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Sunday, June 14, 2009

Lots More Land

Don't lose any sleep over this, but the ice sheet covering Greenland is melting faster than expected:

Study results indicate that the ice sheet may be responsible for nearly 25 percent of global sea rise in the past 13 years. The study also shows that seas now are rising by more than 3 millimeters a year--more than 50 percent faster than the average for the 20th century.

UAF researcher Sebastian H. Mernild and colleagues from the United States, United Kingdom and Denmark discovered that from 1995 to 2007, overall precipitation on the ice sheet decreased while surface ablation--the combination of evaporation, melting and calving of the ice sheet--increased. According to Mernild's new data, since 1995 the ice sheet lost an average of 265 cubic kilometers per year, which has contributed to about 0.7 millimeters per year in global sea level rise. These figures do not include thermal expansion--the expansion of the ice volume in response to heat--so the contribution could be up to twice that.

Is this a good thing, a bad thing, or neither? It certainly has consequences. The sea level is apparently rising due to melting ice around the globe, and that has implications for coastal cities and agriculture. The oceans will get somewhat less salty which will have implications for marine ecology, but no one really knows how these things are going to play out. One thing that we do know, though, is that if the ice covering Greenland continues to recede, far more land is going to become available for use not only by humans but also by plants and animals. Vast tracts of land in Greenland could within a century or so become habitat for all sorts of creatures which are currently confined to more restricted ranges.

More land will also be available for agriculture, mining, and who knows what all else. This is true not just of Greenland but also North America and Russia. The idea that a changing climate is a global disaster is rather short-sighted. It's more likely to be, like most things, a mixed bag. The point is we just don't know yet.

RLC