Coldest Christmas in decades: Why does a hotter Earth bring harsh winter storms? – MarketWatch
The calendar flipped to winter this week and promptly ushered in what the National Weather Service is calling a “once-in-a-generation type event” that will hobble holiday travel by air and road on some of the busiest days of the year.
While it may seem contradictory, climate change may be contributing to more extreme winter weather. Snow, wind and bitter wind chills for the states that are used to them are not news. But the fact that these events persist even while Earth is warming is a baffling phenomenon that some scientists are linking mostly to increased precipitation in a warmer atmosphere.
As the week draws to its end, a storm dumped more than a foot of snow and possible blizzard conditions to parts of the Midwest, and the weather service warns of “life-threatening” wind chills for millions.
The National Weather Service reported that temperatures across the central High Plains plummeted 50 degrees Fahrenheit in just a few hours.
“This is not like a snow day when you were a kid,” President Joe Biden warned Thursday in the Oval Office after a briefing from federal officials. “This is serious stuff.”
More than 90 million people are under winter weather alerts and more than 87 million are under wind chill alerts. The alerts include 37 states, dipping as far south as the Texas-Mexico border.
In 2021, record-breaking snowstorms knocked out power for nearly 4.5 million homes in Texas as icy conditions and heating demands overwhelmed much of the region’s power supply, which is fed by a combination of natural gas NG00,
Right now, the number of people under winter alerts and wind chill alerts has grown to over 100 million people, or roughly a third of the U.S. population, according to the National Weather Service.
The cold will persist for Christmas weekend, marking this year as the coldest Christmas in roughly 40 years for portions of the Plains and Midwest.
Why does a warming Earth still bring severe winters?
There are a couple of factors at work when it comes to climate change and winter weather.
For sure, winters overall are getting milder and shorter, but that doesn’t mean intense snowstorms and record-breaking frost won’t break through. And when they do hit, regions may find themselves having grown more complacent due to the warming trends.
For one, as the warming atmosphere traps water vapor deeper and deeper into the calendar year, that precipitation leads to heavier snowfall when the temperatures do drop.
Another factor is the rapidly warming Arctic, which some scientists believe is weakening the jet stream and causing disruptions of the polar vortex.
The polar vortex refers to bands of wind and low air pressure near the North Pole, which normally lock cold air over Arctic. When those bands break down, icy air can escape south in the form of freezing winters, EarthJustice detailed.
Over the past century, large increases in carbon dioxide, methane and other greenhouse gas emissions CL00,
The United Nations has called for global leaders and the private sector to enact policies that hold the temperature to a no more than 1.5 degree Celsius increase, or risk even greater loss of life and economic cost. Already, a rise in global temperatures is fueling climate disasters and making typical natural disasters potentially more extreme, across the seasons. That has included extreme heat and extra flooding, more powerful hurricanes and deadly drought.
Always room for further study
Meteorologist Bob Henson taked with Yale University’s Climate Connections about the ongoing study of climate change and winter extremes, and what persists as an evolving field of discovery.
“There has been quite a lively and vigorous debate in the research community, largely centered around the group of folks who pioneered this research in the early 2010s, of the idea that the jet stream might be torquing more in the winter, and what we call ‘weather weirding’ might be producing more intense winter extremes,” he said, in the interview.
Other researchers, Henson said, show that winters have generally been getting milder in the U.S. and less snowy. And long-term global computer models indicate we can expect them to continue doing so.
But neither does Henson suggest that global warming means we should entirely rethink winter.
“I would say that regardless of whether or how much climate change is involved, it’s still wintertime. Nobody ever said global warming would eliminate winter,” he told Yale Climate Connections.
“We’re still in the mid-latitudes of the Northern Hemisphere. We’re far enough north to get really cold and snowy winter weather,” he said. “So it may not be climate change so much as just the continuation of the climate variability we’ve always had, perhaps intensified in a few cases by this jet stream weirding being associated with the Arctic warming.”