The Arctic's oldest, thickest ice is melting and may undermine the entire Arctic ice cap, NASA satellite photos show. Some 965,300 square miles of perennial ice, more than a year old, has melted over the past year—a 50% decrease. Losses of older, hardier frost are even greater: Three quarters of ice more than 6 years old has melted in the past 12 months.
"It's like looking at a Hollywood set," one scientist said. "It may look OK but if you could see behind you'd see it's just empty." A melted Arctic would not raise sea levels, but can increase global warming by replacing reflective ice with dark water—which absorbs more sunlight, Reuters reports. (More Arctic Circle stories.)