WASHINGTON — Hit by a second bout of extremely warm winter temperatures in recent days, the Arctic has flattened out, just as it did when hit by similarly dramatic heat in November.
The area of the Arctic Ocean covered by floating sea ice is far smaller than it was in 2012 at this time of year. And while 2012 holds the all-time record for lowest ice extent in September, 2016 has been beating it since mid-October.
The current extent of Arctic ice sea also is far smaller than it was at the same time in 2010, which previously held the record for lowest Arctic sea ice extent in late December, according to records from the National Snow and Ice Data Center that date to 1979.
What has happened this year in the Arctic, and particularly the high Arctic, appears to be not only out of the norm for a stable climate — like the one on Earth before fossil fuels — but also for what you might expect from our supercharged, artificially warmed climate.
Such is the upshot of a recently published ‘‘detection and attribution’’ analysis of November’s and December’s Arctic warmth by a group of scientists who found that ‘‘it is extremely unlikely that this event would occur in the absence of human-induced climate change.’’
The analysis was conducted by a World Weather Attribution, a consortium of researchers who are perfecting the study of how a changing climate affects local weather.
It came out last week, but the researchers said that in light of another burst of Arctic warmth since, the analysis holds up. If anything, the ensuing temperatures were slightly hotter than they had expected, said Andrew King, a researcher at the University of Melbourne who worked on the study.
An ‘‘attribution’’ analysis of this type uses a variety of techniques to determine the odds of a weather event occurring with or without human interference in the climate. In this case, the scientists used three methods that all came to the same broad conclusion, King said.
Mid-November saw an early winter ‘‘heat wave’’ with the temperature on Nov. 11 reaching 19 degrees, which is 27 degrees above normal for the time of year. The monthly mean November temperature was 23 degrees above normal on the pole
‘‘I find the study very persuasive because they addressed the same question using three different approaches and got consistent answers,’’ says Phil Duffy, the president of the Woods Hole Research Center, which focuses on climate change.
