GREENLAND ICE SHEET, GREENLAND
July 15, 2006
On the surface of the Greenland Ice Sheet east of Kangerlussuaq, a meltwater stream known by the French word “moulin” (in English it means “mill,” as in windmill). Meltwater produced by spring and summer warming collects in moulins that drill their way down through the ice. The water then flows out the base of the glacier and into the ocean. The more water there is, the more it lubricates the glacier bed and the faster the ice flows into the sea. Global warming has caused melting many dozens of miles further inland and many hundreds of feet higher than just a quarter century ago. Says eminent scientist and EIS adviser Dr. Konrad Steffen, “The melt season is getting longer, starting earlier, and ending later.” At his Swiss Camp research site on the ice, springtime temperatures have increased 5.4 deg. F (3 deg. C) and winter temperatures 9 deg. F (5 deg. C) since measurements began in 1993. As a consequence, while twenty-two cubic miles of Greenland ice melted in 1996, 54 cubic miles melted in 2005. Current Intergovernmental Panel on Climate Change (IPCC) estimates of global sea level rise--1/8 inch per year--include only water produced by atmospheric warming and not by increased glacier instability from meltwater. The estimate therefore UNDERSTATES sea level rise to be anticipated if the atmosphere continues heating up (the next IPCC report in 2009 will almost certainly adjust its estimates to account for this crucial factor).
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