tag:theconversation.com,2011:/es/topics/antarctica-1189/articlesAntarctica – The Conversation2024-03-19T10:31:00Ztag:theconversation.com,2011:article/2259512024-03-19T10:31:00Z2024-03-19T10:31:00ZClimate change is speeding up in Antarctica<figure><img src="https://images.theconversation.com/files/582246/original/file-20240305-26-pkbcjj.jpg?ixlib=rb-1.1.0&rect=7%2C7%2C5317%2C2985&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption"></span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/es/image-photo/aerial-perspective-showcases-dramatic-melting-icebergs-2406809335">Mongkolchon Akesin / Shutterstock</a></span></figcaption></figure><p>In recent years, Antarctica has experienced a series of unprecedented heatwaves. On 6 February 2020, temperatures of 18.3C were recorded, the <a href="https://wmo.int/news/media-centre/wmo-verifies-one-temperature-record-antarctic-continent-and-rejects-another">highest ever seen on the continent</a>, beating the previous record of 17.5C which had only been set a few years earlier.</p>
<p>Around February 2022, another strong heatwave in Antarctica led to <a href="https://www.nature.com/articles/s41612-023-00529-6">record-breaking surface ice melt</a>. In March of the same year, <a href="https://theconversation.com/a-heatwave-in-antarctica-totally-blew-the-minds-of-scientists-they-set-out-to-decipher-it-and-here-are-the-results-220672">East Antarctica saw its strongest ever heatwave</a>, with temperatures soaring to <a href="https://journals.ametsoc.org/view/journals/clim/37/3/JCLI-D-23-0175.1.xml">30C or 40C higher than the average</a> in some areas.</p>
<p>Over the last year, we have seen the <a href="https://www.nature.com/articles/s43247-023-00961-9">lowest levels of Antarctic sea ice coverage since records began</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/574389/original/file-20240208-30-cwo3t5.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/574389/original/file-20240208-30-cwo3t5.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/574389/original/file-20240208-30-cwo3t5.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=379&fit=crop&dpr=1 600w, https://images.theconversation.com/files/574389/original/file-20240208-30-cwo3t5.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=379&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/574389/original/file-20240208-30-cwo3t5.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=379&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/574389/original/file-20240208-30-cwo3t5.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=476&fit=crop&dpr=1 754w, https://images.theconversation.com/files/574389/original/file-20240208-30-cwo3t5.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=476&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/574389/original/file-20240208-30-cwo3t5.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=476&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Record-breaking temperatures during the heatwave on 6 February 2020.</span>
<span class="attribution"><span class="source">González-Herrero et al. (2022)</span></span>
</figcaption>
</figure>
<p>Events in recent years have bordered on the unbelievable, and it is difficult not to link them to climate change. In fact, studies have already emerged that clearly attribute some of these heatwaves to global warming: one of our investigations strongly suggests that without the influence of climate change, <a href="https://www.nature.com/articles/s43247-022-00450-5">2020’s record-breaking temperatures would not have occurred</a>.</p>
<hr>
<p>
<em>
<strong>
Leer más:
<a href="https://theconversation.com/a-heatwave-in-antarctica-totally-blew-the-minds-of-scientists-they-set-out-to-decipher-it-and-here-are-the-results-220672">A heatwave in Antarctica totally blew the minds of scientists. They set out to decipher it – and here are the results</a>
</strong>
</em>
</p>
<hr>
<h2>Antarctica’s changing climate</h2>
<p>In 2009, <a href="https://www.nature.com/articles/nature08649">a study quantified the speed of ecosystem migration due to climate change on a global scale</a>, and documented, essentially, the speed at which certain species have to move to ensure their survival. It concluded that biomes were moving at a speed between 0.8 and 12.6km per decade, with an average speed of 4.2km per decade.</p>
<p>In our <a href="https://www.sciencedirect.com/science/article/pii/S0048969723071012">more recent study</a>, published in February 2024, we adapted this measurement of speed and applied it to the edges of Antarctica. To do this, we tracked the southward migration of the zero-degree isotherm.</p>
<p>The zero-degree isotherm is an imaginary line that encloses the areas that are at zero degrees or lower. Its southward movement means that the area with temperatures below zero Celsius in Antarctica is getting smaller and smaller. Given that water freezes at zero degrees, this movement will have serious consequences for ecosystems and for the <a href="https://oceanservice.noaa.gov/facts/cryosphere.html">cryosphere</a> (areas of the Earth where water is frozen).</p>
<p>Our calculations show that the zero-degree isotherm has moved at a speed of 15.8km per decade since 1957 in the area surrounding the Antarctic, while on the Antarctic peninsula itself it has moved at 23.9km per decade. As a result, it now sits over 100km south of where it was in the mid 20th century. </p>
<p>These measurements show that the speed of climate change on the edge of Antarctica is four times faster than the average of other ecosystems.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/574396/original/file-20240208-16-lty35i.gif?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/574396/original/file-20240208-16-lty35i.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/574396/original/file-20240208-16-lty35i.gif?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=180&fit=crop&dpr=1 600w, https://images.theconversation.com/files/574396/original/file-20240208-16-lty35i.gif?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=180&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/574396/original/file-20240208-16-lty35i.gif?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=180&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/574396/original/file-20240208-16-lty35i.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=226&fit=crop&dpr=1 754w, https://images.theconversation.com/files/574396/original/file-20240208-16-lty35i.gif?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=226&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/574396/original/file-20240208-16-lty35i.gif?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=226&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Evolution of the annual and seasonal position of the zero-degree isotherm in Antarctica between 1957 and 2020. The initials indicate the seasons for each measurement. MAM: autumn, JJA: winter, SON: spring, DJF: summer.</span>
<span class="attribution"><span class="source">González-Herrero et al. (2024)</span></span>
</figcaption>
</figure>
<h2>The effects of emissions</h2>
<p>To predict the consequences of the southward migration of the zero-degree isotherm, we ran our data through twenty different climate models. Although there is some variation in the shift of the isotherm among the models, all agree that it will move significantly further southward over the next few decades. </p>
<p>The models also predict that, over the coming decades, the isotherm’s movement will accelerate regardless of emissions. However, the extent of its southward movement in the second half of the 21st century will depend on how much carbon we emit.</p>
<p>If we continue at our current rate of emissions, the zero-degree isotherm will continue to advance at a similar rate before slowing down during the second half of the 21st century. However, if emissions are higher, the isotherm’s migration will accelerate continuing its southward movement until the end of the century.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/574401/original/file-20240208-22-ihn1pw.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/574401/original/file-20240208-22-ihn1pw.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/574401/original/file-20240208-22-ihn1pw.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=472&fit=crop&dpr=1 600w, https://images.theconversation.com/files/574401/original/file-20240208-22-ihn1pw.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=472&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/574401/original/file-20240208-22-ihn1pw.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=472&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/574401/original/file-20240208-22-ihn1pw.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=593&fit=crop&dpr=1 754w, https://images.theconversation.com/files/574401/original/file-20240208-22-ihn1pw.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=593&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/574401/original/file-20240208-22-ihn1pw.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=593&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Change in the summertime position of the zero-degree isotherm over the course of the 21st century. Based on IPCC climate scenario SSP5-8.5, whereby current emission levels are approximately doubled by 2050.</span>
<span class="attribution"><a class="source" href="https://www.sciencedirect.com/science/article/pii/S0048969723071012">Adapted by González-Herrero et al. (2024)</a></span>
</figcaption>
</figure>
<h2>Impacts on the cryoshpere and ecosystems</h2>
<p>The zero-degree isotherm’s southward movement will not remain solely in the atmosphere, it will also affect the cryosphere (all of the frozen areas of Antarctica) and the biosphere (the species that live there).</p>
<p>Changes in the isotherm’s position will mean more liquid rain instead of snow in the outermost regions of the continent, though it may in fact cause increased snowfall in other areas. </p>
<p>Reduced snowfall on the frozen sea – <a href="https://www.slf.ch/en/news/sea-ice-and-snow-act-as-a-sun-shield-for-our-oceans/">which acts as insulation</a> – may lead to accelerated loss of sea ice during summer thaw periods.</p>
<p>Although the effects on permafrost, ice shelves and continental ice are still uncertain, it will undoubtedly affect the peripheral glaciers of the Antarctic Peninsula. These constitute one of the largest potential sources of sea level rise in the coming decades. </p>
<p>Changes in the cryosphere will also lead to changes in ecosystems. <a href="https://www.nature.com/articles/nature22996">New areas will become habitable thanks to thawing ice</a>, but with more areas above zero degrees, <a href="https://www.cnet.com/science/climate/features/the-alien-invasion-of-antarctica-is-only-just-beginning/">invasive species from warmer, more hospitable continents may be able to settle</a>, and they will compete with native species for resources.</p><img src="https://counter.theconversation.com/content/225951/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sergi González Herrero no recibe salario, ni ejerce labores de consultoría, ni posee acciones, ni recibe financiación de ninguna compañía u organización que pueda obtener beneficio de este artículo, y ha declarado carecer de vínculos relevantes más allá del cargo académico citado.</span></em></p>The sub-zero area of Antarctica has shrunk by over 100km since the 1950s.Sergi González Herrero, Científico atmosférico, Universitat de BarcelonaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2233552024-02-27T03:59:52Z2024-02-27T03:59:52ZAntarctica provides at least $276 billion a year in economic benefits to the world, new research finds<p>All humanity benefits from Antarctica and the Southern Ocean that surrounds it. To some, these benefits may seem priceless. But in our market-driven world, calculating the economic value of the environment can be a useful tool in garnering support for its protection.</p>
<p>That was the intention of our <a href="https://www.nature.com/articles/s43017-024-00523-3.epdf?sharing_token=PpnmQW5bBZoeto6HXuLTmNRgN0jAjWel9jnR3ZoTv0NpXJejaaCEU9Spel0tQ4_D5xytf5GOfKj8MW19s9SeUGZlrMbJxh0GP-z0UqK3wAgOqv5MLY-uK7EKrx2oqMwWQL2LDJCL00_kB-POPezpsKN0Zh4yzFU2skwqzPmOXxk%3D">new research</a>. We crunched the numbers on the value of services Antarctica and the Southern Ocean provide in terms of fisheries, tourism and various natural processes that support Earth’s functioning. </p>
<p>And the result? We calculate the economic value at a whopping US$180 billion (A$276 billion) each year. We hope our findings will help prioritise conservation actions in Antarctica and galvanise international support to protect the region from the ravages of climate change.</p>
<h2>Benefits seen, and unseen</h2>
<p>The many benefits nature provides to humans are known as “ecosystem services”. </p>
<p>Some services provided by Antarctica and the Southern Ocean are invisible to most people. For example, the Southern Ocean absorbs carbon dioxide (CO₂) from the atmosphere, and ice in the region reflects heat. These processes help regulate Earth’s climate</p>
<p>The Southern Ocean also helps transport water around the globe, which helps distribute heat, fresh water, carbon and nutrients. These are known as “regulating” services.</p>
<p>We can think about the value of these services in terms of the cost that would accrue if it was not provided. For example, the Antarctic ice sheet contains <a href="https://www.bas.ac.uk/about/antarctica/geography/ice/">30 million cubic kilometres</a> of ice. If that ice melted as a result of global warming, the effects on coastal communities around the world would be catastrophic. </p>
<p>Other benefits provided by the Antarctic region are more visible. For example, humans rely on toothfish and krill for food, pharmaceuticals and dietary supplements. A warmer and more acidic Southern Ocean would affect fish stocks – both in the region and elsewhere – and some species may become extinct. </p>
<p>The Antarctic region also provides cultural services such as hosting vital scientific research. And in recent years, Antarctica has experienced a surge in tourist numbers.</p>
<p>So how much are these services actually worth to humanity? Our research examined that question.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/antarctica-is-the-only-continent-without-a-permanent-human-population-but-it-has-inspired-a-wealth-of-imaginative-literature-220041">Antarctica is the only continent without a permanent human population, but it has inspired a wealth of imaginative literature</a>
</strong>
</em>
</p>
<hr>
<h2>Crunching the numbers</h2>
<p>We used various methods to estimate the value of each service. Some, such as the provision of food, can be easily calculated by looking at what the market is willing to pay. Others, such as the avoidance of harm due to CO₂ absorption, are more complicated to ascribe value to.</p>
<p>Let’s start with tourism. Visitor numbers to Antarctica – mostly by ship – have increased markedly in recent decades, from about 8,000 a year in 1993–1994 to 105,000 in 2022–2023. We estimate the annual value of the Antarctic tourism industry at about US$820 million.</p>
<p>And what about the benefits of fisheries? Considering the tonnes of toothfish and krill caught in the region, we estimate the value at about US$370 million per year. </p>
<p>Finally, we estimated the economic value of “regulating services” such as carbon storage, sea level regulation and light reflection. We did this by multiplying estimates of the value of carbon stored in the Southern Ocean by estimates of the social cost of carbon.</p>
<p>This was a complex calculation, which we explain in greater detail in our paper. Overall, we estimate the value of the region’s regulating services at about US$179.3 billion a year.</p>
<p>All up, this brings the total value of Antarctica and the Southern Ocean’s ecosystem services to about US$180 billion a year. This is a conservative estimate which excludes some ecosystem services.</p>
<p>For example, the Antarctic Circumpolar Current and neighbouring ocean gyres – which distribute Antarctic nutrients around the world – are thought to help boost the value of global fisheries by about US$2.8 billion. We did not include this in the calculation above to avoid double-counting with other regulating services.</p>
<p>And due to a lack of data, we could not even roughly estimate the value of scientific work in Antarctica, so this is also excluded. But Antarctic research may have prevented significant damage to livelihoods and infrastructure across the world – for example, by monitoring changes in ice and sea levels – and we can expect this contribution to increase in future. </p>
<p>And the region provides other important services that we don’t have enough information to estimate, such as medicinal ingredients yet to be discovered.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/a-heatwave-in-antarctica-totally-blew-the-minds-of-scientists-they-set-out-to-decipher-it-and-here-are-the-results-220672">A heatwave in Antarctica totally blew the minds of scientists. They set out to decipher it – and here are the results</a>
</strong>
</em>
</p>
<hr>
<h2>What role for the Antarctic Treaty?</h2>
<p>As the Southern Ocean becomes warmer and more acidic, its natural systems will undergo huge changes. This will reduce the many benefits the Antarctic region provides, at great cost to the world. So how should the global community respond? </p>
<p>The Antarctic and Southern Ocean is governed by the <a href="https://www.ats.aq/index_e.html">Antarctic Treaty</a>, which was adopted in 1959. The threats we’ve outlined were not anticipated at the time, and the treaty does not address them. </p>
<p>Treaty parties have the authority to safeguard some ecosystem services, such as tourism, fishing and science. But are unable to effectively safeguard others, such as regulating services when the threat comes from outside the Antartctic area. </p>
<p>The treaty has evolved over the years. Now it must go further, to safeguard the huge benefits – economic and otherwise – the region provides to the world.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-antarctic-treaty-is-turning-60-years-old-in-a-changed-world-is-it-still-fit-for-purpose-162849">The Antarctic Treaty is turning 60 years old. In a changed world, is it still fit for purpose?</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/223355/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Natalie Stoeckl is on the Scientific Expert Panel for Queensland's sustainable fisheries strategy and was a member of the Reef 2050 Expert panel, and the Wet Tropics Scientific Advisory Board.</span></em></p><p class="fine-print"><em><span>Rachel Baird 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>In our market-driven world, calculating the economic value of the environment can be a useful tool in garnering support for environmental protection.Rachel Baird, Senior Lecturer , University of TasmaniaNatalie Stoeckl, Professor of Economics, University of TasmaniaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2237682024-02-20T16:52:21Z2024-02-20T16:52:21ZA single Antarctic heatwave or storm can noticeably raise the sea level<p>A heat wave in Greenland and a storm in Antarctica. These kinds of individual weather “events” are increasingly being supercharged by a warming climate. But despite being short-term events they can also have a much longer-term effect on the world’s largest ice sheets, and may even lead to tipping points being crossed in the polar regions.</p>
<p>We have <a href="https://www.nature.com/articles/s43017-023-00509-7.epdf?sharing_token=EJZ02zq3kFQO4XKwZVTBLdRgN0jAjWel9jnR3ZoTv0NlXBkse_V2fGVmyGVwGFcXe8LM4zjSaytnzbxkpU3vleMHbbCbjypxjcJ3p1wJddVoe1nKU4klsbQfMwCvE-m9plem7c8GygdxBfIr9KNkFEXV23v6oF28LZQkvsWpQm4%3D">just published</a> research looking at these sudden changes in the ice sheets and how they may impact what we know about sea level rise. One reason this is so important is that the global sea level is predicted to rise by anywhere between 28 cm and 100cm by the year 2100, according to <a href="https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_Chapter09.pdf">the IPCC</a>. This is a huge range – 70 cm extra sea-level rise would affect many millions more people. </p>
<p>Partly this uncertainty is because we simply don’t know whether we’ll curb our emissions or continue with business as usual. But while possible social and economic changes are at least <a href="https://www.carbonbrief.org/explainer-how-shared-socioeconomic-pathways-explore-future-climate-change/">factored in</a> to the above numbers, the IPCC acknowledges its estimate does not take into account deeply uncertain ice-sheet processes. </p>
<h2>Sudden accelerations</h2>
<p>The sea is rising for two main reasons. First, the water itself is very slightly expanding as it warms, with this process responsible for <a href="https://theconversation.com/how-much-will-our-oceans-warm-and-cause-sea-levels-to-rise-this-century-weve-just-improved-our-estimate-166417">about a third</a> of the total expected sea-level rise. </p>
<p>Second, the world’s largest ice sheets in Antarctica and Greenland are melting or sliding into the sea. As the ice sheets and glaciers respond relatively slowly, the sea will also continue to rise for centuries.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/576797/original/file-20240220-30-8eophf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Large glacier in mountains meeting the ocean" src="https://images.theconversation.com/files/576797/original/file-20240220-30-8eophf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/576797/original/file-20240220-30-8eophf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/576797/original/file-20240220-30-8eophf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/576797/original/file-20240220-30-8eophf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/576797/original/file-20240220-30-8eophf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/576797/original/file-20240220-30-8eophf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/576797/original/file-20240220-30-8eophf.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">Elephant Foot Glacier in northern Greenland.</span>
<span class="attribution"><span class="source">Nicolaj Larsen / shutterstock</span></span>
</figcaption>
</figure>
<p>Scientists have long known that there is a potential for sudden accelerations in the rate at which ice is lost from Greenland and Antarctica which could cause considerably more sea-level rise: perhaps a metre or more in a century. Once started, this would be impossible to stop. </p>
<p>Although there is a lot of uncertainty over how likely this is, there is some evidence that it happened <a href="https://www.nature.com/articles/nature17145">about 130,000 years ago</a>, the last time global temperatures were anything close to the present day. We cannot discount the risk. </p>
<p>To improve predictions of rises in sea level we therefore need a clearer understanding of the Antarctic and Greenland ice sheets. In particular, we need to review if there are weather or climate changes that we can already identify that might lead to abrupt increases in the speed of mass loss.</p>
<h2>Weather can have long-term effects</h2>
<p><a href="https://www.nature.com/articles/s43017-023-00509-7.epdf?sharing_token=EJZ02zq3kFQO4XKwZVTBLdRgN0jAjWel9jnR3ZoTv0NlXBkse_V2fGVmyGVwGFcXe8LM4zjSaytnzbxkpU3vleMHbbCbjypxjcJ3p1wJddVoe1nKU4klsbQfMwCvE-m9plem7c8GygdxBfIr9KNkFEXV23v6oF28LZQkvsWpQm4%3D">Our new study</a>, involving an international team of 29 ice-sheet experts and published in the journal Nature Reviews Earth & Environment, reviews evidence gained from observational data, geological records, and computer model simulations. </p>
<p>We found several examples from the past few decades where weather “events” – a single storm, a heatwave – have led to important long-term changes. </p>
<p>The ice sheets are built from millennia of snowfall that gradually compresses and starts to flow towards the ocean. The ice sheets, like any glacier, respond to changes in the atmosphere and the ocean when the ice is in contact with sea water. </p>
<p>These changes could take place over a matter of hours or days or they may be long-term changes from months to years or thousands of years. And processes may interact with each other on different timescales, so that a glacier may gradually thin and weaken but remain stable until an abrupt short-term event pushes it over the edge and it rapidly collapses. </p>
<p>Because of these different timescales, we need to coordinate collecting and using more diverse types of data and knowledge.</p>
<p>Historically, we thought of ice sheets as slow-moving and delayed in their response to climate change. In contrast, our research found that these huge glacial ice masses respond in far quicker and more unexpected ways as the climate warms, similarly to the frequency and intensity of hurricanes and heatwaves responding to changes with the climate. </p>
<p>Ground and satellite observations show that sudden heatwaves and large storms can have long-lasting effects on ice sheets. For example a heatwave in July 2023 meant at one point <a href="https://www.carbonbrief.org/guest-post-how-the-greenland-ice-sheet-fared-in-2023/">67% of the Greenland ice sheet surface</a> was melting, compared with around 20% for average July conditions. In 2022 unusually warm rain fell on the <a href="https://www.whoi.edu/oceanus/feature/a-cold-case-filed-conger-ice-shelf-collapse/">Conger ice shelf</a> in Antarctica, causing it to disappear almost overnight.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1679391326326980608"}"></div></p>
<p>These weather-driven events have long “tails”. Ice sheets don’t follow a simple uniform response to climate warming when they melt or slide into the sea. Instead their changes are punctuated by short-term extremes. </p>
<p>For example, brief periods of melting in Greenland can melt far more ice and snow than is replaced the following winter. Or the catastrophic break-up of ice shelves along the Antarctic coast can rapidly unplug much larger amounts of ice from further inland. </p>
<p>Failing to adequately account for this short-term variability might mean we underestimate how much ice will be lost in future.</p>
<h2>What happens next</h2>
<p>Scientists must prioritise research on ice-sheet variability. This means better ice-sheet and ocean monitoring systems that can capture the effects of short but extreme weather events. </p>
<p>This will come from new satellites as well as field data. We’ll also need better computer models of how ice sheets will respond to climate change. Fortunately there are already some promising global <a href="http://imbie.org/">collaborative</a> <a href="https://climate-cryosphere.org/about-ismip6/">initiatives</a>.</p>
<p>We don’t know exactly how much the global sea level is going to rise some decades in advance, but understanding more about the ice sheets will help to refine our predictions.</p>
<hr>
<figure class="align-right ">
<img alt="Imagine weekly climate newsletter" src="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p><strong><em>Don’t have time to read about climate change as much as you’d like?</em></strong>
<br><em><a href="https://theconversation.com/uk/newsletters/imagine-57?utm_source=TCUK&utm_medium=linkback&utm_campaign=Imagine&utm_content=DontHaveTimeTop">Get a weekly roundup in your inbox instead.</a> Every Wednesday, The Conversation’s environment editor writes Imagine, a short email that goes a little deeper into just one climate issue. <a href="https://theconversation.com/uk/newsletters/imagine-57?utm_source=TCUK&utm_medium=linkback&utm_campaign=Imagine&utm_content=DontHaveTimeBottom">Join the 30,000+ readers who’ve subscribed so far.</a></em></p>
<hr><img src="https://counter.theconversation.com/content/223768/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Edward Hanna receives funding from the UK's Natural Environment Research Council.
The research was sponsored by the World Climate Research Programme’s Climate and Cryosphere project, the International Arctic Science Committee, and the Scientific Committee on Antarctic Research, and resulted from a collaboration following an Ice Sheet Mass Balance and Sea Level expert group workshop.</span></em></p><p class="fine-print"><em><span>Ruth Mottram received funding for this work from the European Union, Horizon Europe Funding Programme for research and innovation under grant agreement Nr. 101060452 and from the Novo Nordisk Foundation for the Challenge project PRECISE (Predicting Ice Sheets on Earth), grant NNF23OC0081251.
