In 2015, Arctic sea ice reached a maximum extent on 25 February, 15 days earlier than average and the lowest value on record (1979-present). Minimum ice extent in September was the 4th lowest on record. Sea ice continues to be younger and thinner than it was 30 years ago. Changes in sea ice alone are having profound effects on the marine ecosystem (fishes, walruses, primary production) and sea surface temperatures.
Melting occurred over more than 50% of the Greenland Ice Sheet for the first time since the exceptional melting of 2012, and glaciers terminating in the ocean showed an increase in ice velocity and decrease in area. Terrestrial vegetation productivity has been decreasing since 2011.