Antarctica's Doomsday Glacier Is Melting Twice as Fast as We Feared

A Giant on the Move

The Thwaites Glacier — long nicknamed the "Doomsday Glacier" — is melting much faster than scientists previously thought, according to a new study. The findings are alarming not just for their scale, but for what they reveal about how little we truly understood this frozen giant until now.

Located in West Antarctica, Thwaites is roughly the size of Florida and holds enough water to raise global sea levels by over two feet if it collapses. More critically, it acts as a barrier holding back the vast Antarctic ice sheet, which could ultimately contribute to around 10 feet of sea level rise, threatening coastal communities worldwide.

What the New Research Found

New research published in *Nature Communications*, conducted by glaciologists at the University of California in collaboration with NASA's Jet Propulsion Laboratory, reveals that Thwaites is losing mass rapidly and could add up to 1.2 inches (30mm) to global sea levels by 2100 — double previous estimates — even if global warming does not accelerate.

The research team developed a new ice sheet model that better captures the processes occurring at Thwaites' grounding line — the point where the glacier lifts off the seabed and begins to float. Traditional models treated this area as stable, but satellite data reveals it is actually a dynamic "grounding zone" where seawater constantly flushes in and out with the tides, allowing warm ocean water to penetrate deep beneath the ice and accelerate melting. Scientists call this process "tidal pumping," and it had been largely overlooked until now.

That melting process is also accelerating Thwaites' "unpinning" from the Mouginot Ridge — an important underwater bedrock currently stabilizing the glacier from below — and the study concluded there is a 60 percent chance that Thwaites could unpin from the ridge by the end of the century.

Why It Matters Beyond the Numbers

Researchers now say Thwaites could raise global sea levels by up to 1.2 inches by 2100 — twice as much as earlier predictions. That may not sound huge, but for coastal cities, even small rises can make a big difference. Think storm surges that reach further inland, flooding that happens more frequently, and infrastructure that was built for a world that no longer exists.

Thwaites is already responsible for around 4% of worldwide sea level rise. That share is expected to grow. The primary driver is warm ocean water melting the glacier from underneath, fueled by human-induced climate change and fossil fuel emissions. And the feedback loops involved mean that once certain thresholds are crossed, there may be no reversing course.

The Road Ahead

Back in 2019, NASA's Jet Propulsion Laboratory discovered a giant underwater cavity beneath the Thwaites glacier that spread across an area two-thirds the size of Manhattan — a finding that researchers said was likely speeding up the glacier's thinning. The new study suggests the situation has grown considerably more urgent since then.

Experts say more studies are needed to accurately predict the volume of Thwaites' ice loss. But the direction of the science is clear, and it keeps pointing the same way. Each new model, each new dataset, each new expedition to this remote and hostile corner of the planet returns with a version of the same message: things are moving faster than we thought. The world's coastlines — and the hundreds of millions of people who live along them — are running out of time to prepare.