‘Everyone should be concerned’: Antarctic sea ice reaches lowest levels ever recorded. Sat 4 Mar 2023 19.00 GMT With the continent holding enough ice to raise sea levels by many metres if it was to melt, polar scientists are scrambling for answers. For 44 years, satellites have helped scientists track how much ice is floating on the ocean around Antarctica’s 18,000km coastline. The continent’s fringing waters witness a massive shift each year, with sea ice peaking at about 18m sq km each September before dropping to just above 2m sq km by February.But across those four decades of satellite observations, there has never been less ice around the continent than there was last week. By the end of January we could tell it was only a matter of time. It wasn’t even a close run thing,” says Dr Will Hobbs, an Antarctic sea ice expert at the University of Tasmania with the Australian Antarctic Program Partnership. “We are seeing less ice everywhere. It’s a circumpolar event.” In the southern hemisphere summer of 2022, the amount of sea ice dropped to 1.92m sq km on 25 February – an all-time low based on satellite observations that started in 1979. But by 12 February this year, the 2022 record had already been broken. The ice kept melting, reaching a new record low of 1.79m sq km on 25 February and beating the previous record by 136,000 sq km – an area double the size of Tasmania. In the southern hemisphere’s spring, strong winds over western Antarctica buffeted the ice. At the same time, Hobbs says large areas in the west of the continent had barely recovered from the previous year’s losses.The fate of Antarctica – especially the ice on land – is important because the continent holds enough ice to raise sea levels by many metres if it was to melt. While melting sea ice does not directly raise sea levels because it is already floating on water, several scientists told the Guardian of knock-on effects that can. Sea ice helps to buffer the effect of storms on ice attached to the coast. If it starts to disappear for longer, the increased wave action can weaken those floating ice shelves that themselves stabilise the massive ice sheets and glaciers behind them on the land. That’s important because the region is home to the vulnerable Thwaites glacier – known as the “doomsday glacier” because it holds enough water to raise sea levels by half a metre.             https://www.theguardian.com/world/2023/mar/04/everyone-should-be-concerned-antarctic-sea-ice-reaches-lowest-levels-ever-recorded