511989/original/file-20230223-658-i6d7r5.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=756&fit=crop&dpr=1 600w, https://images.theconversation.com/files/511989/original/file-20230223-658-i6d7r5.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=756&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/511989/original/file-20230223-658-i6d7r5.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=756&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/511989/original/file-20230223-658-i6d7r5.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=950&fit=crop&dpr=1 754w, https://images.theconversation.com/files/511989/original/file-20230223-658-i6d7r5.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=950&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/511989/original/file-20230223-658-i6d7r5.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=950&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 Pacific in normal and La Niña conditions.</span>
<span class="attribution"><a class="source" href="https://spaceplace.nasa.gov/la-nina/en/">NASA</a></span>
</figcaption>
</figure>
<p>Teleconnection patterns have now been noticed in all regions of the globe. In northern Europe the most well known is the <a href="https://theconversation.com/the-atlantic-is-entering-a-cool-phase-that-will-change-the-worlds-weather-42497">North Atlantic Oscillation</a>, which describes a link between air pressure in a particular area over Iceland and one over the central North Atlantic near to the Azores. Changes can then be linked to changes in the weather over northern Europe and the UK. </p>
<p>These teleconnection patterns exist because the global atmosphere behaves like a drum. If you hit a drum in one location the whole surface vibrates and the note that the drum sounds depends upon how tight the drum skin is. </p>
<p>In this analogy, heating in the tropical atmosphere plays the role of the drum stick and the waves that spread out across the surface are termed <a href="https://oceanservice.noaa.gov/facts/rossby-wave.html">Rossby waves</a>. The “note” that these waves play is determined by the structure of the atmosphere, but rather than skin tension it is the winds and rotation of the earth that determine the pitch of the atmosphere. </p>
<p>The strongest teleconnection from the tropical Pacific and La Niña is within the Pacific Basin. For example La Niña events tend to mean wetter winters in the Pacific Northwest of the US. </p>
<p>However, Rossby waves can reach all the way across North America and into the North Atlantic, where they can start to affect the weather by tweaking the <a href="https://theconversation.com/why-the-uk-has-only-had-one-named-storm-so-far-this-winter-an-expert-explains-200364">high-altitude jet stream</a> which can in turn affect the storms that are responsible for much of the UK’s winter rain. </p>
<p>Because the behaviour of Rossby waves depends upon the winds in the atmosphere, La Niña’s influence on the North Atlantic is not the same in all seasons. In late winter the Rossby waves from La Niña tend to intensify and shift the Atlantic jet stream towards the North Pole, causing more storms to hit the UK and with them increase the rainfall. </p>
<p>It’s harder to directly link the two in early winter, since in this season the Rossby waves interact with winds that are more affected by the climate state of the tropical Atlantic. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/511822/original/file-20230222-18-5kmt0m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Lighthouse in a storm" src="https://images.theconversation.com/files/511822/original/file-20230222-18-5kmt0m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/511822/original/file-20230222-18-5kmt0m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/511822/original/file-20230222-18-5kmt0m.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/511822/original/file-20230222-18-5kmt0m.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/511822/original/file-20230222-18-5kmt0m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/511822/original/file-20230222-18-5kmt0m.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/511822/original/file-20230222-18-5kmt0m.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The UK is stormier and rainier in late winter during La Niña years (pictured: a lighthouse in Porthcawl, Wales).</span>
<span class="attribution"><span class="source">steved_np3 / shutterstock</span></span>
</figcaption>
</figure>
<h2>An uncertain future</h2>
<p>It’s hard to know exactly what climate change will mean for El Niños and La Niñas. Average sea surface temperature across the Pacific will increase, but that is less important to the generation of these weather patterns than the difference in surface temperature between west and east Pacific about which there is a lot less certainty (in part because the surface temperature in the eastern Pacific is always heavily influenced by the upwelling of deeper colder waters).</p>
<p>Computer programs that model the climate suggest the Pacific’s east-west temperature difference will diminish in future, <a href="https://www.nature.com/articles/s41612-022-00301-2">favouring EL Niños</a> which tends to mean more <a href="https://theconversation.com/four-possible-consequences-of-el-nino-returning-in-2023-198105">droughts in Australia</a> and other severe weather across the Pacific and beyond. However, the past two decades of enhanced temperature differences and prolonged La Niña events <a href="https://journals.ametsoc.org/view/journals/clim/35/14/JCLI-D-21-0648.1.xml">suggest otherwise</a>. The recent three-year La Niña is therefore very interesting, though it’s too soon to draw any firm conclusions.</p>
<p>Changes in the teleconnections are <a href="https://journals.ametsoc.org/view/journals/clim/36/6/JCLI-D-22-0275.1.xml">equally uncertain</a>. Therefore, uncertain changes in the teleconnections on top of uncertain changes in La Niña and El Niño add up to an uncertain outlook for the future. </p>
<hr>
<figure class="align-right ">
<img alt="Imagine weekly climate newsletter" src="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
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<hr><img src="https://counter.theconversation.com/content/196561/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>William Roberts receives funding from UKRI.</span></em></p><p class="fine-print"><em><span>Jayasankar Pillai receives funding from European Union Horizon 2020 programme</span></em></p>The Pacific Ocean climate pattern is the opposite of El Niño.William Roberts, Assistant Professor, Climate Science, Northumbria University, NewcastleJayasankar Pillai, Research Fellow, Geography and Environmental Sciences, Northumbria University, NewcastleLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1976782023-02-28T05:52:56Z2023-02-28T05:52:56ZWhy El Niño doesn’t mean certain drought<p>The Bureau of Meteorology released its latest <a href="http://www.bom.gov.au/climate/enso/">climate driver update</a> on Tuesday, saying the current La Niña has weakened and is “likely near its end”. Most climate models now point to neutral conditions – neither El Niño nor La Niña – through autumn and a trend towards El Niño in early spring. </p>
<p>But it’s too early to say if a <a href="https://www.abc.net.au/news/2023-01-04/bom-forecasts-40-per-cent-chance-el-nino-august-drought-fears/101826780">return to El Niño</a> is imminent. Nor can we say Australia is about to swing back into drought, as many people fear, after <a href="https://www.smh.com.au/environment/weather/from-drought-to-flood-in-three-years-the-nsw-landscape-is-almost-unrecognisable-20221121-p5bzvy.html">three years of heavy rain</a> associated with <a href="https://theconversation.com/la-nina-3-years-in-a-row-a-climate-scientist-on-what-flood-weary-australians-can-expect-this-summer-190542">consecutive La Niñas</a>.</p>
