Thwaites is a runaway climate disaster. New studies show how.

The Thwaites Glacier, colloquially known as the "Doomsday Glacier," is a massive Antarctic ice formation roughly the size of Florida. This glacier holds enough ice to potentially raise global sea levels by up to two feet. However, its edge serves as a protective barrier, maintaining the stability of the West Antarctic ice sheet, a significant portion of which is situated below sea level. As Thwaites deteriorates, this protective barrier weakens, initiating a feedback loop that accelerates melting.

The glacier's future is challenging to predict due to the complex dynamics at play. While satellite observations provide some insights, existing computer models have failed to accurately simulate Thwaites' retreat, rendering them unreliable for long-term forecasts. A crucial piece of the puzzle has now been filled by a recent study published in Nature Communications.

This research, led by glaciologist Mattia Poinelli from the University of California Los Angeles, incorporates previously overlooked dynamics in the glacier's grounding zone, where the ice meets the seabed.

Traditionally, models have viewed the grounding zone as a static boundary, but recent findings suggest it fluctuates with tidal forces. Warm water seeping into the glacier's underbelly, driven by these tidal oscillations, causes cracks and channels that expedite melting. By incorporating this dynamic into their simulations, the researchers were able to closely match the observed changes in Thwaites' retreat, providing a more accurate prediction of its future behavior.

Based on their model, Thwaites could contribute twice as much to sea level rise by the end of the century compared to earlier projections, potentially adding up to 10 feet to global sea levels. This is roughly double the contribution from previous models, which have already estimated Thwaites' share at about 4% of sea level rise over the past three decades, amounting to around 10 centimeters.

This relatively small figure may seem inconsequential, but it is enough to inundate coastal areas and compel communities in regions like North Carolina, the Solomon Islands, and Senegal to relocate to higher ground.

However, the study also explores the potential impact of mitigating climate change or employing geoengineering techniques to reduce ocean temperatures. A separate analysis published in Geophysical Research Letters, conducted by researchers from the British Antarctic Survey, examined how changes in ocean conditions might affect Thwaites' and its comparably large neighbor, Pine Island Glacier.

When ocean melt is "switched off" in the model, each glacier responds differently. Pine Island Glacier could potentially recover ice within a decade and even regain its former size within 80 years, thanks to its relatively intact outer shelf. In contrast, Thwaites would continue to lose ice and contribute to global sea level rise for at least 150 years, regardless of the cooling scenario.

While the prospect of Thwaites' continued disintegration is alarming, the researchers emphasize that each degree of warming has a significant impact on the glacier's stability. Reducing greenhouse gas emissions could buy valuable time for adaptation efforts. The authors conclude that the more we can slow down climate change, the longer we have to prepare for the inevitable changes that Thwaites' retreat will bring.