Greenland Is Falling Apart Since 1972, the giant island's ice sheet has lost 11 quadrillion pounds

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Greenland Is Falling Apart

Since 1972, the giant island’s ice sheet has lost 11 quadrillion pounds of water.

https://www.theatlantic.com/science/archive/2019/04/how-much-ice-has-greenland-lost-climate-change/587431/?utm_source=pocket-newtab



Robinson Meyer

Apr 23, 2019


NASA researchers burn leftover wood on the Helheim Glacier, which is one of the fastest-moving ice floes in Greenland.Lucas Jackson / Reuters

The Greenland Ice Sheet is the world’s second-largest reservoir of fresh water sitting on the world’s largest island. It is almost mind-bogglingly huge.

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Suffice it to say: The Greenland Ice Sheet, which contains enough water to refill the Great Lakes 115 times over, is very large. And it is also falling apart.

A new study finds that the Greenland Ice Sheet added a quarter inch of water to global sea levels in just the past eight years. The research, published Monday in the journal Proceedings of the National Academy of Sciences, covers nearly 20 years previously not included in our detailed understanding of the troubled Greenland Ice Sheet. It finds that climate change has already bled trillions of tons of ice from the island reservoir, with more loss than expected coming from its unstable northern half.


“The glaciers are still being pushed out of balance,” Eric Rignot, a senior scientist at NASA and an author of the paper, told me. “Even though the ice sheet has [sometimes] been extremely cold and had low surface melt in the last year, the glaciers are still speeding up, and the ice sheet is still losing mass.”

The paper casts the transformation of the Greenland Ice Sheet as one of the profound geological shifts of our time. Scientists measure the mass of ice sheets in “gigatons”—each unit equal to 1 billion metric tons, or roughly the same amount of water that New York or Los Angeles uses in a year. Greenland, according to the study, has lost 4,976 gigatons of water since 1972. That’s enough water to fill 16 trillion bathtubs or 1.3 quadrillion gallon jugs. That much water weighs about 11 quadrillion pounds. (A quadrillion is 1 with 15 zeros after it.)

More worryingly, the paper finds that Greenland lost about half of that ice—roughly 2,200 gigatons—in the years between 2010 and 2018. The ice sheet has also failed to gain mass in any year since 1998.

This melting isn’t happening at a steady pace, in other words. Greenland’s demise seems to be accelerating. .....................................

Read: Ancient Rome’s collapse is written into Arctic ice

That’s an alarming result, because it means glaciers might now be shrinking Greenland from the bottom faster than hot weather can melt it from the top.
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Rignot believes that the new study should make glaciologists look anew at the speed with which Greenland could collapse. The ice sheet’s bleeding-out could eventually raise global sea levels by as much as 25 feet. So the key question, Rignot said, is “How fast can you make these entities fall apart?” The answer will matter to all of us. The surface of Greenland doesn’t have to move through magic to other parts of the world—already, today, its deluge is on its way.