<p>Putting aside the <a href="https://www.abc.net.au/news/2021-04-03/autumn-climate-reset-clouding-forecasters-crystal-balls/100043614#:%7E:text=Autumn%20is%20the%20most%20difficult,drivers%20become%20clearer%20in%20winter">uncertainties in long-range forecasts</a> of El Niño, there are other factors that will determine whether Australia returns to drought.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1630450224236773377"}"></div></p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/explainer-el-nino-and-la-nina-27719">Explainer: El Niño and La Niña</a>
</strong>
</em>
</p>
<hr>
<h2>Drought prediction is complex</h2>
<p><a href="http://www.bom.gov.au/climate/about/?bookmark=enso">El Niño</a> is, of course, a well-known <a href="http://www.bom.gov.au/climate/updates/articles/a008-el-nino-and-australia.shtml">contributor to drought events</a>. But a number of diverse climate drivers affecting different regions should be included in these discussions. </p>
<p>The other two most frequently mentioned drivers are the <a href="http://www.bom.gov.au/climate/about/?bookmark=iod">Indian Ocean Dipole</a> and <a href="http://www.bom.gov.au/climate/about/?bookmark=sam">Southern Annular Mode</a>. These, along with the <a href="http://www.bom.gov.au/climate/about/?bookmark=stridge">Sub-tropical Ridge</a>, fluctuations of the <a href="http://www.bom.gov.au/climate/about/?bookmark=mjo">Madden-Julian Oscillation</a> and local weather systems, can make dry periods worse or provide rainfall relief.</p>
<p>Drought prediction is also complex due to the nature of drought itself. Drought is a <a href="https://www.sciencedirect.com/science/article/pii/S0921818116301382?via%3Dihub">creeping disaster</a>. Its build-up is slow and predicting drought requires accurate long-range rainfall forecasts. </p>
<p>However, the range of drivers contributing to rainfall over seasons makes accurate forecasting in Australia challenging. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/from-floods-to-fire-a-climate-scientist-on-the-chances-el-nino-will-hit-australia-this-year-197408">From floods to fire? A climate scientist on the chances El Niño will hit Australia this year</a>
</strong>
</em>
</p>
<hr>
<h2>What is a drought?</h2>
<p>Drought is simply a <a href="https://www.drought.gov/what-is-drought/drought-basics">shortage of water to meet demand</a>. But this definition has an underlying complexity: demand changes depending on who requires the water. As a result, we have different types of droughts depending on the type of water shortage. </p>
<p>Drought begins with a <a href="https://www.sciencedirect.com/science/article/pii/S2212094722001074">lack of rain and snowfall</a>. This is known as meteorological drought. When these deficiencies are sustained, evaporation demand leads to decreases in soil moisture and river flow into dams. As we continue to consume water and plants use up moisture, these storages decline even further without rain to refill them. </p>
<p>When we reach critical levels of dams and soil moisture we have <a href="https://drought.unl.edu/Education/DroughtIn-depth/TypesofDrought.aspx">hydrological</a> and <a href="https://www.drought.gov/topics/agriculture">agricultural</a> drought. A long hydrological or agricultural drought then leads to devastating impacts on the <a href="https://www.nature.com/articles/s41612-021-00220-8">environment</a>, <a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/wrcr.20123">economy and society</a>. </p>
<p>This evolution of drought is known as <a href="https://hess.copernicus.org/articles/24/1985/2020/">propagation</a>. It usually takes months or seasons. During this time, we’ve most likely passed from the influence of one climate driver to another. </p>
<h2>What causes a drought?</h2>
<p>Our understanding of drought took off from studies focusing on the impacts and causes of the <a href="https://www.theguardian.com/world/2006/nov/08/australia.drought">Millennium Drought</a> between 1997 and 2010. </p>
<p>At first, <a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/wrcr.20123">El Niño was identified as a major player in this period</a>, suppressing autumn rainfall in south-eastern Australia. Over time, the significant effects of the <a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2008GL036801">Indian Ocean Dipole</a> and <a href="https://journals.ametsoc.org/view/journals/clim/27/9/jcli-d-13-00322.1.xml">Southern Annular Mode</a> were identified as adding to the extreme dry conditions.</p>
<p>All three climate modes acted in concert to sustain and prolong the Millennium Drought over a vast area.</p>
<p>Looking over our entire climate records reveals that drought impacts vary through <a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2009GL041067">space and time</a>. Behind this variability is the different roles of the drivers in causing long dry periods. </p>
<p>The contribution of a given driver to drought is also different for different areas of Australia. For example, <a href="https://www.publish.csiro.au/es/pdf/ES21009">our research</a> shows the various drivers can explain 75% of the rainfall deficit during drought onset for areas across southern Australia, but only 30% for the subtropics and tropics.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/new-report-shows-alarming-changes-in-the-entire-global-water-cycle-197535">New report shows alarming changes in the entire global water cycle</a>
</strong>
</em>
</p>
<hr>
<h2>Will we be in drought in 2023?</h2>
<p>A return to El Niño could trigger a drought for some regions of Australia. However, our catchments are displaying <a href="http://www.bom.gov.au/climate/drought/#tabs=Soil-moisture">wet to slightly drier than average conditions</a> and our dams are generally <a href="http://www.bom.gov.au/climate/drought/#tabs=Water">full</a>. We would need significant drying for a severe drought such as <a href="http://www.bom.gov.au/climate/drought/knowledge-centre/previous-droughts.shtml">2017-2019 or 1982-1983</a> to take hold.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/512534/original/file-20230227-18-6l2gf1.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Map of Australia showing soil moisture levels" src="https://images.theconversation.com/files/512534/original/file-20230227-18-6l2gf1.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/512534/original/file-20230227-18-6l2gf1.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=412&fit=crop&dpr=1 600w, https://images.theconversation.com/files/512534/original/file-20230227-18-6l2gf1.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=412&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/512534/original/file-20230227-18-6l2gf1.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=412&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/512534/original/file-20230227-18-6l2gf1.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=518&fit=crop&dpr=1 754w, https://images.theconversation.com/files/512534/original/file-20230227-18-6l2gf1.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=518&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/512534/original/file-20230227-18-6l2gf1.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=518&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Recent root-zone soil moisture levels are average to above average across most of Australia.</span>
<span class="attribution"><a class="source" href="http://www.bom.gov.au/climate/drought/#tabs=Soil-moisture">Bureau of Meteorology</a></span>
</figcaption>
</figure>
