Major glaciers in the West Antarctic Ice Sheet are melting faster than expected, and the entire sheet is now headed for inevitable collapse, according to two research papers publicised this week.
The first, from the journal Geophysical Research Letters, draws on 40 years of observations of West Antarctica’s glaciers and multiple lines of evidence to conclude that glaciers on the West Antarctic Ice Sheet have “passed the point of no return”, according to lead author Eric Ruginot of NASA’s JPL .
A second study in Science reports that within as little as 200 years the massive Thwaites Glacier‘s will recede past an underwater rocky ridge now stalling its retreat. Their modelling suggests that the glacier will then cascade into rapid collapse, destablising the ice sheet many kilometres inland and causing significant sea level rise.
Professor Tim Naish, Director of the Antarctic Research Centre at Victoria University of Wellington, comments:
“The vulnerability of the West Antarctic Ice Sheet to widespread and irreversible collapse has long been proposed, but the lack of a detailed understanding of how fast it will go hampers the accuracy of future sea-level rise projections being made by the IPCC. In their latest report the IPCC acknowledged that ‘unpredictable melting of the West Antarctic Ice Sheet’ could lead to significantly higher sea-levels than the 1m increase presently projected for the end of the century.
“This latest research increases certainty that the observed retreat and thinning of glaciers in the Amundsen Sea is part of more widespread, unstable response to ocean warming that may now be irreversible.
“Our inability to accurately predict the rate of future collapse of WAIS and its contribution to global sea-level rise is the highest priority being tackled by the Antarctic glaciological community, and was a number one issue identified at an international Antarctic research planning workshop held last month in Queenstown. This new study is an important step towards understanding what we will be in for, and that we are now committed to sea-level rise driven by Antarctic ice sheet melting for centuries to come!”
In the news:
Antarctic glaciers in irreversible decline – One News (TVNZ)
West Antarctic glaciers melting – NASA – Radio NZ News
Ice sheet melt to cause unstoppable sea level rise – NZ Herald (AP)