</span></em></p>To narrow our predictions of global sea level rise, we need to know more about these sudden ‘non-linear’ changes to ice sheets.Edward Hanna, Professor of Climate Science and Meteorology, University of LincolnRuth Mottram, Climate Scientist, National Centre for Climate Research, Danish Meteorological InstituteLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2200412024-01-14T19:06:15Z2024-01-14T19:06:15ZAntarctica is the only continent without a permanent human population, but it has inspired a wealth of imaginative literature<figure><img src="https://images.theconversation.com/files/568797/original/file-20240111-17-upafl3.jpg?ixlib=rb-1.1.0&rect=5%2C0%2C3860%2C2590&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Christopher Wood/Shutterstock</span></span></figcaption></figure><p>When I was working on my book <a href="https://www.amazon.com.au/Antarctica-Fiction-Imaginative-Narratives-South-ebook/dp/B009ZRNPW4">Antarctica in Fiction</a>, friends and colleagues would joke about what an easy task I had taken on. How many writers would choose to set a novel in a continent with no permanent human population? Surely a dozen or so books would cover it. </p>
<p>To begin with, I too vastly underestimated the work involved. I quickly found that there are many hundreds of novels set in Antarctica, even if you limit the selection to those available in English.</p>
<p>Over ten years later, I still have my work cut out keeping up with the proliferating new titles. Early exploring expeditions continue to be revisited. Contemporary threats to the region – climate change in particular – are generating new, often disturbing, stories. </p>
<p>A question I am sometimes asked is whether people who set novels in Antarctica have – or should have – travelled there themselves. Increasingly, writers do visit the ice continent with national programs, tourist vessels and NGOs. A research project I currently lead, <a href="https://www.utas.edu.au/research/projects/creative-antarctica">Creative Antarctica</a>, has sought to identify Australian writers and artists who have travelled to Antarctica for professional purposes. Our team has found over a hundred of them. </p>
<p>But while a voyage south is necessary research for a specific kind of narrative, my reading has taught me that it is possible to write an excellent novel set in Antarctica relying entirely on other people’s reports. </p>
<p>The five recent Antarctic novels described below offer a reasonably representative introduction to Antarctic fiction as a whole. They range stylistically between literary and genre fiction, and thematically across heroic (and not-so-heroic) explorers, climate warriors, alien invaders and hapless tourists. </p>
<p>Apart from Antarctic tragics like me, few people will enjoy them all, but most readers will likely find something to match their version of cool.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/200-years-of-exploring-antarctica-the-worlds-coldest-most-forbidding-and-most-peaceful-continent-129607">200 years of exploring Antarctica – the world's coldest, most forbidding and most peaceful continent</a>
</strong>
</em>
</p>
<hr>
<h2><em>Terra Nova</em></h2>
<p>Set in the early 20th century, Henriette Lazaridis’s <a href="https://www.simonandschuster.com/books/Terra-Nova/Henriette-Lazaridis/9781639362424">Terra Nova</a> (2022) is a fictionalised version of the “race to the Pole” between expeditions led by Robert F. Scott and Roald Amundsen. </p>
<p>These two expeditions – particularly Scott’s – have generated a long line of literary responses, including Kåre Holt’s <a href="https://www.goodreads.com/book/show/6404236-the-race">The Race</a> (1976), Beryl Bainbridge’s <a href="https://www.goodreads.com/en/book/show/220464">The Birthday Boys</a> (1991) and Rebecca Hunt’s <a href="https://www.penguin.com.au/books/everland-9780141962221">Everland</a> (2014). </p>
<p>Lazaridis’ version focuses less on the explorers than those they leave behind. The main protagonist is Viola, who is the wife of Heywoud, the novel’s Scott-equivalent explorer. She is also the lover of Watts, the expedition’s photographer, who accompanies Heywoud on his march to the Pole. </p>
<p>Viola is herself a talented photographer. In the men’s absence, she becomes increasingly involved – personally and artistically – in the suffragette movement. </p>
<p>Photographs both reveal and conceal in Terra Nova. Watts captures evidence that undermines his leader’s triumphant claim to priority; Viola’s images of the suffragette protesters on a hunger strike bring out an endurance and stoicism that prompts her to question who the real heroes are.</p>
<p>While the polar love triangle feels contrived, and the parallel between suffragettes and explorers is a little laboured, the novel drives home the broad point that while men were fighting to reach the furthest ends of the Earth, women were fighting simply to be full citizens. </p>
<p>Those interested in gender and polar exploration might also pick up another Antarctic historical novel, Ally Turner’s <a href="https://www.amazon.com.au/All-White-Spaces-Ally-Wilkes/dp/1789097835">All the White Spaces</a> (2022), in which a trans man stows away on a fictional expedition in 1920. Though overwritten at times, the novel makes innovative use of polar-gothic tropes to explore masculinity, grief and survivor guilt in the midst of what Ernest Shackleton famously termed “<a href="https://www.nls.uk/learning-zone/geography-and-exploration/shackleton-and-wordie/south/">the white warfare of the South</a>”.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/what-led-to-antarctic-explorer-captain-scotts-death-178810">What led to Antarctic explorer Captain Scott's death</a>
</strong>
</em>
</p>
<hr>
<h2><em>Cold People</em></h2>
<p>What if all of humanity were suddenly forced to move to Antarctica? </p>
<p>This is the premise of bestselling British author Tom Rob Smith’s <a href="https://www.simonandschuster.com.au/books/Cold-People/Tom-Rob-Smith/9781471133114">Cold People</a> (2023). The story begins when a burgeoning holiday romance is rudely interrupted by an alien invasion. The advanced beings give all humans just one month to reach Antarctica or face unspecified but ominous-sounding consequences. </p>
<p>No reason is provided for this required exile, although some suspect the aliens, having witnessed humans’ impact on the planet’s climate, decided to take executive action. In any case, the extraterrestrials exit the narrative as abruptly as they entered, their motivations remaining mysterious. </p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/567806/original/file-20240104-27-ilr9rm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/567806/original/file-20240104-27-ilr9rm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/567806/original/file-20240104-27-ilr9rm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=925&fit=crop&dpr=1 600w, https://images.theconversation.com/files/567806/original/file-20240104-27-ilr9rm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=925&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/567806/original/file-20240104-27-ilr9rm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=925&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/567806/original/file-20240104-27-ilr9rm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1162&fit=crop&dpr=1 754w, https://images.theconversation.com/files/567806/original/file-20240104-27-ilr9rm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1162&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/567806/original/file-20240104-27-ilr9rm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1162&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p>Cold People explores how far the survivors, eking out a living on a frozen continent, might be willing and able to adapt themselves in order for their species to continue. </p>
<p>The novel is the latest in a series of post-apocalyptic narratives, in which Antarctica is conceived as a refuge in a damaged planet. The causes range from geoengineering (Gerald Heard’s novella <a href="https://www.geraldheard.com/books/2017/7/15/the-lost-cavern">The Thaw Plan</a>) to a pandemic (Sakyo Komatsu’s <a href="https://www.goodreads.com/en/book/show/15800498">Virus</a>), nuclear war (David Graham’s <a href="https://en.wikipedia.org/wiki/Down_to_a_Sunless_Sea_(Graham_novel)">Down to a Sunless Sea</a>) and climate change (Paul McCauley’s <a href="https://www.hachette.com.au/paul-mcauley/austral-a-gripping-climate-change-thriller-like-no-other">Austral</a>). </p>
<p>Cold People dilutes its impact by exploring too many new ideas at once, but it is worth reading just for the ironic images its strange scenario produces – for example, when the aliens deposit humanity’s cultural heritage on the polar plateau, so that the Statue of Liberty, the Egyptian pyramids and the Taj Mahal sit together on the ice.</p>
<h2><em>The Art of Breaking Ice</em></h2>
<p>Rachael Mead’s The Art of Breaking Ice (2023) is based on the real experiences of Australian <a href="https://www.naa.gov.au/blog/smuggled-antarctic">Nel Law</a>, who travelled to Antarctica with her husband in the early 1960s, thereby becoming the first Australian woman and the first female artist to visit the continent. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/568161/original/file-20240108-19-ehqzbd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/568161/original/file-20240108-19-ehqzbd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/568161/original/file-20240108-19-ehqzbd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=917&fit=crop&dpr=1 600w, https://images.theconversation.com/files/568161/original/file-20240108-19-ehqzbd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=917&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/568161/original/file-20240108-19-ehqzbd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=917&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/568161/original/file-20240108-19-ehqzbd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1153&fit=crop&dpr=1 754w, https://images.theconversation.com/files/568161/original/file-20240108-19-ehqzbd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1153&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/568161/original/file-20240108-19-ehqzbd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1153&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p>Mead has also visited Antarctica, more than once – something evident in the precision of her descriptions. When a poet and novelist writes about an artist’s experiences in Antarctica, it is hard not to read the work at least partly autobiographically. Certainly, Mead’s artistry is evident in the novel, though more at the level of the sentence than the narrative. </p>
<p>Nel Law is depicted not only as a lone artist among sceptical scientists, but a woman on a ship full of often hostile men. Mead very effectively evokes the discomfort of women subject to men’s unwanted attentions and constant judgement.</p>
<p>Though The Art of Breaking Ice is mostly set over 50 years ago, its subject resonates with recent reports about <a href="https://theconversation.com/women-in-antarctica-face-assault-and-harassment-and-a-legacy-of-exclusion-and-mistreatment-190620">workplace behaviour in national Antarctic programs</a>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/nel-law-stowed-away-on-her-husbands-ship-to-antarctica-she-was-the-first-australian-woman-to-see-its-crystalline-strangeness-207326">Nel Law stowed away on her husband’s ship to Antarctica. She was the first Australian woman to see its ‘crystalline strangeness’</a>
</strong>
</em>
</p>
<hr>
<h2><em>Thaw</em></h2>
<p>Like Lazaridis’s Terra Nova, Dennis Glover’s <a href="https://www.blackincbooks.com.au/books/thaw">Thaw</a> (2023) deals with Scott’s second expedition, though Glover reimagines the experiences of the actual explorers rather than fictionalised versions of them. He finds a new angle by focusing on lesser-known expedition members, including meteorologist George Simpson. </p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/568155/original/file-20240108-23-h0fb3j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/568155/original/file-20240108-23-h0fb3j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/568155/original/file-20240108-23-h0fb3j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=917&fit=crop&dpr=1 600w, https://images.theconversation.com/files/568155/original/file-20240108-23-h0fb3j.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=917&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/568155/original/file-20240108-23-h0fb3j.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=917&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/568155/original/file-20240108-23-h0fb3j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1153&fit=crop&dpr=1 754w, https://images.theconversation.com/files/568155/original/file-20240108-23-h0fb3j.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1153&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/568155/original/file-20240108-23-h0fb3j.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1153&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p>Glover couples this historical narrative with a near-future plot, in which Simpson’s great-granddaughter, a celebrity climate activist, becomes obsessed with the idea that melting ice might be revealing buried artefacts from the expedition. Once she arrives in Antarctica, the second plot accelerates rapidly, the novel coming to resemble an eco-thriller.</p>
<p>The historical sections of Thaw are carefully researched and evoked. Whether or not Glover has travelled to Antarctica, he has certainly spent time immersed in the archives of the <a href="https://www.spri.cam.ac.uk/">Scott Polar Research Institute</a> (renamed the “British Institute for Polar Studies” in the novel). </p>
<p>The near-future characters can feel a little cartoonish and the eco-thriller plot strains credulity. The awkwardness points to the challenges – identified most prominently by Amitav Ghosh in <a href="https://press.uchicago.edu/ucp/books/book/chicago/G/bo22265507.html">The Great Derangement</a> (2016) – of writing about something as vast as climate change within the traditional confines of the literary novel. To my mind, a more successful, although much more oblique, example can be found in Jon McGregor’s <a href="https://www.penguinrandomhouse.com/books/676211/lean-fall-stand-by-jon-mcgregor/">Lean Fall Stand</a> (2021), the product of a writer’s residency with the British national Antarctic program. </p>
<p>Nonetheless, Thaw is definitely worth reading for anyone interested in Scott, climate change science, and ways in which they might be unexpectedly connected.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/why-australians-should-care-about-the-south-pole-62050">Why Australians should care about the South Pole</a>
</strong>
</em>
</p>
<hr>
<h2><em>Midnight</em></h2>
<p>My final cold book is Amy McCulloch’s <a href="https://www.penguin.com.au/books/midnight-9780241534915">Midnight</a> (2023), a thriller set on an Antarctic tourist cruise ship. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/568162/original/file-20240108-29-3zhgg9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/568162/original/file-20240108-29-3zhgg9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/568162/original/file-20240108-29-3zhgg9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=899&fit=crop&dpr=1 600w, https://images.theconversation.com/files/568162/original/file-20240108-29-3zhgg9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=899&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/568162/original/file-20240108-29-3zhgg9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=899&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/568162/original/file-20240108-29-3zhgg9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1130&fit=crop&dpr=1 754w, https://images.theconversation.com/files/568162/original/file-20240108-29-3zhgg9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1130&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/568162/original/file-20240108-29-3zhgg9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1130&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p>The tagline – “When the sun never sets, there’s no place to hide …” – might elicit a groan, and even more worrying is the publisher’s plot summary, which promises “tantalising glimpses of polar bears” (polar bears live exclusively in the Arctic). But there are no such infelicities in the novel itself, which draws from the author’s experience as an Antarctic tourist.</p>
<p>Midnight is one of several recent novels dealing with the Antarctic tourist industry, including Midge Raymond’s romance-cum-disaster-narrative <a href="https://www.textpublishing.com.au/books/my-last-continent">My Last Continent</a> (2016) and Iliya Prigogine’s modernistic offering <a href="https://www.versobooks.com/en-gb/products/112-the-lamentations-of-zeno">The Lamentations of Zeno</a> (2011). </p>
<p>This trend in Antarctic fiction is not surprising, given that <a href="https://theconversation.com/more-than-100-000-tourists-will-head-to-antarctica-this-summer-should-we-worry-about-damage-to-the-ice-and-its-ecosystems-192843">over 100,000 tourists visited last summer season</a>, about 20 times the number of scientists and station personnel. </p>
<p>Antarctic tourists face all manner of peril in fiction, and you can’t help wondering if this isn’t some kind of narrative punishment for their perceived intrusion on Antarctica’s pristine icescape – indeed, Prigogine’s novel makes this explicit. </p>
<p>McCulloch, however, is less moralistic. She takes advantage of the confined spaces and the dangers that can arise on a vessel in an extreme environment. In doing so, she follows a tradition of Antarctic thrillers that goes back at least to Hammond Innes’ bestseller <a href="https://www.penguin.com.au/books/the-white-south-9781448156955">The White South</a> (1949), set on a factory whaling ship. </p>
<p>While McCulloch has not quite hit her stride as a thriller writer – the cliffhangers and one-liners seem parachuted in – she is better on character and setting. Knife-wielding serial killer aside, Midnight recounts many aspects of the Antarctic cruise ship voyage that chimed with my experiences, and the narrative was absorbing enough to keep me turning pages.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/more-than-100-000-tourists-will-head-to-antarctica-this-summer-should-we-worry-about-damage-to-the-ice-and-its-ecosystems-192843">More than 100,000 tourists will head to Antarctica this summer. Should we worry about damage to the ice and its ecosystems?</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/220041/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Elizabeth Leane receives funding from the Australian Research Council, the Dutch Research Council and the Australian Antarctic Division. She also receives funding and/or in-kind support from several Antarctic tour operators. She is a board member of the Mawson's Huts Foundation.</span></em></p>Five recent novels about the Antarctic make for cool reading on a hot summer day.Elizabeth Leane, Professor of Antarctic Studies, School of Humanities, College of Arts, Law and Education, University of TasmaniaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2206722024-01-09T19:17:25Z2024-01-09T19:17:25ZA heatwave in Antarctica totally blew the minds of scientists. They set out to decipher it – and here are the results<figure><img src="https://images.theconversation.com/files/568365/original/file-20240109-23-ijfvqy.jpeg?ixlib=rb-1.1.0&rect=0%2C0%2C3941%2C970&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source"> DM Bergstrom</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Climate scientists don’t like surprises. It means our deep understanding of how the climate works isn’t quite as complete as we need. But unfortunately, as climate change worsens, surprises and unprecedented events keep happening.</p>
<p>In March 2022, Antarctica experienced an extraordinary heatwave. Large swathes of East Antarctica experienced temperatures up to 40°C (72°F) above normal, shattering temperature records. It was the <a href="https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2023GL104910">most intense</a> heatwave ever recorded anywhere in the world.</p>
<p>So shocking and rare was the event, it blew the minds of the Antarctic climate science community. A major global research project was launched to unravel the reasons behind it and the damage it caused. A team of 54 researchers, including me, delved into the intricacies of the phenomenon. The team was led by Swiss climatologist Jonathan Wille, and involved experts from 14 countries. The collaboration resulted in two <a href="https://journals.ametsoc.org/view/journals/clim/37/3/JCLI-D-23-0175.1.xml#:%7E:text=At%20the%20peak%20of%20the,possible%20under%20future%20climate%20projections.">groundbreaking papers</a> published today.</p>
<p>The results are alarming. But they provide scientists a deeper understanding of the links between the tropics and Antarctica – and give the global community a chance to prepare for what a warmer world may bring.</p>
<h2>Head-hurting complexity</h2>
<p>The papers tell a complex story that began half a world away from Antarctica. Under <a href="http://www.bom.gov.au/climate/updates/articles/a020.shtml">La Niña conditions</a>, tropical heat near Indonesia poured into the skies above the Indian Ocean. At the same time, repeated weather troughs pulsing eastwards were generating from southern Africa. These factors combined into a late, Indian Ocean tropical cyclone season.</p>
<p>Between late February and late March 2022, 12 tropical storms had brewed. Five storms revved up to become tropical cyclones, and heat and moisture from some of these cyclones mashed together. A meandering jet stream picked up this air and swiftly transported it vast distances across the planet to Antarctica.</p>
<p>Below Australia, this jet stream also contributed to blocking the eastward passage of a high pressure system. When the tropical air collided with this so-called “blocking high”, it caused the most intense atmospheric river ever observed over East Antarctica. This propelled the tropical heat and moisture southward into the heart of the Antarctic continent. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/like-rivers-in-the-sky-the-weather-system-bringing-floods-to-queensland-will-become-more-likely-under-climate-change-176711">Like rivers in the sky: the weather system bringing floods to Queensland will become more likely under climate change</a>
</strong>
</em>
</p>
<hr>
<h2>Luck was on Antarctica’s side</h2>
<p>The event caused the vulnerable Conger Ice Shelf to <a href="https://theconversation.com/conger-ice-shelf-has-collapsed-what-you-need-to-know-according-to-experts-180077">finally collapse</a>. But the impacts were otherwise not as bad as they could have been. That’s because the heatwave struck in March, the month when Antarctica transitions to its dark, extremely cold winter. If a future heatwave arrives in summer – which is more likely under climate change – the results could be catastrophic.</p>
<p>Despite the heatwave, most inland temperatures stayed below zero. The spike included a new all-time temperature high of -9.4°C (15.1°F) on March 18 near Antarctica’s Concordia Research Station. To understand the immensity of this, consider that the previous March maximum temperature at this location was -27.6°C (-17.68°F). At the heatwave’s peak, 3.3 million square kilometres in East Antarctica – an area about the size of India – was affected by the heatwave.</p>
<p>The impacts included widespread rain and surface melt along coastal areas. But inland, the tropical moisture fell as snow – lots and lots of snow. Interestingly, the weight of the snow offset ice loss in Antarctica for the year. This delivered a temporary reprieve from Antarctica’s contribution to global sea-level rise.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/568364/original/file-20240109-25-o9q0sw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="An ice shelf before (left) and after (right) a collapse." src="https://images.theconversation.com/files/568364/original/file-20240109-25-o9q0sw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/568364/original/file-20240109-25-o9q0sw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=381&fit=crop&dpr=1 600w, https://images.theconversation.com/files/568364/original/file-20240109-25-o9q0sw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=381&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/568364/original/file-20240109-25-o9q0sw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=381&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/568364/original/file-20240109-25-o9q0sw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=478&fit=crop&dpr=1 754w, https://images.theconversation.com/files/568364/original/file-20240109-25-o9q0sw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=478&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/568364/original/file-20240109-25-o9q0sw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=478&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">These images, acquired by the Copernicus Sentinel-2 satellites on January 30 2022 (left) and March 21 2022 (right), show the Conger ice shelf before and after the collapse, which was triggered by a shocking heatwave.</span>
<span class="attribution"><a class="source" href="https://www.copernicus.eu/en/media/image-day-gallery/collapse-conger-ice-shelf">European Union, Copernicus Sentinel-2 satellite imagery</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>Learning from the results</h2>
<p>So what are the lessons here? Let’s begin with the nice bit. The study was made possible by international collaboration across Antarctica’s scientific community, including the open sharing of datasets. This collaboration is a touchstone of the Antarctic Treaty. It serves as a testament to the significance of peaceful international cooperation and should be celebrated. </p>
<p>Less heartwarmingly, the extraordinary heatwave shows how compounding weather events in the tropics can affect the vast Antarctic ice sheet. The heatwave further reduced the extent of sea ice, which was already at record lows. This loss of sea ice was exacerbated this <a href="https://theconversation.com/devastatingly-low-antarctic-sea-ice-may-be-the-new-abnormal-study-warns-212376">year</a> resulting in the lowest summer and winter sea ice ever recorded. It shows how disturbances in one year can compound in later years.</p>
<p>The event also demonstrated how tropical heat can trigger the collapse of unstable ice shelves. Floating ice shelves don’t contribute to global sea-level rise, but they acts as dams to the <a href="https://theconversation.com/antarctic-tipping-points-the-irreversible-changes-to-come-if-we-fail-to-keep-warming-below-2-207410">ice sheets behind them</a>, which do contribute.</p>
<p>This research calculated that such temperature anomalies occur in Antarctica about once a century, but concluded that under climate change, they will occur more frequently. </p>
<p>The findings enable the global community to improve its planning for various scenarios. For example, if a heatwave of similar magnitude hit in summer, how much ice melt would there be? If an atmospheric river hit the <a href="https://theconversation.com/antarcticas-doomsday-glacier-how-its-collapse-could-trigger-global-floods-and-swallow-islands-173940">Doomsday glacier</a> in the West Antarctic, what rate of sea level rise would that trigger? And how can governments across the world <a href="https://theconversation.com/who-moves-and-who-pays-managed-retreat-is-hard-but-lessons-from-the-past-can-guide-us-196038">prepare coastal communities</a> for sea level rise greater than currently calculated?</p>
<p>This research contributes another piece to the complex jigsaw puzzle of climate change. And reminds us all, that delays to action on climate change will raise the price we pay.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/record-smashing-heatwaves-are-hitting-antarctica-and-the-arctic-simultaneously-heres-whats-driving-them-and-how-theyll-impact-wildlife-179659">Record-smashing heatwaves are hitting Antarctica and the Arctic simultaneously. Here’s what’s driving them, and how they’ll impact wildlife</a>
</strong>
</em>
</p>
<hr>
<p><em>This article has been amended to correct an error in converting a 40°C temperature difference from Celsius to Fahrenheit.</em></p><img src="https://counter.theconversation.com/content/220672/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Dana M Bergstrom past position was at the Australian Antarctic Division. She is affiliated with the Pure Antarctic Foundation, a groups of scientists and artists interesting in communication science and knowledge to the broader community.</span></em></p>A heatwave in 2022 redefined scientific expectations of the Antarctic climate. Now the global community must prepare for what a warmer world may bring.Dana M Bergstrom, Honorary Senior Fellow, University of WollongongLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2167382023-12-22T00:08:48Z2023-12-22T00:08:48ZAvian influenza has killed millions of seabirds around the world: Antarctica could be next<p>Antarctica is often imagined as the last untouched wilderness. Unfortunately, <a href="https://www.woah.org/en/disease/avian-influenza/">avian influenza</a> (“bird flu”) is encroaching on the icy continent. The virus has already reached the <a href="https://maps.app.goo.gl/QvLgto7pq8ggDALd6">sub-Antarctic islands</a> between the Antarctic Peninsula and South America. It’s only a matter of time before it reaches the Antarctic continent. </p>
<p>So far avian influenza has been detected in several seabird species on <a href="https://www.bas.ac.uk/media-post/first-confirmed-cases-of-avian-influenza-in-the-antarctic-region/">South Georgia Island</a> and the <a href="https://falklands.gov.fk/agriculture/avian-influenza">Falkland (Malvinas) Islands</a>. These birds are known to travel to Antarctica. Researchers also suspect avian influenza caused mass deaths of southern elephant seals. </p>
<p>The arrival of avian influenza in Antarctica could have potentially catastrophic consequences for the wildlife, decimating large populations. </p>
<p>Antarctic avian influenza outbreaks may also disrupt tourism and research activities during the busy summer season. So what can we do during this challenging time? </p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1726658388245811583"}"></div></p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/migrating-birds-could-bring-lethal-avian-flu-to-australias-vulnerable-birds-204793">Migrating birds could bring lethal avian flu to Australia's vulnerable birds</a>
</strong>
</em>
</p>
<hr>
<h2>The bird flu pandemic</h2>
<p>We are in the midst of a “panzootic” – a large-scale pandemic of <a href="https://www.woah.org/en/disease/avian-influenza/">avian influenza</a>, which is occurring across the world and has affected more than 200 species of wild birds.</p>
<p>While this strain of avian influenza (H5N1) <a href="https://www.nature.com/articles/s41586-023-06631-2">is an old foe</a>, the genetics and epidemiology of the virus have shifted. Once mostly found in poultry, it is now infecting large numbers of wild birds. Migrating birds have <a href="https://www.nature.com/articles/s41559-023-02182-x">spread the virus</a> with substantial outbreaks now occurring in Europe, Asia, Africa, North America and South America. </p>
<p>Avian influenza has devastated seabird populations around the world, including a 70% reduction of <a href="https://onlinelibrary.wiley.com/doi/10.1111/ibi.13275">northern gannets</a> on Bass Rock in the United Kingdom. Many birds are diseased, with signs including loss of coordination, watery eyes, head twisting, breathing distress or lethargy. </p>
<p>Beyond birds, this virus may have killed more than <a href="https://papers.ssrn.com/sol3/papers.cfm?abstract_id=4611782">30,000 South American sea lions</a> and over <a href="https://www.lanacion.com.ar/sociedad/puerto-madryn-murieron-mas-de-200-crias-de-elefantes-marinos-en-las-ultimas-dos-semanas-nid27102023/">2,500 southern elephant seal</a> pups in South America. In South Georgia mass deaths have been observed in <a href="https://www.bas.ac.uk/media-post/additional-cases-of-avian-flu-hpai-confirmed-on-south-georgia/">elephant seal pups</a> but the virus was not detected in samples sent for laboratory tests.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/invasive-species-are-threatening-antarcticas-fragile-ecosystems-as-human-activity-grows-and-the-world-warms-172058">Invasive species are threatening Antarctica's fragile ecosystems as human activity grows and the world warms</a>
</strong>
</em>
</p>
<hr>
<h2>Bird flu moving further south</h2>
<p>The first detection of avian influenza near Antarctica occurred in early October on Bird Island, <a href="https://www.bas.ac.uk/media-post/additional-cases-of-avian-flu-hpai-confirmed-on-south-georgia/">South Georgia</a>, in brown skuas (seabirds similar to large gulls). </p>
<p>A case on the Falkland (Malvinas) Islands was confirmed a few weeks later in another seabird species, the southern fulmar. </p>
<p>Genetic analysis revealed the virus entered these regions on <a href="https://www.biorxiv.org/content/10.1101/2023.11.23.568045v1">two separate occasions</a>.</p>
<p>Skuas and kelp gulls were highlighted as species <a href="https://www.scar.org/library/science-4/life-sciences/antarctic-wildlife-health-network-awhn/5973-risk-assessment-avian-influenza/file/">most likely to spread the virus to the Antarctic continent</a> in a recent risk assessment, as they travel into the region from South America. They are also highly susceptible to avian influenza, with related species in the <a href="https://www.nature.scot/avian-flu-causes-another-challenging-summer-seabirds#:%7E:text=Pink%2Dfooted%20geese%2C%20herring%20gulls,breeding%20population%20of%20great%20skua">Northern Hemisphere suffering losses of more than 60%</a>. </p>
<h2>What does this mean for Antarctica?</h2>
<p>The Antarctic Peninsula, with its <a href="https://www.scar.org/research-features/climate-expansion-ice-free-habitat/">ice-free areas</a>, is an important breeding ground for many key Antarctic species. </p>
<p>Critically, those species – and others, including the iconic Emperor penguin – live in <a href="https://www.bas.ac.uk/about/antarctica/wildlife/penguins/">dense colonies</a> and are not found elsewhere in the world, making them particularly vulnerable to disease outbreaks.</p>
<p>Outbreaks on the Antarctic Peninsula will also be extremely disruptive to the tourism industry. More than <a href="https://iaato.org/information-resources/data-statistics/">104,000 people</a> visited as tourists in the 2022–23 season. People visit to see wildlife, make a continental landing, and enjoy the scenery.</p>
<p>Once avian influenza is confirmed at a particular location, sites will be <a href="https://iaato.org/iaato-2022-23-biosecurity-protocols-regarding-avian-influenza/">closed to tourists</a>. This will lead to a different experience for visitors, with land-based wildlife encounters pivoting to cruise-based activities. </p>
<h2>What are we doing?</h2>
<p>The <a href="https://www.scar.org/science/awhn/">Antarctic Wildlife Health Network</a> of the Scientific Committee on Antarctic Research has developed recommendations for the research and tourism communities. </p>
<p>These recommendations include information around biosecurity, testing and reporting of cases. The network’s <a href="https://scar.org/library-data/avian-flu">database</a> collates information on suspected and confirmed cases of the H5N1 avian influenza strain in the Antarctic region. This is central to rapid data sharing.</p>
<p>During the 2022–23 season, a <a href="https://www.biorxiv.org/content/10.1101/2023.10.24.563692v1.full.pdf">small number of researchers</a> tested suspected cases and conducted surveys, which excluded the presence of avian influenza. </p>
