The National Snow and Ice Data Center says Arctic sea ice melted this summer to the second lowest level since scientists started keeping records more than 50 years ago.
The amount of ice covering the Arctic hit its lowest point late
last week. Scientists calculated 1.67 million square miles of ice.
Only in 2007 was there less summer sea ice, which has been
dramatically declining since scientists began using satellites to
monitor melt in 1979. Other records go back to 1953.
Each summer, sea ice melts and then refreezes starting in the
fall. The summer minimum is a key measurement for scientists
monitoring man-made global warming. This year's level is 36 percent
below the average minimum of 2.59 million square miles.
