Using computer models and data collected in the past decade, some climate scientists now believe that a major Antarctica ice sheet is in the process of collapsing.
One team combined data on the recent retreat of the 182,000-square-kilometer Thwaites Glacier with a model of the glacier’s dynamics to forecast its future. In a paper published online today in Science, they report that in as few as 2 centuries Thwaites Glacier’s outermost edge will recede past an underwater ridge now stalling its retreat. Their modeling suggests that the glacier will then cascade into rapid collapse. The second team, writing in Geophysical Research Letters (GRL), describes recent radar mapping of West Antarctica’s glaciers and confirms that the 600-meter-deep ridge is the final obstacle before the bedrock underlying the glacier dips into a deep basin.
Because inland basins connect Thwaites Glacier to other major glaciers in the region, both research teams say its collapse would flood West Antarctica with seawater, prompting a near-complete loss of ice in the area. “The next stable state for the West Antarctic Ice Sheet might be no ice sheet at all,” says the Science paper’s lead author, glaciologist Ian Joughin of the University of Washington (UW), Seattle.
This result really falls under the category of the uncertainty of science. Though the data suggests a glacier that is part of the much larger West Antarctica ice sheet is melting, the prediction that the ice sheet itself will collapse sometime in the next two centuries is solely based on computer models that have all too often turned turned out to be wrong.