In this July 15, 2011 photo, in freezing temperatures, a researcher walks from an outhouse to the primary facility at Summit Station, a small U.S. National Science Foundation research center situated ... more 
In this July 15, 2011 photo, in freezing temperatures, a researcher walks from an outhouse to the primary facility at Summit Station, a small U.S. National Science Foundation research center situated 10,500 feet above sea level, on top of the Greenland ice sheet. The primary facility is periodically jacked up on its support columns to stay above accumulating snow. Across Greenland's vast white landscape, small teams of researchers from around the world are searching for clues to the potential effects of global warming on Greenland's ice. (AP Photo/Brennan Linsley) less 
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Associated Press | Photo By Brennan Linsley
Sun, Aug 14, 2011 9:28 AM EDT