On December 5, 2012, the National Oceanic and Atmospheric
Administration (NOAA) released its annual Arctic Report Card,
covering late 2011 through late 2012. The report listed a number
of significant events in a record-breaking and sometimes
sobering year. One of the biggest stories was the record-low sea
ice extent in the Arctic Ocean. Arctic sea ice shrinks and grows
every year, typically reaching its minimum in September. The
last decade, however, has seen a series of below-normal extents,
with new records set in 2002, 2005, 2007, and 2012. By mid-
September 2012, Arctic sea ice had dropped to 3.41 million
square kilometers (1.32 million square miles), which was
significantly below the 2007 record of 4.17 million square
kilometers (1.61 million square miles). (See Visualizing the
2012 Sea Ice Minimum for prior Earth Observatory coverage of
this event.) NOAA data for high latitudes during June indicated
that snow cover extent has declined by 17.6 percent per
decade—an even faster rate of decline than the sea