<p>This year, through the generosity of industry partners, we will dramatically expand this effort. The network will conduct surveys across the Antarctic and sub-Antarctic to monitor the presence and impact of the virus on wildlife. </p>
<p>Safety and biosecurity measures have been boosted across the <a href="https://www.comnap.aq/heightened-risk-of-hpai-in-antarctica">scientific community</a> and <a href="https://iaato.org/wp-content/uploads/2020/04/IAATO_Don_t_Pack_a_Pest.EN_190070.pdf">tourism industry</a> to reduce the risk of people spreading the virus. This should ensure essential scientific research and tourism activities can continue safely. </p>
<p>New measures now in place include:</p>
<ul>
<li>disinfection of boots and outer clothing</li>
<li>wearing of N95 masks, protective glasses and gloves when working with wildlife</li>
<li>restrictions on access to infected sites.</li>
</ul>
<p>Tourism can play an important role in detecting and monitoring the spread of the virus, alerting authorities to new cases in locations not visited by scientists. </p>
<p>The International Association of Antarctica Tour Operators is on high alert. Extra training for <a href="https://iaato.org/polar-stakeholders-response-to-avian-influenza-as-2023-24-antarctic-season-begins/">field staff</a> will help them identify wildlife illness quickly. </p>
<h2>Antarctica is connected</h2>
<p>Many threats to Antarctica – including climate change, pollution, and pathogens – originate elsewhere. Climate change is expected to <a href="https://www.who.int/europe/news/item/01-07-2022-new-report-highlights-the-impact-of-changes-in-environment-on-one-health#:%7E:text=Climate%20change%20and%20rising%20temperatures,of%20both%20pathogens%20and%20vectors.">increase the spread of infectious diseases in wildlife</a> and Antarctica is not immune.</p>
<p>Disease surveillance and information sharing between all those active in the far south are vital to help minimise the impacts of avian influenza and future disease threats. </p>
<p>The avian influenza example highlights the connectivity of our world, and why we need to care for the planet at home in order to protect the far south. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/ancient-pathogens-released-from-melting-ice-could-wreak-havoc-on-the-world-new-analysis-reveals-209795">Ancient pathogens released from melting ice could wreak havoc on the world, new analysis reveals</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/216738/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Hanne E F Nielsen receives funding from the Australian Research Council, Linkage partner organisation Intrepid Travel, the Dutch Research Council, and the Australian Antarctic Division. Hurtigruten Australia provides in-kind support for fieldwork.</span></em></p><p class="fine-print"><em><span>Michelle Wille has an honorary appointment with the WHO Collaborating Centre for Reference and Research on Influenza. </span></em></p><p class="fine-print"><em><span>Meagan Dewar 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>A deadly strain of bird flu is circulating in animals. So far the virus has been detected in seabirds on islands near Antarctica. What does this mean for wildlife, tourism and research?Hanne E F Nielsen, Senior lecturer, University of TasmaniaMeagan Dewar, Lecturer in the School of Science, Psychology and Sport, Federation University AustraliaMichelle Wille, Senior research fellow, The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2188102023-12-21T19:08:14Z2023-12-21T19:08:14ZWhat octopus DNA tells us about Antarctic ice sheet collapse<figure><img src="https://images.theconversation.com/files/563522/original/file-20231205-29-pymbyu.jpg?ixlib=rb-1.1.0&rect=17%2C26%2C5973%2C3961&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 we want to understand the future, it’s often useful to look at the past. And even more useful if you use octopus DNA to peer into worlds long gone. </p>
<p>About 125,000 years ago, the Earth was in its last warm period between ice ages. Global average temperatures during this interglacial period were about 0.5–1.5°C warmer than pre-industrial levels. </p>
<p>This has strong parallels with our time. For a <a href="https://www.bbc.com/news/science-environment-66857354">third of 2023</a>, the Earth’s temperature has been 1.5°C warmer than the pre-industrial era, driven by climate change. </p>
<p>For <a href="https://www.nature.com/articles/271321a0">almost 50 years</a> physical scientists have sought the answer to whether or not the vast West Antarctic Ice Sheet collapsed the last time global temperatures were this high. Rather than relying only on geological sampling, we turned to the DNA of a small Antarctic octopus for clues to the deep past. </p>
<p>The DNA had an answer. Our <a href="https://science.org/doi/10.1126/science.ade0664">new research</a> shows yes, it most likely collapsed. </p>
<p>The West Antarctic Ice Sheet is <a href="https://www.science.org/doi/10.1126/science.aaz5487">very susceptible to warming</a>. If it melts, it has enough water to raise global sea levels by 3.3 to 5 metres.</p>
<h2>Of octopuses and giant ice sheets</h2>
<p>Sediment records and other ice cores show us that the ice sheet retreated at some point during the last ~1 million years in the late Pleistocene, but the exact timing and extent of any collapse remain ambiguous.</p>
<p>To get a more precise answer, we looked to cephalopod genetics. </p>
<p>Every organism’s DNA is a history book, and we now have the technology to read it. We can use DNA to look back in time and pinpoint when different populations of animals were interbreeding. </p>
<p>Turquet’s octopus (<em>Pareledone turqueti</em>) is fairly small, weighing up to 600 grams. They live on the seafloor all around Antarctica, but individuals don’t move far from home. Antarctica is so vast that populations in different regions cannot usually interbreed. </p>
<p>Deep under West Antarctica lies gaps in the rocks. At present, these are filled by the ice sheet, making the Weddell, Amundsen and Ross seas separate from each other. </p>
<p>If the ice melted, seaways would open up and connect these isolated basins. Octopuses could directly migrate into these regions and the evidence of their breeding would be laid down in DNA. </p>
<p>But if the ice sheet didn’t melt, we would only see evidence of breeding between octopus populations along the circumference of the continent.</p>
<p>We compared DNA patterns in Turquet octopus genomes all around Antarctica to see if there were direct and unique connections between octopus populations in the Weddell, Amundsen and Ross seas. We used statistical models to figure out if these connections could be explained by their present day connections around the Antarctic coastline.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/we-can-still-prevent-the-collapse-of-the-west-antarctic-ice-sheet-if-we-act-fast-to-keep-future-warming-in-check-215878">We can still prevent the collapse of the West Antarctic ice sheet – if we act fast to keep future warming in check</a>
</strong>
</em>
</p>
<hr>
<p>The story was clear in the DNA: yes, there had been direct connections between these three octopus populations. Their connections could not be statistically explained by interbreeding around the present day Antarctic coastline. These populations could only come into contact through seaways now blocked by the West Antarctic Ice Sheet. </p>
<p>Even more interesting, we first found direct connections between the three populations during the mid-Pliocene, 3 million to 3.6 million years ago when temperatures were 2–3°C hotter and sea levels 25m higher than today. This supports <a href="https://www.nature.com/articles/nature07867">existing geological evidence</a> that the West Antarctic Ice Sheet collapsed during that era. </p>
<p>The most recent DNA signatures of direct connections between the octopuses of these three seas was during the last interglacial period around 125,000 years ago. That suggests the ice sheet collapsed when the global average temperature was around 1.5°C hotter than pre-industrial levels.</p>
<p>Our work provides the first empirical evidence the West Antarctic Ice Sheet could begin to collapse if we exceed the Paris Agreement goal of limiting warming to 1.5°C or even 2°C. </p>
<h2>This discovery took effort across disciplines and countries</h2>
<p>To use animal DNA as a proxy for changes in the ice sheet, we had to work across disciplines and countries. Bringing together physical scientists and biologists gave rise to new ways to answer long standing questions of vital importance to all of us. </p>
<p>We also turned to museum collections for samples. Some dated back three decades – well before the genetic sequencing and analytical techniques we used were available. This demonstrates the vital importance of careful sample preservation, linked with metadata, with specimens protected for future access.</p>
<p>Interdisciplinary science is hard. It requires time, effort, and an open mind to appreciate new terminologies, scales and approaches. Journal editors and scientists can be reluctant to review such papers, as some aspects of the research will necessarily be outside the area of their expertise. But we hope our results show the value of this approach. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/C6cX0wQP5NA?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">The Antarctic seafloor is covered in marine life. Many of their ancestors also lived through climate changes in the past.</span></figcaption>
</figure>
<h2>What’s next?</h2>
<p>We hope to continue using DNA as a proxy to explore other parts of Antarctica with poorly understood climate histories. </p>
<p>There is a <a href="https://onlinelibrary.wiley.com/doi/10.1111/gcb.16356">wealth of information</a> on Antarctica’s recent and distant past also hidden in other types of biological data in moss beds and peat profiles, vertebrate animal colonies and living terrestrial and marine invertebrates. To date, very few of these biological archives have been brought into our understanding of Antarctica’s past climates. </p>
<p>As the world heats up at an unprecedented rate, we need to use these types of approaches to understand what else is likely to happen down on the ice. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/increasing-melting-of-west-antarctic-ice-shelves-may-be-unavoidable-new-research-216030">Increasing melting of West Antarctic ice shelves may be unavoidable – new research</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/218810/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sally Lau receives funding from the Australian Research Council (ARC). </span></em></p><p class="fine-print"><em><span>Jan Strugnell receives funding from the Australian Research Council (ARC), the Fisheries Research and Development Corporation (FRDC), the Department of Agriculture Water and the Environment through the National Environmental Science Program (NESP) and the Queensland Government through the Queensland Citizen Science Grants.</span></em></p><p class="fine-print"><em><span>Nerida Wilson receives funding from the Australian Research Council (ARC), Interact for Change and the Morris Animal Foundation (Wild Genomes).</span></em></p>Did the enormous West Antarctic Ice Sheet collapse the last time global temperatures were 1.5°C above preindustrial levels? The answer lay in the DNA of an octopus.Sally Lau, Postdoctoral Research Fellow, James Cook UniversityJan Strugnell, Professor Marine Biology and Aquaculture, James Cook UniversityNerida Wilson, Adjunct Senior Research Fellow, The University of Western AustraliaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2195332023-12-13T17:19:17Z2023-12-13T17:19:17ZAntarctic study proves glacier has undergone irreversible retreat – highlighting potential for widespread ice loss<figure><img src="https://images.theconversation.com/files/565184/original/file-20231212-19-asy8hd.JPG?ixlib=rb-1.1.0&rect=0%2C418%2C2437%2C1880&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Ice on the Antarctic peninsula flowing along a channel into an ice shelf in the ocean.</span> <span class="attribution"><span class="source">Hilmar Gudmundsson</span></span></figcaption></figure><p><a href="https://www.antarcticglaciers.org/antarctica-2/west-antarctic-ice-sheet-2/pine-island-glacier/">Pine Island glacier</a> is one of the fastest flowing outlets of ice from the west <a href="https://www.pnas.org/doi/abs/10.1073/pnas.1812883116">Antarctic ice sheet</a>, draining an area three-quarters the size of the UK. In recent decades, the glacier has been retreating rapidly and losing ice, contributing more to global sea level rise than any other Antarctic glacier. </p>
<p>The speed of the glacier’s retreat and the rate that is has been losing ice has led to concerns about how stable the region is. <a href="https://tc.copernicus.org/articles/17/3761/2023/">Model results show</a> that this region of west Antarctica could collapse in the future. If it does, then it could raise global mean sea level by several metres.</p>
<p>There have been periods of rapid global sea-level rise <a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2011RG000371">in the past</a> (by 1cm–2cm per year). This probably happened because glaciers were losing mass at an accelerated rate. One of the key mechanisms responsible for this is known as “<a href="https://www.antarcticglaciers.org/antarctica-2/west-antarctic-ice-sheet-2/marine-ice-sheets/">marine ice sheet instability</a>”. </p>
<p>When glaciers, like those in west Antarctica, experience a small retreat due to some change in the climate, they can continue retreating even if the change is reversed. Essentially, the glacier gets pushed beyond a tipping point, whereby it experiences rapid mass loss until it reaches a new state.</p>
<p>This kind of retreat is irreversible because the change in climate needed for the glacier to recover its original position is much greater than what initially caused it to retreat. This instability mechanism is well understood in theory, and models show it could happen in west Antarctica in the future. But until now there has been no proof that it had happened in the past.</p>
<p>In a <a href="https://www.nature.com/articles/s41558-023-01887-y">new study</a>, we found that Pine Island Glacier experienced irreversible mass loss and retreat, starting in the 1940s. Our model suggests that a temporary increase in melting under its floating ice shelf was enough to push the glacier past a tipping point.</p>
<p>This phase of accelerated retreat had finished by the 1990s. But, in a <a href="https://tc.copernicus.org/articles/15/1501/2021/">separate study</a> where we used the same model, we found that the glacier will cross future tipping points unless global warming is kept within safe limits.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/565188/original/file-20231212-29-11ree3.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A glacier flowing into the ocean in west Antarctica." src="https://images.theconversation.com/files/565188/original/file-20231212-29-11ree3.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/565188/original/file-20231212-29-11ree3.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/565188/original/file-20231212-29-11ree3.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/565188/original/file-20231212-29-11ree3.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/565188/original/file-20231212-29-11ree3.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/565188/original/file-20231212-29-11ree3.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/565188/original/file-20231212-29-11ree3.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">If it collapses, the west Antarctic ice sheet could raise global mean sea level by several metres.</span>
<span class="attribution"><span class="source">Hilmar Gudmundsson</span></span>
</figcaption>
</figure>
<h2>What happened?</h2>
<p>Before the 1940s, Pine Island Glacier extended further than it does today. Its grounding line – the point at which glacial ice begins to float in the ocean rather than being in contact with the ground – was situated 40km further downstream on a shallow ridge on the seabed. This ridge provided a stable position for the glacier, keeping it in place, possibly for at least 5,000 to 10,000 years.</p>
<p>Recent <a href="https://www.science.org/doi/full/10.1126/science.1244341">observations</a> show that ocean conditions beneath the floating ice shelf change from year to year. Every so often, warmer waters come into contact with the floating underside of the ice, causing a lot of melting from below. In the 1940s, a climate anomaly in west Antarctica, which has been <a href="https://www.pnas.org/doi/abs/10.1073/pnas.0803627105">linked to a large El Niño event</a>, possibly triggered a temporary change in ocean conditions. </p>
<p>We found that an increase in melting due to changed ocean conditions beneath the ice shelf would have led to the thinning of its grounded ice further upstream. This caused a gap to open between the grounded glacier and seabed, allowing warmer ocean waters to flow beyond the ridge. These results are supported by <a href="https://www.nature.com/articles/nature20136">evidence</a> recovered from the sediments under the present-day ice shelf.</p>
<p>Once warmer waters circulate beneath the newly exposed ice, it triggers further melting and thinning, at an even faster rate. Our model shows that this sparked rapid retreat and accelerated ice flow over the following two to three decades, culminating with the detachment of the ice shelf from the ridge between the late 1970s and the early 1980s. The pattern and timescale of retreat shown in our model is consistent with <a href="https://www.nature.com/articles/ngeo890">observations</a> of changes in the glacier.</p>
<h2>Irreversible change</h2>
<p>After the ice shelf detached from the ridge, there was a slowdown in ice flow and a more gradual retreat. This retreat only stopped when the grounding line reached a shallow section of bedrock in the early 1990s. </p>
<p>Our analysis shows that the phase of rapid retreat between the 1940s and 1970s was irreversible. If ocean conditions cooled and there was lower melting beneath the shelf during that period, then this would have been unable to stop the ongoing mass loss. </p>
<p>These results show us that if there is a significant increase in melting at the base of a glacier’s floating ice shelf, it can retreat past a tipping point. This means that even if conditions cool down, the loss of ice mass may be irreversible.</p>
<p>The future implications of this are clear. What occurred before could happen again. If we cross future ice sheet tipping points, simply reverting back to the previous climate conditions might not be enough to fix the damage.</p>
<hr>
<figure class="align-right ">
<img alt="Imagine weekly climate newsletter" src="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p><strong><em>Don’t have time to read about climate change as much as you’d like?</em></strong>
<br><em><a href="https://theconversation.com/uk/newsletters/imagine-57?utm_source=TCUK&utm_medium=linkback&utm_campaign=Imagine&utm_content=DontHaveTimeTop">Get a weekly roundup in your inbox instead.</a> Every Wednesday, The Conversation’s environment editor writes Imagine, a short email that goes a little deeper into just one climate issue. <a href="https://theconversation.com/uk/newsletters/imagine-57?utm_source=TCUK&utm_medium=linkback&utm_campaign=Imagine&utm_content=DontHaveTimeBottom">Join the 20,000+ readers who’ve subscribed so far.</a></em></p>
<hr><img src="https://counter.theconversation.com/content/219533/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Brad Reed receives funding from The Natural Environment Research Council and UK Research and Innovation.</span></em></p><p class="fine-print"><em><span>Hilmar Gudmundsson receives funding from The Natural Environment Research Council, NSF and EU Horizon 2020 programme. </span></em></p><p class="fine-print"><em><span>Mattias Green receives funding from The Natural Environment Research Coucil. </span></em></p>Pine Island Glacier passed a tipping point decades ago, and it could do again in the future.Brad Reed, Research Fellow in the Department of Geography and Environmental Sciences, Northumbria University, NewcastleHilmar Gudmundsson, Professor of Glaciology, Northumbria University, NewcastleMattias Green, Professor in Physical Oceanography, Bangor UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2116162023-12-11T00:10:55Z2023-12-11T00:10:55ZDoing science in Antarctica has harmed an environment under great pressure. Here’s how we can do better<figure><img src="https://images.theconversation.com/files/545892/original/file-20230901-29-db42h5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The Argentine research station, Base Primavera, on the Antarctic Peninsula.</span> <span class="attribution"><span class="source">Shaun Brooks</span></span></figcaption></figure><p>Scientific research in Antarctica has played a key role in many important discoveries of the past century. But it has also come at a considerable cost to the environment. </p>
<p>Science in Antarctica is typically based at one of the <a href="https://www.comnap.aq/antarctic-facilities-information">77 research stations</a>. While their role is to support science, their isolation means they need to provide the infrastructure of a town.</p>
<p>As well as the local impacts of these stations, the Antarctic environment is facing massive challenges from external pressures such as climate change. The loss of sea ice could mean some of the continent’s <a href="https://www.theguardian.com/commentisfree/2023/aug/28/emperor-penguin-extinction">most iconic wildlife face extinction</a> this century. For example, the early melting of sea ice recently led to complete <a href="https://www.nature.com/articles/s43247-023-00927-x">breeding failure</a> at several emperor penguin colonies. </p>
<p>So how can we keep doing research in Antarctica while minimising our impact on the environment? This question led to <a href="https://doi.org/10.1016/j.jenvman.2023.119711">our new research</a> published in the Journal of Environmental Management.</p>
<p>We found little evidence of conservation planning and few limits on permissible activities such as building new stations, despite Antarctica being declared a natural reserve. This has left plenty of room to improve planning, technology and research methods to reduce impacts on the fragile Antarctic environment.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/devastatingly-low-antarctic-sea-ice-may-be-the-new-abnormal-study-warns-212376">Devastatingly low Antarctic sea ice may be the ‘new abnormal', study warns</a>
</strong>
</em>
</p>
<hr>
<h2>What are the impacts of all these stations?</h2>
<p>The <a href="https://doi.org/10.1038/s41893-019-0237-y">majority of stations</a> were built before the <a href="https://www.ats.aq/e/protocol.html">Protocol on Environmental Protection to the Antarctic Treaty</a> took effect in the late 1990s. These older stations were established during an era when environmental protection was a lower priority. </p>
<p>As a result, some stations were located in the most rare and sensitive ice-free areas. They probably would not be built there today, but only <a href="https://link.springer.com/chapter/10.1007/978-3-642-84074-6_19">a few have been removed</a>. Most old stations continue to operate. </p>
<p>At the larger stations, in addition to living quarters and laboratories, facilities include sewage and power plants, bulk fuel tanks and handling, roads, workshops, helipads, runways, wharfs, quarries, fire stations and even one short-lived <a href="https://theconversation.com/remembering-antarcticas-nuclear-past-with-nukey-poo-99934">nuclear reactor</a>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/remembering-antarcticas-nuclear-past-with-nukey-poo-99934">Remembering Antarctica's nuclear past with 'Nukey Poo'</a>
</strong>
</em>
</p>
<hr>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/545895/original/file-20230901-23-qww3zz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/545895/original/file-20230901-23-qww3zz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/545895/original/file-20230901-23-qww3zz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/545895/original/file-20230901-23-qww3zz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/545895/original/file-20230901-23-qww3zz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/545895/original/file-20230901-23-qww3zz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/545895/original/file-20230901-23-qww3zz.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">Russia’s Bellingshausen Station was established in 1968.</span>
<span class="attribution"><span class="source">Shaun Brooks</span></span>
</figcaption>
</figure>
<p>Adding to the impacts are <a href="https://www.antarctica.gov.au/antarctic-operations/airp/">ongoing demands</a> to expand stations. This might be to provide new scientific apparatus to answer new questions, house more people, improve logistical capacity, or increase the safety of ageing infrastructure. </p>
<p>This background means research stations are often industrial-looking sites, with <a href="https://www.theguardian.com/world/2023/aug/10/pollution-at-australias-largest-antarctic-research-station-exceeded-guidelines-for-almost-20-years">industrial-scale environmental impacts</a>. It’s a stark contrast to the near-pristine natural reserve they are situated in. </p>
<p>The stations that support science to help understand Antarctica have created the most intense human impacts on the place. These impacts include:</p>
<ul>
<li><p>a growing disturbance footprint on rare but vital ice-free areas</p></li>
<li><p>marine contamination that rivals the <a href="https://www.sciencedirect.com/science/article/abs/pii/0025326X92906894">most polluted harbours</a> in the world</p></li>
<li><p><a href="https://www.sciencedirect.com/science/article/pii/S0301479718301257">fuel spills</a></p></li>
<li><p><a href="https://theconversation.com/invasive-species-are-threatening-antarcticas-fragile-ecosystems-as-human-activity-grows-and-the-world-warms-172058">non-native species introductions</a>, including weeds and invertebrates</p></li>
<li><p><a href="https://www.cambridge.org/core/journals/antarctic-science/article/impacts-of-local-human-activities-on-the-antarctic-environment/7115297BBC0C028462C20110F7F3B36C">disturbance to wildlife</a>. </p></li>
</ul>
<p>Many stations have displaced some of the best areas of habitat for plants and animals. </p>
<p>Environmental management and impact assessments are now routine practice in Antarctica, and do curtail impacts. However, these practices do not stop the footprint of stations from continuing to spread. </p>
<p>In a case study of a long-established Antarctic station, Australia’s Casey, we found the area of heavy disturbance expanded by 18% and the area of medium disturbance by 42% over a 16-year period. This growth has encroached on one of the <a href="https://theconversation.com/antarcticas-moss-forests-are-drying-and-dying-103751">most important areas</a> of vegetation in Antarctica.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/for-the-first-time-we-can-measure-the-human-footprint-on-antarctica-112856">For the first time, we can measure the human footprint on Antarctica</a>
</strong>
</em>
</p>
<hr>
<h2>So what are the answers?</h2>
<p>Using better technology is one option. This can include installing cleaner sewage treatment to reduce contamination of the <a href="https://www.tandfonline.com/doi/abs/10.1111/j.1751-8369.2008.00056.x">marine environment</a>. And using passive design and <a href="https://www.sciencedirect.com/science/article/pii/S0960148109004467">renewable energy</a> can reduce fuel handling and storage. </p>
<p>Similarly, substituting harmful research practices with techniques that have fewer impacts is another option. Researchers have, for example, determined the prey species of penguins <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0082227">from poo</a>, rather than handling the birds. </p>
<p>As well as better technology and different research methods, a systematic approach to conservation planning, which identifies the best ways to protect the environment, will help.</p>
<p>Our international team looked into best-practice conservation planning for reserves elsewhere in the world. We adapted these approaches to the unique characteristics of each region of Antarctica and to the various ways in which stations operate. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/545896/original/file-20230901-23-par0qb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/545896/original/file-20230901-23-par0qb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=337&fit=crop&dpr=1 600w, https://images.theconversation.com/files/545896/original/file-20230901-23-par0qb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=337&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/545896/original/file-20230901-23-par0qb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=337&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/545896/original/file-20230901-23-par0qb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/545896/original/file-20230901-23-par0qb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/545896/original/file-20230901-23-par0qb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The Chilean base Presidente Eduardo Frei Montalva alongside the Teniente Rodolfo Marsh Martin Airport and Russian Bellingshausen Station on King George Island.</span>
<span class="attribution"><span class="source">Shaun Brooks</span></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/ive-spent-40-years-studying-antarctica-the-frozen-continent-has-never-needed-our-help-more-211520">I've spent 40 years studying Antarctica. The frozen continent has never needed our help more</a>
</strong>
</em>
</p>
<hr>
<p>We deliberately designed our conservation planning approach to support station operators to continue to provide new science capabilities. However, we did it in a way that minimises long-term environmental impacts.</p>
<p>For conservation planning to work properly, we need more environmental monitoring data. And data collection must be sustained over a long time.</p>
<p>In the absence of legal limits, we also encourage station operators to set their own self-imposed limits on their footprint and restore degraded areas no longer used. The less area we impact, the more room it gives Antarctic species to shift and adapt to a changing climate.</p><img src="https://counter.theconversation.com/content/211616/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>This work was funded and supported by the Australian Antarctic Division, Australian Antarctic Science project 4565.</span></em></p>The proliferation of Antarctic research stations – 77 in all – is increasing knowledge of the continent but also the human impacts. A new study has identified the best ways to limit these impacts.Shaun Brooks, Fieldwork Coordinator/Research Technician, CSIROLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2158782023-11-13T19:46:16Z2023-11-13T19:46:16ZWe can still prevent the collapse of the West Antarctic ice sheet – if we act fast to keep future warming in check<figure><img src="https://images.theconversation.com/files/558742/original/file-20231110-25-yntvos.jpg?ixlib=rb-1.1.0&rect=44%2C125%2C5946%2C2892&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/layers-serrated-ice-shelf-ross-iced-2349087529">Shutterstock/Farjana.rahman</a></span></figcaption></figure><p>Projecting when and how fast the West Antarctic Ice Sheet will lose mass due to current and future global ocean warming – and the likely impact on sea level rise and coastal communities – is a priority for climate science.</p>
<p>We know deep water flowing towards and around Antarctica is <a href="https://www.nature.com/articles/s41558-022-01424-3">warming</a>, and the fringes of the West Antarctic Ice Sheet (<a href="https://www.gns.cri.nz/research-projects/west-and-east-antarctic-ice-sheets/">WAIS</a>) are increasingly vulnerable to ocean-driven melting. </p>
<p>Submerged continental shelves along large portions of West Antarctica, including offshore Pine Island and Thwaites glaciers in the Amundsen Sea, are already bathed by upwelling arms of this <a href="https://www.science.org/doi/full/10.1126/science.1256117">relatively warm water</a>. </p>
<p>Ice shelves in this region – massive floating slabs of ice that flow out from the coast – are already <a href="https://www.science.org/doi/10.1126/sciadv.adi0186">losing mass</a>. Because ice shelves float, their melting doesn’t affect sea levels. But they hold back land-based ice, which does. </p>
<p>Recent <a href="https://www.nature.com/articles/s41558-023-01818-x">research</a> suggests increasing flow of warm deep water in this area will speed up the melting of the WAIS over the coming decades, regardless of future anthropogenic greenhouse gas emissions. </p>
<p>This would mean global <a href="https://climateactiontracker.org/">net-zero emissions targets</a> cannot limit the amount of future sea-level rise caused by the melting of the WAIS. This poses significant challenges for coastal communities in low-lying regions as they plan for and adapt to unavoidable change. </p>
<p>Our project, an ambitious international collaboration known as the “Sensitivity of the WAIS to 2°C” (<a href="https://www.swais2c.aq/">SWAIS2C</a>), aims to retrieve sediments from the seafloor beneath the Ross Ice Shelf to explore how West Antarctica responded to warmer periods in Earth’s past – and what might happen in a warming future. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/increasing-melting-of-west-antarctic-ice-shelves-may-be-unavoidable-new-research-216030">Increasing melting of West Antarctic ice shelves may be unavoidable – new research</a>
</strong>
</em>
</p>
<hr>
<h2>We may have (some) time</h2>
<p>While it may appear too late to slow or stop the retreat of the WAIS in areas where the ocean cavities beneath ice shelves are already “warm”, the inevitable demise of the entire WAIS is not so certain. There are also regions where ice shelf cavities are currently “cold”. </p>
<p>The Ross and Ronne-Filchner are Earth’s largest ice shelves and currently buttress and stabilise large regions of ice in the West Antarctic interior. The ocean cavity that lies beneath the Ross Ice Shelf is <a href="https://www.science.org/doi/10.1126/science.203.4379.438">cold</a>, generally characterised by temperatures at or <a href="https://www.pnas.org/doi/full/10.1073/pnas.1910760117">below minus 1.8°C</a>. </p>
<p>A recent <a href="https://www.nature.com/articles/s43247-021-00289-2">ice sheet modelling study</a> shows these large ice shelves and the WAIS will remain largely intact under <a href="https://gmd.copernicus.org/articles/13/3571/2020/">low-emissions pathways</a> which aim to keep warming close to or below 2°C above pre-industrial values. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/widespread-collapse-of-west-antarcticas-ice-sheet-is-avoidable-if-we-keep-global-warming-below-2-169651">Widespread collapse of West Antarctica's ice sheet is avoidable if we keep global warming below 2℃</a>
</strong>
</em>
</p>
<hr>
<p>Modelling experiments indicate an emissions pathway in line with the goals of the <a href="https://unfccc.int/process-and-meetings/the-paris-agreement">Paris agreement</a> can still limit the total contribution to sea level rise coming from the Antarctic ice sheet to 0.12–0.44 metres by 2100 (0.45–1.57 metres by 2300).</p>
<p>Importantly, these experiments also show that spatial patterns of ice thinning and retreat in the Amundsen Sea region are similar for 2100 compared to 2015 (see figure below) under both low and high emissions. </p>
<p>The clearest contrasts between the scenarios occur in the Ross Sea sector, where the grounding line of the ice shelf advances in low-emissions (“sustainable”) scenarios but the shelf ice thins or even collapses in high-emissions (“fossil fuel intensive”) scenarios. </p>
<figure class="align-center ">
