Sunday, April 16, 2017

Slice of Greenland Ice Melts into Oblivion

Coastal glaciers in terminal decline as Greenland ice runs into the ocean and threatens to raise sea levels by the end of the century.

A coastal glacier in southern Greenland mirrored in the sea. (Image Credit: Claire Rowland / Flickr) Click to Enlarge.
By the century’s end, some of Greenland’s ice will have vanished forever.

New research shows that the coastal glaciers and ice caps are melting faster than they ever have done, and they may even have already reached the point of no return two decades ago.  That is because they have passed the stage at which they can refreeze their own meltwater.

These peripheral glaciers and icecaps cover an estimated 100,000 square kilometers of the island. And when they have gone, the world’s oceans will have risen by four centimeters (1.6 in).

Body of Greenland ice
But scientists reporting in Nature Communications journal say most of the Greenland ice – the biggest body of ice in the northern hemisphere – is still safe.  Were all of its ice to melt, sea levels would rise by at least seven meters (23 ft).

“Higher altitudes are colder, so the highest ice caps are still relatively healthy at the moment,” says study leader Brice Noël, a PhD student of polar glaciology and Arctic climate modelling at the University of Utrecht in the Netherlands.

“However, we see melting occur higher and higher.  That’s a big problem, because that ‘melting line’ is moving towards the altitude where most of the ice mass is.

“The main ice sheet in the interior of Greenland is much more elevated and isn’t doing too bad yet.  But we can already see an increase in the altitude of the ‘melting line’ there as well.”

Read more at Slice of Greenland Ice Melts into Oblivion

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