Boston Globe: ‘Why is it so cold? Some researchers say there may be a surprising culprit: climate change’ – But meteorologist ridicules claim as scientific ‘garbage’

As climate change reshapes winter in New England, the brutal winds and bitter cold of December felt like a throwback to seasons past.

Scientists say these bone-chilling days do not mean that climate change took a vacation. In fact, instead of contradicting the reality of global warming, some researchers have suggested that surges in Arctic air could be one of its strange new hallmarks.

The overall trend still holds: New England winters are becoming undeniably shorter, milder, and less snowy. But some new research links climate change with disrupting the rings of fast-moving wind that circle the Arctic, unleashing frigid air to head south.

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This December marked the coldest in years for parts of New England. The region kicked off the month with an early winter snowstorm and strong blasts of Arctic air that drove record-setting low temperatures. More cold snaps followed, culminating in an icy New Year’s Eve complete with snow showers. In Boston, temperatures in the city averaged slightly below freezing at 31.3 degrees Fahrenheit, making it the chilliest December since 2017.

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To understand how a warming climate can unleash such bitter cold, some climate experts are looking north.

Some research suggests that rapid warming in the Arctic can make the polar vortex, a mass of frigid air swirling above the North Pole, more likely to stretch down over North America. As climate change warms the Arctic faster than the rest of the planet, the ice floating on the Arctic Ocean is disappearing, which may be causing the polar vortex to weaken or become elongatedmore often.

Sitting farther south is the polar jet stream, fueled by the temperature contrast between the Arctic and temperate regions. As the Arctic warms, that temperature difference is shrinking, potentially making the jet stream more likely to meander and driving certain extreme weather patterns.

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Not all researchers agree. A Dartmouth team challenged the idea that the jet stream’s recent meandering waves are unusual in a study published in June. They analyzed the jet stream’s winter variability since 1901 and found that the jet stream was wavier — bending off of its relatively straight course — during periods of the 20th century than it is today.

“We don’t think there’s strong evidence yet that climate change is making this sort of cold snap and jet stream waviness more intense,” said Jacob Chalif, a Dartmouth graduate student and co-author. “At least not yet.”

Kate Selig can be reached at [email protected].