1 Warmer Air, Not Just Water, Driving Melt
According to a study published in the journal Nature Geoscience, Greenland is losing about 250 billion metric tons of ice each year. Those losses are accelerating over time. Two factors are responsible: Warmer air temperatures are melting the surface of the ice sheet, while glaciers at its edge are dissolving into the ocean. Scientists previously thought the ice loss was mostly due to warming ocean water melting the ice at its edges. But the new study found that higher air temperatures play a significant role.ae0fcc31ae342fd3a1346ebb1f342fcb
2 A Double Whammy
Warm air causes the surface of the ice sheet to melt, and the runoff is deposited into the oceans. Scientists say this churns the waters, which causes heat to rise from the oceans and further warm the waters that touch the ice. The overall effect is that the glaciers melt faster.
3 Warming Air Causes Oceans To Stir Up Ice Melt
Donald Slater, the study’s lead author and a scientist at the University of Edinburgh, compared the process to ice cubes in a glass of water, which melt faster in warmer water—and when the water is stirred. Higher air temperatures in Greenland “effectively result in a stirring of the ocean close to the ice sheet, causing faster melting of the ice sheet by the ocean,” he said.
4 Bad News for Coastal U.S.
The researchers found that the glaciers’ disappearance “could push up ocean levels to a degree that even New York and San Francisco will have to prepare for a new normal,” MarketWatch reported. “Scientists are particularly concerned about the effects that a melting ice sheet could have on some coastal U.S. cities, such as New York City; Washington, D.C.; San Francisco; and New Orleans. These popular metro areas could become underwater cities if ice sheets melt enough to raise the sea level significantly.”
5 Less Global Warming Could Have Reduced Melting
The study found that if Earth’s atmosphere hadn’t warmed over the last few decades, melting of Greenland’s glaciers would have been reduced by as much as a third overall. In northwestern Greenland, it could have been reduced by as much as half. “This, unfortunately, adds to the overwhelming body of evidence showing the sensitivity of the Greenland ice sheet to climate change, hence the need for urgent action to reduce greenhouse gas emissions,” said Slater.
