FILE - This July 4, 2012 file photo provided by Ian Joughin 

FILE - This July 4, 2012 file photo provided by Ian Joughin shows surface melt water rushing along the surface of the Greenland Ice Sheet through a supra-glacial stream channel, southwest of Ilulissat, Greenland. Polar ice sheets are now melting three times faster than in the 1990s and the acceleration of the melting, especially in Greenland, has ice scientists worried. Michel Jarraud, secretary general for the World Meteorological Organization, says the most troubling climate development in 2012 was the melting at the top of the world. (AP Photo/Ian Joughin)
Associated Press
FILE - This July 4, 2012 file photo provided by Ian Joughin shows surface melt water rushing along the surface of the Greenland Ice Sheet through a supra-glacial stream channel, southwest of Ilulissat, Greenland. Polar ice sheets are now melting three times faster than in the 1990s and the acceleration of the melting, especially in Greenland, has ice scientists worried. Michel Jarraud, secretary general for the World Meteorological Organization, says the most troubling climate development in 2012 was the melting at the top of the world. (AP Photo/Ian Joughin)
View Comments