Thwaites Glacier Melting Faster Than Thought, Doubling Sea-Level Threat

Key points

• Thwaites Glacier, spanning 192,000 sq km, is losing 50 billion tonnes of ice annually.
• New models reveal a 'grounding zone' where tidal pumping allows warm water to melt the ice core.
• The glacier has a 60% chance of detaching from the stabilizing Mouginot Ridge by 2100.
• Even if ocean warming stopped, Thwaites would continue losing ice for at least 150 years.
• Total collapse of the West Antarctic ice sheet could raise sea levels by up to 5 meters.

Background

Thwaites Glacier, often called the 'Doomsday Glacier,' has been monitored since the 1980s due to its rapid retreat. It currently contributes 4% to global sea-level rise. Previous studies, including a 2019 NASA discovery of a large underwater cavity, highlighted the glacier's vulnerability. Recent archive data shows polar ice sheets have shed 11.3 trillion tonnes of ice since 1979, with glaciers flowing faster into the ocean being the primary driver.

How outlets are covering it

Al Jazeera and CNN emphasize the new 'grounding zone' model, which doubles sea-level projections to 1.2 inches by 2100. CNN highlights the potential for 10 feet of rise if the West Antarctic ice sheet collapses. New Scientist focuses on a separate study showing that Thwaites will continue losing ice for 150 years even if ocean warming stops, attributing this to the glacier's 'long memory' of past destabilization. While Al Jazeera and CNN focus on the accelerated melting rate, New Scientist stresses the inevitability of future loss regardless of mitigation efforts.

Why it matters

The findings suggest that coastal flooding risks are significantly underestimated. Even with immediate emissions cuts, the glacier's momentum and current ocean temperatures will drive continued ice loss. This impacts global coastal cities, potentially submerging areas from Miami to Manila, and underscores the urgency of climate action to limit the rate of ice loss.

What to watch

Researchers plan to deploy instruments in 2028 to directly observe seawater flushing at Thwaites' grounding line. Further studies are needed to accurately predict ice loss volumes and understand the long-term stability of the West Antarctic ice sheet. Continued monitoring of ocean temperatures and glacier retreat will be crucial for updating sea-level rise forecasts.