<p>During 1976-1977, a weak El Niño developed <a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2015GL065703">alongside a neutral Indian Ocean Dipole</a>. This followed a <a href="https://earthobservatory.nasa.gov/images/150691/la-nina-times-three">triple-dip La Niña</a> similar to the one we have just been through. After the El Niño developed, the resulting spring and summer rainfall was <a href="http://www.bom.gov.au/climate/maps/rainfall/?variable=rainfall&map=decile&period=6month&region=nat&year=1977&month=03&day=31">above average</a> for much of eastern Australia. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/505019/original/file-20230117-11910-lii11w.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/505019/original/file-20230117-11910-lii11w.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=413&fit=crop&dpr=1 600w, https://images.theconversation.com/files/505019/original/file-20230117-11910-lii11w.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=413&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/505019/original/file-20230117-11910-lii11w.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=413&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/505019/original/file-20230117-11910-lii11w.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=519&fit=crop&dpr=1 754w, https://images.theconversation.com/files/505019/original/file-20230117-11910-lii11w.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=519&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/505019/original/file-20230117-11910-lii11w.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=519&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The weak El Niño in 1976-1977 brought above-average rainfall for eastern Australia.</span>
<span class="attribution"><a class="source" href="http://www.bom.gov.au/climate/maps/rainfall/?variable=rainfall&map=decile&period=6month&region=nat&year=1977&month=03&day=31">Source: Bureau of Meteorology</a></span>
</figcaption>
</figure>
<p>This shows not all El Niño events equate to drying if the right conditions align. Even the most recent El Nino in 2018-19 had <a href="http://www.bom.gov.au/climate/maps/rainfall/?variable=rainfall&map=decile&period=6month&region=nat&year=2019&month=03&day=31">mixed impacts</a> on Australian rainfall. </p>
<p>It is also important to remember that drought depends on who requires water and when. </p>
<p><a href="https://iopscience.iop.org/article/10.1088/1748-9326/ab2103/meta">Flash droughts</a> consist of a series of dry weeks and high temperatures. We are still learning about their relationship with the larger climate drivers and if we can predict them. But flash droughts can <a href="https://theconversation.com/flash-droughts-can-dry-out-soil-in-weeks-new-research-shows-what-they-look-like-in-australia-161286">devastate agriculture</a> if they happen at the wrong time.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/flash-droughts-can-dry-out-soil-in-weeks-new-research-shows-what-they-look-like-in-australia-161286">'Flash droughts' can dry out soil in weeks. New research shows what they look like in Australia</a>
</strong>
</em>
</p>
<hr>
<p>The <a href="https://www.sydney.edu.au/news-opinion/news/2021/12/13/black-summer-2019-20-bushfires-cost-farmers-5-billion-australia.html">scars of 2017-2019</a>, which culminated in the Black Summer bushfires, are still fresh in the minds of many who may see El Nino as an unwelcome visitor. However, the complexity of our climate system and the creeping nature of drought are major challenges to forecasting drought months in advance. </p>
<p>As a result, it is hard to simply equate a projected El Niño to impending drought.</p><img src="https://counter.theconversation.com/content/197678/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Danielle Verdon-Kidd receives funding from the Australian Research Council (ARC)</span></em></p><p class="fine-print"><em><span>Abraham Gibson does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Not all El Niño events lead to drought in Australia. Other factors are involved and it will take some time for drought to develop now catchments are wet and most dams are full.Abraham Gibson, Research Fellow, Faculty of Science and Engineering, Southern Cross UniversityDanielle Verdon-Kidd, Associate Professor, School of Environmental and Life Sciences, University of NewcastleLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2003642023-02-23T17:47:02Z2023-02-23T17:47:02ZWhy the UK has only had one named storm so far this winter – an expert explains<p><a href="https://www.metoffice.gov.uk/about-us/press-office/news/weather-and-climate/2023/storm-otto-named-by-danish-met-service#:%7E:text=A%20low%2Dpressure%20system%20which,75mph%20to%20some%20northern%20areas.">Storm Otto</a>, which was named by the Danish Meteorological Institute, hit Scotland and north-east England last Friday (February 17 2023) with wind gusts of over 80mph, disrupting power to 61,000 homes. </p>
<p>Otto was the first named storm of the UK’s current winter storm season and the first to hit the country’s shores since <a href="https://www.metoffice.gov.uk/binaries/content/assets/metofficegovuk/pdf/weather/learn-about/uk-past-events/interesting/2022/2022_01_storms_dudley_eunice_franklin_r1.pdf">storms Dudley, Eunice and Franklin</a> last February. Over the course of a week, these three storms barrelled in from the North Atlantic causing wind and flood damage worth over <a href="https://www.perils.org/losses">€3.7 billion (£3.2 billion) in insured losses</a> across Europe. </p>
<p>The UK has seen only a few notable instances of stormy weather so far this winter. For example, heavy rainfall in the first few weeks of January led to <a href="https://www.itv.com/news/westcountry/2023-01-19/pictures-show-scale-of-flooding-on-somerset-levels">flooding on the Somerset Levels</a>. But this storm was not intense enough to be named. This happens only when a <a href="https://www.metoffice.gov.uk/weather/warnings-and-advice/uk-storm-centre/index">storm has the potential</a> to be severe enough to cause an amber or red warning. </p>
<p>But storms are a common feature of winters in the UK. Since the current naming scheme started in 2016, between five and ten named storms have hit the UK each winter. So what’s been going on with the weather this year and why did the UK wait such a long time between named storms? </p>
<h2>Variable UK weather</h2>
<p>Chance can always play a role, particularly in the case of UK weather. </p>
<p>A narrow band of strong winds in the upper atmosphere, known as the jet stream, steers storms that originate over the North Atlantic towards Europe and the UK. But the jet stream itself is naturally very variable and can shift in position and strength. This can cause the UK’s weather to vary a lot from year to year. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/Lg91eowtfbw?wmode=transparent&start=4" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">What is the jet stream and how does it affect our weather?</span></figcaption>
</figure>
<p>The UK has therefore gone long periods without large storms before. For example, the <a href="https://digital.nmla.metoffice.gov.uk/">winter of 1985-86</a> was relatively quiet and was marked by storms at either end of the season with only one strong storm in January.</p>
<h2>La Niña conditions</h2>
<p>A global weather phenomenon called La Niña is also likely to have contributed to this year’s weather. La Niña is one phase of the <a href="https://www.climate.gov/news-features/blogs/enso/what-el-ni%C3%B1o%E2%80%93southern-oscillation-enso-nutshell">El Niño Southern Oscillation</a> and is characterised by relatively cool sea surface temperatures in tropical areas of the Pacific. This winter, sea surface temperatures in the tropical Pacific Ocean have been <a href="https://iri.columbia.edu/our-expertise/climate/forecasts/enso/current/">nearly 1°C cooler</a> than average. </p>
<p>La Niña can influence the weather experienced in the northern hemisphere. Cooler sea surface temperatures in the Pacific shift the position of rainfall in the tropics. These changes then propagate into the mid-latitudes, almost like ripples on a pond, and influence the position of the jet stream over the North Atlantic.</p>
<p>The impact of La Niña on weather in the North Atlantic is different in early and late winter. </p>
