Far south, where the Antarctic ice meets the sea, a glacier roughly the size of Britain is revealing that its fate may be decided in places no one could easily see. Researchers have found that warm ocean water is creeping several kilometres beneath Thwaites, gnawing at ice where it rests on the seabed, a process long absent from the models used to forecast the future. Accounting for it roughly doubles the glacier's possible contribution to sea-level rise by 2100, to about 30 millimetres. It is a reminder that the planet's slow machinery can hide its most consequential movements beneath the sur
Thwaites 'Doomsday Glacier' Melts Faster Than Models Predicted, Doubling Sea-Level Rise Estimates by 2100
No proven intervention can quickly stop the glacier's retreat
Mark
Why does this study change the picture if we already knew Thwaites was melting?
Mimi
Because it adds a place the melting happens that models mostly skipped: warm water reaching several kilometres under the ice. Counting it roughly doubles the 2100 estimate, to as much as 30 millimetres.
Mark
Thirty millimetres sounds small.
Mimi
It's for this one glacier by 2100. It's also about the same share the glacier already represents, 4 per cent of sea-level rise today, being pushed higher. And the full collapse figure from the Thwaites collaboration is around 65 centimetres, over a much longer time.
Luke
Let me slow that down. The 30 mm is a ceiling, "up to," and it comes from one modelling study. It isn't a measurement.
Mimi
Fair. It's a projection built on simulations.
Mark
What about the 60 per cent figure for the Mouginot Ridge?
Luke
That's also a simulation result, and it depends on assuming a grounding zone 4 to 6 kilometres wide. If that assumption is off, the probability changes. We don't know from this reporting how well that width is observed.
Mimi
Right, and losing the ridge contact is what could weaken the brake on retreat.
Mark
Can emissions cuts stop it?
Mimi
They can limit further ocean warming. But a 2026 British Antarctic Survey study found ice loss could continue at least 150 years even with ocean melting switched off in simulations.
Luke
And this article is a secondhand account of CNN's account of the study. The details of the methods and uncertainty ranges aren't here, so confidence should stay moderate.
O Pulso
- Warm seawater is slipping beneath Thwaites Glacier, eating away at ice that older forecasts barely accounted for.
- Projected sea-level rise from this one glacier could roughly double, to as much as 30 millimetres by 2100.
- Simulations show a 60 per cent chance the glacier loses its grip on the Mouginot Ridge by century's end.
- Scientists say cutting emissions is the only lever that slows the melting, yet even then the retreat may continue for 150 years or more.
- Coastal communities are being urged to strengthen defences, plan for flooding and restore mangroves and other natural barriers now.
Far south, where the Antarctic ice meets the sea, a glacier roughly the size of Britain is revealing that its fate may be decided in places no one could easily see. Researchers have found that warm ocean water is creeping several kilometres beneath Thwaites, gnawing at ice where it rests on the seabed, a process long absent from the models used to forecast the future. Accounting for it roughly doubles the glacier's possible contribution to sea-level rise by 2100, to about 30 millimetres. It is a reminder that the planet's slow machinery can hide its most consequential movements beneath the surface, and that what we choose to emit today shapes the ocean that does the work.
Thwaites Glacier is roughly the size of Britain, and a new study suggests that the part that matters most may have been overlooked by the models used to forecast its future. Researchers from the University of California, Irvine, and NASA's Jet Propulsion Laboratory report that warm ocean water is working its way several kilometres under the ice, melting it from below where it meets the seabed.
When this process is included, the glacier's projected contribution to sea-level rise by 2100 rises to as much as 30 millimetres, roughly double earlier estimates. Lead researcher Mattia Poinelli's simulations show a 60 per cent chance that the glacier loses contact with the Mouginot Ridge, an underwater feature that currently helps hold it back, by 2100. Co-author Eric Rignot said earlier projections had struggled because key physical processes were missing.
The glacier is already changing fast. Its western sector has retreated about 25 kilometres since 1996, and it now accounts for around 4 per cent of global sea-level rise. Warm, salty water intensified by climate change is thinning the floating ice shelf, and as the grounding line retreats inland, more ice is exposed to the sea. A complete collapse could eventually raise global seas by around 65 centimetres.
The consequences reach far beyond the glacier itself: higher seas, flooding, erosion and storm damage in low-lying regions, and possible destabilisation of neighbouring ice. Scientists stress that cutting emissions is the most effective way to slow the melt, though a 2026 study suggests the retreat could continue for at least 150 years. The priority now is to limit warming while preparing coasts for the rise that is already on its way.
Thwaites Glacier is roughly the size of Britain, and a new study says the part of it that matters most may be a zone that standard ice-sheet models have largely left out. Researchers from the University of California, Irvine, and NASA's Jet Propulsion Laboratory report that warm ocean water is working its way several kilometres beneath the glacier, melting ice from below in the area where it meets the seabed.
When the team accounted for that process, the glacier's projected contribution to global sea-level rise by 2100 climbed to as much as 30 millimetres. That is roughly double what earlier estimates held. The findings were reported by CNN and relayed by the Times of India.
Lead researcher Mattia Poinelli ran simulations that included a grounding zone 4 to 6 kilometres wide. In those runs, there is a 60 per cent probability that the glacier loses contact with the Mouginot Ridge by 2100. The ridge is an underwater feature that currently helps hold back the glacier's retreat. Co-author Eric Rignot said existing projections had struggled to capture how fast the ice is being lost because key physical processes were missing from the earlier models.
The glacier is already one of Antarctica's fastest-changing. In its fastest-flowing western sector it has retreated about 25 kilometres since 1996. Its ice loss currently accounts for about 4 per cent of global sea-level rise. According to the International Thwaites Glacier Collaboration, a complete collapse could eventually raise global sea levels by around 65 centimetres.
The main driver is relatively warm, salty ocean water, a process intensified by climate change. The British Antarctic Survey says this water reaches the floating ice shelf and the grounding zone, thinning the ice and weakening the structure that slows the flow of inland ice toward the sea. As the glacier thins, the grounding line retreats inland and exposes more ice to seawater. The seabed under parts of Thwaites also slopes deeper toward the Antarctic interior, so water can penetrate further beneath the ice. NASA research has flagged this feedback as a major concern.
The most immediate consequence of a substantial retreat would be higher seas, with greater risk of coastal flooding, erosion and storm-surge damage in low-lying regions. Thwaites could also destabilise neighbouring glaciers, raising the potential contribution of the wider West Antarctic Ice Sheet. Large volumes of freshwater entering the Southern Ocean could alter its salinity and density, potentially affecting ocean circulation and the movement of heat and nutrients.
Scientists say the most effective way to limit further melting is to cut greenhouse gas emissions rapidly, since a warming ocean is what melts the glacier from below. But the retreat may not stop quickly. A 2026 study led by the British Antarctic Survey found Thwaites could keep losing ice for at least 150 years even when ocean-driven melting was switched off in simulations. Researchers say no proven intervention can quickly halt it. The priority, they say, is to limit warming while preparing for unavoidable sea-level rise with stronger coastal protection, better flood planning and restoration of natural barriers such as mangroves. The Mouginot Ridge, and whether the glacier stays attached to it, is the threshold to watch.
Citações Notáveis
Existing projections struggled to capture the speed of ice loss because key physical processes were missing from earlier models.— Eric Rignot, study co-author (paraphrased)
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