Freak cold in Texas has scientists discussing whether climate change is to blame

https://www.reuters.com/article/us-global-weather-polar-vortex/freak-cold-in-texas-has-scientists-discussing-whether-climate-change-is-to-blame-idUSKBN2AH2O7

 

By Tom Balmforth

February 17, 20213:13 PM

The freak cold spell that has killed at least 21 Americans and shut down power for days in Texas has revived scientific discussion over whether climate change could be delivering this week’s chill.

Scientists say global warming – specifically the rapid warming of the Arctic – is a possible, if not likely, culprit in the extreme weather.

Historically, frigid temperatures have typically been contained within the Arctic by a jet stream circling the polar region. In fact, along with the spinning of the planet, it’s the contrast in temperatures and atmospheric pressures between the Arctic and lower latitudes that results in the winds.

But as the Arctic has warmed more than twice as fast as the global average over the last three decades, that contrast can be less pronounced, said Paul Beckwith, a climate system scientist in Ottawa. That could cause the polar jet stream to slow down and meander, so that it carries more warmer air toward the pole and frigid air further south, he said.

“What we’re seeing this year is an extreme example of what happens when the jet stream trough goes really deep southward,” Beckwith said.

“I think it’s a rock-solid case,” he said. But “it might take a bit of time for the science to catch up and find all the details” to prove it.

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scientists have found a strong correlation between extreme winter weather in 12 U.S. cities and warmer temperatures in the Arctic over the last 50 years, according to research published in 2018 in the Nature Communications journal.

The United States may not be the only country affected, either.

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While Semenov acknowledges there is still not enough data to establish a firm climate link in the pattern, he said research pointing to the theory of a “wavier” polar jet stream due to Arctic warming was compelling.

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