Greenland’s Ice Sheet Could Melt Faster Than Previously Thought, Studies Suggest

Floridians and residents of other coastal communities beware: There are changes afoot on one of Earth’s largest ice sheets that could accelerate global sea level rise.

Two new studies on Greenland’s melting ice sheet are redefining previous scientific models and research on the topic, suggesting that the ice sheet, capable of raising sea levels by more than 20 feet if it melted entirely, could melt faster than previously thought. And as NASA says, if Greenland’s ice sheet were to melt faster, it could cause a “global-scale catastrophe” by raising sea levels and altering global weather patterns.

The first study used seven years of NASA satellite data from close to 100,000 different locales across Greenland’s ice sheet and discovered that glacial melt varies greatly from glacier-to-glacier on the world’s largest island.  That’s important because previous scientific models used to project Greenland’s glacial melt and the corresponding sea level rise were based off just four of Greenland’s 242 glaciers, NASA reports.

“The problem is that these models have been applied to four glaciers only, one of which has not been changing much, to predict how these glaciers [Greenland’s ice sheet] may change in the future,” Kees van der Veen, a study co-author, told NBCNews.com. “Our results show that this is not appropriate because of how differently individual glaciers have changed over the last decade.”

For instance, the study found “rapid shrinking” at a glacier in southeastern Greenland, not accounted for in current models, that could hint at a faster future rate of melt than current models predict.

The second study,  conducted by a different group of international scientists, found changes just beneath the surface of Greenland that could speed-up glacial melt.

Scientists discovered an increase in permanent bodies of warmer water — known as supraglacial lakes — located beneath snowpack close to the surface, along the outer edges of Greenland’s ice sheet. As the Guardian notes, the study predicts that global temperature rise will cause the area that these lakes encompass — which was previously limited to an area around Greenland’s coast — to double in size by 2060. 

And as Lora Koenig, an author on the study, said in a press conference, the presence of these supraglacial lakes is bad news for Greenland’s ice sheet.

“For the stability of the ice sheet, water is not a good thing to have, especially persisting year-round,” Koenig said in a press conference. “More year-round water means more heat is available to warm the ice,” Koenig told NASA.

Warming from these supraglacial lakes accelerates melt, potentially increasing sea level rise, according to NBC News. Projections from the Intergovernmental Panel on Climate Change (IPCC) put Greenland’s contributions to sea level rise at 8.7 inches by 2100, but those permanent pockets of water could thin the ice sheet, accelerate melt and increase those totals.

“When the ice sheet is thinner it is at a slightly lower elevation and at the mercy of warmer air temperatures than it would have been if it were thicker, increasing the size of the melt zone around the edge of the ice sheet,” study lead author Amber Leeson, told NBCNews.com

Just how these new studies will change projections for Greenland ice melt remains to be seen, but the studies will make future research on Greenland’s melt more accurate, the studies’ authors said.

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Michael Harvey

Michael Harvey has been a contributing writer and journalist for the Pluto Daily since January 2014.

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