Arctic sea ice hits record wintertime low

Arctic sea ice has hit a record low for the third year in a row. It’s the paltriest maximum extent seen since recordkeeping began in 1979, scientists at NASA and the National Snow and Ice Data Center announced March 22.

Total sea ice cover on the Arctic Ocean peaked on March 7, satellite observations show, reaching a total area of 14.42 million square kilometers. That’s around 100,000 square kilometers smaller than the previous record, a statistical tie between 2015 and 2016, and 1.22 million square kilometers smaller than the 1981 to 2010 average.

Unusually warm autumn and winter temperatures, including a series of extreme winter heat waves, are largely responsible for capping the Arctic sea ice extent this year, the scientists propose. Satellite observations also showed that this winter’s ice cover is slightly thinner than in recent years. Together, the meager maximum extent and thin ice could spell trouble for this year’s minimum sea ice extent, expected during September.

Shrinking Arctic ice could hasten warming, spread pollution, allow previously isolated species to mingle and open new shipping routes.