<img alt="This graph shows how much ice West Antarctica is expected to lose under different emissions scenarios." src="https://images.theconversation.com/files/557970/original/file-20231107-253869-8wvy1y.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/557970/original/file-20231107-253869-8wvy1y.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=346&fit=crop&dpr=1 600w, https://images.theconversation.com/files/557970/original/file-20231107-253869-8wvy1y.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=346&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/557970/original/file-20231107-253869-8wvy1y.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=346&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/557970/original/file-20231107-253869-8wvy1y.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=435&fit=crop&dpr=1 754w, https://images.theconversation.com/files/557970/original/file-20231107-253869-8wvy1y.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=435&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/557970/original/file-20231107-253869-8wvy1y.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=435&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">In high-emissions scenarios, the Ross Ice Shelf would thin or even collapse.</span>
<span class="attribution"><span class="source">Authors provided</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<h2>Observation gaps from key Antarctic regions</h2>
<p>Global surface temperature is <a href="https://www.pnas.org/doi/abs/10.1073/pnas.2207183120">likely to exceed 1.5°C</a> above pre-industrial values by the early 2030s. It may warm by as much as 4.4°C by the end of this century. </p>
<p>Our current global policy and action trajectory will yield 2.7°C of warming by the end of century, but more ambitious pledges and targets could keep global warming to 2.0°C. We need to know how sensitive the large, cold-cavity ice shelves are to these increases in global temperature. </p>
<p>Ice sheet modelling suggests rapid cuts in emissions can still limit WAIS melt, but we lack direct observations to support these findings. Collecting new data from locations around the WAIS margin will offer insights into present-day changes and a possible future response to warming. </p>
<p>Significant effort to address data gaps has been made in the Amundsen Sea around the <a href="https://thwaitesglacier.org/">Thwaites Glacier</a> region, but observations beneath the Ross Ice Shelf, especially near the point where the WAIS begins to float, are limited. The <a href="https://www.swais2c.aq/">SWAIS2C project</a> aims to address this knowledge gap. </p>
<h2>Tapping the geological record</h2>
<p>SWAIS2C is an international collaboration involving scientists, drillers, engineers and science communicators. Our team will travel to the Siple coast, close to the centre of West Antarctica, to melt holes through the ice shelf at two sites. </p>
<p>Oceanographic measurements and geophysical observations at each site will improve our understanding of current ocean mechanics and ice sheet dynamics. But to understand the potential future contribution to sea-level rise from melting of the WAIS, we will need to turn to the geological record.</p>
<p>Seafloor sediments from beneath the Ross Ice Shelf represent an archive of climate information from warmer periods in Earth’s history and offer a means to “see” how the ice shelf and ice sheet responded to past warmth. </p>
<p>We will drill up to 200 metres below the seafloor to recover a geological record of changing rock types that reflect environmental conditions at the time they formed. </p>
<figure class="align-center ">
<img alt="A conceptual diagram to show how a drill string will be lowered to the seafloor beneath the Ross Ice Shelf." src="https://images.theconversation.com/files/558722/original/file-20231109-25-4osg01.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/558722/original/file-20231109-25-4osg01.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=313&fit=crop&dpr=1 600w, https://images.theconversation.com/files/558722/original/file-20231109-25-4osg01.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=313&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/558722/original/file-20231109-25-4osg01.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=313&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/558722/original/file-20231109-25-4osg01.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=394&fit=crop&dpr=1 754w, https://images.theconversation.com/files/558722/original/file-20231109-25-4osg01.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=394&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/558722/original/file-20231109-25-4osg01.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=394&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">This conceptual diagram of the SWAIS2C drilling system shows how a drill string will be lowered to the seafloor beneath the Ross Ice Shelf.</span>
<span class="attribution"><span class="source">Authors provided</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>These data will allow us to identify previous episodes when the ice shelf thinned and disintegrated, driving retreat of the WAIS interior. Environmental data from these intervals will identify the regional climatic conditions that drove this retreat and help determine the sensitivity of the system to increases in global mean temperature. </p>
<hr>
<p><em>SWAIS2C builds on other successful international scientific drilling programmes in the Ross Sea region, including <a href="https://www.wgtn.ac.nz/antarctic/research/past-research-prog/andrill">ANDRILL</a> and <a href="https://iodp.tamu.edu/scienceops/expeditions/ross_sea_ice_sheet_history.html">IODP</a> and is supported by <a href="https://www.icdp-online.org/projects/by-continent/polar-regions/antarctica/swais-2c-antarctica/">ICDP</a>.</em></p>
<hr><img src="https://counter.theconversation.com/content/215878/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Richard Levy receives funding from the Antarctic Science Platform supported by the New Zealand Ministry for Business Innovation and Employment. </span></em></p><p class="fine-print"><em><span>Dan Lowry receives funding from the Antarctic Science Platform supported by the New Zealand Ministry for Business Innovation and Employment.</span></em></p><p class="fine-print"><em><span>Huw Horgan receives funding from the Antarctic Science Platform supported by the New Zealand Ministry for Business Innovation and Employment. </span></em></p><p class="fine-print"><em><span>Tina van de Flierdt receives funding from the Natural Environment Research Council in the United Kingdom. </span></em></p><p class="fine-print"><em><span>Denise Kulhanek, Gavin Dunbar, Molly Patterson, and Nick Golledge do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Seafloor sediments from beneath the Ross Ice Shelf represent an archive of warmer periods in Earth’s past. An ambitious international project aims to uncover what we can learn about our hotter future.Richard Levy, Principal Scientist/Environment and Climate Research Leader, GNS ScienceDan Lowry, Ice Sheet & Climate Modeller, GNS ScienceDenise Kulhanek, Professor of Marine Micropaleontology, University of KielGavin Dunbar, Senior Lecturer in Palaeoclimate, Te Herenga Waka — Victoria University of WellingtonHuw Joseph Horgan, Research Scientist, Swiss Federal Institute of Technology ZurichMolly Patterson, Assistant Professor in Geology, Binghamton University, State University of New YorkNick Golledge, Professor of Glaciology, Te Herenga Waka — Victoria University of WellingtonTina van de Flierdt, Professor of Isotope Geochemistry, Imperial College LondonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2160302023-10-23T15:19:25Z2023-10-23T15:19:25ZIncreasing melting of West Antarctic ice shelves may be unavoidable – new research<figure><img src="https://images.theconversation.com/files/555284/original/file-20231023-21-tlq49h.jpg?ixlib=rb-1.1.0&rect=0%2C666%2C4592%2C2385&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/icebergs-antarctic-continent-165228470">Evgeny Kovalev SPB/Shutterstock</a></span></figcaption></figure><p>The rate at which the warming Southern Ocean melts the West Antarctic ice sheet will speed up rapidly over the course of this century, regardless of how much emissions fall in coming decades, <a href="https://www.nature.com/articles/s41558-023-01818-x">our new research</a> suggests. This ocean-driven melting is expected to increase sea-level rise, with consequences for coastal communities around the world.</p>
<p>The Antarctic ice sheet, the world’s largest volume of land-based ice, is a system of interconnected glaciers comprised of snowfall that remains year-round. Coastal ice shelves are the floating edges of this ice sheet which stabilise the glaciers behind them. The ocean melts these ice shelves from below, and if melting increases and an ice shelf thins, the speed at which these glaciers discharge fresh water into the ocean increases too and sea levels rise. </p>
<p>In West Antarctica, particularly the Amundsen Sea, this process has been underway for decades. Ice shelves are <a href="https://doi.org/10.1126/science.aaa0940">thinning</a>, glaciers are <a href="https://doi.org/10.1002/2013GL059069">flowing faster</a> towards the ocean and the ice sheet is <a href="https://doi.org/10.1038/s41586-018-0179-y">shrinking</a>. While ocean temperature measurements in this region are limited, modelling suggests it may have <a href="https://doi.org/10.1029/2021gl094566">warmed as a result of climate change</a>.</p>
<p>We chose to model the Amundsen Sea because it is the most vulnerable sector of the ice sheet. We used a regional ocean model to find out how ice-shelf melting will change here between now and 2100. How much melting can be prevented by reducing carbon emissions and slowing the rate of climate change – and how much is now unavoidable, no matter what we do?</p>
<h2>Rapid change is locked in</h2>
<p>We used the UK’s national supercomputer <a href="https://www.archer2.ac.uk/">ARCHER2</a> to run many different simulations of the 21st century, totalling over 4,000 years of ocean warming and ice-shelf melting in the Amundsen Sea.</p>
<p>We considered different trajectories for fossil fuel burning, from the best-case scenario where global warming is limited to 1.5°C in line with the Paris Agreement, to the worst, in which coal, oil and gas use is uncontrolled. We also considered the influence of natural variations in the climate, such as the timing of events such as El Niño.</p>
<p>The results are worrying. In all simulations there is a rapid increase over the course of this century in the rate of ocean warming and ice-shelf melting. Even the best-case scenario in which warming halts at 1.5°C, something that is <a href="https://www.scientificamerican.com/article/the-world-will-likely-miss-1-5-degrees-c-why-isnt-anyone-saying-so/">considered ambitious</a> by many experts, entails a threefold increase in the historical rate of warming and melting.</p>
<p>What’s more, there is little to no difference between the scenarios up to 2045. Ocean warming and ice-shelf melting in the 1.5°C scenario is statistically the same as in a mid-range scenario, which is closer to what existing pledges to reduce fossil fuel use over the coming decades would produce.</p>
<p>The worst-case scenario shows more melting than the others, but only from around mid-century onwards, and many experts think this amount of future fossil fuel burning is <a href="https://doi.org/10.1016/j.eneco.2017.04.015">unrealistic</a> anyway. </p>
<p>The results imply that we are now committed to rapid ocean warming in the Amundsen Sea until at least 2100, regardless of international policies on fossil fuels.</p>
<p>The increases in warming and melting are the result of ocean currents strengthening and driving more warm water from the deep ocean towards the shallower ice shelves along the coast. Other <a href="https://doi.org/10.1029/2021GL094566">studies</a> have suggested this process is behind the ice shelf thinning measured by satellites. </p>
<h2>How much will the sea level rise?</h2>
<p>Melting ice shelves are a major cause of sea-level rise, but not the whole story. We can’t put a number on how much sea levels will rise without also simulating the flow of Antarctic glaciers and the rate of snow accumulating on the ice sheet, which our model didn’t include. </p>
<p>But we have every reason to believe that increased ice-shelf melting in this region will cause the rate at which sea levels are rising to speed up. </p>
<p>The West Antarctic ice sheet is already contributing substantially to global sea-level rise and is losing about <a href="https://doi.org/10.5194/essd-15-1597-2023">80 billion tonnes of ice a year</a>. It contains enough ice to cause <a href="https://doi.org/10.1038/s41561-019-0510-8">up to 5 metres of sea-level rise</a>, but we don’t know how much of it will melt, and how quickly. Our colleagues around the world are <a href="https://doi.org/10.1038/s41586-021-03302-y">working hard to answer this question</a>.</p>
<h2>Courage and hope</h2>
<p>There are some consequences of climate change that can no longer be avoided, no matter how much fossil fuel use falls. Substantial melting of West Antarctica up to 2100 may now be one of them.</p>
<p>How do you tell a bad news story? The conventional wisdom is that you’re supposed to give people hope: to say that there’s a disaster behind one door, but we can avoid it if only we choose a different one. What do you do when your science tells you that all doors lead to the same disaster?</p>
<p><a href="https://onbeing.org/blog/kate-marvel-we-need-courage-not-hope-to-face-climate-change/">Kate Marvel</a>, an atmospheric scientist, said that when it comes to climate change, “we need courage, not hope … Courage is the resolve to do well without the assurance of a happy ending”. In this case, courage means shifting our attention to the longer term. </p>
<p>The future will not end in 2100, even if most people reading this will no longer be around. Our simulations of the 1.5°C scenario show ice-shelf melting starting to plateau by the end of the century, suggesting that further changes in the 22nd century and beyond may still be preventable. Reducing sea-level rise after 2100, or even slowing it down, could save many coastal cities. </p>
<p>Courage means accepting the need to adapt, protecting coastal communities where it’s possible to do so, and rebuilding or abandoning them where it’s not. By predicting future sea-level rise in advance, we’ll have time to plan for it – rather than wait until the ocean is on our doorstep.</p>
<hr>
<figure class="align-right ">
<img alt="Imagine weekly climate newsletter" src="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p><strong><em>Don’t have time to read about climate change as much as you’d like?</em></strong>
<br><em><a href="https://theconversation.com/uk/newsletters/imagine-57?utm_source=TCUK&utm_medium=linkback&utm_campaign=Imagine&utm_content=DontHaveTimeTop">Get a weekly roundup in your inbox instead.</a> Every Wednesday, The Conversation’s environment editor writes Imagine, a short email that goes a little deeper into just one climate issue. <a href="https://theconversation.com/uk/newsletters/imagine-57?utm_source=TCUK&utm_medium=linkback&utm_campaign=Imagine&utm_content=DontHaveTimeBottom">Join the 20,000+ readers who’ve subscribed so far.</a></em></p>
<hr><img src="https://counter.theconversation.com/content/216030/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kaitlin Naughten receives funding from UK Research and Innovation and the National Environment Research Council. She is a member of Prospect.</span></em></p><p class="fine-print"><em><span>Jan De Rydt receives funding from UK Research and Innovation and the EU Horizon Europe funding programme.</span></em></p><p class="fine-print"><em><span>Paul Holland receives funding from UK Research and Innovation, Natural Environment Research Council and EU Horizon Europe funding programmes. He is a member of the Labour Party and Prospect.</span></em></p>Humanity has lost control of West Antarctic ice-sheet melting.Kaitlin Naughten, Ocean-Ice Modeller, British Antarctic SurveyJan De Rydt, Associate Professor of Polar Glaciology and Oceanography, Northumbria University, NewcastlePaul Holland, Ocean and Ice Scientist, British Antarctic SurveyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2155292023-10-17T19:08:11Z2023-10-17T19:08:11ZMore than 200 scientists from 19 countries want to tell us the Southern Ocean is in trouble<figure><img src="https://images.theconversation.com/files/554159/original/file-20231017-15-ht1j0s.jpg?ixlib=rb-1.1.0&rect=28%2C4%2C3155%2C2110&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Pat James, Australian Antarctic Division</span></span></figcaption></figure><p>While the Southern Ocean around Antarctica has been <a href="https://theconversation.com/the-southern-ocean-absorbs-more-heat-than-any-other-ocean-on-earth-and-the-impacts-will-be-felt-for-generations-189561">warming for decades</a>, the annual extent of winter sea ice seemed relatively stable – compared to the Arctic. In some areas Antarctic sea ice was even increasing. </p>
<p>That was until 2016, when <a href="https://www.nature.com/articles/s43247-023-00961-9">everything changed</a>. The annual extent of winter sea ice stopped increasing. Now we have had <a href="https://theconversation.com/devastatingly-low-antarctic-sea-ice-may-be-the-new-abnormal-study-warns-212376">two years of record lows</a>.</p>
<p>In 2018 the international scientific community agreed to produce the first marine ecosystem assessment for the Southern Ocean. We modelled the assessment process on a working group of the Intergovernmental Panel on Climate Change (IPCC). So the resulting “<a href="https://zenodo.org/records/8359585">summary for policymakers</a>” being released today is like an IPCC report for the Southern Ocean. </p>
<p>This report can now be used to guide decision-making for the protection and conservation of this vital region and the diversity of life it contains. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/554187/original/file-20231017-2786-gzvb0u.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Map showing the number of authors from different regions, illustrating the international nature of the assessment process." src="https://images.theconversation.com/files/554187/original/file-20231017-2786-gzvb0u.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/554187/original/file-20231017-2786-gzvb0u.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=271&fit=crop&dpr=1 600w, https://images.theconversation.com/files/554187/original/file-20231017-2786-gzvb0u.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=271&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/554187/original/file-20231017-2786-gzvb0u.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=271&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/554187/original/file-20231017-2786-gzvb0u.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=341&fit=crop&dpr=1 754w, https://images.theconversation.com/files/554187/original/file-20231017-2786-gzvb0u.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=341&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/554187/original/file-20231017-2786-gzvb0u.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=341&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Global participation (numbers of authors from different regions) in the assessment.</span>
<span class="attribution"><a class="source" href="https://zenodo.org/records/8359585">Constable, A.J. et al (2023) Marine Ecosystem Assessment for the Southern Ocean.</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/fractured-foundations-how-antarcticas-landfast-ice-is-dwindling-and-why-thats-bad-news-207814">Fractured foundations: how Antarctica's 'landfast' ice is dwindling and why that's bad news</a>
</strong>
</em>
</p>
<hr>
<h2>Why should we care about sea ice?</h2>
<p>Sea ice is to life in the Southern Ocean as soil is to a forest. It is the foundation for Antarctic marine ecosystems.</p>
<p>Less sea ice is a danger to all wildlife – from krill to emperor penguins and whales.</p>
<p>The sea ice zone provides essential food and safe-keeping to young Antarctic krill and small fish, and seeds the expansive growth of phytoplankton in spring, nourishing the entire food web. It is a platform upon which penguins breed, seals rest, and around which whales feed. </p>
<p>The international bodies that manage Antarctica and the Southern Ocean under the <a href="https://www.ats.aq/index_e.html">Antarctic Treaty System</a> urgently need better information on marine ecosystems. Our report helps fill this gap by systematically identifying options for managers to maximise the resilience of Southern Ocean ecosystems in a changing world.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1705569410604314758"}"></div></p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/emperor-penguins-face-a-bleak-future-but-some-colonies-will-do-better-than-others-in-diverse-sea-ice-conditions-214625">Emperor penguins face a bleak future – but some colonies will do better than others in diverse sea-ice conditions</a>
</strong>
</em>
</p>
<hr>
<h2>An open and collaborative process</h2>
<p>We sought input from a wide range of people across the entire Southern Ocean science community. </p>
<p>We sought to answer questions about the state of the whole Southern Ocean system - with an eye on the past, present and future.</p>
<p>Our team comprised 205 authors from 19 countries. They authored <a href="https://www.frontiersin.org/research-topics/10606/marine-ecosystem-assessment-for-the-southern-ocean-meeting-the-challenge-for-conserving-earth-ecosystems-in-the-long-term#overview">24 peer-reviewed papers</a>. We then distilled the findings from these papers into our summmary for policymakers. </p>
<p>We deliberately modelled the multi-disciplinary assessment process on a working group of the IPCC to distill the science into an easy-to-read and concise narrative for politicians and the general public alike. It provides a community assessment of levels of certainty around what we know.</p>
<p>We hope this “sea change” summary sets a new benchmark for translating marine research into policy responses. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/554169/original/file-20231017-15-6w52ns.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A graphic illustrating how the system-level assessment of marine ecosystems came together, showing a group of people at a table with concentric circles in the background including observations, drivers of change and ecosystem services" src="https://images.theconversation.com/files/554169/original/file-20231017-15-6w52ns.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/554169/original/file-20231017-15-6w52ns.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=749&fit=crop&dpr=1 600w, https://images.theconversation.com/files/554169/original/file-20231017-15-6w52ns.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=749&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/554169/original/file-20231017-15-6w52ns.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=749&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/554169/original/file-20231017-15-6w52ns.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=942&fit=crop&dpr=1 754w, https://images.theconversation.com/files/554169/original/file-20231017-15-6w52ns.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=942&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/554169/original/file-20231017-15-6w52ns.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=942&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Our system-level assessment addressed the multiple drivers of ecosystem change in the Southern Ocean.</span>
<span class="attribution"><a class="source" href="https://zenodo.org/records/8359585">Constable, A.J. et al (2023) Marine Ecosystem Assessment for the Southern Ocean.</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span>
</figcaption>
</figure>
<h2>So what’s in the report?</h2>
<p>Southern Ocean habitats, from the ice at the surface to the bottom of the deep sea, are changing. The warming of the ocean, decline in sea ice, melting of glaciers, collapse of ice shelves, changes in acidity, and direct human activities such as fishing, are all impacting different parts of the ocean and their inhabitants.</p>
<p>These organisms, <a href="https://theconversation.com/an-ocean-like-no-other-the-southern-oceans-ecological-richness-and-significance-for-global-climate-151084">from microscopic plants to whales</a>, face a changing and challenging future. Important foundation species such as Antarctic krill are likely to decline with consequences for the whole ecosystem.</p>
<p>The assessment stresses climate change is the most significant driver of species and ecosystem change in the Southern Ocean and coastal Antarctica. It calls for urgent action to curb global heating and ocean acidification.</p>
<p>It reveals an urgent need for international investment in <a href="https://theconversation.com/we-landed-a-camera-on-venus-before-seeing-parts-of-our-own-oceans-its-time-to-ramp-up-observations-closer-to-home-212970">sustained, year-round and ocean-wide</a> scientific assessment and observations of the health of the ocean. </p>
<p>We also need to develop better integrated models of how individual changes in species along with human impacts will translate to system-level change in the different food webs, communities and species.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1711094111305089149"}"></div></p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/antarcticas-heart-of-ice-has-skipped-a-beat-time-to-take-our-medicine-202729">Antarctica's heart of ice has skipped a beat. Time to take our medicine</a>
</strong>
</em>
</p>
<hr>
<h2>What’s next?</h2>
<p>Our report will be tabled at <a href="https://meetings.ccamlr.org/en">this week’s international meeting</a> of the Commission for the Conservation of Antarctic Marine Living Resources in Hobart.</p>
<p>The commission is the international body responsible for the conservation of marine ecosystems in the Southern Ocean, with membership of 26 nations and the European Union.</p>
<p>It is but one of the bodies our new report can assist. Currently assessments of change in habitats, species and food webs in the Southern Ocean are compiled separately for at least ten different international organisations or processes.</p>
<p>The Southern Ocean is a crucial life-support system, not just for Antarctica but for the entire planet. So many other bodies will need the information we produced for decision-making in this critical decade for action on climate, including the IPCC itself.</p>
<p>Beyond the science, the assessment team has delivered important lessons about how coordinated, collaborative and consultative approaches can deliver ecosystem information into policymaking. Our first assessment has taken five years, but this is just the beginning. Now we’re up and running, we can continue to support evidence-based conservation of Southern Ocean ecosystems into the future. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/record-low-antarctic-sea-ice-is-another-alarming-sign-the-oceans-role-as-climate-regulator-is-changing-204680">Record low Antarctic sea ice is another alarming sign the ocean's role as climate regulator is changing</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/215529/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Andrew J Constable has worked for the Australian Public Service in the Australian Antarctic Division, received funding from Pew Charitable Trusts, and, for the marine ecosystem assessment for the Southern Ocean, he received funding from environmental and fisheries non-government organisations (details are identified in the Summary for Policy Makers).</span></em></p><p class="fine-print"><em><span>Jess Melbourne-Thomas receives funding from the Climate Systems Hub of the Australian Government’s National Environmental Science Program, and the Fisheries Research and Development Corporation.</span></em></p>The first comprehensive assessment of trends in Southern Ocean ecosystems reveals an urgent need to address climate change. The summary for policymakers can guide decision-makers.Andrew J Constable, Adviser, Antarctica and Marine Systems, Science & Policy, University of TasmaniaJess Melbourne-Thomas, Transdisciplinary Researcher & Knowledge Broker, CSIROLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2129702023-10-16T19:05:34Z2023-10-16T19:05:34ZWe landed a camera on Venus before seeing parts of our own oceans – it’s time to ramp up observations closer to home<p>Viewed from the Voyager 1 space probe as it passed beyond the edge of the solar system, Earth and Venus might not look too different – same diameter, similar mass and distance from the Sun.</p>
<p>But from a human perspective, Venus is a hostile spot. Its much denser atmosphere enables a greenhouse effect on steroids, with <a href="https://doi.org/10.1007/s11214-018-0467-8">surface temperatures approaching 500°C</a>.</p>
<figure class="align-right ">
<img alt="An image of Venus as captured by the Mariner spacecraft during the 1970s" src="https://images.theconversation.com/files/546621/original/file-20230906-28-tkmbon.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/546621/original/file-20230906-28-tkmbon.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=469&fit=crop&dpr=1 600w, https://images.theconversation.com/files/546621/original/file-20230906-28-tkmbon.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=469&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/546621/original/file-20230906-28-tkmbon.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=469&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/546621/original/file-20230906-28-tkmbon.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=590&fit=crop&dpr=1 754w, https://images.theconversation.com/files/546621/original/file-20230906-28-tkmbon.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=590&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/546621/original/file-20230906-28-tkmbon.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=590&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">An image of Venus captured from a spacecraft.</span>
<span class="attribution"><span class="source">NASA</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>While the timeline that brought Venus’ climate to where it is today is still being researched, the critical difference between the two planetary systems is the ocean. <a href="https://doi.org/10.1038/s41586-021-03873-w">Venus possibly never had one</a>, but oceans on Earth have shielded us from the worst climate impacts by storing around 90% of the heat captured by the changing atmosphere.</p>
<p>We have managed to <a href="https://coolcosmos.ipac.caltech.edu/ask/44-Has-a-spacecraft-ever-landed-on-Venus-">land a camera on the surface of Venus</a>, with the Soviet space probe Venera 9 in 1975. Like the “Earth rise” image captured during the Apollo 8 mission in 1968, this again proved the power of visual imagery. Yet we’re still learning about our own oceans. </p>
<p>The first images of the surface of Venus arrived a year before we <a href="https://theconversation.com/explorer-robert-ballards-memoir-finds-shipwrecks-and-strange-life-forms-in-the-oceans-darkest-reaches-161042">discovered mid-ocean hydrothermal vents</a> and three years before we first looked beneath an Antarctic ice shelf.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/climate-scientists-explore-hidden-ocean-beneath-antarcticas-largest-ice-shelf-90006">Climate scientists explore hidden ocean beneath Antarctica's largest ice shelf</a>
</strong>
</em>
</p>
<hr>
<p>If we want to better understand the climate-regulating role of Earth’s oceans, we must increase the effort we put into observing them, with a focus on our planet’s largest heat sink, the Southern Ocean.</p>
<figure class="align-center ">
<img alt="Sea ice up against an ice shelf." src="https://images.theconversation.com/files/547436/original/file-20230911-24-b3mmo6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/547436/original/file-20230911-24-b3mmo6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=222&fit=crop&dpr=1 600w, https://images.theconversation.com/files/547436/original/file-20230911-24-b3mmo6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=222&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/547436/original/file-20230911-24-b3mmo6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=222&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/547436/original/file-20230911-24-b3mmo6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=279&fit=crop&dpr=1 754w, https://images.theconversation.com/files/547436/original/file-20230911-24-b3mmo6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=279&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/547436/original/file-20230911-24-b3mmo6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=279&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Sea ice up against an ice shelf.</span>
<span class="attribution"><span class="source">Craig Stevens/K132/NIWA</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<h2>Direct observations</h2>
<p>Thanks to a variety of Earth-orbiting satellites and resource-intensive computer simulations, we have made progress in observing Earth’s oceans. </p>
<p>But as powerful and all-encompassing as these observations are, we still make surprise discoveries, such as vent systems on the seafloor and <a href="https://doi.org/10.3389/fmars.2021.642040">life in under-ice cavities</a>. This is why we need to continue exploring and ramp up our capacity to measure the oceans directly. </p>
<p>Nowhere is this more true than in the Southern Ocean, the connector of all oceans. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/an-ocean-like-no-other-the-southern-oceans-ecological-richness-and-significance-for-global-climate-151084">An ocean like no other: the Southern Ocean's ecological richness and significance for global climate</a>
</strong>
</em>
</p>
<hr>
<p>Several unique features distinguish the Southern Ocean from Earths’ other oceans. One is Antarctica’s sea ice – the continent’s skirt of frozen ocean that comes and goes with the seasons. </p>
<p>The <a href="https://theconversation.com/as-antarctic-sea-ice-continues-its-dramatic-decline-we-need-more-measurements-and-much-better-models-to-predict-its-future-213747">dramatic decline in Antarctic sea ice</a> is of concern to the climate science community because of its several major roles: as a mirror that reflects solar energy back into space, a pump that ventilates the deep ocean, and an essential habitat for polar life, from algae to Emperor penguins.</p>
<p>The Southern Ocean’s other unique feature is the Antarctic Circumpolar Current – a massive flywheel of energy driven by winds, spinning non-stop from west to east. The flow rate in this giant ocean current dwarfs even the largest river, the Amazon, by three orders of magnitude. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/explainer-how-the-antarctic-circumpolar-current-helps-keep-antarctica-frozen-106164">Explainer: how the Antarctic Circumpolar Current helps keep Antarctica frozen</a>
</strong>
</em>
</p>
<hr>
<figure class="align-center ">
<img alt="Shipboard view of ocean and ice" src="https://images.theconversation.com/files/547433/original/file-20230911-25-op4og6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/547433/original/file-20230911-25-op4og6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/547433/original/file-20230911-25-op4og6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/547433/original/file-20230911-25-op4og6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/547433/original/file-20230911-25-op4og6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/547433/original/file-20230911-25-op4og6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/547433/original/file-20230911-25-op4og6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Ocean sensors being retrieved by the Korean icebreaker IBRV Araon in Robertson Bay, Antarctica.</span>
<span class="attribution"><span class="source">Fiona Elliott/NIWA/ANTA1801</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<h2>Fostering collaboration</h2>