<p>Early in the season, La Niña tends to <a href="https://journals.ametsoc.org/view/journals/clim/31/11/jcli-d-17-0716.1.xml">shift the jet stream to the south</a>, steering storms that would normally hit the UK towards southern Europe. This may partly explain the bouts of stormy weather that brought flooding to Portugal, Spain and Italy in November and December of 2022. On December 7, <a href="https://www.efas.eu/en/news/floods-portugal-and-spain-december-2022">flash flooding</a> swept through the streets of Lisbon, the capital of Portugal, after 82.3mm of rain fell in 24 hours.</p>
<h2>Sudden stratospheric warming</h2>
<p>Later in the winter season, La Niña tends to shift the jet stream back towards the north and should bring stormier weather to the UK. During a typical winter, cooling air causes a vortex of westerly winds to form in the stratosphere, 10-50km above the Arctic. </p>
<p>The <a href="https://www.metoffice.gov.uk/weather/learn-about/weather/atmosphere/polar-vortex#:%7E:text=What%20is%20the%20Polar%20Vortex,about%20it%20for%20many%20years.">stratospheric polar vortex</a>, as it is called, remains remarkably stable most winters. But some years, the polar vortex slows and breaks up suddenly, causing the stratospheric air over the Arctic to warm rapidly. Called a sudden stratospheric warming, such an event has been occurring since <a href="https://blog.metoffice.gov.uk/2023/02/07/are-we-expecting-a-sudden-stratospheric-warming/">mid-February</a>.</p>
<p>These <a href="https://www.metoffice.gov.uk/weather/learn-about/weather/types-of-weather/wind/sudden-stratospheric-warming">sudden stratospheric warmings</a>, and the rapid slow down of the polar vortex, causes the North Atlantic jet stream below to slow down and meander. In some cases, sudden stratospheric warming can create a large area of high pressure over the North Atlantic and Scandinavia, bringing a spell of dry weather to northern Europe. This happened following the last <a href="https://www.rmets.org/metmatters/polar-vortex-sudden-stratospheric-warmings-and-beast-east">sudden stratospheric warming</a> event in January 2021. </p>
<p>But the effect of a sudden stratospheric warming on the UK’s weather can vary. The European blocking associated with sudden stratospheric warming can sometimes bring in freezing air from Europe, increasing the risk of snow. This was the case in late February 2018, where a sudden stratospheric warming drew winds from the Eurasian continent, causing storms and severe snowfall to affect much of the UK – known as the <a href="https://www.rmets.org/metmatters/beast-east-bites-uk">“beast from the east”</a>.</p>
<p>Although the UK might expect some colder weather in the next few weeks, there is no indication in current weather forecasts that this year’s sudden stratospheric warming will lead to the extreme cold weather seen in 2018.</p>
<p>This winter has been less stormy than usual. Yet, the UK relies on rain from North Atlantic storms to refill its rivers, reservoirs and aquifers. This is particularly important this year given last year’s exceptionally hot and dry summer that lead to drought conditions in much of the UK. </p>
<p>Despite only having one named storm, <a href="https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1136621/Monthly_water_situation_report_for_England_January_2023.pdf">rainfall across most of the UK</a> has fortunately been around or above average since October. This has helped to replenish water resources. But even then, <a href="https://www.gov.uk/government/news/one-hot-dry-spell-away-from-drought-returning-this-summer-national-drought-group-warns">East Anglia and Cornwall</a> remain in drought. So to top up the UK’s water resources and banish the spectre of a 2023 drought, a few more moderate storms over the next few months would be very welcome.</p>
<hr>
<figure class="align-right ">
<img alt="Imagine weekly climate newsletter" src="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
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<p><strong><em>Don’t have time to read about climate change as much as you’d like?</em></strong>
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<hr><img src="https://counter.theconversation.com/content/200364/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Len Shaffrey receives funding from the Natural Environment Research Council and the European Commission's Horizon Europe funding scheme.</span></em></p>An expert explains why the UK’s winter has been relatively calm.Len Shaffrey, Professor of Climate Science, National Centre for Atmospheric Science, University of ReadingLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1985052023-02-09T19:11:53Z2023-02-09T19:11:53ZMillions of satellite images reveal how beaches around the Pacific vanish or replenish in El Niño and La Niña years<p>If you’ve been visiting the same beach for a few summers, you’ll have seen it change. While beaches look static, they’re actually one of the most dynamic regions on Earth. Winds, waves and tides stir and push sand around constantly. Storms can claw out huge volumes of sand and move it elsewhere. </p>
<p>On top of these changes is a hidden force – the El Niño Southern-Oscillation (ENSO) climate cycle. Our <a href="https://www.nature.com/articles/s41561-022-01117-8">new research</a> explores how this cycle affects beaches around the Pacific Rim. Using cutting-edge satellite technology, we tracked changes over 40 years. </p>
<p>What did we find? The cycle matters a great deal. While the natural ENSO Pacific climate phenomenon affects weather patterns around the world, we haven’t fully understood how it affects beaches. </p>
<p>The main impact? Coastal storms intensified by the ENSO cycle. Storms can rapidly strip sand from beaches to create sandbars, dump it out at sea, or replenish another beach. These changes threaten to undermine beachfront properties and roads as well as beach habitats. </p>
<p>For Australia, if a La Niña is predicted to arrive in the next six months, coastal communities prone to erosion should prepare for storms stripping away sand. Our recent repeat La Niñas brought large waves and heavy erosion along the New South Wales and southern Queensland coast. During this period, houses <a href="https://www.theguardian.com/australia-news/2020/jul/18/nsw-central-coast-houses-partially-collapse-after-beach-erosion-caused-by-swells">almost fell</a> into the sea in the NSW Central Coast, while wild waves made a <a href="https://www.sunshinecoastnews.com.au/2023/02/05/in-photos-how-passage-has-changed-in-one-year/">new passage</a> through Bribie Island. </p>
<p>During El Niño, Australia’s beaches recover, while beaches from California to Chile erode. </p>
<p>But as climate change ramps up, the effects of these ENSO cycles may become <a href="https://www.nature.com/articles/s43017-021-00199-z">more intense</a>.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/506712/original/file-20230127-24-5hynl.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/506712/original/file-20230127-24-5hynl.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/506712/original/file-20230127-24-5hynl.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/506712/original/file-20230127-24-5hynl.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/506712/original/file-20230127-24-5hynl.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=565&fit=crop&dpr=1 754w, https://images.theconversation.com/files/506712/original/file-20230127-24-5hynl.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=565&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/506712/original/file-20230127-24-5hynl.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=565&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Extreme beach erosion during a coastal storm in 2020 at Wamberal, Central Coast, NSW.</span>
<span class="attribution"><span class="source">Christopher Drummond/UNSW Water Research Laboratory.</span></span>
</figcaption>
</figure>
<h2>What did we find?</h2>
<p>We analysed millions of satellite images, looking for changes in beach width during El Niño and La Niña periods in southeast Australia, New Zealand, Chile, Peru, Mexico, California and Japan. </p>
