New research has shown that much of Antarctica is warming more than previously thought, and for the past 50 years, it has been getting warmer at a rate comparable to the rest of the world.
"In fact, the warming in West Antarctica is greater than the cooling in East Antarctica, meaning that on average the continent has gotten warmer," said Eric Steig, a University of Washington (UW) professor of Earth and space sciences and director of the Quaternary Research Center at the UW.
"West Antarctica is a very different place than East Antarctica, and there is a physical barrier, the Transantarctic Mountains, that separates the two," he added.
For years, it was believed that a relatively small area known as the Antarctic Peninsula was getting warmer, but that the rest of the continent - including West Antarctica, the ice sheet most susceptible to potential future collapse - was cooling.
Steig noted that the West Antarctic Ice Sheet, with an average elevation of about 6,000 feet above sea level, is substantially lower than East Antarctica, which has an average elevation of more than 10,000 feet.
While the entire continent is essentially a desert, West Antarctica is subject to relatively warm, moist storms and receives much greater snowfall than East Antarctica.
The study found that warming in West Antarctica exceeded one-tenth of a degree Celsius per decade for the last 50 years and more than offset the cooling in East Antarctica.
The researchers devised a statistical technique that uses data from satellites and from Antarctic weather stations to make a new estimate of temperature trends.
"While other interpolations had been done previously, no one had really taken advantage of the satellite data, which provide crucial information about spatial patterns of temperature change," said Steig.
Satellites calculate the surface temperature by measuring the intensity of infrared light radiated by the snowpack, and they have the advantage of covering the entire continent.
The scientists found temperature measurements from weather stations corresponded closely with satellite data for overlapping time periods.
That allowed them to use the satellite data as a guide to deduce temperatures in areas of the continent without weather stations.
According to Steig, "Simple explanations don't capture the complexity of climate. The thing you hear all the time is that Antarctica is cooling and that's not the case.
"If anything, it's the reverse, but it's more complex than that. Antarctica isn't warming at the same rate everywhere, and while some areas have been cooling for a long time the evidence shows the continent as a whole is getting warmer," he added.