A recent study has re-evaluated predictions regarding the Thwaites Glacier in Antarctica, often referred to as the 'Doomsday Glacier' due to its potential impact on global sea levels.
The research indicates that a catastrophic collapse of the glacier, which could lead to rapid sea-level rise, is less likely to occur this century than previously anticipated.
Thwaites Glacier, located in West Antarctica, contributes approximately 4 percent to the annual increase in sea levels and contains enough ice to raise levels by over two feet if it completely melts, according to the International Thwaites Glacier Collaboration (ITGC).
Published in Science Advances and led by researchers from Dartmouth College, the study focused on marine ice cliff instability (MICI), a process predicting that collapsing ice shelves expose towering ice cliffs that may crumble under their own weight, causing rapid glacier retreat.
Despite being a key component in severe climate models, MICI has never been observed in real-world conditions. The Dartmouth team utilized updated computer simulations to conclude that MICI is unlikely to occur at Thwaites this century. Even if the glacier's ice shelf were to collapse today, the resulting ice cliffs might not be tall enough to trigger the feared chain reaction.
Professor Mathieu Morlighem, the study's lead author, emphasized that while the Antarctic is not safe, the most extreme predictions for this century appear less probable.
These findings contest high-risk scenarios presented by organizations like the United Nations Intergovernmental Panel on Climate Change (IPCC), which had included MICI-driven collapse in its extreme sea-level rise projections.
Despite the reduced likelihood of a dramatic collapse, the melting of Thwaites and adjacent glaciers remains a significant concern. The underlying bedrock of Thwaites slopes downward, complicating efforts to slow its retreat once it begins losing more ice than it gains from snowfall.
Since 2018, the ITGC, a partnership between the U.S. and U.K., has been monitoring Thwaites, which is roughly the size of Florida. Recently, scientists had warned of a possible imminent collapse.
While the risk of a sudden collapse this century may have diminished, the long-term consequences of Antarctic ice loss continue to pose a serious issue, with current sea levels rising by 0.13 inches annually, driven largely by polar ice melt.