A recent study has challenged some of the most alarming predictions about Antarctica’s Thwaites Glacier, dubbed the “doomsday glacier,” because of the seismic effects it could have on the world’s oceans.

Research has suggested that a catastrophic glacier collapse, which could lead to rapid and dramatic sea-level rise, is less likely this century than previously thought.

The Thwaites Glacier in West Antarctica is a prime target for climatologists due to its unstable nature and significant contribution to global sea level rise.

It currently accounts for about 4 percent of annual sea-level rise and holds enough ice to lift it by more than two feet if it melts completely, according to the International Thwaites Glacier Collaboration (ITGC).

But the findings offer a glimmer of hope amid growing concerns about the effects of climate change on Antarctica.

Published in Scientific advances and led by researchers at Dartmouth College, the study reexamined a process known as sea ice reef instability (MICI).

MICI predicts that when the ice shelves collapse, they will expose towering ice cliffs that could collapse under their own weight and set off a chain reaction of rapid glacier retreat.

While the MICI featured prominently in the worst climate models, it had never been observed in real-world conditions and had previously been simulated using older, low-resolution models.

Using updated computer simulations, the Dartmouth team found that MICI is unlikely to occur in Thwaites this century. Even if the glacier’s entire ice shelf were to collapse today, the resulting ice cliffs would likely not be tall enough to break up and set off the catastrophic chain reaction previously feared.

“We are not saying Antarctica is safe,” Professor Mathieu Morlighem, lead author of the study from Dartmouth College, said in a statement.

“Sea level rise is still a pressing issue, but we believe the most extreme predictions for this century are less likely.”

These findings challenge the high-risk scenarios in reports by bodies such as the UN’s Intergovernmental Panel on Climate Change (IPCC). While the IPCC has included MICI-driven collapse in its projections of extreme sea-level rise, new research suggests Thwaites’ retreat is likely to remain gradual into the 21st century.

Even without MICI, the melting of Thwaites and neighboring glaciers remains a significant problem.

The bedrock beneath Thwaites slopes downward as it moves inland, making it difficult to slow its retreat once it starts losing more ice than it gains through snow.

As climate warming accelerates this process, glacier instability may still have long-term consequences.

Since 2018, the ITGC, a collaboration between the US and Great Britain, has been closely monitoring Thwaites, a glacier roughly the size of Florida.

Even months ago, scientists warned that the glacier could be headed for an imminent collapse.

She added: “Thwaites and I are already past the breaking point.”

Although the risk of a dramatic collapse this century may be reduced, the long-term effects of Antarctic ice loss remain a pressing concern.

According to NASA, sea levels are currently rising by 0.13 inches per year. Much of this rise is due to melting ice in the polar regions.

“The sooner we prioritize and try to understand these changes, the more we will prepare future generations to succeed in mitigation,” Riverman said.

Link

Morlighem, M., Goldberg, D., Barnes, JM, Bassis, JN, Benn, DI, Crawford, AJ, Gudmundsson, GH, & Seroussi, H. (2024). The West Antarctic Ice Sheet may not be vulnerable to sea ice reef instability during the 21st century. Scientific advances, 10(34), eado7794. https://doi.org/10.1126/sciadv.ado7794

Correction 12/13/24 5:29 AM ET: Typos in the first paragraph have been corrected.