Antarctic Glacier Melt Could Raise Global Sea Level by Nearly 3 Meters

Totten Glacier (Esmee van Wijk/Australian Antarctic Division)

An international group of scientists say if climate change continues at its current rate, Antarctica’s Totten Glacier might become so unstable that it could eventually release enough water to produce an almost 3 meter rise in the global sea-level sometime in the next several hundred years.

A year ago, this same group of scientists from Great Britain, Australia, New Zealand and the United States found warm water flowing beneath a segment of the glacier, which is causing more melting than had been expected.

Studying the advance and withdrawal history of the largest glacier in the East Antarctic Ice Sheet led the researchers to their findings, recently published in the journal, Nature.

They found unfettered climate change could, within the next century, push the giant glacier into a period of an irreversible and rapid retreat.

The calving front of the Totten Glacier ice shelf (Tas van Ommen/Australian Antarctic Division)

Although the Eastern Antarctic Ice Sheet is considered to be more stable than the smaller western ice sheet, the study finds the Totten Glacier isn’t doing as well and is currently losing a tremendous amount of ice.

If it moves back another 100 to 150 kilometers from its current location, the researchers say the front of the glacier will wind up resting on some unstable geology.

This is something, they say, could set it on a path of a much more rapid retreat, moving the glacier up to 300 kilometers further inland, in the coming centuries, than its current coastal front.

Once it moves onto the region where the underlying geology is unstable, the scientists say the glacier’s melting at that point will be unstoppable – at least until it continues to move back onto more stable ground – and will discharge a great quantity of water that would raise global sea-levels by up to 2.9 meters.

“The evidence coming together is painting a picture of East Antarctica being much more vulnerable to a warming environment than we thought,” said the study’s co-author Martin Siegert, Co-Director of the Grantham Institute at Imperial College London. “This is something we should worry about. Totten Glacier is losing ice now, and the warm ocean water that is causing this loss has the potential to also push the glacier back to an unstable place.”

The researchers point out that since the East Antarctic Ice Sheet is the largest ice mass on Earth, any small changes to it will in turn have a significant global impact.