Antarctic Ice Melting May Be Worse Than Thought

Melting Ice: Climate Change Reaching 'Irreversible' Levels
Two Adelie penguins stand atop a block of melting ice on a rocky shoreline at Cape Denison, Commonwealth Bay, in East Antarctica on January 1, 2010. Pauline Askin/Reuters

You may have heard that Antarctic ice is melting, but new research shows that it's even worse than suspected.

A study published Monday in the journal Nature Geoscience found that a huge floating section of ice, abutting one of eastern Antarctica's largest glaciers, may be more vulnerable to melting than previously thought. As this ice shelf thins and melts, it allows the Totten Glacier behind it to flow more rapidly to the sea. And scientists think this melting-and-flowing process, which has accelerated in recent years, has reached an irreversible stage where even an abrupt cessation of carbon dioxide emissions, which contribute to global warming, couldn't stop the process.

The scientists estimate that the Totten Glacier, which is 90 miles long and roughly 20 miles thick, also contains enough water to raise global sea levels by 11 feet. And that's a conservative estimate, researchers say.

"It's only one glacier, but it's changing now, and it is significant for sea levels globally," says study co-author Martin Siegert, a researcher at Imperial College London, in a statement. "The 3.5-meter [11-foot] rise may take several centuries to complete, but now the process has started, it is likely irreversible. This is another example of how human-induced climate change could be triggering major changes, with knock-on impacts that will be felt globally."

The study found that the ice shelf that helps to hold back the Totten Glacier may be being bathed in a current of warm water, and is increasingly susceptible to this flow as the ice thins and allows more space for oceanic currents to reach the shelf. It was previously thought that the inlet in which the ice shelf is found was more isolated from warm water currents, but the new study found a trough that connects it to the deep ocean.