<p>Lying in the satellite data was clear evidence of cyclical change. Along southeast Australia’s coastline, beaches tended to erode during prolonged La Niña periods, while regaining sand and recovering during El Niño years. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-wild-weather-of-la-nina-could-wipe-out-vast-stretches-of-australias-beaches-and-sand-dunes-191941">The wild weather of La Niña could wipe out vast stretches of Australia's beaches and sand dunes</a>
</strong>
</em>
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<hr>
<p>The reverse was true on the other side of the Pacific, around 13,000 kilometres away. From California down through Mexico to Chile and Peru, we saw beaches narrow during El Niño periods and widen out again during La Niña periods. </p>
<p>Why? Storms and sea levels. During El Niño events, large storms develop in the northern Pacific, sending energetic waves crashing onto the coastlines of California and Mexico — creating the perfect conditions for big wave surfing. During this period, the sea level is well above average too. Combined, bigger waves, storms and a higher baseline pillage sandy beaches. This is particularly pronounced in the eastern Pacific. </p>
<p>Knowing this, we can be better prepared. If you’re in Australia and the <a href="http://www.bom.gov.au/climate/enso/outlook/">ENSO outlook</a> suggests a La Niña is coming, it might be time for councils to replenish erosion prone beaches. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/507768/original/file-20230202-4615-1iaiaf.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/507768/original/file-20230202-4615-1iaiaf.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/507768/original/file-20230202-4615-1iaiaf.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=198&fit=crop&dpr=1 600w, https://images.theconversation.com/files/507768/original/file-20230202-4615-1iaiaf.PNG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=198&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/507768/original/file-20230202-4615-1iaiaf.PNG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=198&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/507768/original/file-20230202-4615-1iaiaf.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=249&fit=crop&dpr=1 754w, https://images.theconversation.com/files/507768/original/file-20230202-4615-1iaiaf.PNG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=249&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/507768/original/file-20230202-4615-1iaiaf.PNG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=249&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">ENSO outlook for February 2023.</span>
<span class="attribution"><span class="source">Australian Bureau of Meteorology</span></span>
</figcaption>
</figure>
<h2>Monitoring the many moods of a beach</h2>
<p>Monitoring coastal change has long been carried out with on-ground techniques, such as GPS equipment, quadbikes and drones. These methods require human operators, which makes them expensive and limits the area and duration of observations. That’s why we have very limited on-ground observations of beach change along much of the world’s coastline.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/506722/original/file-20230127-14-x05xf1.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/506722/original/file-20230127-14-x05xf1.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/506722/original/file-20230127-14-x05xf1.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/506722/original/file-20230127-14-x05xf1.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/506722/original/file-20230127-14-x05xf1.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/506722/original/file-20230127-14-x05xf1.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/506722/original/file-20230127-14-x05xf1.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">On-ground survey techniques to monitor beaches.</span>
<span class="attribution"><span class="source">Larry Paice/UNSW Water Research Laboratory.</span></span>
</figcaption>
</figure>
<p>That’s where satellites can help. Earth observation satellites have been capturing regular images of the world’s coastlines for four decades. Now we have the tools to interrogate the satellite images and track the evolution of sandy beaches.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/australia-relies-on-data-from-earth-observation-satellites-but-our-access-is-high-risk-82985">Australia relies on data from Earth observation satellites, but our access is high risk</a>
</strong>
</em>
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<hr>
<p>We developed the open-source tool <a href="https://github.com/kvos/CoastSat">CoastSat</a> to automatically map the position of the shoreline on freely available satellite images, using cutting-edge image processing and machine learning techniques.</p>
<figure class="align-center ">
<img alt="CoastSat toolbox" src="https://images.theconversation.com/files/507753/original/file-20230202-19-6lbgd6.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/507753/original/file-20230202-19-6lbgd6.gif?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=522&fit=crop&dpr=1 600w, https://images.theconversation.com/files/507753/original/file-20230202-19-6lbgd6.gif?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=522&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/507753/original/file-20230202-19-6lbgd6.gif?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=522&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/507753/original/file-20230202-19-6lbgd6.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=656&fit=crop&dpr=1 754w, https://images.theconversation.com/files/507753/original/file-20230202-19-6lbgd6.gif?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=656&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/507753/original/file-20230202-19-6lbgd6.gif?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=656&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Changes to the shoreline can be automatically detected, as in this animation of changes at Narrabeen-Collaroy beach, Sydney.</span>
<span class="attribution"><span class="source">Killian Vos</span></span>
</figcaption>
</figure>
<p>With tools like these, we can monitor coastal changes across thousands of beaches over the last 40 years. You can see how your local beach has changed on the interactive <a href="http://coastsat.wrl.unsw.edu.au/">CoastSat website</a>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-wild-weather-of-la-nina-could-wipe-out-vast-stretches-of-australias-beaches-and-sand-dunes-191941">The wild weather of La Niña could wipe out vast stretches of Australia's beaches and sand dunes</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/198505/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kilian Vos receives funding from the United States Geological Survey (USGS). </span></em></p><p class="fine-print"><em><span>Mitchell Harley receives funding from the Australian Research Council. He is the NSW Chair of the Australian Coastal Society</span></em></p>We can now monitor coastal changes across thousands of beaches over the last 40 years, from Australia, New Zealand and Japan, to Chile, Peru, Mexico and California. Here’s what our new tool uncovered.Kilian Vos, Research Associate, UNSW SydneyMitchell Harley, Scientia Senior Lecturer, UNSW SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1986672023-01-30T00:53:29Z2023-01-30T00:53:29ZWhat’s driving the potato chip shortage and when will it pass?<figure><img src="https://images.theconversation.com/files/506751/original/file-20230127-24-behu61.jpg?ixlib=rb-1.1.0&rect=0%2C23%2C3888%2C2560&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>Potatoes are among Australia’s <a href="https://www.agriculture.gov.au/sites/default/files/documents/potatoes-infographic.pdf">favourite</a> vegetables. However, we are facing a shortage of processed potatoes, especially of frozen chips. Coles introduced a two-item <a href="https://www.coles.com.au/help/product-limits">limit</a> for shoppers seeking frozen potato products. Fish and chip businesses are under pressure and some are <a href="https://www.news.com.au/lifestyle/food/fish-and-chip-shop-owners-anger-at-mcdonalds-launching-potato-scallops-amid-shortage/news-story/78812fa4d53410e3091e894cda9bc986">outraged</a> McDonald’s is launching a new potato product in the middle of a crisis.</p>
