EVERY 40 hours, the Greenland ice sheet loses a cubic kilometre of water as icebergs crash into the Atlantic. That’s the same amount of water as Los Angeles consumes in a year. The most detailed study yet of the “ice balance” of the world’s second largest ice sheet puts the total annual loss, after allowing for snowfall, at 220 cubic kilometres. That is more than twice the amount lost a decade ago.
“These results absolutely floored us,” says Eric Rignot of the California Institute of Technology in Pasadena, who led the study (Science, vol 311, p 986). “The glaciers…
