Antarctica’s ‘dating’ glacier headed for catastrophic collapse

A six-year study of Antarctica’s vast Twaites Glacier has ended with a bleak outlook for its future.

Dubbed the “Doomsday Glacier,” this giant mass of ice is as big as the UK or Florida, and its collapse alone would raise sea levels by 65 centimeters. Worse, it is predicted to trigger a more widespread loss of the ice sheet covering West Antarctica, causing a disastrous 3.3 meters of sea level rise, threatening cities such as New York, Kolkata, and Shanghai.

It’s an extremely remote and difficult region to reach, but over the past six years, a joint UK-US research programme, the International Thwaites Glacier Collaboration (ITGC), has sent 100 scientists there by plane, boat and underwater robot to study the ice’s movements in detail. “It’s been an enormous challenge, but we’ve learned a lot,” says Ted Scambos of the University of Colorado Boulder.

These findings include the fact that the Thwaites Glacier is particularly vulnerable because it sits on bedrock well below sea level and is being melted from below by warm ocean waters. What’s more, the bedrock slopes downwards towards the interior of the ice sheet, meaning that as the glacier retreats, more ice will be exposed to warmer ocean waters, threatening to accelerate its collapse.

“The ice sheet is getting deeper and deeper,” says ITGC team member Matthew Morlighem of Dartmouth College in Hanover, New Hampshire. “We know it’s unstable.” He and his colleagues used computer models to predict the future state of the glaciers as we change the concentration of carbon dioxide in the atmosphere, and found that “in almost every carbon-emissions scenario, we run into this instability,” causing the glacier front to retreat inland. The key question is how quickly this will happen.

“It’s not going to lead to an immediate, catastrophic retreat in the next year or two, but at the same time we’re confident that the Thwaites Ice Sheet will continue to retreat and that it will eventually accelerate,” said Rob Larter of the British Antarctic Survey, another team member. “We can’t predict exactly when that will happen.”

But ultimately, ITCG researchers say that by the end of 2023^rd Thwaites Glacier and much of the West Antarctic Ice Sheet could be lost in the 21st century.

The bit of good news is that there’s still time to influence how fast this process happens with drastic efforts to cut carbon emissions. “We can buy ourselves some time,” says Morligem. “We can still control how quickly the switzerland loses mass.”