Greenland Ice Sheet more vulnerable to climate change than previously thought

[unhappycamper]

http://www.sciencedaily.com/releases/2014/09/140929090553.htm



A scientist explores the remains of a supraglacial lake after it has drained.

Greenland Ice Sheet more vulnerable to climate change than previously thought
Date: September 29, 2014
Source: University of Cambridge
Summary: A new study finds that the Greenland Ice Sheet, which covers 1.7 million square kilometers and contains enough ice to raise sea levels worldwide by seven meters, is less stable and more sensitive to climate change than previously thought.

A new model developed by researchers at the University of Cambridge has shown that despite its apparent stability, the massive ice sheet covering most of Greenland is more sensitive to climate change than earlier estimates have suggested, which would accelerate the rising sea levels that threaten coastal communities worldwide.

In addition to assessing the impact of the increasing levels of meltwater created and spilled into the ocean each year as the climate continues to warm, the new model also takes into account the role that the soft, spongy ground beneath the ice sheet plays in its changing dynamics. Details are published today (29 September) in the journal Nature Communications.

The Greenland Ice Sheet, which is the second-largest ice sheet in the world, covers 1.7 million square kilometres -- an area roughly eight times the size of the United Kingdom -- and contains enough ice to raise sea levels by more than seven metres if it were to be lost altogether.

Currently, due to surface melting alone, it is losing ice at a net annual rate of 200 gigatonnes, equating to 0.6 millimetres of sea level rise. A similarly large, but ultimately more uncertain source of sea level rise is tied to a net annual ice loss caused by increased movement of the ice sheet, which results in more ice being discharged into the ocean. Globally, sea levels are rising at three millimetres annually.