Antarctica warming faster than predicted

New research suggests that West Antarctica has warmed much more than scientists had thought over the last half-century, an ominous finding given that the huge ice sheet there may be vulnerable to long-term collapse, with potentially drastic effects on sea level.

A report released Sunday by the journal Nature Geoscience found that the temperature at a research station in the middle of West Antarctica has warmed by 4.4 degrees Fahrenheit since 1958. That is roughly twice as much as scientists previously thought and three times the overall rate of global warming, making central West Antarctica one of the fastest-warming regions on Earth.

“The surprises keep coming,” said Andrew J. Monaghan, a scientist at the National Center for Atmospheric Research in Boulder, Colo., who took part in the study. “When you see this type of warming, I think it’s alarming.”

Warming in Antarctica is relative. West Antarctica remains an exceedingly cold place, with average annual temperatures in the center of the ice sheet that are nearly 50 degrees F below freezing.

But the temperature there does sometimes rise above freezing in the summer, and the new research raises the possibility that it might begin to happen more often, potentially weakening the ice sheet through surface melting. The ice sheet is already under attack at the edges by warmer ocean water, and scientists are on alert for any fresh threat.