Shrinking Arctic ice prompts changes in National Geographic atlas

Arctic sea ice minimum 2013 (Ill. by NASA)

The shrinking of the Arctic ice sheet in the upcoming 10th edition of the National Geographic Atlas of the World is one of the most striking changes in the publication’s history, geographers say.


In the 10th edition, which will be released September 30, the multiyear ice is much smaller in area than on previous maps. The reduction in multiyear ice is so noticeable compared with previous editions that National Geographic Geographer Juan José Valdés calls it “the biggest visible change other than the breakup of the U.S.S.R.”

As the ocean heats up due to global warming, Arctic sea ice has been locked in a downward spiral. Since the late 1970s, the ice has retreated by 12 percent per decade, worsening after 2007, according to NASA. May 2014 represented the third lowest extent of sea ice during that month in the satellite record, according to the National Snow and Ice Data Center (NSIDC). “You hear reports all the time in the media about this,” Valdés said. “Until you have a hard-copy map in your hand, the message doesn’t really hit home.”

National Geographic’s senior GIS cartographer Rosemary Wardley and Juan José Valdés relied on two government resources that track Arctic ice data: NASA and the NSIDC. To map the multiyear ice, they took data from a 30-year study by NASA, published in 2012, the National Geographic’s web site reads.