<p>The rapid changes in the Southern Ocean and Antarctica make it clear we need to increase our capacity to observe and measure this environment. But it is a very expensive place to work. </p>
<p>While it is not quite Venus in terms of difficulty, measurements have to target and prioritise the major science questions.</p>
<p>Earlier this year, more than 300 researchers gathered for the first <a href="https://soos.aq/soos-symposium-2023">Southern Ocean Observing Symposium</a> in Hobart to express their growing concern. They came together to assess the state of the ocean and to develop new ways to collaborate, share information and to connect efforts from national research programmes as much as possible. </p>
<p>A <a href="https://doi.org/10.3389/fmars.2023.1206119">recent analysis</a> looked at how we might measure connections between the Ross Sea and far-East Antarctica. These are critical because major ice-free ocean areas, known as polynyas, and the massive ice shelf in the Ross Sea region, influence waters flowing westward into East Antarctica.</p>
<h2>The risks of the unknown</h2>
<p>We are entering a new era of observing the Southern Ocean. The urgency of the climate emergency has prompted a range of new technologies to be deployed to monitor and understand the changing conditions, including a fleet of autonomous <a href="https://niwa.co.nz/oceans/research-projects/argo-floats">Argo floats</a> that monitor temperature and salinity at depth. </p>
<figure class="align-center ">
<img alt="Argo profiling floats in the Southern Ocean." src="https://images.theconversation.com/files/552459/original/file-20231006-31-s0epyn.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/552459/original/file-20231006-31-s0epyn.gif?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=544&fit=crop&dpr=1 600w, https://images.theconversation.com/files/552459/original/file-20231006-31-s0epyn.gif?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=544&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/552459/original/file-20231006-31-s0epyn.gif?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=544&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/552459/original/file-20231006-31-s0epyn.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=683&fit=crop&dpr=1 754w, https://images.theconversation.com/files/552459/original/file-20231006-31-s0epyn.gif?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=683&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/552459/original/file-20231006-31-s0epyn.gif?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=683&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Argo profiling floats in the Southern Ocean.</span>
<span class="attribution"><a class="source" href="https://argo.ucsd.edu/">Howard Freeland/Argo Program</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>It isn’t cheap to track changes in such a remote location. Sending ships and deploying robust instrumentation, and then retrieving the gear and data, all adds up. But it is almost certainly far less expensive than responding to the impacts of climate change.</p>
<p>The lack of direct observations is one reason we continue to be surprised by changes in the region. As a community, we have been caught out by the sudden decline in sea ice around Antarctica. But the lack of a consistent method to <a href="https://doi.org/10.1029/2020GL090866">measure sea ice thickness over large areas</a> has been a known major gap in our knowledge for decades.</p>
<p>The Venus analogy may be a stretch, but there is little doubt the observations in the Southern Ocean and around Antarctica are a harbinger of changes to a climate system that, to date, has enabled our species and cultures to flourish.</p><img src="https://counter.theconversation.com/content/212970/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Craig Stevens receives funding from the New Zealand Ministry for Business, Innovation and Employment (MBIE), Antarctica New Zealand Antarctic Science Platform (ASP), MBIE Strategic Science Investment Fund and the New Zealand Royal Society Te Apārangi Marsden Fund. He is on the Council of the New Zealand Association of Scientists.</span></em></p><p class="fine-print"><em><span>Natalie Robinson 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 rapid changes in the Southern Ocean and Antarctica highlight the urgency of better direct observations and measurements, beyond satellite monitoring and modelling.Craig Stevens, Professor in Ocean Physics, University of Auckland, Waipapa Taumata RauNatalie Robinson, Marine Physicist, National Institute of Water and Atmospheric ResearchLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2146252023-10-01T22:11:48Z2023-10-01T22:11:48ZEmperor penguins face a bleak future – but some colonies will do better than others in diverse sea-ice conditions<figure><img src="https://images.theconversation.com/files/551076/original/file-20230928-25-8vdn1c.jpeg?ixlib=rb-1.1.0&rect=85%2C145%2C5637%2C3303&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Sara Labrousse/French Polar Institute</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>The long-term future looks bleak for Emperor penguins, but our <a href="https://www.science.org/doi/10.1126/sciadv.adg8340">new research</a> shows some birds may be able to survive in certain conditions, depending on where they live, at least for the next few decades. </p>
<p>Over the past two years, Antarctic sea ice has declined dramatically, prompting scientists to suggest it could reach a “<a href="https://www.nature.com/articles/s43247-023-00961-9">new state</a>”. </p>
<p>A <a href="https://www.nature.com/articles/s43247-023-00927-x">study</a> based on satellite images shows that sea ice broke out early in Antarctica’s Bellingshausen Sea in 2022, potentially resulting in breeding failures across several Emperor penguin colonies in that region.</p>
<p>Our research shows Emperors form colonies in surprisingly diverse environmental conditions that vary depending on location around the continent. Within each of these regions, there is little difference between where birds make their homes and other sites, suggesting they could shift if they had to. This provides a ray of hope in an otherwise bleak outlook.</p>
<p>Emperor penguins may be the only birds to rarely set foot on land. They are unique among penguin species in that they breed on sea ice during the harsh Antarctic winter. </p>
<figure class="align-center ">
<img alt="A colony of male Emperor penguins, with young chicks." src="https://images.theconversation.com/files/551077/original/file-20230928-23-68fszb.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/551077/original/file-20230928-23-68fszb.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/551077/original/file-20230928-23-68fszb.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/551077/original/file-20230928-23-68fszb.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/551077/original/file-20230928-23-68fszb.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/551077/original/file-20230928-23-68fszb.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/551077/original/file-20230928-23-68fszb.jpeg?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">Male Emperor penguins incubate eggs and raise the chicks on sea ice during the Antarctic winter.</span>
<span class="attribution"><span class="source">Sara Labrousse/French Polar Institute</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>We know that they need “fast ice” – the coastal sea ice attached to the Antarctic continent or ice shelves. But they actually inhabit a range of fast-ice locations that differ in the timing of ice formation, how much ice forms and breaks, and even how close they get to other penguin species. </p>
<p>Depending on where they are along the Antarctic coast, Emperors make use of the habitat available to them. Their behaviour may be flexible enough to allow some colonies to cope better in a warming world. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/as-antarctic-sea-ice-continues-its-dramatic-decline-we-need-more-measurements-and-much-better-models-to-predict-its-future-213747">As Antarctic sea ice continues its dramatic decline, we need more measurements and much better models to predict its future</a>
</strong>
</em>
</p>
<hr>
<h2>Why fast ice is important</h2>
<p>Emperor penguins rely on fast ice as a stable platform for their breeding season. Female Emperors lay their eggs and the males incubate them for about two and a half months.</p>
<p>Even though Antarctica’s sea ice is diminishing, this refers to a measure known as “sea ice extent”, which includes all sea ice covering the polar ocean, whether it is fast ice or drifting pack ice. </p>
<p>A decrease in sea ice extent is not necessary linearly linked to a drop in the area covered by fast ice (although the reverse is true).</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/fractured-foundations-how-antarcticas-landfast-ice-is-dwindling-and-why-thats-bad-news-207814">Fractured foundations: how Antarctica's 'landfast' ice is dwindling and why that's bad news</a>
</strong>
</em>
</p>
<hr>
<p>If fast ice were to disappear, we would expect more than 90% of Emperor colonies to become functionally extinct by the end of the century. However, our study suggests that in the short to medium term, we should consider the differences in the penguins’ breeding habitats when we think about ways to protect them. </p>
<h2>Emperors are unlikely to move far</h2>
<p>By looking a little closer at different fast-ice habitats, we found Emperor penguins have certain preferences. The persistence of the ice (how long it lasts into the summer) was important because chicks had more time to develop their water-proof swimming feathers. </p>
<p>In some cases, being close to Adélie penguins made a difference. In other cases, Emperors preferred sites with shallow ocean depths below the colony. </p>
<p>Our results suggest that two of these habitat conditions support larger colonies: stable fast ice that lasts throughout the breeding season (with only small changes in the growth and retreat seasonal cycle) and a good balance between a fast-ice platform that is wide enough to raise chicks but close enough to the ocean to get food for them.</p>
<figure class="align-center ">
<img alt="Emperor penguins jumping back onto the ice after foraging trips in the ocean." src="https://images.theconversation.com/files/551079/original/file-20230928-19-qatzri.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/551079/original/file-20230928-19-qatzri.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/551079/original/file-20230928-19-qatzri.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/551079/original/file-20230928-19-qatzri.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/551079/original/file-20230928-19-qatzri.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/551079/original/file-20230928-19-qatzri.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/551079/original/file-20230928-19-qatzri.jpeg?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">Emperor penguins need access to the ocean to feed their chicks during the breeding season.</span>
<span class="attribution"><span class="source">Sara Labrousse/French Polar Institute</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>We need further studies to clarify these links and the relationship between population size and habitat quality. In our study, we weren’t able to consider prey availability and there may be other factors that play an important role. </p>
<p>Previous <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.14864">research</a> has already shown that Emperor penguins have limited capacity to disperse to find more suitable climate refuges. This is supported by the genetic partitioning among the penguin populations in different Antarctic regions we studied. </p>
<p>It is therefore unlikely Emperors would move far to avoid more severe climate impacts, even if “better” habitats existed and could host larger colonies.</p>
<figure class="align-center ">
<img alt="A group of Emperor penguins, seen from the back" src="https://images.theconversation.com/files/551080/original/file-20230928-21-84w4ie.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/551080/original/file-20230928-21-84w4ie.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/551080/original/file-20230928-21-84w4ie.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/551080/original/file-20230928-21-84w4ie.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/551080/original/file-20230928-21-84w4ie.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/551080/original/file-20230928-21-84w4ie.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/551080/original/file-20230928-21-84w4ie.jpeg?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">Emperors don’t easily move to other breeding sites, even if the conditions are better.</span>
<span class="attribution"><span class="source">Sara Labrousse/French Polar Institute</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<h2>Protecting penguin habitat</h2>
<p>Climate change is currently one of the main pressures driving Emperor penguins closer to extinction. </p>
<p>However, the latest <a href="https://www.ipbes.net/global-assessment">global assessment</a> by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (<a href="https://www.ipbes.net/">IPBES</a>) clearly identified fishing activities as historic and current drivers of the erosion of marine biodiversity worldwide.</p>
<p>This is also true for Antarctica. While fishing pressure there is limited to a fraction of the global fishing fleet, some of the largest vessels target krill, a tiny shrimp-like crustacean consumed by many Antarctic predators, including Emperor penguins.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/ive-spent-40-years-studying-antarctica-the-frozen-continent-has-never-needed-our-help-more-211520">I've spent 40 years studying Antarctica. The frozen continent has never needed our help more</a>
</strong>
</em>
</p>
<hr>
<p>With climate models predicting further reductions in sea ice extent, new fishing grounds could open and amplify pressure on other Antarctic wildlife. </p>
<p>If we want to live in a world with Emperor penguins, the most important thing to do would be to cut greenhouse gas emissions steeply. Another key action could be to prevent fishing in areas where climate change will have the most impact. </p>
<p>In this respect, truly protected areas are one conservation tool at our disposal. Now that our research provides more detailed information about penguin habitats, we can begin the process of more careful planning for conservation. </p>
<p>The world’s <a href="https://www.mfat.govt.nz/en/environment/antarctica-and-the-southern-ocean/ross-sea-region-marine-protected-area/">largest marine protected area</a> exists in the Ross Sea, which is home to about 25% of the world’s Emperor penguins. Lessons we learn from protection there could help mitigate future declines of Emperors around Antarctica.</p><img src="https://counter.theconversation.com/content/214625/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sara Labrousse is affiliated with LOCEAN/CNRS. </span></em></p><p class="fine-print"><em><span>Michelle LaRue receives funding from the National Science Foundation and NASA. </span></em></p>If we want to live in a world with Emperor penguins, we need to cut emissions steeply and protect parts of the ocean around Antarctica where climate change will have the biggest impact.Sara Labrousse, Chercheuse en écologie polaire, Sorbonne UniversitéMichelle LaRue, Associate Professor in Conservation Biology, University of CanterburyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2123762023-09-13T09:02:14Z2023-09-13T09:02:14ZDevastatingly low Antarctic sea ice may be the ‘new abnormal’, study warns<p>For most of us, Antarctic sea ice is an abstraction – something far away we may have seen on a documentary. But the radiant white sheets of ice floating on the seas around the snowy continent are a crucial component of Earth’s climate processes.</p>
<p>Sea ice insulates the ocean, reflects heat, drives currents, supports ecosystems and protects ice shelves. It also has an annual seasonal cycle – some of the ice melts, then freezes again.</p>
<p>Every year, the cycle of freeze and melt around Antarctica has been extremely reliable. Until recently. </p>
<p>In a new study <a href="https://doi.org/10.1038/s43247-023-00961-9">published today in Communications Earth & Environment</a>, we have found a preliminary indication that Antarctic sea ice may have entered a new state of diminished coverage.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/UPXLWa6CHlk?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">The seasonal expansion and contraction of Antarctic sea ice (Animation by NASA/GSFC Science Visualisation Studio)</span></figcaption>
</figure>
<h2>A sudden, dramatic loss</h2>
<p>For many years, while the Arctic lost sea ice, the Antarctic did not. Then, in the spring of 2016, Antarctic sea-ice coverage dropped dramatically. Over two years, the Antarctic lost as much sea ice as the Arctic <a href="https://www.pnas.org/doi/10.1073/pnas.1906556116">had lost in three decades</a>. Since then, Antarctic sea ice has been below average almost constantly. </p>
<p>This past Southern Hemisphere summer, Antarctic sea ice was the lowest it has ever been, with dire consequences. In late 2022 we saw the <a href="https://www.nature.com/articles/s43247-023-00927-x">heartbreaking loss of 10,000 emperor penguin chicks</a>, when the sea ice they lived on melted before they had grown their waterproof feathers.</p>
<p>On February 19 2023, Antarctic sea ice set a new record minimum of 1.77 million square kilometres, 36% below the 1979–2022 average for the summer minimum.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/antarcticas-heart-of-ice-has-skipped-a-beat-time-to-take-our-medicine-202729">Antarctica's heart of ice has skipped a beat. Time to take our medicine</a>
</strong>
</em>
</p>
<hr>
<p>Since then, things have gone from bad to worse. The winter around Antarctica is cold and dark. Ever since we’ve had satellites to measure it, the surface of the ocean has reliably frozen into sea ice at about the same pace every winter, even following low sea ice summers. <a href="https://www.abc.net.au/news/2023-07-24/antarctic-sea-ice-levels-nosedive-five-sigma-event/102635204">Except for this year</a>.</p>
<p>This winter we have seen the largest negative anomaly – deviation from the norm – since reliable satellite measurements began in the late 1970s. What’s more, this record negative anomaly happened at a time of year when there has historically been very little variation from one year to the next.</p>
<p>Something has fundamentally changed Antarctic sea ice this year.</p>
<h2>Two main drivers of sea ice</h2>
<p>In our study, we used a statistical algorithm to identify three different periods in the sea-ice record. The first was a neutral sea-ice period from November 1978 to August 2007, the second a high sea-ice period from September 2007 to August 2016, and the third a low sea-ice period from September 2016 until now.</p>
<p>Our analysis of the relationship between sea ice and the underlying ocean suggests this current low sea-ice period may represent a new state or “regime” for Antarctic sea ice. What does that mean?</p>
<p>Sea ice forms a thin layer between the ocean and the atmosphere. Therefore, it is affected by both.</p>
<p>On timescales of days and weeks, the atmosphere is what controls sea ice – it forms when the air above is cold, and is blown around by the wind.</p>
<p>However, the ocean is crucial in determining how the sea ice responds to the atmosphere. The waters beneath are what influences sea ice variation and change in the long term.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/why-antarcticas-sea-ice-cover-is-so-low-and-no-its-not-just-about-climate-change-109572">Why Antarctica's sea ice cover is so low (and no, it's not just about climate change)</a>
</strong>
</em>
</p>
<hr>
<p>Lately, sea ice seems to be responding to atmospheric drivers differently than it did in the past, suggesting an influence from the slowly varying ocean may be important.</p>
<p><a href="https://www.nature.com/articles/s41467-018-07865-9">Research published in 2019</a> suggested ocean warming may have played a role in the low sea ice extent observed in the 2016/17 summer.</p>
<p>Building on this hypothesis, our study examined the long-term variations in sea ice and ocean temperature, finding that ocean warming has pushed Antarctic sea ice into a new low-extent state.</p>
<h2>A clear warming trend</h2>
<p>Using data from ocean temperature measurements 100-200m below the surface, we found a clear warming trend over the period for which we have reliable observations.</p>
<p>Importantly, strong subsurface ocean warming began in 2015, in the same regions that lost substantial sea ice in 2016. This is a key indication the ocean was important in driving the low sea ice in 2016. Since then, the warm subsurface ocean seems to be maintaining the low sea-ice coverage.</p>
<p>Prior to 2016 there was no relationship between the amount of sea ice at the summertime minimum and the amount at the following wintertime maximum. Since 2016 there is a strong relationship. This change suggests something has fundamentally altered the relationship between the ocean and the sea ice.</p>
<p>Together, this evidence suggests the overall way of how Antarctic ice behaves in the atmosphere-ocean-sea ice system has changed.</p>
<p>Our results suggest that even though the record-breaking low sea ice we’ve seen this year is shocking, it is likely to be the new abnormal.</p>
<p>We may now be seeing the inevitable decline in Antarctic sea ice, long projected by climate models. The Antarctic region is changing rapidly. To understand these rapid shifts, we urgently need to support fieldwork in sea ice, and develop computer models that will help us to understand the changes we are already seeing, and to predict what the future will look like.</p>
<p>Reduced sea ice will have serious implications for Southern Ocean ecosystems and global consequences for the climate system. Dramatic changes in a seasonal cycle as reliable and critical as Antarctic sea ice underscores the urgency to reduce fossil fuel emissions.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/record-low-antarctic-sea-ice-is-another-alarming-sign-the-oceans-role-as-climate-regulator-is-changing-204680">Record low Antarctic sea ice is another alarming sign the ocean's role as climate regulator is changing</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/212376/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Edward Doddridge receives funding from the Australian Research Council.</span></em></p><p class="fine-print"><em><span>Ariaan Purich receives funding from the Australian Research Council. </span></em></p>Sea ice around Antarctica has always followed a predictable seasonal cycle. Now, we’ve experienced a sudden dramatic loss, and the changes are here to stay.Edward Doddridge, Research Associate in Physical Oceanography, University of TasmaniaAriaan Purich, Lecturer in Climate Variability and Change, Monash UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2115202023-08-21T20:18:03Z2023-08-21T20:18:03ZI’ve spent 40 years studying Antarctica. The frozen continent has never needed our help more<figure><img src="https://images.theconversation.com/files/543611/original/file-20230821-252667-2ea691.jpg?ixlib=rb-1.1.0&rect=41%2C0%2C4559%2C2586&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Patti Virtue</span></span></figcaption></figure><p>After decades immersed in Antarctic science, I’ve learned that physical and biological changes rarely occur smoothly. More often than not, they unfold in sharp steps. Right now, Antarctica’s climate and ecosystems are experiencing disturbing changes.</p>
<p>Much of this winter’s sea ice is <a href="https://theconversation.com/antarctica-is-missing-a-chunk-of-sea-ice-bigger-than-greenland-whats-going-on-210665">missing</a>. A crucial <a href="https://theconversation.com/torrents-of-antarctic-meltwater-are-slowing-the-currents-that-drive-our-vital-ocean-overturning-and-threaten-its-collapse-202108">ocean current</a> is slowing down, and glaciers and ice shelves are <a href="https://theconversation.com/antarctic-tipping-points-the-irreversible-changes-to-come-if-we-fail-to-keep-warming-below-2-207410">disintegrating</a>.</p>
<p>On land, fragile moss ecosystems are <a href="https://theconversation.com/existential-threat-to-our-survival-see-the-19-australian-ecosystems-already-collapsing-154077">collapsing</a>. Majestic emperor penguins may be headed for <a href="https://theconversation.com/antarcticas-emperor-penguins-could-be-extinct-by-2100-and-other-species-may-follow-if-we-dont-act-196563">extinction</a>. And pollution from human activity in Antarctica has left a <a href="https://www.theguardian.com/world/2023/aug/10/pollution-at-australias-largest-antarctic-research-station-exceeded-guidelines-for-almost-20-years">toxic legacy</a>.</p>
<p>It’s almost certain <a href="https://www.theguardian.com/world/2023/aug/08/drastic-action-needed-to-limit-worsening-extreme-events-in-antarctica-scientists-warn">things will get worse</a>. On Friday, hundreds of international scientists called for an <a href="https://soos.aq/soos-symposium-2023">urgent expansion</a> – not contraction – of Southern Ocean science in response to the emerging climate crisis. This adds to the <a href="https://www.theguardian.com/world/commentisfree/2023/aug/04/antarctica-heatwaves-sea-ice-levels-melting">scientific chorus</a> claiming we have only a narrow window to save the planet. </p>
<p>I’ve spent 40 years in Antarctic and subantarctic research. Some 22 of those were spent at the federal government’s <a href="https://www.antarctica.gov.au/about-us/">Australian Antarctic Division</a>; my final day there was last Thursday. No longer a public servant, I feel compelled, as a private citizen now, to publicly stand up for the icy continent and <a href="https://www.abc.net.au/listen/programs/sundayextra/antarctica/102746764">the benefit of Antarctic science</a> to society.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/antarctic-alarm-bells-observations-reveal-deep-ocean-currents-are-slowing-earlier-than-predicted-206289">Antarctic alarm bells: observations reveal deep ocean currents are slowing earlier than predicted</a>
</strong>
</em>
</p>
<hr>
<h2>Crucial to life as we know it</h2>
<p>Antarctica matters. What happens there affects global weather patterns and sea levels.</p>
<p>But Antarctica’s climate is changing. <a href="https://www.abc.net.au/news/2023-08-21/ocean-tempertature-records-2023/102701172">Record-breaking stored heat</a> is melting ice shelves from underneath, setting off a chain reaction. Without the buttressing of the ice shelves, glaciers flow faster to the sea. In West Antarctica, the Thwaites “doomsday glacier” is <a href="https://abcnews.go.com/International/images-antarcticas-doomsday-glacier-show-melting-below/story?id=97269226">melting faster than predicted</a>. In East Antarctica, lesser-known <a href="https://theconversation.com/conger-ice-shelf-has-collapsed-what-you-need-to-know-according-to-experts-180077">ice shelves have collapsed</a> and glaciers are shrinking, adding to sea-level rise.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/antarcticas-doomsday-glacier-how-its-collapse-could-trigger-global-floods-and-swallow-islands-173940">Antarctica's 'doomsday' glacier: how its collapse could trigger global floods and swallow islands</a>
</strong>
</em>
</p>
<hr>
<p>Antarctica is governed by <a href="https://www.ats.aq/e/antarctictreaty.html">the Antarctic Treaty</a>, negotiated by 12 countries, including Australia, during the Cold War in 1959. Australia’s territory in Antarctica comprises 42% of the continent. </p>
<p>In my view, the treaty is magnificent. It represents a grand vision: a continent set aside for conservation, peace and science.</p>
<p>But Antarctica remains under threat. And the biggest threat of all is climate change. </p>
<p>In June this year, <a href="https://um.fi/current-affairs/-/asset_publisher/gc654PySnjTX/content/helsinki-declaration-on-climate-change-and-the-antarctic">all treaty nations</a>, including Australia, collectively stated:</p>
<blockquote>
<p>changes in Antarctic and Southern Ocean environments are linked to, and influence, climate impact drivers globally.</p>
</blockquote>
<p>They added “further irreversible change is likely” without “accelerated efforts” to reduce greenhouse gas emissions.</p>
<p>Scientific research is crucial in the face of these threats, to help better understand these changes now and over the longer term, and to feed into policy interventions. </p>
<p>Surprisingly a <a href="https://www.abc.net.au/news/2023-07-29/australian-antarctic-division-told-to-find-25m-in-budget/102653756">budget shortfall</a> appears to be inadvertently <a href="https://www.theguardian.com/world/2023/aug/01/australian-antarctic-division-research-program-budget-cuts-climate-science-projects">curtailing plans for science this summer</a>, according to the Guardian Australia.</p>
<p>In July, the ABC reported the Antarctic Division told staff <a href="https://www.abc.net.au/news/2023-07-29/australian-antarctic-division-told-to-find-25m-in-budget/102653756">A$25 million in budget savings</a> was needed this financial year. This led to a review of <a href="https://www.nature.com/articles/d41586-023-02576-8">plans for field research</a> this summer. Reportedly, two out of three permanent research stations (Mawson and Davis) will not be filled with the normal number of scientists this season. That means some planned and approved <a href="https://www.theguardian.com/world/2023/aug/01/australian-antarctic-division-research-program-budget-cuts-climate-science-projects">projects will not be going ahead this year</a>, including surveys on sea-ice thickness and landfast sea ice. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/fractured-foundations-how-antarcticas-landfast-ice-is-dwindling-and-why-thats-bad-news-207814">Fractured foundations: how Antarctica's 'landfast' ice is dwindling and why that's bad news</a>
</strong>
</em>
</p>
<hr>
<p>The Greens claim the $25 million hit to the Antarctic Division represents a <a href="https://greens.org.au/news/media-release/senate-inquiry-aad-mismanagement-established">16% cut to its operating budget</a> for the current financial year.</p>
<p>Seizing an opportunity, the <a href="https://www.theguardian.com/australia-news/2023/aug/09/antarctica-climate-science-projects-liberal-greens-deal">Greens and Liberal Party</a> established a <a href="https://www.aph.gov.au/Parliamentary_Business/Committees/Senate/Environment_and_Communications/AntarcticDivision">Senate inquiry</a> into what they refer to as funding cuts, to report by November 30.</p>
<p>Generally speaking, Antarctic activities receive overwhelmingly bipartisan support. For many decades Australia’s record in Antarctic protection has been impressive. For example, Environment Minister Tanya Plibersek recently tripled the size of the marine protected area around <a href="https://theconversation.com/penguin-paradise-and-geological-freak-why-macquarie-island-deserves-a-bigger-marine-park-201368">Macquarie Island</a>. </p>
<p>Former Labor environment minister <a href="https://www.smh.com.au/environment/conservation/garrett-talks-up-governments-whaling-stance-20100605-xm31.html">Peter Garrett advanced whale conservation</a>. He was instrumental in the campaign against so-called “scientific whaling” in the Antarctic, backed by government scientists, which culminated in Australia’s successful challenge to Japanese whaling in the International Court of Justice in 2014. </p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"725470293662158849"}"></div></p>
<p>Liberal prime minister Malcolm Turnbull funded <a href="https://www.theguardian.com/world/2015/oct/29/malcolm-turnbull-announces-custom-built-icebreaker-for-antarctic-research">Australia’s new icebreaker</a> and <a href="https://www.theguardian.com/environment/2022/aug/10/rats-and-rabbits-invasive-species-macquarie-island-southern-ocean-aoe">feral pest eradication from Macquarie Island</a>. And Labor prime minister Bob Hawke, with treasurer Paul Keating, collaborated with French prime minister Michel Rocard in 1991 to ensure a mining ban and sign the <a href="https://www.ats.aq/e/protocol.html">Madrid Protocol</a> to protect Antarctic ecosystems. </p>
<p>Support for Antarctic Division activities contributed to curtailing the illegal toothfish fishing in Antarctic waters. A regulated, sustainable industry is now in place. Krill fisheries operate according to science-based decisions. Efforts to reduce albatross bycatch in longline fishing were also led by Antarctic Division scientists.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/542753/original/file-20230815-29-5xb8yc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A photo of icy mountains looming over Ross Sea in east Antarctica" src="https://images.theconversation.com/files/542753/original/file-20230815-29-5xb8yc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/542753/original/file-20230815-29-5xb8yc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/542753/original/file-20230815-29-5xb8yc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/542753/original/file-20230815-29-5xb8yc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/542753/original/file-20230815-29-5xb8yc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/542753/original/file-20230815-29-5xb8yc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/542753/original/file-20230815-29-5xb8yc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Mount Martin looms over the Ross Sea in east Antarctica.</span>
<span class="attribution"><span class="source">Dana M Bergstrom</span></span>
</figcaption>
</figure>
<h2>Cleaning up the mess in Antarctica</h2>
<p>The story of Antarctica serves as a compelling reminder humanity must end our reliance on fossil fuels. We must also do a far better job of environmental stewardship – including paying for the scientific research so urgently needed.</p>
<p>Failing to fully support vital Antarctic science in a rapidly unfolding climate emergency, in my view, is unwise.</p><img src="https://counter.theconversation.com/content/211520/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Dana M Bergstrom has received funding from the Australian Antarctic Program. As well as her university affiliation, her recent past position was a Principal Research Scientist with the Australian Antarctic Division.</span></em></p>After several decades in research, including 22 years at the Australian Antarctic Division, this scientist is standing up for our icy continent. Here’s why Antarctic research needs ongoing funding.Dana M Bergstrom, Honorary Senior Fellow, University of WollongongLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2106652023-07-31T15:45:32Z2023-07-31T15:45:32ZAntarctica is missing a chunk of sea ice bigger than Greenland – what’s going on?<p><a href="https://www.worldweatherattribution.org/extreme-heat-in-north-america-europe-and-china-in-july-2023-made-much-more-likely-by-climate-change/">Deadly heatwaves</a>, <a href="https://www.bbc.co.uk/news/world-europe-66295972">raging wildfires</a> and <a href="https://public.wmo.int/en/media/press-release/july-2023-set-be-hottest-month-record">record global temperatures</a> are upon us. But far from the flames, at the southernmost tip of the planet, something just as shocking is unfolding.</p>
<p>It’s Antarctic winter, a time when the area of floating sea ice around the continent should be rapidly expanding. This year though, the freeze-up has been happening in slow motion.</p>
<p>After reaching a <a href="https://youtu.be/zTF5kudGtAQ">record low minimum extent</a> this summer there is now an area of open ocean bigger than Greenland. If the “missing” sea ice were a country, it’d be the tenth largest in the world.</p>
<figure class="align-center ">
