While satellites have confirmed that Greenland has lost a significant part of its ice sheet, a recent study in Science indicates that the ice sheet may be able to slow its melting much quicker than previously thought.
Kurt Kjær of the University of Copenhagen and his Danish colleagues have used aerial photos of the ice sheet, dating back to the early ’80s, to compare episodes of rapid melting in the last few decades.
The Greenland Ice Sheet covers 80% of Greenland, and it’s the second largest on Earth. It dumps 240 billion tons of fresh water into the oceans every year, which accounts for a fifth of the annual sea level rise. If it melts completely, low-lying places like Palau and New York City could be submerged.
The researchers discovered that the ice sheet is a dynamic environment, able to shift quickly from melting to holding firm. The record melt we’ve seen this year could be over in about eight years. This could imply that using the current speed of melting as part of an assumption when trying to predict the sea level rise in the coming century is flawed.
It remains to be seen if current global temperatures favor a quick holding pattern of the Greenland Ice Sheet. It’s also likely that the melting will continue over the coming years, not halt. With enough information, the dynamic systems involved could be simulated and it would be possible to get a clearer picture of how much the sea level will rise in the next few decades. Naturally, basing the predictions on data for the last 30 years is also flawed. Climate change needs to be examined on a longer scale, possible over hundreds or thousands of years to make accurate predictions.
Reference: “Aerial Photographs Reveal Late–20th-Century Dynamic Ice Loss in Northwestern Greenland” by Kurt H. Kjær, Shfaqat A. Khan, Niels J. Korsgaard, John Wahr, Jonathan L. Bamber, Ruud Hurkmans, Michiel van den Broeke, Lars H. Timm, Kristian K. Kjeldsen, Anders A. Bjørk, Nicolaj K. Larsen, Lars Tyge Jørgensen, Anders Færch-Jensen and Eske Willerslev, 3 August 2012, Science.