File Photoof the Antarctic Pine Island glacier
A major ice sheet in western Antarctica is melting, and its collapse is predicted to raise global sea level nearly two feet (61 centimeters), scientists said Monday.
Theories of the ice sheet's impending doom have been circulating for some time, and a study in the journal Science said the process is now expected to take between 200 and 1,000 years.
The thinning of the ice is likely related to global warming, said the study which was funded by NASA and the National Science Foundation.
Airborne radar measurements of the West Antarctic ice sheet allowed scientists to map the underlying bedrock of Thwaites Glacier.
Other satellite measurements provided the height of the ice sheet as it thins out over time.
Scientists used predictive models based on this data to envision how the ice sheet will melt and when, and discovered that such a collapse may be inevitable.
"Previously, when we saw thinning we didn't necessarily know whether the glacier could slow down later, spontaneously or through some feedback," said study author Ian Joughin, a glaciologist at the University of Washington.
"In our model simulations it looks like all the feedbacks tend to point toward it actually accelerating over time; there's no real stabilizing mechanism we can see."
The fastest scenario scientists found for the melting was 200 years and the longest was more than 1,000 years.
Joughin said the most likely melt times were between 200 and 500 years.
"All of our simulations show it will retreat at less than a millimeter of sea level rise per year for a couple of hundred years, and then, boom, it just starts to really go," Joughin said.