Antarctica’s Thwaites Glacier melting faster than thought, could double sea-level contribution

One of the world’s largest glaciers is melting much faster than previously understood and could contribute about twice as much to global sea-level rise by the end of the century as earlier projections suggested.

New research published this week in Nature Communications found that Antarctica’s Thwaites Glacier is rapidly losing mass as warm ocean water pushes several kilometers beneath it and melts the ice from below.

Researchers estimate the process could cause Thwaites to contribute up to 30 millimeters (1.2 inches) to global sea-level rise by 2100, even without additional warming beyond recent conditions.

In previous conventional ice-sheet models, scientists estimated that the Thwaites Glacier would contribute roughly 15 millimeters (about 0.6 inches) to global sea-level rise by the year 2100.

Nicknamed the Doomsday Glacier because of the potentially severe consequences of its collapse, Thwaites covers around 192,000 square kilometers (74,000 square miles) in West Antarctica , roughly the size of Senegal and larger than the US state of Florida.

It forms part of the much larger West Antarctic Ice Sheet and, together with glaciers including Pine Island, acts as a barrier holding back vast quantities of inland ice.

Thwaites currently accounts for around 4% of global sea-level rise and has lost more than 1 trillion tons of ice since 2000, with losses continuing at roughly 50 billion tons annually.

Scientists have closely monitored the glacier since discovering in the 1980s that it was retreating rapidly.