<img alt="graph of Antarctic sea ice extent showing record low 2023 values" src="https://images.theconversation.com/files/539997/original/file-20230728-25-d2qjv2.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/539997/original/file-20230728-25-d2qjv2.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/539997/original/file-20230728-25-d2qjv2.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/539997/original/file-20230728-25-d2qjv2.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/539997/original/file-20230728-25-d2qjv2.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/539997/original/file-20230728-25-d2qjv2.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/539997/original/file-20230728-25-d2qjv2.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Antarctic sea ice extent in 2023 compared to the 1981-2010 average.</span>
<span class="attribution"><span class="source">Zachary Labe</span></span>
</figcaption>
</figure>
<h2>Who cares about Antarctic sea ice?</h2>
<p>In the face of more immediate climate concerns, why does Antarctic sea ice matter?</p>
<p>Floating sea ice is a pivotal climate puzzle piece. Without it, global temperatures would be warmer because its bright, white surface acts like a mirror, reflecting the sun’s energy back to space. This keeps the Antarctic – and by extension, the planet – cool. </p>
<p>Antarctic sea ice also plays a particularly important role in controlling ocean currents and may act as a buffer that <a href="https://theconversation.com/ocean-waves-and-lack-of-sea-ice-can-trigger-antarctic-ice-shelves-to-disintegrate-98177">protects floating ice shelves</a> and glaciers from collapsing and adding to global sea levels. </p>
<p>In short, the loss of Antarctic sea ice matters for the whole planet.</p>
<h2>Southern sea ice: a short history</h2>
<p>Every year Antarctic sea ice undergoes a transformation: from its summer minimum in February, its area increases more than sixfold during the winter freeze-up which reaches its height in September. A clear way to monitor the health of Antarctic sea ice is to track these peaks and troughs. </p>
<p>Records began in 1979 and until 2015, the yearly average extent of frozen sea around Antarctica was increasing ever so slightly. Yet in the past seven years, Antarctic sea ice has changed dramatically. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/540051/original/file-20230730-20-ppopzj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/540051/original/file-20230730-20-ppopzj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/540051/original/file-20230730-20-ppopzj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/540051/original/file-20230730-20-ppopzj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/540051/original/file-20230730-20-ppopzj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/540051/original/file-20230730-20-ppopzj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/540051/original/file-20230730-20-ppopzj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Floating sea ice near the Antarctic peninsula in December 2017.</span>
<span class="attribution"><span class="source">Ella Gilbert</span></span>
</figcaption>
</figure>
<p>After a record high two years prior, the amount of sea ice fell dramatically at the end of 2016 to a record minimum in February 2017. This was followed by successive low years with the southern hemisphere summer record again being broken in February 2022 and most recently, a <a href="https://earthobservatory.nasa.gov/images/151093/antarctic-sea-ice-reaches-another-record-low">new lowest extent</a> of 1.79 million square kilometres being recorded in 2023, a fall of nearly 10% from last year’s summer record. </p>
<p>Since February 2023, slow regrowth has meant sea ice has fallen further and further behind where it should be for the time of year.</p>
<p>And now, in July, what we’re seeing is truly remarkable.</p>
<h2>A complex picture</h2>
<p>Antarctic sea ice, and how it’s affected by climate change, has been so hard to understand because there are so many factors at play. </p>
<p>Wind patterns, storms, ocean currents and air and ocean temperatures all affect how much of the sea around Antarctica is covered by ice and they often push and pull in different directions. This means it can be hard to link the behaviour of Antarctic sea ice in any particular year, or over several years, to just one factor.</p>
<p>This complexity is behind <a href="https://www.nature.com/articles/547275a">the perplexing increase</a> in Antarctic sea ice extent observed between 1979 and 2015, and what makes it so hard to understand current conditions.</p>
<p>Before 2015, contrasting trends in sea ice growth in different regions of the vast continent mostly counterbalanced each other. What’s remarkable about 2023 is that these regional differences are largely absent.</p>
<h2>How rare is it?</h2>
<p>This year’s record low summer minimum and record slow freeze-up are astonishing because they fall so far outside the range we have come to expect. </p>
<p>Antarctic sea ice varies a lot year-to-year, but even by Antarctic standards this is well outside the bounds of normality. Some experts have attempted to put a number on just how rare this would be without climate change and arrived at “<a href="https://www.abc.net.au/news/2023-07-24/antarctic-sea-ice-levels-nosedive-five-sigma-event/102635204">a once in 7.5-million-year event</a>”.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1683556231481286656"}"></div></p>
<p>However, while the current situation is certainly off the charts, those charts don’t go back very far, and so it’s hard to make these sorts of statements with any real certainty.</p>
<p>Given how complex a system it is, we can’t say conclusively whether the past 40 years (the period for which we have satellite observations) are an accurate reflection of the “natural” behaviour of Antarctic sea ice. In fact, there’s <a href="https://www.nature.com/articles/s41558-021-01254-9">good reason</a> to think they aren’t. Which makes it difficult to say exactly how unusual this year’s values are. </p>
<p>However, while we may not be able to put an exact number on it, we know that this is a rare event.</p>
<h2>Is it climate change?</h2>
<p>Compared with Arctic sea ice, the precipitous decline of which can be robustly <a href="https://climate.nasa.gov/vital-signs/arctic-sea-ice/">linked to rising temperatures</a>, Antarctic sea ice has proved more enigmatic.</p>
<p>In response to greenhouse gas emissions, models have long predicted a drop in Antarctic sea ice: a prediction that previously appeared at odds with the data.</p>
<p>As the ocean and atmosphere warm, we might expect sea ice sandwiched between the two to shrink. But as scientists have come to learn, Antarctic sea ice is more complicated than that.</p>
<p>Models seem unreliable on this topic, which means we still don’t know what Antarctic sea ice decline will look like. And while seven days may be a long time in politics, seven years is a short time when it comes to the climate. It is too early to say conclusively whether the recent dramatic fall in Antarctic sea ice extent is simply a blip in the record or, as now seems more likely, the first sign of a longer-lasting reduction induced by climate change.</p>
<h2>What happens in Antarctica doesn’t stay in Antarctica</h2>
<p>Regardless of the vagaries of Antarctic sea ice behaviour, the polar regions play a vital role in the climate system. And they are changing before our very eyes. </p>
<p>Antarctica isn’t just for the penguins: it matters for all of us.</p>
<hr>
<figure class="align-right ">
<img alt="Imagine weekly climate newsletter" src="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p><strong><em>Don’t have time to read about climate change as much as you’d like?</em></strong>
<br><em><a href="https://theconversation.com/uk/newsletters/imagine-57?utm_source=TCUK&utm_medium=linkback&utm_campaign=Imagine&utm_content=DontHaveTimeTop">Get a weekly roundup in your inbox instead.</a> Every Wednesday, The Conversation’s environment editor writes Imagine, a short email that goes a little deeper into just one climate issue. <a href="https://theconversation.com/uk/newsletters/imagine-57?utm_source=TCUK&utm_medium=linkback&utm_campaign=Imagine&utm_content=DontHaveTimeBottom">Join the 20,000+ readers who’ve subscribed so far.</a></em></p>
<hr><img src="https://counter.theconversation.com/content/210665/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ella Gilbert works for the PolarRES project, which has received funding from the European Union’s Horizon 2020 research and innovation programme call H2020-LC-CLA-2018-2019-2020 under grant agreement number 101003590.</span></em></p><p class="fine-print"><em><span>Caroline Holmes works for the British Antarctic Survey and receives funding from the Natural Environment Research Council under project DEFIANT, NE/W004747/1. </span></em></p>Sea ice extent in July 2023 has been around 10% below last year’s record low for the month.Ella Gilbert, Climate Scientist, British Antarctic SurveyCaroline Holmes, Polar Climate Scientist, British Antarctic Survey, Associate Lecturer, The Open UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2073262023-07-17T03:20:12Z2023-07-17T03:20:12ZNel Law stowed away on her husband’s ship to Antarctica. She was the first Australian woman to see its ‘crystalline strangeness’<figure><img src="https://images.theconversation.com/files/536498/original/file-20230710-23-40qsdd.jpg?ixlib=rb-1.1.0&rect=5%2C11%2C3743%2C2521&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Painting by Nel Law</span> <span class="attribution"><span class="source">Australian Antarctic Division</span></span></figcaption></figure><p>I know many people born in 1961 – they are my contemporaries and friends. It doesn’t seem so long ago. Their lives and experiences seem modern to me. They don’t seem old: certainly, none of them have problems working their iPhones. And yet, 60 years is aeons ago when it comes to feminism and gender relations. </p>
<p>In 1961, a woman might be barred from a university position post-marriage if unable to show medical evidence of a hysterectomy. A gay man was coyly, whisperingly, described as a “friend of Dorothy” (and might lose his job if word got out). And a stunned albatross on a ship’s deck was far less of an ill omen than the insulting presence of a woman on board an expedition to <a href="https://theconversation.com/more-than-100-000-tourists-will-head-to-antarctica-this-summer-should-we-worry-about-damage-to-the-ice-and-its-ecosystems-192843">Antarctica</a>. </p>
<p>Rachael Mead’s novel, <a href="https://affirmpress.com.au/publishing/the-art-of-breaking-ice/">The Art of Breaking Ice</a>, imagines several months across 1960–1961, when pioneering Melbourne artist Nel Law stowed away on her explorer husband’s 13th voyage to Antarctica (albeit with his permission). She became not only the first artist in residence on an expedition, but the first Australian woman to step foot on Antarctica.</p>
<hr>
<p><em>Review: The Art of Breaking Ice – Rachael Mead (Affirm Press)</em></p>
<hr>
<p>Nel’s life as a 1960s Camberwell housewife and a talented, though not professional, artist is one in which the activities and ardours and endeavours of a woman are never worthy of the word “work”. (That word is quarantined for the use of men.) </p>
<p>We meet Nel deep in preparation for one of her husband’s “Antarctic-themed” pre-expedition dinner parties: slaving in the kitchen to produce a gustatorily repellent menu of penguins on horseback and seal liver pastries. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/536499/original/file-20230710-23-2a4dmw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/536499/original/file-20230710-23-2a4dmw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/536499/original/file-20230710-23-2a4dmw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=421&fit=crop&dpr=1 600w, https://images.theconversation.com/files/536499/original/file-20230710-23-2a4dmw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=421&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/536499/original/file-20230710-23-2a4dmw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=421&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/536499/original/file-20230710-23-2a4dmw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=529&fit=crop&dpr=1 754w, https://images.theconversation.com/files/536499/original/file-20230710-23-2a4dmw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=529&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/536499/original/file-20230710-23-2a4dmw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=529&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Nel with her explorer husband Phillip Law: she stowed away on his thirteenth expedition to Antarctica.</span>
<span class="attribution"><span class="source">Australian Antarctic Division</span></span>
</figcaption>
</figure>
<p>Nel is, foremost, her husband’s wife – agreeably giving up the chance of children because it doesn’t suit her husband’s schedule, disproportionately grieving over the loss of a compensatory cat. And going through “the change” in an era when such things as hot flushes are assiduously disguised, and sanitary products must be washed, wrung out and dried without ever being glimpsed by a member of the male sex. Nel, an “abstract” landscapist, is secretly turning from “oil to watercolour” inside.</p>
<p>The wife of a visiting dinner guest, however, is also a professional art critic. And when she spies Nel’s work on the living room walls, she gives her the courage to imagine what she might be capable of painting. Not from secondary artefacts – her husband’s photographs of Antarctica – but from being in Antarctica herself, painting <em>en plein</em> (if crystal-cold) air.</p>
<p>And so: the stowaway occurs, with a tacit nod from a few institutional VIPs.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/no-woman-could-paint-the-story-of-art-without-men-corrects-nearly-600-years-of-male-focused-art-criticism-184458">'No woman could paint': The Story of Art Without Men corrects nearly 600 years of male-focused art criticism</a>
</strong>
</em>
</p>
<hr>
<h2>An artist’s tools</h2>
<p>Mead demonstrates a formidable knowledge of the Antarctic circle (she has travelled there twice), the machinations of an Antarctic expedition and the realities and rituals of a brutally masculine 1960s ship voyage. Not to mention the tools of an artist: the advantages, nuances and limitations of oil, watercolour, charcoal, pencil. </p>
<p>But it is the human drama of a lone female trapped for several months in a hostile world “meant for men” that makes this novel tick and hum and, dare I say it, throb.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/536500/original/file-20230710-17-fwys8r.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/536500/original/file-20230710-17-fwys8r.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/536500/original/file-20230710-17-fwys8r.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/536500/original/file-20230710-17-fwys8r.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/536500/original/file-20230710-17-fwys8r.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/536500/original/file-20230710-17-fwys8r.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/536500/original/file-20230710-17-fwys8r.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/536500/original/file-20230710-17-fwys8r.jpeg?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">Rachael Mead demonstrates a formidable knowledge of the Antarctic circle and the tools of an artist. (Pcitured: Nel Law)</span>
<span class="attribution"><span class="source">Australian Antarctic Division</span></span>
</figcaption>
</figure>
<p>“Why should this place be only for them?” Nel asks the four necessarily “unattached” female fieldworkers who accompany her for part of the voyage. Yet it clearly is. </p>
<p>Nel proceeds on the voyage as invisibly, as benignly, as she can: amid misogynist mutterings, sexual rumours, condescending takedowns and blatant intimidations. To her deep pain, it is not only the crew and male researchers who are her antagonists, but increasingly, her husband himself. </p>
<p>He reveals himself to be both petulantly, ferociously ambitious, and hard on his comrades – he is known among the crew as “Antarctic Stalin”. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/Cc64uTiuXb0?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">The novel evokes the drama of Nel Law (featured here) as a lone female in a world ‘meant for men’.</span></figcaption>
</figure>
<p>Between navigating the men on board, deploying her artistic skills to men’s research purposes, and managing the myriad menopausal symptoms that imperil her composure, Nel must also sustain the placatory reflex of being wife to a difficult man. “It was a habit, this vigilance – a continual scanning of his emotional temperature, assessing what he needed, calibrating her response.” </p>
<p>Certainly, in 2023, I know this reflex in my own relationships with men – it is not confined to women of the 1960s. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/suburban-living-did-turn-women-into-robots-why-feminist-horror-novel-the-stepford-wives-is-still-relevant-50-years-on-186633">'Suburban living did turn women into robots': why feminist horror novel The Stepford Wives is still relevant, 50 years on</a>
</strong>
</em>
</p>
<hr>
<h2>Marriage’s choppy waters</h2>
<p>Mead has published four poetry collections, and her poetic talents serve her well in describing the indescribable. The spectacle of Antarctica, which appears on a map “like a huge albino tadpole”, but is something vividly other in the flesh – with its mysterious ice and landscapes, the crystalline strangeness of a floating berg, the reek of penguin guano. </p>
<p>And the subtly coloured flesh of the <a href="https://theconversation.com/shrinking-antarctic-glaciers-could-make-adelie-penguins-unlikely-winners-of-climate-change-50851">Adelies penguins</a> she illustrates for her ornithologist friend, Harris – perhaps the only man on board who sees her as a person and artist in her own right, not the private property of her husband, or an interloper.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/536501/original/file-20230710-27-33v20y.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/536501/original/file-20230710-27-33v20y.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/536501/original/file-20230710-27-33v20y.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/536501/original/file-20230710-27-33v20y.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/536501/original/file-20230710-27-33v20y.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/536501/original/file-20230710-27-33v20y.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/536501/original/file-20230710-27-33v20y.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/536501/original/file-20230710-27-33v20y.jpeg?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">Rachael Mead’s poetic talents serve her well. Here, she’s pictured here on one of two trips to Antarctica.</span>
<span class="attribution"><span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The Art of Breaking Ice is the dramatisation of a true story – Mead makes this clear in her author’s note – but it is also the reimagining of stories that remain untold. </p>
<p>The novel is book-ended by contemporary fragments, like a commemorative service for Phil and Nel Law, in which pioneering explorer Phil Law, “Man of Antarctica”, is lionised, and his wife is, well, mentioned. </p>
<p>Nel’s voyage to Antarctica and back, through the choppy and frequently icy waters of a longstanding marriage, is the story of a woman’s right to be, to change, to grow and to love. Mead beautifully tracks Nel’s transition from being an interesting appurtenance to a man’s life, to an interesting woman in her own right.</p><img src="https://counter.theconversation.com/content/207326/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Edwina Preston received funding from Australia Council for the Arts for her latest novel Bad Art Mother</span></em></p>Nel Law’s voyage to Antarctica and back, through the choppy waters of a longstanding marriage, is the story of a woman’s right to be, to change, to grow and to love.Edwina Preston, PhD Candidate, The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2086222023-06-29T20:01:42Z2023-06-29T20:01:42ZA neutrino portrait of our galaxy reveals high-energy particles from within the Milky Way<figure><img src="https://images.theconversation.com/files/534726/original/file-20230629-23-u6xkg.jpg?ixlib=rb-1.1.0&rect=643%2C0%2C1211%2C850&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">IceCube Collaboration/Science Communication Lab for CRC 1491</span></span></figcaption></figure><p>Our Milky Way galaxy is an awe-inspiring feature of the night sky, viewable with the naked eye as a hazy band of stars stretching from horizon to horizon.</p>
<p>For the first time, the IceCube Neutrino Observatory in Antarctica has produced an image of the Milky Way using neutrinos – tiny, ghost-like astronomical messengers. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/534734/original/file-20230629-25-v10rmi.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A photo of the band of the Milky Way with extra shading in blue." src="https://images.theconversation.com/files/534734/original/file-20230629-25-v10rmi.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/534734/original/file-20230629-25-v10rmi.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=337&fit=crop&dpr=1 600w, https://images.theconversation.com/files/534734/original/file-20230629-25-v10rmi.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=337&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/534734/original/file-20230629-25-v10rmi.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=337&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/534734/original/file-20230629-25-v10rmi.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/534734/original/file-20230629-25-v10rmi.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/534734/original/file-20230629-25-v10rmi.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A portrait of the Milky Way combining visible light and neutrino emissions (in blue).</span>
<span class="attribution"><span class="source">IceCube Collaboration/US National Science Foundation (Lily Le & Shawn Johnson)/ESO (S. Brunier)</span></span>
</figcaption>
</figure>
<p>In <a href="http://dx.doi.org/10.1126/science.adc9818">research published today</a> in the journal Science, the IceCube Collaboration – an international group of more than 350 scientists – presents evidence of high-energy neutrino emission coming from the Milky Way.</p>
<p>We have not yet figured out exactly where in our galaxy these particles are coming from. But today’s result brings us closer to finding some of the galaxy’s most extreme environments.</p>
<h2>Neutrino astronomy</h2>
<p>Neutrinos offer a unique view of the cosmos as they can travel directly from places no other radiation or particles can escape from. This makes them very interesting to astronomers, because neutrinos offer a window into the extreme cosmic environments that create another kind of particle called cosmic rays.</p>
<p>Cosmic rays are high-energy particles that permeate our Universe, but their origins are difficult to pin down. Cosmic rays are electrically charged, which means their path through space is scrambled by magnetic fields, and by the time one arrives at Earth there is no way to tell where it came from. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/spotting-astrophysical-neutrinos-is-just-the-tip-of-the-icecube-20499">Spotting astrophysical neutrinos is just the tip of the IceCube</a>
</strong>
</em>
</p>
<hr>
<p>However, the environments that accelerate cosmic rays to extraordinary energies also produce neutrinos – and neutrinos have no electric charge, so they travel in nice straight lines. So if we can detect the path of neutrinos arriving at Earth, this will point back to where the neutrinos were created. </p>
<p>But detecting those neutrinos is not so easy. </p>
<h2>How to hunt neutrinos</h2>
<p>The IceCube Neutrino Observatory is not far from the South Pole. It uses more than 5,000 light sensors arrayed throughout a cubic kilometre of pristine Antarctic ice to search for signs of high-energy neutrinos from our galaxy and beyond. </p>
<p>Vast numbers of neutrinos are streaming through Earth all the time, but only a tiny fraction of them bump into anything on their way through.</p>
<p>Each neutrino interaction makes a tiny flash of light – and those tiny flashes are what the IceCube sensors look out for. The direction and energy of the neutrino can be determined from the amount and pattern of light detected.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/534733/original/file-20230629-23-b8qav.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/534733/original/file-20230629-23-b8qav.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/534733/original/file-20230629-23-b8qav.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/534733/original/file-20230629-23-b8qav.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/534733/original/file-20230629-23-b8qav.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/534733/original/file-20230629-23-b8qav.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/534733/original/file-20230629-23-b8qav.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/534733/original/file-20230629-23-b8qav.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
<span class="attribution"><span class="source">IceCube Collaboration</span></span>
</figcaption>
</figure>
<p>IceCube has previously detected high-energy neutrinos coming from outside the Milky Way. However, it has been more challenging to isolate the lower-energy neutrinos coming from within our galaxy.</p>
<p>This is because some flashes IceCube detected can be traced to cosmic rays hitting Earth’s atmosphere, which create neutrinos and other particles called muons. To filter out these flashes, IceCube researchers have developed ways to distinguish particles created in the atmosphere and those from further afield by the shape of the light patterns they create in the ice. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/an-antarctic-neutrino-telescope-has-detected-a-signal-from-the-heart-of-a-nearby-active-galaxy-193845">An Antarctic neutrino telescope has detected a signal from the heart of a nearby active galaxy</a>
</strong>
</em>
</p>
<hr>
<p>Filtering out the unwanted detections has made IceCube more sensitive to astrophysical neutrinos. The final breakthrough that allowed the creation of a neutrino image of the Milky Way came from machine-learning methods that improve the identification of cascades of light produced by neutrinos, as well as the determination of the neutrino’s direction and energy.</p>
<h2>Closing in on cosmic rays</h2>
<p>The new neutrino lens on our galaxy will help reveal where the most powerful accelerators of galactic cosmic rays are located. We hope to learn how energetic these particles can get, and the inner workings of these high-energy galactic engines.</p>
<p>However, we are yet to pinpoint these accelerators within the Milky Way. The new IceCube analysis found evidence for neutrinos coming from broad regions of the galaxy, but was not able to discern individual sources.</p>
<p>Our team, at the University of Canterbury in New Zealand and the University of Adelaide in Australia, has a plan to realise that next step.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/534735/original/file-20230629-17-4f6jrd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/534735/original/file-20230629-17-4f6jrd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/534735/original/file-20230629-17-4f6jrd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=342&fit=crop&dpr=1 600w, https://images.theconversation.com/files/534735/original/file-20230629-17-4f6jrd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=342&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/534735/original/file-20230629-17-4f6jrd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=342&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/534735/original/file-20230629-17-4f6jrd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=430&fit=crop&dpr=1 754w, https://images.theconversation.com/files/534735/original/file-20230629-17-4f6jrd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=430&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/534735/original/file-20230629-17-4f6jrd.jpg?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">Five views of the Milky Way: the top two bands show visible light and gamma rays, while the lower three show expected and real neutrino results, plus a measure of the significance of neutrino events detected by IceCube.</span>
<span class="attribution"><span class="source">IceCube Collaboration</span></span>
</figcaption>
</figure>
<p>We are making models to predict the neutrino signal close to likely particle accelerators so we can target our searches for neutrinos. </p>
<p>Undergraduate student Rhia Hewett and PhD student Ryan Burley are examining pairs of accelerator candidates and molecular dust clouds. They plan to estimate the flux of neutrinos produced by cosmic rays interacting in the clouds, after the neutrinos travel from the accelerators. </p>
<p>They will use their results to enable a focused search of IceCube data for the sources of neutrino emissions. We believe this will provide the key to using IceCube to unlock the secrets of the most energetic processes in the Milky Way.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/534731/original/file-20230629-22-fmkvpi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/534731/original/file-20230629-22-fmkvpi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/534731/original/file-20230629-22-fmkvpi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=2067&fit=crop&dpr=1 600w, https://images.theconversation.com/files/534731/original/file-20230629-22-fmkvpi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=2067&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/534731/original/file-20230629-22-fmkvpi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=2067&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/534731/original/file-20230629-22-fmkvpi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=2597&fit=crop&dpr=1 754w, https://images.theconversation.com/files/534731/original/file-20230629-22-fmkvpi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=2597&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/534731/original/file-20230629-22-fmkvpi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=2597&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 timeline of neutrino astronomy.</span>
<span class="attribution"><span class="source">IceCube Collaboration</span></span>
</figcaption>
</figure><img src="https://counter.theconversation.com/content/208622/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jenni Adams has received funding from the Marsden Fund Council from New Zealand Government funding, managed by the Royal Society Te Apārangi. </span></em></p>Neutrinos are some of nature’s most elusive particles, but new research has used them to create an image of our own galaxy.Jenni Adams, Professor, Physics and Astronomy, University of CanterburyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2073552023-06-28T15:12:36Z2023-06-28T15:12:36ZFrom raising the global sea level to crushing life on the seafloor – here’s why you should care about icebergs<figure><img src="https://images.theconversation.com/files/534283/original/file-20230627-23-8yvpno.jpg?ixlib=rb-1.1.0&rect=26%2C13%2C4375%2C2923&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Icebergs in Disko Bay, western Greenland.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/icebergs-disco-bay-near-ilulissat-greenland-1888385068">Chris Christophersen/Shutterstock</a></span></figcaption></figure><p>Late in the evening of April 14 1912, the <a href="https://theconversation.com/titanic-twist-1912-wasnt-a-bad-year-for-icebergs-after-all-25621">RMS Titanic collided with an iceberg</a> in the north-west Atlantic. In just over two and a half hours, the Titanic sank, claiming the lives of 1,514 people.</p>
<p>The Titanic disaster is one good reason to understand icebergs better. But their significance extends far beyond posing a risk to ships and other offshore structures. Icebergs are crucial to monitor because of their profound impact on the natural world and human societies.</p>
<p>Icebergs are formed when chunks of ice break off from the front of glaciers and floating ice shelves. They exist in a range of sizes, from small formations known as “growlers” and “bergy bits” (that extend up to 5 metres above sea level), to larger icebergs aptly referred to as “giants”. </p>
<p>In 2000, one of Antarctica’s largest icebergs, <a href="https://earthobservatory.nasa.gov/images/552/iceberg-b-15-ross-ice-shelf-antarctica">called B-15</a>, had a surface area roughly the same size as Jamaica. Since then, <a href="https://earthobservatory.nasa.gov/images/92238/end-of-the-journey-for-iceberg-b-15z">B-15 has fractured</a> into a number of smaller pieces and most have melted away. </p>
<p>Icebergs that break off from an already floating ice shelf do not displace ocean water when they melt, just as melting ice cubes do not raise the liquid level in a glass. But when an ice shelf collapses, it no longer holds back inland glacial ice. This inland ice will then move faster and can rapidly release new icebergs, which displace ocean water and contribute to sea level rise. </p>
<p>In 2022, Antarctica’s <a href="https://theconversation.com/conger-ice-shelf-has-collapsed-what-you-need-to-know-according-to-experts-180077">Conger ice shelf</a> collapsed. Some of the continent’s other large <a href="https://www.antarcticglaciers.org/glaciers-and-climate/changing-antarctica/shrinking-ice-shelves/ice-shelves/">ice shelves</a> are also thought to be at risk of collapse in the future, particularly those around the unstable West Antarctic ice sheet. The collapse of the West Antarctic ice sheet alone could <a href="https://www.antarcticglaciers.org/question/ice-antarctica-melt-much-global-sea-level-rise-quickly-likely-happen/">raise the global sea level by 3.2 metres</a>. </p>
<figure class="align-center ">
<img alt="A glacier calving large chunks of ice into the ocean." src="https://images.theconversation.com/files/534292/original/file-20230627-15-c2x0zd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/534292/original/file-20230627-15-c2x0zd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/534292/original/file-20230627-15-c2x0zd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/534292/original/file-20230627-15-c2x0zd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/534292/original/file-20230627-15-c2x0zd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/534292/original/file-20230627-15-c2x0zd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/534292/original/file-20230627-15-c2x0zd.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 chunk of ice breaking off from a glacier in Neko Harbour, Antarctica.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/neko-harbor-glacier-calving-andvord-bay-1556725400">Steve Allen/Shutterstock</a></span>
</figcaption>
</figure>
<p>Global warming accelerates not only iceberg release, but also the rate at which icebergs melt. As icebergs melt, they release freshwater to the ocean. </p>
<p>In the northern hemisphere, a surplus of freshwater from the Greenland ice sheet in the future has the potential to weaken or even shut down the North Atlantic Conveyor “pump”, which circulates warm tropical waters northwards. If the North Atlantic Conveyor pump is significantly affected, the northern hemisphere could be plunged into <a href="https://www.tandfonline.com/doi/abs/10.1080/00167487.2005.12094137">sub-zero, glacial conditions</a>. </p>
<h2>‘Scouring’ the seabed</h2>
<p>Icebergs are often thought of as floating masses of ice. Yet their undersides regularly come into contact with the seabed, gouging out sediment on the seafloor to form “scour” marks. Some <a href="https://www.int-res.com/abstracts/meps/v186/p1-8/">15–20% of the world’s oceans</a> are affected by this phenomenon.</p>
