FILE - In this Thursday Aug. 18, 2005 file photo an iceberg is seen in Disko Bay, Greenland, above the arctic circle. Scientists are monitoring a massive pool of fresh water in the Arctic Ocean that could spill into the Atlantic and potentially alter the ocean currents that bring Western Europe its moderate climate. The oceanographers said Tuesday April 5, 2011, the unusual accumulation has been caused by Siberian and Canadian rivers dumping more water into the Arctic, and from melting sea ice. Both are consequences of global warming. (AP Photo/John McConnico, File)