Ice is melting faster worldwide, with greater sea-level rise anticipated, studies show.
From the thin ice shield covering most of the Arctic Ocean to the mile-thick mantle of the polar ice sheets, ice losses have soared from about 760 billion tons per year in the 1990s to more than 1.2 trillion tons per year in the 2010s, a new study released Monday shows. That is an increase of more than 60 percent, equating to 28 trillion tons of melted ice in total — and it means that roughly 3 percent of all the extra energy trapped within Earth’s system by climate change has gone toward turning ice into water.
“That’s like more than 10,000 ‘Back to the Future’ lightning strikes per second of energy melting ice around-the-clock since 1994,” said William Colgan, an ice-sheet expert at the Geological Survey of Denmark and Greenland. “That is just a bonkers amount of energy.”
There is good reason to think the rate of ice melt will continue to accelerate. A second, NASA-backed study on the Greenland ice sheet, for instance, finds that no less than 74 major glaciers that terminate in deep, warming ocean waters are being severely undercut and weakened.
And it asserts that the extent of this effect, along with its implications for rising seas, is still being discounted by the global scientific community.
Failing to fully account for the role of ocean undercutting means sea-level rise from the ice sheets may be underestimated by “at least a factor of 2,” the new paper in the journal Science Advances finds.
“It’s like cutting the feet off the glacier rather than melting the whole body,” said Eric Rignot, a study co-author and a glacier researcher at NASA’s Jet Propulsion Laboratory and the University of California at Irvine. “You melt the feet and the body falls down, as opposed to melting the whole body.”