<p>As with so many staples and fresh produce items in the past two years – lettuce, milk and eggs to name a few – the problem is a temporary imbalance between supply and demand.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1618783544633085952"}"></div></p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/floods-pandemics-wars-and-the-market-whats-driving-the-price-of-milk-191064">Floods, pandemics, wars and the market: what's driving the price of milk</a>
</strong>
</em>
</p>
<hr>
<h2>Soaring demand</h2>
<p>Let’s start with demand, which is <a href="https://www.expertmarketresearch.com/reports/frozen-potato-products-market">soaring</a>. </p>
<p>Countries like <a href="https://theconversation.com/china-wants-more-people-to-eat-potatoes-how-changing-national-diets-could-help-fix-our-global-food-crisis-podcast-196159">China</a> are pushing potato consumption as part of their food security policy, and rising urbanisation worldwide is <a href="https://www.potatonewstoday.com/2023/01/11/report-quick-service-restaurants-drive-global-frozen-potato-market-industry-booming-in-the-asia-pacific/">driving up</a> consumption of ready-to-eat and ready-to-cook foods.</p>
<p>Fast-food chains are cashing in on the opportunity. McDonald’s is set to <a href="https://qsrmedia.com.au/franchising/news/mcdonalds-eyes-100-more-restaurants-over-next-three-years-part-600m-investment-plan">continue</a> its <a href="https://www.theaustralian.com.au/business/property/maccas-will-open-another-11-restaurants-this-year/news-story/29eba1f5ca9e7f94bf57cc93a40a13cf#:%7E:text=McDonald's%20will%20open%20another%2011,by%20the%20end%20of%20December">expansion</a> in Australia. In 2020, McDonald’s Australia purchased over <a href="https://www.nzherald.co.nz/lifestyle/mcdonalds-australia-has-revealed-its-mammoth-2020-shopping-list/YEV2IUV6RIH5SK2AKRPFPLQMCY/">133,000</a> tons of potatoes. With the launch of its potato <a href="https://www.news.com.au/lifestyle/food/eat/mcdonalds-launches-new-potato-menuitem-aussies-cant-agree-on/news-story/8869e8002dd01ca1605382299a4c611b">scallops</a> with chicken salt product, demand for processed potatoes should only increase. </p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1614920267775590402"}"></div></p>
<h2>Supply won’t keep up</h2>
<p>On the supply side, potato growers worldwide had to take action against higher cultivation costs.</p>
<p>European countries exporting frozen potatoes to Australia are facing much higher <a href="https://www.reuters.com/business/energy/why-europe-faces-climbing-energy-bills-2022-09-02/">energy</a> bills. Many growers <a href="https://www.mintecglobal.com/top-stories/2023/24-my-eu-potato-contracts-up-20-30-y-o-y-amid-higher-production-costs">sold</a> supplies early in the season to save on storage, which demands a lot of energy to control for temperature and humidity. </p>
<p>That means <a href="https://ausveg.com.au/app/uploads/2021/12/Potatoes-Australia-PotatoLink-Summer-2021_2022.pdf">fewer</a> potatoes are available to export as we move into the year.</p>
<p>In New Zealand, the main exporter to Australia, vast amounts of rainfall in the past month are set to momentarily <a href="https://www.stuff.co.nz/business/farming/cropping/130908464/more-frequent-extreme-wet-weather-likely-to-mean-potato-shortage-higher-prices">reduce yields</a>, as potatoes need dry soil and sunlight before harvest.</p>
<p>Australian potato farmers are also struggling with the weather. Central regions to the production of processed potatoes in South Australia, Tasmania, and Victoria were hit by <a href="https://static1.squarespace.com/static/56cbdd3e20c647ad15b4d92f/t/5f711efb080c5d3cdcb609c3/1601249025851/Australian+Potato+Industry+2019.pdf">extreme weather events</a> in the past few months. Existing crops were lost to <a href="https://www.sbs.com.au/news/article/whats-causing-australias-frozen-chip-shortage-and-how-long-will-it-last/ljhcvjctq">floods</a>, and planting new crops was significantly delayed.</p>
<p>The pain Australians are feeling now is not new to our neighbours in New Zealand, who had their own “chipocalypse” just a few years ago.</p>
<p>In 2017, up to <a href="https://www.theguardian.com/world/2017/oct/16/chipocalypse-potato-shortage-in-new-zealand-sparks-crisp-crisis">30%</a> of New Zealand’s potato production in some areas was ruined by heavy rain.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/506953/original/file-20230129-15-xxwvw6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A flooded town is seen form the sky via an aerial shot taken by a drone." src="https://images.theconversation.com/files/506953/original/file-20230129-15-xxwvw6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/506953/original/file-20230129-15-xxwvw6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/506953/original/file-20230129-15-xxwvw6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/506953/original/file-20230129-15-xxwvw6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/506953/original/file-20230129-15-xxwvw6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=425&fit=crop&dpr=1 754w, https://images.theconversation.com/files/506953/original/file-20230129-15-xxwvw6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=425&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/506953/original/file-20230129-15-xxwvw6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=425&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Widespread flooding is also contributing to shortages.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>Recovery is on the way, but…</h2>
<p>Potato farmers will recover.</p>
<p>What we see now is partly a reflection of the inclement weather from two or three months ago. With La Niña predicted to <a href="https://www.theguardian.com/australia-news/2022/oct/26/la-nina-weather-pattern-australia-to-end-in-early-2023-bom-bureau-predicts">end</a>, fewer floods are expected for 2023.</p>
<p>Later this year could well see healthy yields, bringing relief to potato farmers. Give them a full <a href="https://greenharvest.com.au/Plants/Information/PotatoGrowing.html">cycle</a> and in about four months current shortages may be over, especially if prices continue to <a href="https://www.agriculture.gov.au/abares/data/weekly-commodity-price-update/australian-horticulture-prices">soar</a>.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1618093677028737025"}"></div></p>
<p>But this will not be the last shortage we will see, thanks to some relatively new factors in the farming landscape.</p>
<p>First, small farmers are quitting. </p>
<p>The 2020 European Union farm <a href="https://ec.europa.eu/eurostat/web/agriculture/census-2020#:%7E:text=The%20EU's%20Agricultural%20Census%202020%20has%20a%20new%20structure%2C%20consisting,a%20representative%20sample%20of%20farms">census</a> show consolidation is not slowing, with about <a href="https://www.farmersjournal.ie/800-eu-farmers-quit-the-sector-every-day-between-2010-and-2020-740899">800 farmers</a> quitting the sector every day.</p>
<p>In 2021-22 the Australian Bureau of Statistics registered <a href="https://www.abs.gov.au/statistics/industry/agriculture/agricultural-commodities-australia/latest-release">87,800</a> agricultural businesses, compared to about <a href="https://www.ausstats.abs.gov.au/ausstats/subscriber.nsf/0/20042E8A21DCF545CA25786C0015898B/$File/71210_2009-10.pdf">134,000</a> in 2009-10 – roughly a 35% reduction. </p>
