Cartoon by Daniel Garcia

Scientists say Arctic warming could be to blame for blasts of extreme cold

By Scott Dance

The Washington Post: The data is clear: Rising global temperatures mean winters are getting milder, on average, and the sort of record-setting cold that spanned the country Friday is becoming rarer. But at the same time, global warming may be altering atmospheric patterns and pushing harsh outbreaks of polar air to normally moderate climates, according to scientists who are actively debating the link.

Drastic changes in the Arctic, which is warming faster than anywhere else on Earth, are at the center of the discussion. Shifts in Arctic ice and snow cover are triggering atmospheric patterns that allow polar air to spread southward more often, according to recent research.

“We’ve seen the same situation basically the last three years in a row,” said Jennifer Francis, senior scientist at the Woodwell Climate Research Center in Massachusetts. “Here we go again.”

But understanding any link between planetary warming and extreme cold remains a work in progress. Many climate scientists still emphasize that even if frigid air escapes the Arctic more often, that air will nonetheless become milder over time.

More than a million without power as frigid air overtakes eastern U.S.

The debate started with a research paper Francis co-authored in 2012. It gets revived whenever an extreme-cold event creates headlines, such as in 2021, when Texas’s energy grid was overwhelmed by a storm that killed 246 people.

Francis’s research hypothesized that Arctic warming was reducing the contrast between polar and tropical temperatures, weakening the jet stream, a band of strong winds in the upper atmosphere that helps guide weather patterns. A weaker jet stream would allow weather systems to more easily swing from the Arctic down into mid-latitude regions that typically have temperate climates.

Since then, observations of jet stream patterns have not confirmed the hypothesis, said Daniel Swain, a climate scientist at UCLA. But the research inspired a flurry of follow-up studies that Swain expects will eventually clarify a link between climate change and cold-weather outbreaks >>>