Reuters: The Greenland ice sheet melted at a record rate this year, the largest ever since satellite measurements began in 1979, a top climate scientist reported on Monday. "The amount of ice lost by Greenland over the last year is the equivalent of two times all the ice in the Alps, or a layer of water more than one-half mile (800 meters) deep covering Washington DC," said Konrad Steffen of the University of Colorado at Boulder. Using data from military and weather …