In 2007, Greenland set a melting record

From San Francisco, at a meeting of the American Geophysical Union

The duration and extent of ice melt across high-altitude portions of the Greenland ice sheet last year were the highest they’ve been in recent decades, satellite observations indicate.

By measuring microwave radiation reflected from a snow-covered patch of ice, scientists can discern if any of the snow has melted, says Marco Tedesco, an electrical engineer at NASA’s Goddard Space Flight Center in Greenbelt, Md.