Two Studies Point the Same Way on Thwaites: Retreat Locked In for 150 Years

A team of glaciologists from the University of California, Irvine and NASA found that Thwaites — the planet's widest glacier, nicknamed the Doomsday Glacier — is melting "more aggressively" than previously projected. The consequence, according to the research, is that its contribution to global sea level rise could be double current estimates.

The numbers behind that matter. Thwaites currently accounts for around 4% of global sea level rise. It holds enough water to raise seas by more than 2 feet if it collapsed. Because it also acts as a cork holding back the wider Antarctic ice sheet, its collapse could ultimately lead to around 10 feet of rise — a figure that would reshape coastlines from Miami to Manila.

The second study, led by the British Antarctic Survey and published on 13 October 2026, tested a deliberately extreme scenario. Researchers completely switched off the melting effects of the ocean beneath Thwaites and neighbouring Pine Island Glacier in three independent computer models. Even with that heat source removed entirely, the models showed Thwaites continuing to lose ice for at least the next 150 years.

The methodology is worth stating plainly. The glacier kept retreating anyway.

Taken together, the two studies narrow the space for optimism in different ways. The UC Irvine and NASA work suggests the upper end of sea level projections may be too low. The BAS work suggests the lower end of the timeline is fixed: even drastic ocean cooling would not halt the retreat within 150 years.

That shifts the practical question. If prevention is off the table for a century and a half, the relevant policy work becomes adaptation — how coastal planners account for a contribution that may double, and how they prepare for a glacier whose retreat no longer depends on what happens to ocean temperatures.

What remains unclear is how much of the projected doubling in sea level impact comes from specific melting mechanisms, and how the two research efforts relate to each other. The evidence does not yet answer either question.