The melting West Antarctic ice sheet is past the point of no return, two studies found Monday and scientists say the melt will change coastlines and create the need to revise all sea level rise projects by at least 3 feet.
Although it's smaller than the East Antarctic ice sheet, the West Antarctic ice sheet is particularly vulnerable to melting from warm ocean waters because it sits on top of bedrock below sea level, NASA said. If it melts completely, it could add 13 feet of water to sea level, Business Insider reported.
Scientific papers by the journals Science and Geophysical Research Letters came to similar conclusions by different means, according to The New York Times.
Both groups of scientists found that West Antarctic glaciers had retreated far enough to set off an inherent instability in the ice sheet, one that experts have feared for decades.
NASA called a telephone press conference Monday to highlight the urgency of the findings.
In one of the new papers, a team led by Eric Rignot, a glaciologist at the University of California, Irvine, used satellite and air measurements to document an accelerating retreat during the past several decades of six glaciers draining into the Amundsen Sea region.
“Today we present observational evidence that a large sector of the West Antarctic ice sheet has gone into irreversible retreat,” Rignot said at the NASA press conference. “It has passed the point of no return.”
Those six glaciers alone could cause the ocean to rise four feet as they disappear, Rignot said, possibly within a couple of centuries. He also said their disappearance will most likely destabilize other sectors of the ice sheet, so the ultimate rise could be triple that.
A separate team led by Ian Joughin of the University of Washington studied one of the most important glaciers, Thwaites, using sophisticated computer modeling, coupled with recent measurements of the ice flow. That team also found that a slow-motion collapse had become inevitable. Even if the warm water now eating away at the ice were to dissipate, it would be “too little, too late to stabilize the ice sheet,” Joughin said. “There’s no stabilization mechanism.”