We are aware that the Greenland Ice Sheet is melting rapidly due to the global warming. But a new study reveals that it is vanishing at a much faster rate than previously thought possible. Scientists at the University at Buffalo provide a comprehensive picture of how Greenland’s glaciers have changed since 2003. Findings of the study were published in the journal Proceedings of the National Academy of Sciences.
Greenland Ice Sheet second-largest ice body on the Earth
The Greenland Ice Sheet is the second-largest body of ice on the planet after the Antarctica Ice Sheet. With an area of 1.7 square kilometers or 80% of the surface of Greenland, it is five times the size of Kansas and New York State combined. Scientists estimate that if Greenland Ice Sheet melts completely, the world’s oceans could rise by up to 20 feet, causing extensive damage to coastal communities.
Led by Cornelis J. van der Veen, scientists said that the current ice sheet modeling studies are far too simplistic to accurately predict how much the Greenland Ice Sheet will contribute to sea level rise. They found that, between 2003 and 2009, the Greenland Ice Sheet has lost about 243 metric gigatons of ice every year. It added about 0.68 millimeter of water to the oceans per year.
Why current simulations are not accurate
Current computer simulations take into account the four well-studied glaciers, Helheim, Jakobshavn, Petermann and Kangerlussuaq to forecast how the whole Greenland Ice Sheet will melt. Based on this, the current models suggest that the Greenland Ice Sheet will increase the sea level by 22cm by 2100. But the new research shows that these four glaciers are not the representatives of the activity across the entire Greenland Ice Sheet.
That’s because the current estimates don’t take into account the new lakes identified by van der Veen and colleagues. Lakes tend to absorb more heat when then form on top of the ice sheet. It’s primarily because they are darker than the ice they lie upon. What’s more, the meltwater of lakes that form inland drains to the base of the ice sheet, boosting the rate of the ice flow to the sea.
Existing lakes for the Greenland Ice Sheet about 60 miles from the coast, which are at a warmer altitude than the interior. But the new study found that lakes could spread much further inland.