<p><a href="https://www.sciencedirect.com/science/article/pii/S0277379116303638">Research</a> that I co-authored in 2016 on iceberg scouring in East Greenland, found that icebergs can disturb sediment up to several metres below the seabed. This disturbance poses a risk to offshore marine structures such as buried pipelines and telecommunication cables.</p>
<p>Icebergs can also crush plants and animals when they collide with the seabed. These organisms, such as seagrasses and molluscs, are important stores of carbon in polar regions. In areas of West Antarctica, referred to as <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/gcb.13523">“iceberg killing fields”</a>, iceberg scouring may recycle around 80,000 tonnes of carbon back into the atmosphere each year. </p>
<h2>Ocean fertilisers (and polluters)</h2>
<p>But it’s not all bad news. Some icebergs contain substantial amounts of iron-rich sediment, known as “dirty ice”. These icebergs <a href="https://www.nature.com/articles/s41467-019-13231-0">fertilise the ocean</a> by supplying important nutrients to marine organisms such as phytoplankton. </p>
<p>Following the passage of an iceberg, there is an increase in organism growth and levels of chlorophyll (the green pigment in plants used for photosynthesis) in the surrounding water. This can result in vibrant blooms that extract CO₂ from the atmosphere as they grow. </p>
<p><a href="https://www.nature.com/articles/ngeo2633">One study</a> on icebergs in the Southern Ocean found that these blooms can be up to ten times the length of the iceberg and can persist for more than a month. Blooms in the wake of icebergs off Antarctica have the capacity to absorb <a href="https://www.cbc.ca/news/science/icebergs-climate-change-1.3401729#:%7E:text=Ocean%20blooms%20in%20the%20wake,as%20Sweden%20or%20New%20Zealand.">up to 40 million tonnes of carbon</a> each year.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/534296/original/file-20230627-29-a5yqmx.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A satellite image of a phytoplankton bloom in the Ross Sea, Southern Ocean." src="https://images.theconversation.com/files/534296/original/file-20230627-29-a5yqmx.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/534296/original/file-20230627-29-a5yqmx.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/534296/original/file-20230627-29-a5yqmx.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/534296/original/file-20230627-29-a5yqmx.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/534296/original/file-20230627-29-a5yqmx.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/534296/original/file-20230627-29-a5yqmx.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/534296/original/file-20230627-29-a5yqmx.jpeg?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">January 22, 2011: a phytoplankton bloom in the Ross Sea, Southern Ocean.</span>
<span class="attribution"><a class="source" href="https://earthobservatory.nasa.gov/images/48949/bloom-in-the-ross-sea">Norman Kuring/NASA Goddard Space Flight Center</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>But icebergs hold more than just nutrients in their icy structures. Glacier ice may harbour <a href="https://microbiomejournal.biomedcentral.com/articles/10.1186/s40168-021-01106-w">ancient bacterial and viral microbes</a>, even including <a href="https://www.tandfonline.com/doi/full/10.1657/1938-4246-44.4.432">buried faecal microorganisms</a>. These microbes will eventually emerge at the glacier’s surface or in icebergs where they will enter natural ecosystems and could pose a threat to human health. </p>
<p><a href="https://journals.sagepub.com/doi/pdf/10.1177/03091333221107376">Research</a> has also identified various other contaminants within glaciers. These include soot, nuclear fallout, potentially toxic elements such as arsenic, mercury and lead, nitrogen-based contaminants such as fertilisers and animal waste, microplastics and persistent organic pollutants such as pesticides and solvents. </p>
<p>Scientists are, however, exploring the possibility of <a href="https://www.nature.com/articles/s41598-022-26952-y#:%7E:text=A%20long%2Dheld%20idea%20is,United%20Arab%20Emirates%20(UAE)">towing icebergs to water-scarce regions</a>. An iceberg holding 20 billion gallons of freshwater could potentially <a href="https://www.theguardian.com/environment/2017/may/05/could-towing-icebergs-to-hot-places-solve-the-worlds-water-shortage">meet the water needs of a million people</a> for five years – provided that the water is uncontaminated. </p>
<p>Icebergs have an impact on our oceans, atmosphere and societies. As the climate emergency intensifies and our glaciers and ice sheets continue to recede, the significance of icebergs will only grow, for better or worse.</p>
<hr>
<figure class="align-right ">
<img alt="Imagine weekly climate newsletter" src="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p><strong><em>Don’t have time to read about climate change as much as you’d like?</em></strong>
<br><em><a href="https://theconversation.com/uk/newsletters/imagine-57?utm_source=TCUK&utm_medium=linkback&utm_campaign=Imagine&utm_content=DontHaveTimeTop">Get a weekly roundup in your inbox instead.</a> Every Wednesday, The Conversation’s environment editor writes Imagine, a short email that goes a little deeper into just one climate issue. <a href="https://theconversation.com/uk/newsletters/imagine-57?utm_source=TCUK&utm_medium=linkback&utm_campaign=Imagine&utm_content=DontHaveTimeBottom">Join the 20,000+ readers who’ve subscribed so far.</a></em></p>
<hr><img src="https://counter.theconversation.com/content/207355/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Lorna Linch 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>Icebergs don’t just pose a risk to ships – they have a profound impact on the natural world and human societies.Lorna Linch, Principal Lecturer in Physical Geography, University of BrightonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2078142023-06-23T22:03:40Z2023-06-23T22:03:40ZFractured foundations: how Antarctica’s ‘landfast’ ice is dwindling and why that’s bad news<figure><img src="https://images.theconversation.com/files/532866/original/file-20230620-29-tpniz5.jpg?ixlib=rb-1.1.0&rect=34%2C0%2C3888%2C1862&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Landfast ice 'breaks out'</span> <span class="attribution"><span class="source"> Justin Chambers/AAD</span>, <span class="license">Author provided</span></span></figcaption></figure><p>There’s more to Antarctic ice than meets the eye. Sea ice is not a uniform crust overlying the salty Southern Ocean. </p>
<p>Our <a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2022RG000770">new research</a> is the first to review the many crucial roles of <a href="https://www.antarctica.gov.au/about-antarctica/ice-and-atmosphere/sea-ice/fast-ice/">“landfast” sea ice</a> around Antarctica. Landfast ice is frozen seawater that is fastened to the coast. It acts like a belt around the Antarctic coast, regulating the flow of ice shelves and glaciers into the sea. And it’s crucial habitat for Weddell seals and emperor penguins.</p>
<p>Satellites can easily estimate the horizontal extent of sea ice, but determining the type of ice is far more difficult. Our deeper analysis of satellite images reveals landfast sea ice extent declined to a record low of just 123,200 square km in March 2022. That’s well below the normal March range of 168,600-295,200 square km. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/533616/original/file-20230623-17-3388jo.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/533616/original/file-20230623-17-3388jo.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/533616/original/file-20230623-17-3388jo.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=455&fit=crop&dpr=1 600w, https://images.theconversation.com/files/533616/original/file-20230623-17-3388jo.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=455&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/533616/original/file-20230623-17-3388jo.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=455&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/533616/original/file-20230623-17-3388jo.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=572&fit=crop&dpr=1 754w, https://images.theconversation.com/files/533616/original/file-20230623-17-3388jo.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=572&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/533616/original/file-20230623-17-3388jo.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=572&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Distribution of anomalies in Antarctic fast-ice extent in early-mid March 2022. Red shading indicates negative anomalies, with a value of -1.0 indicating a lack of fast ice in 2022, in a region that has had early-mid March fast-ice cover every year from 2000 to 2021. Inset (b) is a time series of early-mid March fast-ice extent from 2000 to 2022. (Source: Reviews of Geophysics, CC BY-NC)</span>
</figcaption>
</figure>
<p>Much of the ice lost in 2022 had been present since 2000, when high-quality records began. If this trend persists, the consequences for the climate and for Southern Ocean ecosystems could be catastrophic. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/antarcticas-heart-of-ice-has-skipped-a-beat-time-to-take-our-medicine-202729">Antarctica's heart of ice has skipped a beat. Time to take our medicine</a>
</strong>
</em>
</p>
<hr>
<h2>Getting a grip on landfast ice</h2>
<p>Antarctic sea ice drives the circulation of the world’s oceans. The “overturning” circulation begins in Antarctica when very salty, dense brine (created as the ice forms) sinks to the bottom of the ocean. This “bottom water” spreads away from Antarctica to reach the northern hemisphere. </p>
<p>This crucial circulation is <a href="https://www.abc.net.au/news/2023-03-30/dramatic-south-ocean-circulation-changes-study/102154690">projected to slow due to glacial melt</a>, because the input of more buoyant fresh water dilutes the denser brine. This raises the spectre of a further slowing or worse, total shut down of deep ocean currents as in the disaster movie, “<a href="https://en.wikipedia.org/wiki/The_Day_After_Tomorrow">The Day After Tomorrow</a>”. We know concentrated regions of sea ice formation tend to occur next to landfast ice, so the changes we are seeing are likely to further reduce this deep ocean circulation.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/torrents-of-antarctic-meltwater-are-slowing-the-currents-that-drive-our-vital-ocean-overturning-and-threaten-its-collapse-202108">Torrents of Antarctic meltwater are slowing the currents that drive our vital ocean 'overturning' – and threaten its collapse</a>
</strong>
</em>
</p>
<hr>
<p>Global climate models are <a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2019GL086729">not particularly skilful</a> at reproducing the recent history of Antarctic sea ice, giving limited confidence in our ability to predict its future. There are many reasons for this, but one of the main ones is an overly simplistic representation of the sea ice. </p>
<p>Landfast sea ice is not represented in any global climate model. These models treat all sea ice as if it’s able to drift, whereas in reality up to 15% of ice should be held still by being anchored to land or grounded icebergs. </p>
<p>This is a big problem because, as our study reveals, if we don’t properly simulate it, we are likely to get all kinds of inaccurate flow-on effects, including an incorrect amount of sea ice (and hence dense water) produced by our models. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/532851/original/file-20230620-51741-lvtx2f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/532851/original/file-20230620-51741-lvtx2f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/532851/original/file-20230620-51741-lvtx2f.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/532851/original/file-20230620-51741-lvtx2f.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/532851/original/file-20230620-51741-lvtx2f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/532851/original/file-20230620-51741-lvtx2f.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/532851/original/file-20230620-51741-lvtx2f.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">Icebreaker Aurora Australis in landfast ice.</span>
<span class="attribution"><span class="source">Jan Lieser</span></span>
</figcaption>
</figure>
<h2>Wildlife depends on landfast ice</h2>
<p>Landfast ice supports a unique community of algae, krill, small crustaceans called copepods, molluscs and fish. They are adapted to live within and below the ice where conditions are harsh. </p>
<p>These species form a complex food web around ice algae, using the ice as a nursery ground. Life within landfast ice requires wide-ranging survival strategies. Drastic changes could mean cascading effects on the entire food web.</p>
<p>Seals and penguins rely on this environment for resting, hunting and breeding. Emperor penguins have a unique approach to raising a family that requires stable ice, which only landfast ice can provide. Reduced ice extent, increased fragmentation and earlier breakup can lead to population declines of this iconic species. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/533066/original/file-20230621-23-ivmc60.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/533066/original/file-20230621-23-ivmc60.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=337&fit=crop&dpr=1 600w, https://images.theconversation.com/files/533066/original/file-20230621-23-ivmc60.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=337&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/533066/original/file-20230621-23-ivmc60.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=337&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/533066/original/file-20230621-23-ivmc60.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/533066/original/file-20230621-23-ivmc60.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/533066/original/file-20230621-23-ivmc60.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Adélie penguins toboggan on landfast ice.</span>
<span class="attribution"><span class="source">Pat Wongpan</span></span>
</figcaption>
</figure>
<h2>Deeper knowledge is crucial for climate forecasts</h2>
<p>Only a few areas of Antarctic landfast ice are regularly sampled. These areas are found near Antarctic research stations and are generally separated by thousands of kilometres of coast. </p>
<p>Additionally, scientists can often only safely collect sea ice cores from smooth ice thick enough to support people. So sampling is skewed to favour the unbroken crème brûlée-type crust over the shattered meringue of rough landfast ice.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/532819/original/file-20230620-51741-xp3jyz.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/532819/original/file-20230620-51741-xp3jyz.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/532819/original/file-20230620-51741-xp3jyz.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/532819/original/file-20230620-51741-xp3jyz.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/532819/original/file-20230620-51741-xp3jyz.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/532819/original/file-20230620-51741-xp3jyz.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/532819/original/file-20230620-51741-xp3jyz.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">Scientists traverse smooth landfast ice near Casey Station to reach a site where they collect ice cores.</span>
<span class="attribution"><span class="source">Matthew Corkill</span></span>
</figcaption>
</figure>
<p>To better understand rough landfast ice and a slew of other poorly understood ice types, we need repeat ice core measurements along with more detailed satellite studies. We also need the capability to model each ice type accurately.</p>
<p>Our research has ensured landfast ice is earmarked for inclusion in the next iteration of our national climate model, which aims to better simulate the interactions between sea ice of all types and the Southern Ocean. Without this ability, we are missing a key ingredient in the recipe of Australia’s climate future.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/record-low-antarctic-sea-ice-is-another-alarming-sign-the-oceans-role-as-climate-regulator-is-changing-204680">Record low Antarctic sea ice is another alarming sign the ocean's role as climate regulator is changing</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/207814/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Alexander Fraser receives funding from the Australian Government via the Australian Antarctic Program Partnership and the Australian Research Council, as well as from the Antarctic Science Foundation.</span></em></p><p class="fine-print"><em><span>Christine Weldrick receives funding from the Australian Government via the Australian Antarctic Program Partnership. </span></em></p><p class="fine-print"><em><span>Laura Dalman receives funding from the Australian Government via the Australian Antarctic Program Partnership.</span></em></p><p class="fine-print"><em><span>Pat Wongpan receives funding from the Australian Government via the Australian Antarctic Program Partnership. </span></em></p><p class="fine-print"><em><span>Matthew Corkill 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>More trouble in Antarctica: the extent of frozen seawater fastened to the coast (called landfast ice) hit a record low in March 2022. If this trend persists, the consequences could be catastrophic.Alexander Fraser, Senior Researcher in Antarctic Remote Sensing, University of TasmaniaChristine Weldrick, Antarctic Marine Zooplankton Ecologist, University of TasmaniaLaura Dalman, PhD candidate, University of TasmaniaMatthew Corkill, PhD candidate, University of TasmaniaPat Wongpan, Quantitative Sea Ice Biogeochemist/Ecologist, University of TasmaniaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2065312023-06-13T20:06:04Z2023-06-13T20:06:04ZCan next week’s special meeting in Chile break the deadlock over East Antarctica’s marine park proposal?<figure><img src="https://images.theconversation.com/files/531542/original/file-20230613-21-xm2j5w.jpg?ixlib=rb-1.1.0&rect=26%2C0%2C2968%2C1998&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/underwater-world-antarctica-1188050665">Ivan Hoermann, Shutterstock</a></span></figcaption></figure><p>Amid the challenges of climate change, resource extraction and pollution, the survival of species and ecosystems depends on setting aside protected areas. But plans to establish marine protected areas in East Antarctica have stalled. </p>
<p>Next week, the 27-member <a href="https://www.ccamlr.org/">Commission for the Conservation of Antarctic Marine Living Resources</a> will gather at a <a href="https://meetings.ccamlr.org/en/ccamlr-sm-iii">special meeting</a> in Santiago, Chile, to try to break the deadlock. There’s much at stake, given the seemingly implacable opposition from China and Russia. China appears more concerned about fishing for krill than conservation, while Russia’s objections are less clear.</p>
<p>The need for Antarctic marine protected areas was first discussed in response to the <a href="https://www.un.org/en/conferences/environment/johannesburg2002">2002 United Nations World Summit on Sustainable Development</a>. The formal plan was adopted three years later, in 2005. While China had not yet joined the commission at that time, it was a member when the commission reaffirmed this commitment in 2011. </p>
<p>These areas were meant to protect a representative suite of Antarctic marine environments, such as unique seafloor communities, deepwater canyons, and highly productive coastal and oceanic food webs. They were to be developed, assessed and agreed on the basis of the best available science. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/a-krill-aquarium-climate-research-and-geopolitics-how-australias-800-million-antarctic-funding-will-be-spent-177609">A krill aquarium, climate research, and geopolitics: how Australia's $800 million Antarctic funding will be spent</a>
</strong>
</em>
</p>
<hr>
<h2>Slow progress on Antarctica’s marine parks</h2>
<p>So far, two marine protected areas have been agreed by the commission: South Orkney Islands Southern Shelf in 2009; and the Ross Sea Region in 2016. Since then, the commission has been unable to agree on any further proposals, including the <a href="https://www.antarctica.gov.au/about-antarctica/law-and-treaty/ccamlr/marine-protected-areas/eampa/">East Antarctic Region marine protected area</a>. This was first proposed by Australia in 2011. It’s the oldest of those proposed but not yet agreed. The commission has also been unable to adopt the research and monitoring plans or the reviews of the existing marine protected areas.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/531537/original/file-20230613-25-xm2j5w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A map showing the proposed East Antarctica Marine Protected Area zones" src="https://images.theconversation.com/files/531537/original/file-20230613-25-xm2j5w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/531537/original/file-20230613-25-xm2j5w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=317&fit=crop&dpr=1 600w, https://images.theconversation.com/files/531537/original/file-20230613-25-xm2j5w.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=317&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/531537/original/file-20230613-25-xm2j5w.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=317&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/531537/original/file-20230613-25-xm2j5w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=399&fit=crop&dpr=1 754w, https://images.theconversation.com/files/531537/original/file-20230613-25-xm2j5w.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=399&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/531537/original/file-20230613-25-xm2j5w.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=399&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 map showing the proposed East Antarctica Marine Protected Area zones.</span>
<span class="attribution"><a class="source" href="https://www.antarctica.gov.au/about-antarctica/law-and-treaty/ccamlr/marine-protected-areas/eampa/">Australian Antarctic Division</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>This year, the United Nations agreed to a treaty on the conservation and sustainable use of marine biological diversity in areas <a href="https://press.un.org/en/highlights/BBNJ">beyond national jurisdiction</a>. This treaty will be up for adoption at a final conference session on June 19-20, 2023. </p>
<p>This treaty sets a global target of 30% of the global oceans to be in marine protected areas by 2030. This will be the likely yardstick against which the Commission’s future performance will be measured. So far, the commission’s marine protected area achievement is just 4.7% of the area of Southern Ocean that it is responsible for.</p>
<p>Of the 27 member countries of the commission, 21 have formally committed their support for the East Antarctic Region marine protected area. Only China and Russia have repeatedly opposed this and other proposals. They are now challenging the commission’s consensus agreement to establish the marine protected area network in Antarctica.</p>
<h2>The shrinking East Antarctic Region Marine Protected Area</h2>
<p>The proposed East Antarctic Region marine protected area initially consisted of seven distinct areas designed to protect the diversity of environments in the region. Since then, Australia and its partners, now numbering 17, have granted many compromises in the quest for consensus. The number of distinct areas has been reduced to three and fishing is allowed unless explicitly excluded. </p>
<p>To specifically accommodate China’s concerns about future krill fishing, Australia sacrificed the unique and special Prydz Bay region. That’s despite the fact China’s krill fishing aspirations could be more than adequately met from the rest of the region. Nonetheless, Russia and China continue to withhold consensus on this proposal. </p>
<p>Increasingly, the rhetoric opposing marine protected areas is centred around an argument that invokes a “balance” between “conservation” (in this case, the establishment of marine protected areas), and “rational use” (in this case the right to fish). On both legal and practical grounds, the conservation versus rational use argument centres on the very core of the international agreement that covers the oceans of the region, the <a href="https://www.ccamlr.org/en/document/publications/text-convention-conservation-antarctic-marine-living-resources">Convention on the Conservation of Antarctic Marine Living Resources</a>. </p>
<p>The convention was agreed in 1980 to protect all Antarctic species from potential over exploitation. Its objective was – and remains – clearly centred on conservation in the region. Fishing is allowed, as long as the species and ecosystems of the region are conserved. The convention states that its objective “is the conservation of Antarctic marine living resources”. It identifies those resources as “populations of fin fish, molluscs, crustaceans and all other species of living organisms, including birds” and clarifies that “conservation” includes “rational use”, if such rational use can be conducted with minimal impact on the ecosystem. </p>
<p>In recent years, Russia and China have both argued that there is too much emphasis on conservation. They state that there needs to be a <a href="https://www.wilsoncenter.org/blog-post/no-20-marine-protected-areas-antarctica-has-chinas-hand-been-revealed">re-balancing between fishing and conservation</a>. In constructing this argument, they are engaging in a wilful reinterpretation of the convention – and ignoring the significant time dedicated by the commission to fisheries management. </p>
<h2>A reliance on consensus</h2>
<p>The commission, like the rest of the <a href="https://www.ats.aq/index_e.html">Antarctic Treaty System</a>, makes decisions on the basis of consensus. This means that some decisions may take quite some time to be agreed, but the strength of consensus is that all parties are then committed to the final result. </p>
<p>Consensus is built on trust and good faith. But consensus will be undermined when agreement is withheld in bad faith, or used as a means to achieve other objectives. The actions of one or a few that withhold consensus, or who negotiate in bad faith, could, if not confronted, undermine all decision-making in the commission, including decisions on sustainable fisheries. </p>
<h2>Now is not the time for endless compromise</h2>
<p>We must not continue compromising for an apparent “quick win”. The East Antarctic Region marine protected area has been evaluated by the commission’s scientific committee, and the commission has repeatedly reached the point where only Russia and China withhold agreement. It is this behaviour that needs to be explicitly challenged, not the marine protected area proposal itself. </p>
<p>These nations need to explain their specific concerns, and in the spirit of consensus, provide workable alternatives that meet their obligations under the conventions and accommodate the aspirations of all members. </p>
<p>Australia has held many discussions with China and Russia over the years to help resolve their issues. With China, these discussions have been thorough and cordial, and it is clear this nation has a deep and comprehensive understanding of the marine protected area proposal. Several bilateral meetings have also been held with Russia; however, it remains unclear what their specific objections are, particularly as they are no longer fishing. </p>
<p>There are no obstacles to China agreeing to the East Antarctic Region marine protected area proposal now. They have agreed to two large Antarctic marine protected areas in the past. The East Antarctic marine protected area poses no substantive obstacle to China’s aspirations in the region, including their stated desire to harvest krill.</p>
<p>There is much at stake at this upcoming special meeting, including the reputation of the Commission for the Conservation of Antarctic Marine Living Resources. The protection of the Antarctic requires that a way forward on marine protected areas be found.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/australia-wants-to-install-military-technology-in-antarctica-heres-why-thats-allowed-122122">Australia wants to install military technology in Antarctica – here's why that's allowed</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/206531/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Marcus Haward receives funding from the Australian Research Council and the Blue Economy Cooperative Research Centre.</span></em></p><p class="fine-print"><em><span>Lynda Goldsworthy and Tony Press do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>China and Russia have been blocking international plans to protect marine life in East Antarctica. Will next week’s special meeting in Chile break the deadlock? Australia hopes so.Lynda Goldsworthy, Research Associate, University of TasmaniaMarcus Haward, ProfessorTony Press, Adjunct Professor, Institute for Marine and Antarctic Studies, University of TasmaniaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2053412023-06-12T16:30:04Z2023-06-12T16:30:04ZSlowing deep Southern Ocean current may be linked to natural climate cycle – but that’s no reason to stop worrying about melting Antarctic ice<figure><img src="https://images.theconversation.com/files/531344/original/file-20230612-26322-pkq9fp.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C6000%2C2820&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The Weddell Sea helps power the great ocean conveyor, which moves heat, carbon dioxide and nutrients around Earth's ocean basins.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/sea-fog-andtabular-icebergs-weddell-1706028745">Janelle Lugge/Shutterstock</a></span></figcaption></figure><p>Our <a href="https://www.nature.com/articles/s41558-023-01695-4">new research</a> in the Antarctic suggests that the vital layer of cold water on the sea bed, which circulates the globe and influences the ocean’s ability to continue absorbing much of the rise in atmospheric heat and greenhouse gas emissions, is heating up and shrinking. </p>
<p>Much of this is a result of human-made climate change, which is melting Antarctic ice shelves and disrupting the complex system that controls this circulation. But it appears, as far as the past 30 years are concerned, a natural cycle may have been partly responsible for the changes observed.</p>
<p>The ocean has absorbed more than <a href="https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_Chapter07.pdf">90% of the excess heat</a> and around <a href="https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_Chapter05.pdf">30% of the extra carbon dioxide</a> humans have generated since the start of the industrial age. This has greatly reduced the impact of climate change at the Earth’s surface where we live.</p>
<p>Most of this exchange of gases and heat between the atmosphere and the ocean happens in the Southern Ocean around Antarctica through the complex vertical movement of water. One of the biggest drivers of this vertical movement is the production of what oceanographers call Antarctic bottom water.</p>
<p>Around the Antarctic coastline, seawater near freezing point contacts the much colder air and freezes into sea ice, expelling salt and consuming freshwater to leave cold, salty and dense water. </p>
<p>The vast majority of this dense water is produced at only a few locations around Antarctica. In these places, wind blowing off the frigid continent continually pushes newly formed sea ice away from the surrounding ice shelves to create areas of open water known as polynyas.</p>
<p>These polynya ice factories produce great volumes of cold and salty water which cascade down Antarctica’s continental slope like a submarine waterfall to the ocean bottom. Once there, Antarctic bottom water, the world’s deepest and densest water mass and the biggest of its kind spreads around the globe, storing carbon from the atmosphere for hundreds or even thousands of years. </p>
<p>As Antarctic bottom water moves north along the sea floor it drives the great ocean conveyor, also known as the <a href="https://www.nature.com/articles/ngeo1391">overturning circulation</a>: currents that redistribute heat, carbon and nutrients around ocean basins and regulate the global climate.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/530705/original/file-20230607-15-gmdp7o.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/530705/original/file-20230607-15-gmdp7o.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/530705/original/file-20230607-15-gmdp7o.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=397&fit=crop&dpr=1 600w, https://images.theconversation.com/files/530705/original/file-20230607-15-gmdp7o.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=397&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/530705/original/file-20230607-15-gmdp7o.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=397&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/530705/original/file-20230607-15-gmdp7o.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=499&fit=crop&dpr=1 754w, https://images.theconversation.com/files/530705/original/file-20230607-15-gmdp7o.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=499&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/530705/original/file-20230607-15-gmdp7o.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=499&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Mist (or ‘sea smoke’) indicates the Weddell Sea is losing heat to the atmosphere as it forms sea ice.</span>
<span class="attribution"><span class="source">Andrew Meijers</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Our new research used observations from ships and satellites to reveal that the bottom water volume in the Weddell Sea, the Atlantic sector of the Southern Ocean and one of the biggest producers of this water mass, has decreased by more than 20% over the past 30 years, causing the deep Weddell Sea to warm four times faster than the global average. </p>
<p>Our evidence suggests weakening offshore winds in the region are to blame for polynyas shrinking and making less of the cold, dense, salty water which feeds Antarctic bottom water and drives the global ocean conveyor. This could slow down the deep overturning circulation, with profound implications for the climate system. </p>
<p><a href="https://www.nature.com/articles/s41586-023-05762-w">Previous studies</a> have linked the slowing global ocean conveyor with less cold, dense water forming in the Southern Ocean due to increasing meltwater from ice shelves. While man-made climate change is significant, our new research suggests that natural variability in wind and sea ice are also important.</p>
<h2>What’s up with the wind in the Weddell Sea?</h2>
<p>Weaker winds blowing offshore in the southern Weddell Sea over the past 30 years have limited the size of the coastal polynya, which in turn has produced less sea ice. </p>
<p>We found that this change in the wind seems to be linked to surface temperature changes over the tropical Pacific during the same period, part of a natural cycle similar to El Niño, known as the <a href="https://theconversation.com/meet-el-ninos-cranky-uncle-that-could-send-global-warming-into-hyperdrive-72360">Interdecadal Pacific Oscillation</a>.</p>