<p>That does not mean less food, but more concentration and therefore more <a href="https://www.agriculture.gov.au/sites/default/files/sitecollectiondocuments/ag-food/publications/food-stats/daff-food-stats-2010-11.pdf">risk</a>. An extreme event hitting a group of small farmers is normally offset by their peers in the next town. When a very large farm is hit by the same event, often there is no immediate alternative.</p>
<p>Then there’s climate change. <a href="https://theconversation.com/la-nina-3-years-in-a-row-a-climate-scientist-on-what-flood-weary-australians-can-expect-this-summer-190542">Weather patterns</a> are <a href="https://origin.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/ONI_v5.php">changing</a> and will <a href="https://www.epa.gov/climate-indicators/weather-climate#:%7E:text=Rising%20global%20average%20temperature%20is,with%20human%2Dinduced%20climate%20change.">continue</a> to do so in the foreseeable future. Australia could go from a rare three year La Niña straight into a <a href="https://www.theguardian.com/australia-news/2023/jan/04/australia-could-swing-from-three-years-of-la-nina-to-hot-and-dry-el-nino-in-2023">hot and dry El Niño</a>. </p>
<p>This much volatility demands new skills and advanced, coordinated planning to save for a raining day.</p>
<h2>So, what can farmers and governments do to prepare?</h2>
<p>Of course, there have been bumper harvests as well — just look at Western Australia’s <a href="https://www.graincentral.com/news/third-bumper-harvest-to-challenge-supply-chain-anz/">grain</a> crops this summer. But some of the value of these exceptional yields is lost to transportation and storage bottlenecks.</p>
<p>With proper conditions, many grains, fruits and vegetables can be <a href="https://www.potatogrower.com/2019/03/top-5-factors-to-successful#:%7E:text=In%20general%2C%20the%20optimum%20long,weight%20loss%20and%20sprout%20control">stockpiled</a> for long periods of time. Stored correctly, potatoes can go for <a href="https://www.sciencedirect.com/science/article/abs/pii/S0023643802001743">months</a> without spoiling. Processed and frozen chips will last even longer inside industrial freezers. </p>
<p>If storage costs can be brought down – which has a lot to do with interest rates and electricity bills – farmers can keep surplus coming from bumper harvests instead of selling them immediately at discounted prices. Quicker deals with friendly international partners can also provide faster imports in dire times.</p>
<p>It’s up to Australia to create the right conditions to better cope with more volatility, so empty shelves can become a thing of the past.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/food-shortages-five-ways-to-fix-unfair-supply-chains-197974">Food shortages: five ways to fix 'unfair' supply chains</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/198667/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Flavio Macau is affiliated with the Australasian Supply Chain Institute (ASCI).</span></em></p>As with so many staples and foods in the past two years – lettuce, milk and eggs to name a few – the problem is a temporary imbalance between supply and demand. Here’s what’s happening with potatoes.Flavio Macau, Associate Dean - School of Business and Law, Edith Cowan UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1974082023-01-18T01:57:34Z2023-01-18T01:57:34ZFrom floods to fire? A climate scientist on the chances El Niño will hit Australia this year<p>After three soggy years of La Niña in a row, Australia has endured record-breaking floods, the latest of which has inundated <a href="https://theconversation.com/disastrous-floods-in-wa-why-were-we-not-prepared-197407">the Kimberley</a> in Western Australia and across <a href="https://www.abc.net.au/news/2023-01-17/qld-weather-system-brings-rainfall-floodwaters-chance-of-cyclone/101859094">north and central Queensland</a>. </p>
<p>While the rains may have initially been a relief after the heat, drought and fires that came before, they have long outstayed their welcome. Thankfully, the <a href="http://www.bom.gov.au/climate/enso/index.shtml#tabs=Overview">latest update</a> from the Bureau of Meteorology (BOM) points to a continuing weakening of La Niña – but it also points to the possibility of El Niño emerging by the autumn.</p>
<p>You can think of El Niño as being like the opposite of La Niña. While La Niña is known for bringing cooler, rainy weather, El Niño brings hot, dry conditions. This means it’s often associated with drought, heatwaves and bushfires. The world’s hottest year on record in 2016 was an El Niño year. </p>
<p>Let’s take a closer look at BOM’s forecast and what Australians can expect in the coming months. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/disastrous-floods-in-wa-why-were-we-not-prepared-197407">Disastrous floods in WA – why were we not prepared?</a>
</strong>
</em>
</p>
<hr>
<h2>The difference between El Niño, La Niña and climate change</h2>
<p>La Niña and El Niño events are “climate drivers”, which means they are part of the natural oscillations of the Earth’s climate. Human-caused climate change, on the other hand, acts over a longer term, steadily bringing up the planet’s average temperature and exacerbating some of the impacts of La Niña and El Niño events.</p>
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<p>La Niña is characterised by cooler waters than normal in the tropical eastern Pacific near Peru and Ecuador and warmer waters in the west Pacific including around northern Australia. </p>
<p>When we have La Niña we have an increased chance of wet conditions over northern and eastern Australia, especially in spring. The past three years with consecutive La Niña events have followed this pattern.</p>
<p>In contrast, El Niño is associated with warmer waters over the central and eastern Pacific Ocean and cooler waters in the west. El Niño conditions bring an increased chance of warmer and drier conditions in Australia.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/504821/original/file-20230117-19-38cp78.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/504821/original/file-20230117-19-38cp78.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/504821/original/file-20230117-19-38cp78.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=360&fit=crop&dpr=1 600w, https://images.theconversation.com/files/504821/original/file-20230117-19-38cp78.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=360&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/504821/original/file-20230117-19-38cp78.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=360&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/504821/original/file-20230117-19-38cp78.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=452&fit=crop&dpr=1 754w, https://images.theconversation.com/files/504821/original/file-20230117-19-38cp78.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=452&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/504821/original/file-20230117-19-38cp78.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=452&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">This graph of a key metric, known as the Niño-3.4 index, shows El Niño conditions are expected in coming months. It uses the Bureau of Meteorology’s prediction system.</span>
<span class="attribution"><span class="source">Bureau of Meteorology</span></span>
</figcaption>
</figure>
<p>For now we have a dissipating La Niña, and there is strong confidence it will continue to weaken over the coming weeks. We expect it to be properly finished by the end of summer.</p>
<h2>The likelihood of El Niño forming</h2>
<p>As we look further ahead, our confidence in what will happen next reduces. BOM’s outlook suggests El Niño conditions could arrive by late autumn, but other <a href="http://www.bom.gov.au/climate/enso/index.shtml#tabs=Pacific-Ocean">forecast models</a> point to a lower chance of El Niño emerging at all.</p>
