Antarctic ice slipping faster into the sea

Climate change scientists have been proved wrong - but the sceptics won't be crowing.

Just four years ago the UN's Intergovernmental Panel on Climate Change predicted that Antarctica would not contribute significantly to sea level rise in the 21st century. But glaciologists meeting at the Royal Society in London this week argued that the continent could already be the principal cause of rising sea levels.

The edges of the Antarctic ice sheets are crumbling at an unprecedented rate, says Andy Shepherd of the University of Cambridge. In one area, around the Amundsen Sea in West Antarctica, the Pine Island and Thwaites glaciers are dumping more than 110 cubic kilometres of ice each year. Warmer ocean waters circulating beneath the two glaciers are melting their bases and triggering an ever-faster slide into the ocean. The two glaciers are discharging ice three times as fast as a decade ago, and if they disappeared completely they could raise sea levels worldwide by more than a metre on their own.

Eric Rignot of NASA's Jet Propulsion Laboratory in Pasadena, California, reported that in many places the break-up of floating ice shelves at the continent's edge has triggered faster flows.