A slow-motion and irreversible collapse of a massive cluster of glaciers in Antarctica has begun, and could cause sea levels to rise across the planet by another 4 feet within 200 years, scientists concluded in two studies released Monday.
Researchers had previously estimated that the cluster in the Amundsen Sea region of the West Antarctic Ice Sheet would last for thousands of years despite global climate change. But the new studies found that the loss is underway now as warming ocean water melts away the base of the ice shelf, and is occurring far more rapidly than scientists expected.
The warming water is tied to several environmental phenomena, including a warming of the planet driven by emissions from human activity and depleted ozone that has changed wind patterns in the area, the studies found.
“There is no red button to stop this,” said Eric Rignot, a University of California, Irvine professor of Earth system science and the lead author of one of the studies, conducted with NASA’s Jet Propulsion Laboratory and scheduled for publication in a journal of the American Geophysical Union.
The six glaciers have passed “the point of no return,” Rignot said, which means that total collapse — the melted retreat of the glaciers — cannot be prevented. “The only question is how fast it’s going to go.”
Antarctica, surrounding the South Pole, is the largest mass of ice on the planet, containing an estimated 80 percent of the world’s fresh water. Its scale is difficult to fathom. One environmental foundation said that if you loaded the ice onto cargo ships and started counting the vessels, one per second, it would take 860 years before you were finished counting.
The loss of even a portion of that ice would have consequences across the globe. Scientists have surmised its possibility for decades, and have braced for confirmation, which in effect arrived Monday.