“Key glaciers in West Antarctica are in an irreversible retreat,” says a study team led by the US space agency (Nasa)
It analysed 40 years of observations of six big ice streams draining into the Amundsen Bay and concluded that nothing now can stop them melting away.
Although these are abrupt changes, the timescales involved are likely measured in centuries, the researchers add.
If the glaciers really do disappear, they would add roughly 1.2m to global sea level rise.
Prof Eric Rignot from NASA said warm ocean water was relentlessly eating away at the glaciers’ fronts and that the geometry of the sea bed in the area meant that this erosion had now entered a runaway process.
“We present observational evidence that a large section of the West Antarctic Ice Sheet has gone into a state of irreversible retreat; it has passed the point of no return,” the agency glaciologist explained.
