'No Quick Fix' as Antarctic Sea Ice Hits Record Low, Scientists Link Losses to Fossil Fuel Burning

Sea ice around Antarctica has fallen to its lowest level since satellites began watching it in 1979, and it has done so by beating the record minimum set only a year earlier. That finding comes from a study in the journal Frontiers in Environmental Science, and the scientists behind it say the continent is "suffering" because fossil fuels are being burned.

The authors, drawn from institutions across the UK, Chile and South Africa, have been cataloguing extreme events in Antarctica. They say it is "virtually certain" that the severity of such events will grow unless greenhouse gas emissions are brought under control. Their paper identifies nearly a dozen ways human activity is changing the region: melting sea ice and land ice, collapsing ice shelves, warming oceans and atmosphere, the near-extinction of some marine animals, and the arrival of foreign species such as moss and grass.

The most striking single event they point to is a winter heatwave in March 2022. In east Antarctica, temperatures climbed nearly 40C above the norm, from around -50C to about -10C. Had it struck in summer, the scientists said, it would have started melting the surface of the ice sheets, something they say they have never seen. The researchers acknowledge a limit on what can be proved: Antarctica's harsh climate and remoteness mean less data exists to link such events unequivocally to human-induced climate change. But they say events like this are to be expected on a warming planet.

Professor Martin Siegert, a glaciologist at the University of Exeter, said it was possible the heatwave was a one-in-1,000-year event, but called that so unlikely that it is scientifically reasonable to assume a link to a heating planet. "Antarctica is suffering as a consequence of burning fossil fuels and there will be more to come," he said. He added that the scientific community has been shocked by this season's lack of sea ice, far below previous years, and that the heatwave and the loss of ice shelves were not really relevant in 1990.

Recovery, if it comes, will be slow. Caroline Holmes, a polar climate scientist at the British Antarctic Survey and a study co-author, told a briefing for journalists it will take decades if not centuries for these things to recover. "There's no quick fix to replacing this ice," she said, adding that it will take a long time even if it is possible. Dr Anna Hogg of the University of Leeds, who watches the changes day to day, said she finds the scale of change already under way surprising and staggering. She said collapsed ice shelves would take centuries to recover, if they can at all.

Ice shelf collapse matters even though it does not directly raise sea levels, because the ice is already floating. What changes is the pace at which ice from the land pours into the sea through glaciers, which speeds up sea level rise. Scientists do not expect it anytime soon, but if all of Antarctica's ice melted, global sea level would rise by 57 metres.

The researchers describe extreme events combining in cascading, multiplying effects that reach across the world and also threaten native species. They are calling for more environmental protection to conserve ecosystems that are increasingly exposed. Melting ice could open easier access for ships carrying more people, for example, who would then need to take more care not to carry non-native seeds on their boots. Jane Rumble, the UK Foreign Office's head of polar regions, said the department is looking to give better protection to emperor penguins, a "climate vulnerable" species.

Scientists are especially concerned about the next few years, when the warming effects of El Nino take hold.