In a year of record-high temperatures and record-low sea ice, the Arctic appears poised to witness another frightening scenario: temperatures at the North Pole so high that they might even swing above freezing, something not typically seen until May.
For the second year in a row, December temperatures in the Arctic are much higher than normal. On Thursday, it’s possible that temperatures could climb as much as 50° F (about 28° C) above normal, bringing temperatures close to, or potentially above, 32° F.
Record-low levels of Arctic sea ice might be at least partly responsible for the high temperatures. Ryan Maue, a meteorologist with WeatherBell Analytics, told the Washington Post that the temperatures are being brought to the North Pole by a storm east of Greenland, and that record-low sea ice makes it easier for warm air to travel northward unencumbered.
Since roughly September, the Arctic has experienced much warmer than normal temperatures — November was a record 18 degrees above normal, according to the National Snow and Ice Data Center. According to the National Oceanic and Atmospheric Administration’s annual arctic report card, released December 13, surface air temperatures for the Arctic this year have been “by far” the highest since 1900.
— Capital Weather Gang (@capitalweather) December 20, 2016
That warm up has resulted in seriously decreased sea ice, which tied at the end of the summer for the second-lowest minimum extent on record. And that, in turn, helps fuel some of the persistent warming seen at the Arctic, because low sea ice means that more of the sun’s heat is absorbed by the ocean, which in turn slowly releases that heat into the air through fall and winter.
According to analysis released by the World Weather Attribution project — a group of scientists associated with the website Climate Central — human-fueled climate change is also playing a role in the current record warmth. Using both observational and computer modeling, the group found global warming is both intensifying heat in the Arctic, and making such events more frequent.
“The analysis revealed that the temperatures experienced this November and December in the Arctic would have been extremely unlikely before the pre-industrial, pre-global warming days of the 1800s,” the group said. “This current North Pole heat event is still a rare occurrence — roughly two percent chance every year — even in our warmer world of today.”
And while the high temperatures currently plaguing the Arctic are still rare, some scientists worry that they could be occurring with increasing frequency. December 2015 saw high temperatures of a similar magnitude as this year, also brought about by a large Arctic storm pulling warm air towards the North Pole. Scientists aren’t ready to draw conclusions just yet — they point out that big Arctic storms have brought temperature swings to the Arctic before, and can occur as often as once or twice a decade. But Kent Moore, a physics professor at the University of Toronto, told Mashable that temperature extremes are growing at twice the rate that the Arctic is warming.
Temperature swings can have a big impact on the Arctic’s delicate ecosystems. If temperatures rise to a point where rain is falling instead of snow, that can create icy conditions that can block important routes for animals like reindeer, cutting them off from their food supply. A rain-snow event like that killed 61,000 reindeer on Russia’s Yamal Peninsula in 2013.