Greenland ice sheet won't disappear all at once

Posted by TG Daily Staff



Greenland's ice sheet is rapidly melting, but an international team of scientists say predicting its complete disappearance would be premature.



Indeed, this is not the first time in recent history that the ice sheet has retreated, only to stabilize once again a few years later.

"We've used a combination of old aerial photographs from the 80's to construct a digital elevation map and recent satellite data. In this way we've been able to gain an overview of the thinning of the ice sheet over the last 30 years in northwestern Greenland," explained senior researcher Shfaqat Abbas Khan of the Technical University of Denmark (DTU).

"We are the first who have been able to show that the Greenland Ice Sheet was on as a dramatic diet at the end of the 80's as it is today. On the positive side our results show that despite a significant thinning in peripheral regions from 1985-1992; the thinning slowed and then died out."

University of Copenhagen Associate Professor Kurt H. Kjær expressed similar sentiments, noting that a number of reports "presuppose" the melting will accelerate to the same degree as during the past decade.



"That air temperatures have increased and melting has intensified is relatively well-understood. [Yet], it turns out that the ice sheet behaves more dynamically and is able to more quickly stabilize itself in comparison to what many other models and computer calculations otherwise predict."



"Our results show that the thinning of the ice sheet at the end of the 80's and beginning of the 90's eased over a 4-8 year period, after which a period of stability occurred until 2003. Our conclusion is therefore, that if we judged against longer periods of time, the current thinning of the ice sheet is likely to ease within an 8-year period."



Kjær also emphasized that active variations in ice thinning makes it difficult to predict how much the world's oceans will rise over a longer period of time as a result of Greenland glacial melt-water runoff.

"However, it is certain that many of the present calculations and computer models of ice sheet conditions that built upon a short range of years since 2000 must be reassessed. It is too early to proclaim the 'ice sheet's future doom' and subsequent contribution to serious water problems for the world.

"In this context it should be mentioned that the Greenland bedrock rises as the ice sheet in the peripheral regions and especially near the coast is in retreat and becoming thinner. This highlights the enormous forces that are at play in Greenland and of how difficult it is to predict what it means for Greenland as well as the rest of the world," he added.