As the windiest, driest, coldest continent on earth, Antarctica is no stranger to extreme weather. So, you might be surprised to discover that while Sheffield has been toughing it out under storms Ciara and Dennis, the continent of Antarctica reached a balmy high of 20℃ on Sunday 9 February this year. Is it time to take a winter break down south?
This record-high temperature, recorded at Seymour Island, hails a new kind of extreme weather for this continent: extreme heat. Although this latest temperature record is surprising, it is not unexpected that such extreme records are being realised now. Historically, Antarctica has been the fastest-warming continent in the southern hemisphere, with temperatures rising by an average of 3℃ overall over the last 50 years. While this may not seem like a lot, it is worth bearing in mind that average air temperatures across the planet have only risen by 0.74℃ over the whole of the last century. 3℃ of warming in Antarctica alone is demonstrative of how our polar regions are the most likely to be affected by climate change of anywhere on earth.
Temperatures are not just rising in Antarctica; they’re becoming more volatile too. The past 20 years have seen large fluctuations in the Antarctic climate, particularly in the Antarctic Peninsula, where Seymour Island is located. This is telling of the important effect which rising sea temperatures have on the terrestrial climate, as sea surface temperatures to the west of the continent and surrounding the peninsula have increased by an average of 1℃ over the last 50 years.
Home to 70 per cent of the world’s freshwater in the form of ice and snow, climatic changes in Antarctica have large knock-on effects for the global hydrological cycle. If all this ice were to melt, sea levels would rise by 50 to 60 metres, wiping out all coastal cities as well as much habitable land. Even though this scenario is unlikely, it is predicted that we will face oceans between 30-110 centimetres higher than they presently are by the end of this century. Another threat posed by such increasing temperatures is the breakup of the Arctic Peninsula. Already, glaciers have been lost from the peninsula, which contributes to increasing sea levels as well as further warming through the reduction of the surface albedo. Albedo is the measure of the fraction of light reflected by a body. Thus, something white, such as snow, will reflect more light having a higher albedo. As warming temperatures lead to ice melt, the Earth’s albedo is lowering. This will increase further warming due to the exposure of dark surfaces in places where snow and ice should be.
These consequences of warming don’t just impact us, they also impact on what little biodiversity this barren continent holds. Chinstrap penguins, one of the key species of Antarctica, have declined by 50 per cent since the 1970s. This is thought to be down to global heating, which has seen huge reductions in the sea ice cover on which these penguins rely.
The record-high temperature recently recorded in Antarctica is, while in itself an anomaly, overall indicative of the general trend of rising temperatures in the last decades. Climate change is spurring more variable fluctuations in temperature than would be expected of this region, and Antarctica is suffering the effects of global heating more severely than the rest of the globe. Warming in recent decades is pushing the Antarctic ecosystem to the edge, endangering both its resident wildlife and, ultimately, ourselves. It now remains to be seen whether our efforts to mitigate climate change in the upcoming decades will be successful, and if (or when) this latest temperature high might be beaten still.