Study: Thwaites Glacier losing ice faster than earlier models, doubling 2100 sea-level estimate

Right · 2A new study says Antarctica's Thwaites Glacier, nicknamed the "Doomsday Glacier", is losing ice faster than earlier models calculated, and could add up to 1.2 inches (30mm) to global sea level by 2100, about double previous estimates. 1 2 Right · 2The paper was published in the journal Nature Communications. GB News says the team came from the University of California, Irvine and NASA's Jet Propulsion Laboratory. 1 2 Right · 2The researchers say older models treated the "grounding line", where ice leaves the land and begins to float, as a narrow and mostly stable boundary. Satellite data, including from the Finnish ICEYE constellation, show it is instead a "grounding zone" several miles across. 1 2

Right · 2In that zone, tides push pressurised, relatively warm seawater far beneath the grounded ice, lifting it and causing melting at its base that older models did not capture. The Daily Mail says the warm water is being driven toward the coast by currents already altered by climate change. 2 1 Right · 1Co-author Eric Rignot of UC Irvine said earlier projections struggled to match observed mass loss "because of missing physics", and that the new model matches the record and gives projections "twice as large as before". The Daily Mail says it reconstructs ice change since the 1990s as four times more pronounced than traditional models. 1 Right · 2The model puts a 60 per cent chance on the glacier detaching from the Mouginot Ridge, one of the seabed features anchoring it, before 2100. Lead author Mattia Poinelli said the glacier would then retreat across a mostly retrograde seafloor toward the South Ridge. 1 2

Right · 1GB News reports that this accelerated loss could occur even without additional global warming, and quotes Rignot saying higher sea levels are to be expected even with immediate emissions cuts because of damage already done. It also says the team plans to travel to Thwaites in 2028 to install instruments to monitor seawater movement beneath the ice. 2 Right · 2The Daily Mail says researchers do not believe total collapse is imminent. The outlets give different figures for a full collapse: the Mail cites 26 inches (65cm) in its opening and 1–2 metres later in the article, while GB News says more than two feet, or around 10 feet once the wider ice sheet it restrains is included. 1 2 Right · 1The Daily Mail adds that studies suggest the glacier's eastern ice shelf may break up soon; it quotes British Antarctic Survey geophysicist Robert Larter, speaking in May, saying that was "very likely to happen sometime this year". 1