Across Canada and the U.S., millions are hunkered down against what feels like the worst cold snap in decades. Toronto’s Pearson airport had to cancel or delay flights on Jan. 7, deeming it unsafe for staff to work outdoors. (Nearby Hamilton was minus 24 C, a record low.) That same morning, hundreds of passengers finally reached Chicago after being stuck overnight on three Amtrak trains that got caught in blowing snow in Illinois. It was so cold in Indianapolis that the mayor temporarily made driving illegal; in Kentucky, an escaped convict turned himself in rather than stay out in the cold. Reporters breathlessly declared Minneapolis to be as frigid as Antarctica or an ice-cream freezer, and Winnipeg as cold as Mars. Canadians love to talk about the weather; but these conditions have stretched even our winter lexicon, requiring a whole new set of colourful terms: polar vortex, frostquake, polar pig and Siberian Express. And the winter’s only half over.
Blustery billionaire Donald Trump took to Twitter to proclaim global warming “bull****,” and of course he wasn’t alone. Calgary’s own Sean Chu, a rookie city councilor, jumped into the fray when he tweeted that the silence from “global warming alarmists,” in light of this record chill, was “deafening.” Still other climate change deniers piled on, apparently confusing weather with climate—two very different phenomena, as exasperated scientists are quick to note. Still, there may be an indirect connection. “It may seem counter-intuitive,” says Matthew Peros of Bishop’s University, “but there could be a link between global warming and the cold snap we’re experiencing.”
Frigid Arctic air is usually kept in place by the jet stream, a west-east air current that marks a boundary of sorts between cold polar air to the north and warmer southern air. The jet stream is driven by that difference in temperature, says Peros, who holds the Canada Research Chair in Climate and Environmental Change. With the Arctic heating up more quickly than southern latitudes (a trend called Arctic amplification), the jet stream seems to be weakening, which could allow for more extreme weather events, including cold snaps like this one, in the future, he explains.
As scientists continue to test this hypothesis, John Smol of Queen’s University snorts at the notion there’s been a “deafening silence” in the face of this deep freeze. “No credible scientist would talk about one hot day in August” as evidence of global warming, says Smol, another Canada Research Chair, who spoke to Maclean’s from Yellowknife, where he was attending a conference. “It’s supposed to be plus 3 C in Calgary tomorrow,” Smol adds. “Does that mean global warming is back again?”