<p>Oscillating sea surface temperatures in the tropical Pacific are strong enough to affect the local air pressure and even <a href="https://www.nature.com/articles/s43017-021-00204-5">influence</a> the wind on both sides of the Antarctic peninsula. This means that the trend in Weddell Sea winds and consequent Antarctic bottom water formation over the past 30 years may also be part of a longer natural cycle.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/531329/original/file-20230612-23-4bck3c.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A map of Antarctica." src="https://images.theconversation.com/files/531329/original/file-20230612-23-4bck3c.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/531329/original/file-20230612-23-4bck3c.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=432&fit=crop&dpr=1 600w, https://images.theconversation.com/files/531329/original/file-20230612-23-4bck3c.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=432&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/531329/original/file-20230612-23-4bck3c.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=432&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/531329/original/file-20230612-23-4bck3c.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=543&fit=crop&dpr=1 754w, https://images.theconversation.com/files/531329/original/file-20230612-23-4bck3c.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=543&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/531329/original/file-20230612-23-4bck3c.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=543&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 Weddell Sea lies east of the Antarctic peninsula, off the tip of South America.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Weddell_Sea#/media/File:Antarctic-seas-en.svg">Rooiratel</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<h2>If it is natural, should we stop worrying?</h2>
<p>Ship-based observations have helped us show that <a href="https://journals.ametsoc.org/view/journals/clim/26/16/jcli-d-12-00834.1.xml">the bottom water layer</a> has been warming and thinning everywhere around Antarctica for decades. In regions other than the Weddell Sea, both recent <a href="https://www.nature.com/articles/s41586-023-05762-w">model predictions</a> and <a href="https://www.nature.com/articles/s41558-023-01667-8">observations</a> suggest that this can be explained by increasing freshwater from melting Antarctic ice shelves, which disrupts the formation of salty and dense water that would otherwise sink.</p>
<p>A similar change was found in the bottom water layer of the Weddell Sea, although the ice shelves here are not melting <a href="https://www.nature.com/articles/s41467-021-22259-0">nearly as rapidly</a> as elsewhere in the Antarctic. This is mainly because the polynya sea ice factory near the coast usually keeps warmer Southern Ocean water at bay.</p>
<p>Although our study suggests that changes in the Weddell Sea are a result of natural variability in the Earth system, they are also part of an Antarctic-wide trend that is not as clearly explained by natural causes. In fact, freshening and shrinking bottom water is consistent with scientific predictions about the melting ice sheet. Satellite observations have shown a <a href="https://www.science.org/doi/10.1126/science.aaz5845">steady loss in ice sheet mass</a> since 2002.</p>
<figure class="align-center ">
<img alt="A thick wall of glacier ending at a shallow bay with a rocky shore in the foreground." src="https://images.theconversation.com/files/531330/original/file-20230612-29-58rjgj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/531330/original/file-20230612-29-58rjgj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=395&fit=crop&dpr=1 600w, https://images.theconversation.com/files/531330/original/file-20230612-29-58rjgj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=395&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/531330/original/file-20230612-29-58rjgj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=395&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/531330/original/file-20230612-29-58rjgj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=496&fit=crop&dpr=1 754w, https://images.theconversation.com/files/531330/original/file-20230612-29-58rjgj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=496&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/531330/original/file-20230612-29-58rjgj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=496&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The Antarctic ice sheet is the largest single mass of ice on Earth.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/thick-wall-glacier-sheet-on-coast-1805491189">Ssawpics/Shutterstock</a></span>
</figcaption>
</figure>
<p>Models are one of the best tools for translating current knowledge of physics and present and past conditions into an understanding of the future climate. But their representation of many important processes, such as Antarctic bottom water formation, is often incomplete. And so it takes ongoing research to advance our understanding of how the Earth system works and refine projections of the future.</p>
<p>More and more evidence indicates that the Antarctic ice sheet is vulnerable to the warming climate and that the melting of this great reservoir of ice will disrupt the overturning circulation that extends throughout the global ocean. This will disrupt the climate and accelerate sea-level rise globally.</p>
<p>As scientists who study the complex interaction between the ocean, ice sheet and atmosphere around Antarctica, we hope that continuing to refine our understanding of the Earth system and future climate projections will help inform decision makers. Systematic efforts are needed to immediately reduce greenhouse gas emissions and slow the pace of global warming.</p>
<hr>
<figure class="align-right ">
<img alt="Imagine weekly climate newsletter" src="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p><strong><em>Don’t have time to read about climate change as much as you’d like?</em></strong>
<br><em><a href="https://theconversation.com/uk/newsletters/imagine-57?utm_source=TCUK&utm_medium=linkback&utm_campaign=Imagine&utm_content=DontHaveTimeTop">Get a weekly roundup in your inbox instead.</a> Every Wednesday, The Conversation’s environment editor writes Imagine, a short email that goes a little deeper into just one climate issue. <a href="https://theconversation.com/uk/newsletters/imagine-57?utm_source=TCUK&utm_medium=linkback&utm_campaign=Imagine&utm_content=DontHaveTimeBottom">Join the 20,000+ readers who’ve subscribed so far.</a></em></p>
<hr><img src="https://counter.theconversation.com/content/205341/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Alessandro Silvano is a Natural Environment Research Council (United Kingdom Research and Innovation) Independent Research Fellow.</span></em></p><p class="fine-print"><em><span>Andrew Meijers receives research funding from the Natural Environment Research Council (United Kingdom Research and Innovation) and the European Commission. </span></em></p><p class="fine-print"><em><span>Shenjie Zhou receives research funding from the Natural Environment Research Council (United Kingdom Research and Innovation) and the European Commission.</span></em></p>Freshening seawater around Antarctica is disrupting a global ocean conveyor which regulates the climate.Alessandro Silvano, NERC Independent Research Fellow in Oceanography, University of SouthamptonAndrew Meijers, Deputy Science Leader, Polar Oceans Team, British Antarctic SurveyShenjie Zhou, Postdoctoral Physical Oceanography, British Antarctic SurveyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2041142023-05-30T20:07:35Z2023-05-30T20:07:35ZPhotos from the field: spying on Antarctic moss using drones, MossCam, smart sensors and AI<figure><img src="https://images.theconversation.com/files/526950/original/file-20230518-15-jkyrps.jpg?ixlib=rb-1.1.0&rect=24%2C0%2C4001%2C3017&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Krystal Randall</span>, <span class="license">Author provided</span></span></figcaption></figure><p>The Antarctic continent conjures visions of white ice and blue sky. But not far from Australia’s Casey Station, 3,880km due south of Perth, moss beds emerge verdant and green. </p>
<p>Sadly, the <a href="https://www.nature.com/articles/s41558-018-0280-0">health of these moss beds is declining</a> due to changing climate conditions, ozone depletion and heatwaves. Yet our understanding of the problem is limited. Conducting research in Antarctica is difficult. Periods of data collection are short, and there can be years between each research opportunity. Fortunately, new technology offers solutions. </p>
<p>In December 2022, we travelled to Casey Station. We spent two months in the field – combining our skills in biology, flying drones, programming and artificial intelligence – to learn more about the moss and find better ways to remotely monitor biological changes. </p>
<p>We mapped large moss beds and trialled a new sensor system that can deliver continuous, year-round moss data. While this research is ongoing, we’re thrilled to share the early results with you here.</p>
<figure class="align-center ">
<img alt="Collecting moss data" src="https://images.theconversation.com/files/527184/original/file-20230519-17-fjyr76.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/527184/original/file-20230519-17-fjyr76.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/527184/original/file-20230519-17-fjyr76.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/527184/original/file-20230519-17-fjyr76.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/527184/original/file-20230519-17-fjyr76.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/527184/original/file-20230519-17-fjyr76.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/527184/original/file-20230519-17-fjyr76.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">The scientists at work near Casey Station. Left to right: Dr Johan Barthélemy and Dr Krystal Randall.</span>
<span class="attribution"><span class="source">Johan Barthélemy</span></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/an-epic-global-study-of-moss-reveals-it-is-far-more-vital-to-earths-ecosystems-than-we-knew-203141">An epic global study of moss reveals it is far more vital to Earth's ecosystems than we knew</a>
</strong>
</em>
</p>
<hr>
<h2>Miniature forests, bustling with life</h2>
<p>Plants need sunlight, warmth and liquid water. Antarctic plants face months of darkness, freezing temperatures and drought from frozen water – but moss has adapted to this hostile environment. </p>
<p>Moss is the dominant plant life in Antarctica. It provides habitat for invertebrates, microbes and fungi, which make up more than 99% of Antarctica’s land biodiversity. The moss beds resemble miniature forests, bustling with life.</p>
<p>Antarctic moss creates its own warm microclimate, using pigments to absorb sunlight. This warmth aids photosynthesis and helps the mosses to melt snow to obtain liquid water. The tiny hills and valleys across moss beds determine the amount of light mosses receive and creates differences in their microclimates and health.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/526968/original/file-20230518-17-yttmb3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A sign to protect the moss beds in Antarctica" src="https://images.theconversation.com/files/526968/original/file-20230518-17-yttmb3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/526968/original/file-20230518-17-yttmb3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/526968/original/file-20230518-17-yttmb3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/526968/original/file-20230518-17-yttmb3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/526968/original/file-20230518-17-yttmb3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/526968/original/file-20230518-17-yttmb3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/526968/original/file-20230518-17-yttmb3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Mosses are the dominant plant life in Antarctica.</span>
<span class="attribution"><span class="source">Krystal Randall</span></span>
</figcaption>
</figure>
<p>Once we reached the moss, we’d carefully balance on rocks to take samples and place data loggers. These consisted of four sensors that measured canopy temperatures at different positions in the moss bed. We also measured photosynthesis and collected moss samples for pigment analysis, which indicates health and stress levels. </p>
<p>The below photo depicts a moss bed with our equipment attached. You can see the complex micro-topography and a mosaic of healthy and stressed mosses. Healthy moss is green and velvety. Stressed mosses are red and eventually turn grey.</p>
<p>Mosses growing just centimetres apart can experience vastly different microclimates. In the photo below, some mosses had warmed up to 19°C (next to the red marker), while only about 30cm away the moss was at 0.6°C (next to the white marker).</p>
<p>Collecting this data enables us to explore connections between the physical structure of the moss beds, microclimates and indicators of moss health.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/antarcticas-moss-forests-are-drying-and-dying-103751">Antarctica's 'moss forests' are drying and dying</a>
</strong>
</em>
</p>
<hr>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/526958/original/file-20230518-15-q1aef2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A moss bed and temperature data logger." src="https://images.theconversation.com/files/526958/original/file-20230518-15-q1aef2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/526958/original/file-20230518-15-q1aef2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/526958/original/file-20230518-15-q1aef2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/526958/original/file-20230518-15-q1aef2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/526958/original/file-20230518-15-q1aef2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/526958/original/file-20230518-15-q1aef2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/526958/original/file-20230518-15-q1aef2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Mosses growing just centimetres apart can experience vastly different climates.</span>
<span class="attribution"><span class="source">Krystal Randall</span></span>
</figcaption>
</figure>
<h2>Smart sensors, cameras and transmitters</h2>
<p>While in Antarctica, we also tested the first prototype of an intelligent, autonomous and long-term sensing platform. It offers scientists more information than previous data-collection devices as it can collect and transmit data over an extended period outside regular summer field campaigns, including winter time.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/527166/original/file-20230519-23-9at7da.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Remote sensing platform" src="https://images.theconversation.com/files/527166/original/file-20230519-23-9at7da.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/527166/original/file-20230519-23-9at7da.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=447&fit=crop&dpr=1 600w, https://images.theconversation.com/files/527166/original/file-20230519-23-9at7da.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=447&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/527166/original/file-20230519-23-9at7da.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=447&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/527166/original/file-20230519-23-9at7da.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=562&fit=crop&dpr=1 754w, https://images.theconversation.com/files/527166/original/file-20230519-23-9at7da.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=562&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/527166/original/file-20230519-23-9at7da.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=562&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 remote sensing platform watching a moss bed.</span>
<span class="attribution"><span class="source">Johan Barthélemy</span></span>
</figcaption>
</figure>
<p>The prototype monitored the moss bed near Casey Station for a month and a half. Its sensors captured light intensity, ambient air temperature and humidity, moss canopy temperature and, finally, energy exchanged between soil and air. A webcam, affectionately nicknamed MossCam, captured regular images of the moss bed.</p>
<p>We also installed the first antenna in Antarctica for <a href="https://www.thethingsnetwork.org/article/the-first-lorawan-gateway-running-in-antarctica">the LoRaWAN wireless network</a>. This network is low power, long range and free to use. This allowed us to send data back to Australia in near real-time and <a href="https://uow.to/mosscam">display it on a website dashboard</a> that is visible to Australians only. </p>
<p>After some early bug fixes, the platform performed better than expected. We brought it home at the end of the season for further refinement and deployment next season.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/ctiW3TZvF5I?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">A 24-hour time-lapse captured by MossCam. Johan Barthelemy.</span></figcaption>
</figure>
<h2>Drones and hyperspectral imaging</h2>
<p>We sent drones on 25 flights, collecting data from two <a href="https://www.ats.aq/e/protected.html">Antarctic Specially Protected Areas</a> (ASPAs 135 and 136). </p>
<p>Operating drones in the Antarctic presents significant challenges. The proximity to the magnetic pole disturbs the GPS navigation, and strong winds make it difficult to fly. Severe cold reduces battery life – and it’s also tough on the operator’s fingers. We customised drones with RTK (<a href="https://blog.emlid.com/introduction-to-rtk-gps/">real-time kinematics</a>, a technique to eliminate position errors) GPS, multiple redundancies and battery warmers to increase their resilience to harsh conditions. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/bDTZ9VveO1o?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">We used a compact mini drone as a reconnaissance unit, scouting new areas and providing videography like this. Juan Sandino.</span></figcaption>
</figure>
<p>Our drones could capture 5,000-10,000 images on each flight. They were also equipped with high-tech sensors. These sensors are programmed to record “spectral signatures”, which is a term we use to describe a kind of optical identity or visual “DNA” that differentiates landscape features like moss, rock and snow within the image. </p>
<p>These images will be stitched together and mapped to their ground coordinates. Using machine learning, we will train a model to identify vegetation, including moss, lichen and cyanobacteria. We will also develop vegetation and hydrology maps, 3D fly-throughs and virtual reality experiences to support decision-making around conservation and management. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/527162/original/file-20230519-23-1z26d2.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/527162/original/file-20230519-23-1z26d2.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=281&fit=crop&dpr=1 600w, https://images.theconversation.com/files/527162/original/file-20230519-23-1z26d2.PNG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=281&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/527162/original/file-20230519-23-1z26d2.PNG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=281&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/527162/original/file-20230519-23-1z26d2.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=353&fit=crop&dpr=1 754w, https://images.theconversation.com/files/527162/original/file-20230519-23-1z26d2.PNG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=353&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/527162/original/file-20230519-23-1z26d2.PNG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=353&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Hyperspectral data showing healthy moss (blue), stressed moss (red) and rock (green).</span>
<span class="attribution"><span class="source">Juan Sandino</span></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/drones-help-scientists-check-the-health-of-antarctic-mosses-revealing-climate-change-clues-83817">Drones help scientists check the health of Antarctic mosses, revealing climate change clues</a>
</strong>
</em>
</p>
<hr>
<h2>One journey ends, while another is just beginning</h2>
<p>Often while we were working, curious penguins wandered over to see what we were doing. Making friends with these locals was always the highlight of the day.</p>
<iframe width="100%" height="758" src="https://www.youtube.com/embed/Wovm6zCZHOM" title="Welcome to our office! Krystal Randall." frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" allowfullscreen=""></iframe>
<p>But after a couple of fantastic months in the field, it was time to pack up and head home. On the 60km journey inland to Wilkins Aerodrome we ventured into the Antarctic Circle. We waited in -20°C to watch our plane land on the blue ice runway before boarding and flying back to Tasmania. There, it felt like we’d just woken up from a dream. </p>
<p>Our Antarctic adventure was over, but we all felt so grateful for the experience. </p>
<p>Now we’re exploring the data, to see what stories it can tell, while further developing our moss sensing platform. We hope to return to Antarctica to deploy it at the end of the year. </p>
<p><em>The authors travelled to Casey Station as part of the Australian Research Council Special Research Initiative Securing Antarctica’s Environmental Future (SAEF).</em></p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/526955/original/file-20230518-19-8b1c34.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Group photo at the Antarctic Circle sign" src="https://images.theconversation.com/files/526955/original/file-20230518-19-8b1c34.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/526955/original/file-20230518-19-8b1c34.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/526955/original/file-20230518-19-8b1c34.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/526955/original/file-20230518-19-8b1c34.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/526955/original/file-20230518-19-8b1c34.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/526955/original/file-20230518-19-8b1c34.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/526955/original/file-20230518-19-8b1c34.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 team as they crossed the Antarctic Circle: Dr Johan Barthélemy (left), Dr Krystal Randall (centre), Ashray Doshi (front), Dr Juan Sandino (right) and Prof Barbara Bollard (back right).</span>
<span class="attribution"><span class="source">Krystal Randall</span></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/toughness-has-limits-over-1-100-species-live-in-antarctica-but-theyre-at-risk-from-human-activity-181258">Toughness has limits: over 1,100 species live in Antarctica – but they're at risk from human activity</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/204114/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Dr Johan Barthélemy received funding from Securing Antarctica’s Environmental Future (SAEF), an Australian Research Council Special Research Initiative. He currently works at NVIDIA.</span></em></p><p class="fine-print"><em><span>Barbara Bollard receives funding from Securing Antarctica's Environmental Future (SAEF), an Australian Research Council (ARC) Special Research Initiative (SRI). </span></em></p><p class="fine-print"><em><span>Juan Sandino is affiliated with the QUT Centre for Robotics (QCR), Australia, and receives funding from Securing Antarctica’s Environmental Future (SAEF), an Australian Research Council (ARC) Special Research Initiative (SRI).</span></em></p><p class="fine-print"><em><span>Dr Krystal Randall is affiliated with the Centre for Sustainable Ecosystem Solutions (CSES) in the School of Earth, Atmospheric and Life Sciences at the University of Wollongong (UOW). Krystal has previously received funding from the Antarctic Science Foundation, and currently receives funding from Securing Antarctica’s Environmental Future (SAEF), an Australian Research Council (ARC) Special Research Initiative (SRI).</span></em></p>It was the trip of a lifetime for an Australian research team studying moss in Antarctica. After two months at Casey Station they returned with great videos and loads of data for further analysis.Johan Barthélemy, Developer Relations Manager, NVIDIA and Honorary Senior Research Fellow, University of Wollongong, University of WollongongBarbara Bollard, Professor of Computational Conservation, Auckland University of TechnologyJuan Sandino, Postdoctoral research fellow, Queensland University of TechnologyKrystal Randall, Postdoctoral Research Fellow, University of WollongongLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2062892023-05-25T20:00:45Z2023-05-25T20:00:45ZAntarctic alarm bells: observations reveal deep ocean currents are slowing earlier than predicted<figure><img src="https://images.theconversation.com/files/528175/original/file-20230525-30-kkbyoh.jpg?ixlib=rb-1.1.0&rect=28%2C0%2C3799%2C2226&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Steve Rintoul</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Antarctica sets the stage for the world’s greatest waterfall. The action takes place beneath the surface of the ocean. Here, trillions of tonnes of cold, dense, oxygen-rich water cascade off the continental shelf and sink to great depths. This Antarctic “bottom water” then spreads north along the sea floor in deep ocean currents, before slowly rising, thousands of kilometres away. </p>
<p>In this way, Antarctica drives a global network of ocean currents called the “overturning circulation” that redistributes heat, carbon and nutrients around the globe. The overturning is crucial to keeping Earth’s climate stable. It’s also the main way oxygen reaches the deep ocean.</p>
<p>But there are signs this circulation is slowing down and it’s happening decades earlier than predicted. This slowdown has the potential to disrupt the connection between the Antarctic coasts and the deep ocean, with profound consequences for Earth’s climate, sea level and marine life.</p>
<p>Our <a href="https://www.nature.com/articles/s41558-023-01667-8">new research</a>, published today in the journal Nature Climate Change, uses real-world observations to decipher how and why the deep ocean around Antarctica has changed over the past three decades. Our measurements show the overturning circulation has slowed by almost a third (30%) and deep ocean oxygen levels are declining. This is happening even earlier than <a href="https://journals.ametsoc.org/view/journals/clim/28/8/jcli-d-14-00381.1.xml">climate models</a> predicted.</p>
<p>We found melting of Antarctic ice is disrupting the formation of Antarctic bottom water. The meltwater makes Antarctic surface waters fresher, less dense, and therefore less likely to sink. This puts the brakes on the overturning circulation. </p>
<figure>
<iframe src="https://player.vimeo.com/video/830053753" width="500" height="281" frameborder="0" webkitallowfullscreen="" mozallowfullscreen="" allowfullscreen=""></iframe>
<figcaption><span class="caption">Now that’s a waterfall: dense water flowing from the continental shelf into the deep ocean in the Ross Sea. Consortium for Ocean-Sea Ice Modelling in Australia (COSIMA) and National Computational Infrastructure.</span></figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/torrents-of-antarctic-meltwater-are-slowing-the-currents-that-drive-our-vital-ocean-overturning-and-threaten-its-collapse-202108">Torrents of Antarctic meltwater are slowing the currents that drive our vital ocean 'overturning' – and threaten its collapse</a>
</strong>
</em>
</p>
<hr>
<h2>Why does this matter?</h2>
<p>As the flow of bottom water slows, the supply of oxygen to the deep ocean declines. The shrinking oxygen-rich bottom water layer is then replaced by warmer waters that are lower in oxygen, further reducing oxygen levels.</p>
<p>Ocean animals, large and small, respond to even small changes in oxygen. Deep-ocean animals are adapted to low oxygen conditions but still have to breathe. Losses of oxygen may cause them to seek refuge in other regions or adapt their behaviour. Models suggest we are <a href="https://www.nature.com/articles/s41467-021-22584-4">locked in</a> to a contraction of the “viable” environment available to these animals with an expected decline of up to 25%. </p>
<p>Slowdown of the overturning may also <a href="https://www.nature.com/articles/s41558-022-01555-7">intensify</a> global warming. The overturning circulation carries carbon dioxide and heat to the deep ocean, where it is stored and hidden from the atmosphere. As the ocean storage capacity is reduced, more carbon dioxide and heat are left in the atmosphere. This feedback accelerates global warming.</p>
<p>Reductions in the amount of Antarctic bottom water reaching the ocean floor also increases <a href="https://journals.ametsoc.org/view/journals/clim/26/16/jcli-d-12-00834.1.xml">sea levels</a> because the warmer water that replaces it takes up more space (<a href="https://www.britannica.com/science/thermal-expansion">thermal expansion</a>).</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/528179/original/file-20230525-25-a15xuo.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A schematic diagram summarising how and why bottom water varies in the Australian Antarctic Basin." src="https://images.theconversation.com/files/528179/original/file-20230525-25-a15xuo.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/528179/original/file-20230525-25-a15xuo.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=372&fit=crop&dpr=1 600w, https://images.theconversation.com/files/528179/original/file-20230525-25-a15xuo.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=372&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/528179/original/file-20230525-25-a15xuo.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=372&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/528179/original/file-20230525-25-a15xuo.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=468&fit=crop&dpr=1 754w, https://images.theconversation.com/files/528179/original/file-20230525-25-a15xuo.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=468&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/528179/original/file-20230525-25-a15xuo.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=468&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Freshening of shelf waters reduces the flow of dense water and slows the deepest parts of the overturning circulation while also reducing deep oxygenation.</span>
<span class="attribution"><span class="source">Kathy Gunn</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Signs of a worrying change</h2>
<p>Making observations of bottom water is challenging. The Southern Ocean is remote and home to the strongest winds and biggest waves on the planet. Access is also restricted by sea ice during winter, when bottom water forms.</p>
<p>This means observations of the deep Southern Ocean are sparse. Nevertheless, repeated full-depth measurements taken from ship voyages have provided glimpses into the changes underway in the deep ocean. The bottom water layer is <a href="https://journals.ametsoc.org/view/journals/clim/26/16/jcli-d-12-00834.1.xml">getting warmer, less dense and thinner</a>.</p>
<p>Satellite data shows the Antarctic ice sheet is <a href="https://www.pnas.org/doi/10.1073/pnas.1812883116">shrinking</a>. Ocean measurements taken downstream of regions of rapid melt show the meltwater is <a href="https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2021JC017808">reducing the salinity</a> (and density) of coastal waters. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/AmSovbt5Bho?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Antarctic ice mass loss over the last few decades based on satellite data, showing that between 2002 and 2020, Antarctica shed an average of ~150 billion metric tonnes of ice per year, adding meltwater to the ocean and raising sea-levels (Source: NASA).</span></figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/antarcticas-heart-of-ice-has-skipped-a-beat-time-to-take-our-medicine-202729">Antarctica's heart of ice has skipped a beat. Time to take our medicine</a>
</strong>
</em>
</p>
<hr>
<p>These signs point to a worrying change, but there are still no direct observations of the deep overturning circulation.</p>
<h2>What did we do?</h2>
<p>We combined different types of observations in a new way, taking advantage of each of their strengths.</p>
<p>The full-depth measurements collected by ships provide snapshots of ocean density, but are usually repeated about once a decade. Moored instruments, on the other hand, provide continuous measurements of density and speed, but only for a limited time at a particular location.</p>
<p>We developed a new approach that combines ship data, mooring records, and a high resolution numerical simulation to calculate the strength of Antarctic bottom water flow and how much oxygen it transports to the deep ocean. </p>
<p>Our study focused on a deep basin south of Australia that receives bottom water from several sources. These sources lie downstream of large meltwater inputs, so this region is likely to provide an early warning of climate-induced deep ocean changes.</p>
<p>The findings are striking. Over three decades, between 1992 and 2017, the overturning circulation of this region slowed by almost a third (30%) causing less oxygen to reach the deep. This slowing was caused by freshening close to Antarctica.</p>
<p>We found this freshening reduces the density and volume of Antarctic bottom water formed, as well as the speed at which it flows. </p>
<p>The observed slowdown would have been even greater if not for a short-lived climate event that drove a <a href="https://www.nature.com/articles/s41561-020-00655-3">partial and temporary recovery of bottom water formation</a>. The recovery, driven by increased salinity, further illustrates the sensitivity of bottom water formation to salinity changes on the Antarctic continental shelf. </p>
<p>Worryingly, these observations show that changes <a href="https://www.nature.com/articles/s41586-023-05762-w">predicted to occur by 2050</a> are already underway. </p>
<figure>
<iframe src="https://player.vimeo.com/video/812260307" width="500" height="281" frameborder="0" webkitallowfullscreen="" mozallowfullscreen="" allowfullscreen=""></iframe>
<figcaption><span class="caption">Abyssal ocean warming driven by Antarctic overturning slowdown, Credit: Matthew England and Qian Li.</span></figcaption>
</figure>
<h2>What next?</h2>
<p>Ice loss from Antarctica is expected to continue, even accelerate, as the world warms. We are <a href="https://library.wmo.int/index.php?lvl=notice_display&id=22272#.ZGNbiRZBxWw">almost certain to cross the 1.5°C global warming threshold by 2027</a>. </p>
<p>More ice loss will mean more freshening, so we can anticipate the slowdown in circulation and deep oxygen losses will continue.</p>
<p>The consequences of a slowdown will not be limited to Antarctica. The overturning circulation extends throughout the global ocean and influences the pace of climate change and sea level rise. It will also be disruptive and damaging for marine life.</p>
<p>Our research provides yet another reason to work harder – and faster – to reduce greenhouse gas emissions.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/record-low-antarctic-sea-ice-is-another-alarming-sign-the-oceans-role-as-climate-regulator-is-changing-204680">Record low Antarctic sea ice is another alarming sign the ocean's role as climate regulator is changing</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/206289/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Matthew England receives funding from the Australian Research Council (ARC).</span></em></p><p class="fine-print"><em><span>Steve Rintoul receives funding from the Australian Antarctic Program Partnership.</span></em></p><p class="fine-print"><em><span>Kathy Gunn 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>Scientists have detected a 30% slowdown of the deep ocean currents that form in Antarctica, with profound consequences for Earth’s climate, sea level and marine life.Kathy Gunn, CSIROMatthew England, Scientia Professor and Deputy Director of the ARC Australian Centre for Excellence in Antarctic Science (ACEAS), UNSW SydneySteve Rintoul, CSIRO Fellow, CSIROLicensed as Creative Commons – attribution, no derivatives.