Column: How Global Warming Causes Extreme Cold
[Editor's Note: The author's political commentary refers mainly to the U.S., but the scientific explanation he provides applies to Canada's extreme-cold winter weather events as well as those in the U.S.]
By Thom Hartmann; originally published in Common Dreams
William Clay didn't realize this was the weekend fossil fuel billionaires' intentional actions would lead to his death, but that's what happened. He died in Buffalo on his 56th birthday, Christmas Eve, and was found frozen to death about a mile from his house, attempting to walk home from the store.
While Buffalo is famous for the intensity of its winter storms, this appears to be worse than anything in recorded history both there and across much of the rest of the nation. It seems Biblical: in Texas, bats are freezing and falling from trees; in Florida cold-stunned iguanas are raining down from palm trees onto unsuspecting pedestrians.
Fossil fuel industry barons win no matter what. They all know accountability for corporate executive decision-making is nonexistent in today's America, corrupted as we have been by five conservatives on the Supreme Court legalizing political bribery. And as long as the GOP has anything to say about it, their hundreds of billions in taxpayer-funded subsidies will never end.
When extreme weather hits the US—be it extreme heat in the summer or extreme cold in the winter—more of their product is burned to create electricity and heating/cooling, earning them more profits.
When weather is "normal" they just go back to bribing climate science deniers and Republican politicians across the nation to block any action to hold them accountable for 60 years of intentional lies.
Last Friday, as the most recent bomb cyclone was blasting much of America, 53.7% of the nation was covered in snow, more than any time since record-keeping began. Casper, Wyoming saw its temperature drop to -42℉, the coldest ever, as similar records going back centuries were shattered across the US. In Denver, for example, temperatures dropped by 47 degrees in a mere 2 hours.
Over 200 million Americans were under winter storm warnings as parts of Texas' privatized, for-profit power grid failed again, joining a dozen other states with deadly power outages. Dozens of people died.
Predictably, shills for the fossil fuel industry (and the suckers who believe them) were imitating Oklahoma Republican Senator James Inhofe from February 2015 when, as Chairman of the Environment and Public Works Committee (taking money from the fossil fuel industry and thus dancing to their tune), Inhofe famously threw a snowball on the Senate floor to, pathetically, try to show there's no global warming.
The twits this past weekend were saying things like, "Love me some global warning."
So, how does global warming produce record-breaking cold?
It appears to have a lot to do with global warming messing with the Jet Stream and the related walls of wind circulating around northern latitudes that in prior decades and centuries largely kept arctic air over the arctic. Now it's ending up in our front yards.
Back in 2012, Rutgers' Dr. Jennifer Francis and the University of Wisconsin's Stephen Vavrus published a hypothesis to explain the increasingly extreme variations in weather we're experiencing in the northern hemisphere. While still the subject of scientific debate, their hypothesis was both elegant and easily understood.
As long as the Arctic Ocean was covered with deep, hard ice it produced a permanent and cold plateau of stable-temperature air. That cold air dome, in turn, stabilized the temperature and pressure of the air above it so the circular flow of high-altitude winds around the Arctic—called the normal "polar vortex"—were largely kept in place at those high, northern latitudes.
We had summer and winter, storms and snow, fronts pushed through quickly by the Jet Stream, but extremes like we've been experiencing for the past decade were the stuff of science fiction disaster movies.
Extreme weather was kept at bay because the "gradient" or difference in temperatures between the cold arctic polar vortex air and the warmer air from our mid-latitudes produced a "wall" of sorts to keep the cold air over the arctic.
In addition to the polar vortex, there's another river of air flowing in a circle around the north pole at a different altitude that largely controls our weather. Called the Jet Stream, it pushes along cold and warm air masses, producing the fronts and weather we experience.
You can see the dynamic in this graphic from NOAA:
North of the Jet Stream is the cold, arctic air; south of it is our warmer air. When parts of the Jet Stream dip down over North America, we often see that phenomenon of cold- and warm-front air-mass collisions producing "fronts" that provoke storms ranging from rainfall to tornadoes to derechos.
As MIT climatologist Judah Cohen told Newsweek last week:
When the polar vortex is in its normal or strong state, there is a strong ribbon or river of air that flows rapidly from west to east…that acts like a barrier that separates cold air to the north over the Arctic and milder air to the south across the mid-latitudes.
When the circulation around the polar vortex becomes less and less circular in shape, the cold air normally confined to the Arctic can expand southward to the mid-latitudes, including the U.S., Europe and East Asia.
But two decades ago the ice covering the top of the world, that cap of arctic sea ice, hit a tipping point and began to melt so completely it was replaced by open water, which is both warmer than ice and, being dark, absorbs rather than reflects heat from the sun.
As NASA's Earth Observatory scientists note: "[A] pattern of steep Arctic sea ice decline began in 2002."
The arctic is now warming several times faster than the mid-latitudes, in part because of this "dark water" phenomenon replacing reflective ice and in part as a consequence of the entire planet's CO2-driven global warming.
As the air above the arctic warms, it reduces the gradient—the difference in temperatures—at the boundaries between the arctic and the mid-latitude air.
When that temperature gradient decreases, so does the strength of the "wall" of the boundary created by arctic air hitting mid-latitude air. As that "wall" which helps hold in place the Jet Stream weakens, the cold air above it can push through, past, or under the Jet Stream. It then ends up in your front yard as -42 temperatures.
This is apparently also why here in Portland we had 3 consecutive 116℉ days two summers ago, killing hundreds of people and millions of trees: hot air from south of us that would normally have been kept to the south by the Jet Stream punched north all the way into Alaska and sat over us for days.
It's also probably why Arctic air covered so much of the US this past week, punching as far south as Texas: air that's normally confined to the arctic broke past its "wall" and drooled down over North America.
And global warming is driving the amplification of the entire process.
At the same time the fossil fuel industry—particularly the oil industry—is enjoying record-breaking profits, thousands of Americans are dying every year from climate change-amped weather ranging from droughts to floods to massive tornadoes and derechos.
Industry CEOs and executives have knowingly lied to us for a half-century about this coming disaster, and most also continue to fund lies and liars while stuffing their money bins fuller every day.
The politicians who take their money and lie about climate change are little better: it's almost impossible to find a Republican, nationally or even at the state level, who's not on the take, directly or indirectly, from this poisonous industry.
How to deal with these moral crimes will be the next challenge confronting both democracy and our criminal justice system as Millennials and Zoomers take political power.
And that reckoning can't come soon enough.