ScienceDaily: If the sheet of ice covering Greenland were to melt in its entirety tomorrow, global sea levels would rise by 24 feet.
Three million cubic kilometers of ice won't wash into the ocean overnight, but researchers have been tracking increasing melt rates since at least 1979. Last summer, however, the melt was so large that similar events show up in ice core records only once every 150 years or so over the last four millennia.
"In July 2012, a historically rare period of extended surface melting...