A review of climate change in Antarctica forecasts that by 2100 the world鈥檚 seas will have risen to levels previously considered too extreme to be realistic.
The review, (PDF), was compiled by 100 scientists associated with the international . Using 20 of the most up-to-date models that take into account the complex behaviour of the ozone hole over Antarctica, as well as the most recent observations of ice loss, the review predicts that the area of sea ice around Antarctica could shrink by 33聽per cent 鈥� 2.6聽million square kilometres 鈥� by 2100, leading to a sea-level rise of 1.4 metres.
鈥淭his is the first comprehensive review of Antarctic climate change that covers how the climate of the icy continent has changed from deep time,鈥� says of the British Antarctic Survey, lead editor of the report. The report also makes predictions about how the Antarctic climate will change over the next century.
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For the past 30 years, the hole in the atmosphere鈥檚 ozone layer above Antarctica has protected the bulk of the continent from the effects of climate change by generating fierce winds. In that time, sea ice around the continent has increased by 10聽per cent.
The new report warns that when the ozone hole heals 鈥� and it will, possibly by the end of the century 鈥� Antarctica will feel the full force of global warming, with temperatures rising by as much as 3聽掳C by 2100.
From sea ice to sea
The report backs the predictions of at Potsdam University, Germany, whose own work suggests that given the speed at which West Antarctica鈥檚 ice sheets are shrinking, sea levels are likely to rise by 1.4聽metres by 2100. In contrast, the , published in 2007, predicted 59聽centimetres.
鈥淚 am not the one to judge my own paper, but there is indeed [some] indication that these higher numbers 鈥� not only from my study, by the way 鈥� are now the new mainstream,鈥� says Rahmstorf.
The IPCC鈥檚 sea-level rise projections are considered to be conservative, as they don鈥檛 take into account the fact that Antarctica鈥檚 loss of ice will accelerate as temperatures rise over the continent.
By 2100, the West Antarctic Ice Sheet alone could lose enough ice mass to raise sea levels globally by 鈥渢ens of centimetres,鈥� Turner says.
Despite the transformations climate change will create on Antarctica, the study concludes on an upbeat note: only a few of the continent鈥檚 species are likely to become extinct by 2100.
Many marine creatures can survive a change in temperature of 5聽to 10聽掳C before dying, but 鈥渁 rise of this magnitude in the Southern Ocean is extremely unlikely by 2100鈥�, the study says.
