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Antarctica faces a catastrophic cascade of extreme environmental events as global warming increases, which will affect climate across the world, scientists have warned in a report commissioned by the UK government.
Under the obligations of the Antarctic Treaty that came into force in 1961 and its subsequent 1998 protocol on environmental protection, signatories must protect the region from the “considerable stress and damage” it faces from accelerating ice melting and rising temperatures, the scientists said.
“Nations must understand that by continuing to explore, extract and burn fossil fuels anywhere in the world, the environment of Antarctica will become ever more affected in ways inconsistent with their pledge,” said Martin Siegert, glaciology professor at the University of Exeter and lead author of the study. “I’m staggered by the amount of change we’ve seen already in the past few years.”
In March 2022, the most extreme “heatwave” ever recorded anywhere in the world took place over the ice dome of East Antarctica where temperatures hit 38.5C above the seasonal normal. “If London experienced an anomaly like that, the temperature would be close to 60C,” he told journalists ahead of the report’s publication in Frontiers in Environmental Science.
The heatwave illustrated the way extreme events can be linked in cascades, the scientists said. It was caused by an “atmospheric river” of warm wet air flowing south from Australia, which also caused the break-up of sea ice and the collapse of the Conger ice shelf covering an area the size of Rome.
Today the area that has refrozen in the Antarctic winter is about 14.7mn sq km — 1.4mn sq km less than last year, which was itself a record low. The amount of sea ice missing this year compared with the average of the past five decades is 2.4mn sq km, an area 10 times greater than the UK.
“We are seeing a new world developing,” said Caroline Holmes, climate scientist at the British Antarctic Survey.
Antarctic changes have repercussions for global climate. Among many other impacts, melting ice contributes to rising sea levels, while shrinking ice cover means that more solar radiation is absorbed by seas and land rather than being reflected back into space by white frozen surfaces.
Since the satellite record began in the 1990s, ice loss from Antarctica has contributed 7.2mm to global sea level rise, said Anna Hogg, polar scientist at Leeds university. Ocean-driven melting and ice-shelf collapse are accelerating the flow of water into the ocean.
As well as reinforcing the need for global action to reduce greenhouse gas emissions, the expected changes required more action to protect Antarctica’s own fragile and vulnerable environments, said Jane Rumble, head of the polar regions department at the UK Foreign Office, which commissioned the report.
The treaty and its environmental protocol “set out the tools we might use to enhance the resilience of Antarctica against climate change”, she said. For example “we’ve been looking at terrain to afford extra protection for emperor penguins due to lack of sea ice . . . They breed on sea ice so they are a very climate vulnerable species.”
Ice loss means that some penguin colonies had had no success at all in raising chicks during the most recent breeding season, added Rumble.