<p>Forecasts of El Niño are challenging several months in advance, but particularly at this time of year when they have to overcome the “<a href="https://www.abc.net.au/news/2021-04-03/autumn-climate-reset-clouding-forecasters-crystal-balls/100043614">autumn predictability barrier</a>”. In autumn, there is less variation in the Pacific Ocean’s temperature and it’s harder to forecast if an El Niño or La Niña will emerge by winter.</p>
<p>We are by no means guaranteed a switch to El Niño, but there is a higher probability of an El Niño forming in the next few months than we’ve seen for several years.</p>
<p>Australia is also affected by other natural climate drivers, such as the <a href="http://www.bom.gov.au/climate/enso/history/ln-2010-12/IOD-what.shtml">Indian Ocean Dipole</a>, which has a strong effect on winter weather. This climate driver is brought about by interactions between ocean currents and the atmosphere, and influences rainfall patterns around the Indian Ocean, including Australia. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/J6hOVatamYs?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Understanding the Indian Ocean Dipole.</span></figcaption>
</figure>
<p>It’s currently forecast to move into a “positive phase” by early winter, which would favour a drier winter over most of Australia as well <a href="http://www.bom.gov.au/climate/enso/index.shtml#tabs=Indian-Ocean">but this is also still uncertain</a>.</p>
<h2>From floods to drought?</h2>
<p>With indications of a shift to El Niño and positive Indian Ocean Dipole, should we expect to swing from floods to drought? </p>
<p><a href="https://theconversation.com/flash-droughts-can-dry-out-soil-in-weeks-new-research-shows-what-they-look-like-in-australia-161286">Drought occurs on different timescales</a>, but Australia’s most devastating droughts, which result in major agricultural losses and water restrictions, require several years of dry conditions.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/504830/original/file-20230117-12-cy3qsx.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/504830/original/file-20230117-12-cy3qsx.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/504830/original/file-20230117-12-cy3qsx.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=209&fit=crop&dpr=1 600w, https://images.theconversation.com/files/504830/original/file-20230117-12-cy3qsx.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=209&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/504830/original/file-20230117-12-cy3qsx.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=209&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/504830/original/file-20230117-12-cy3qsx.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=263&fit=crop&dpr=1 754w, https://images.theconversation.com/files/504830/original/file-20230117-12-cy3qsx.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=263&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/504830/original/file-20230117-12-cy3qsx.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=263&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Longer periods with La Niña or negative Indian Ocean Dipole conditions increase the likelihood of large rainfall deficits in the Murray-Darling Basin.</span>
<span class="attribution"><span class="source">Author provided</span></span>
</figcaption>
</figure>
<p>With our dams full, it’s unlikely we’ll see a major drought form for a while. If we have an extended period without La Niña or negative Indian Ocean Dipole conditions, then drought may <a href="https://theconversation.com/why-drought-busting-rain-depends-on-the-tropical-oceans-132188">start to appear again</a>. However, the drier weather would also raise the risks of other hazards such as heatwaves and bushfires. </p>
<p>The <a href="https://www.nature.com/articles/s43247-020-00065-8">horror 2019-2020 fire season</a> came off the back of a weak El Niño and a strongly positive Indian Ocean Dipole. Indeed, Australia’s <a href="http://www.bom.gov.au/climate/updates/articles/a032.shtml">hottest summer on record</a> was during the El Niño of 2018-2019.</p>
<p>This time, our three consecutive La Niña events have resulted in more vegetation growth. This means next summer, there will be more fuel for fires to burn.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1615279038096105472"}"></div></p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/why-drought-busting-rain-depends-on-the-tropical-oceans-132188">Why drought-busting rain depends on the tropical oceans</a>
</strong>
</em>
</p>
<hr>
<h2>New heights for global temperatures</h2>
<p>El Niño doesn’t just affect Australia. For example, during El Niño events we typically see a weaker Indian monsoon and drier conditions over southern Africa. East Africa, which has suffered greatly <a href="https://theconversation.com/famine-should-not-exist-in-2022-yet-somalia-faces-its-worst-yet-wealthy-countries-pay-your-dues-191952">from drought</a> in recent times, is usually wetter during El Niño.</p>
<p>As El Niño events involve the warming of a large area of the Pacific Ocean they tend to raise the global average surface temperature by about one-tenth of a degree. While that might not sound like very much, it could push the global average surface temperature to record-breaking highs, particularly in the year after an El Niño forms.</p>
<p>Given the planet is rapidly warming due to our continuing high greenhouse gas emissions, and the fact we haven’t had a big El Niño for a while, even a moderate El Niño could mean the world experiences a new record hot year.</p>
<p>There is even the possibility the global average temperature <a href="https://www.newscientist.com/article/2354672-strong-el-nino-could-make-2024-the-first-year-we-pass-1-5c-of-warming/">could surpass 1.5°C</a> above pre-industrial levels for the first time.</p>
<p>While we’re aiming to keep global warming under 1.5°C to meet the Paris Agreement, an individual year above this mark does not mean we have failed. Still, it’s not a good sign if we start to hit that mark.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/famine-should-not-exist-in-2022-yet-somalia-faces-its-worst-yet-wealthy-countries-pay-your-dues-191952">Famine should not exist in 2022, yet Somalia faces its worst yet. Wealthy countries, pay your dues</a>
</strong>
</em>
</p>
<hr>
<h2>Is climate change altering El Niño?</h2>
<p>It’s not yet clear exactly how climate change may be altering El Niño. However, there are indications climate change may be moving El Niño events <a href="https://theconversation.com/el-nino-has-rapidly-become-stronger-and-stranger-according-to-coral-records-115560">towards the central Pacific</a> nearer the international dateline. </p>
<p>Climate change could also possibly strengthen rainfall responses to El Niño and La Niña over the <a href="https://www.nature.com/articles/nature12580">Pacific</a> and <a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2021GL097511">elsewhere</a>. This may worsen both our floods and droughts in Australia, but more research is needed.</p>
<p>Unfortunately, in terms of global temperatures and Australian heatwaves, it’s clear the combination of human-caused climate change and a major El Niño event increases the likelihood of record-breaking events. An El Niño may not be a welcome a reprieve from the past few soggy years. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/el-nino-has-rapidly-become-stronger-and-stranger-according-to-coral-records-115560">El Niño has rapidly become stronger and stranger, according to coral records</a>
</strong>
</em>
</p>
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<img src="https://counter.theconversation.com/content/197408/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Andrew King receives funding from the National Environmental Science Program. </span></em></p>The latest Bureau of Meteorology forecast offers relief from record rain and floods brought about by La Niña. A longer-term outlook for El Niño is still up in the air – but its arrival would be disastrous.Andrew King, Senior Lecturer in Climate Science, The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.