It is not unprecedented to see tornadoes this late in the year. But the ones that ravaged Kentucky and neighboring states Friday, killing at least 74, are likely to end up the most powerful and lethal December storms on record. They were fueled by unusually warm air — temperatures in the area were more than 20 degrees above normal, creating atmospheric conditions more like April than the weeks before Christmas. Meteorologists say the path of the jet stream was another key factor.
Climate change may or may not have played a role in Friday’s rare and deadly storms. But there’s plenty of circumstantial evidence suggesting it did. In fact, climate scientists have been warning us for years that extreme weather events of all sorts would become more frequent as the planet heats up thanks to humankind’s burning of fossil fuels. This year has been one long and tragic “We told you so.”
In February, a freakish cold spell in Texas killed more than 200 people and left millions without power. In March, a crippling sandstorm — caused by worsening desertification — turned the Beijing sky an eerie orange.
In June, an unprecedented heat wave sent temperatures in the Pacific Northwest soaring into the triple digits. Residents of Portland had to ditch their flannel and fleece when thermometers measured an all-time high of 116 degrees. Lytton, B.C., hit an all-time high for all of Canada — an unbelievable 121 degrees; the following day, an uncontrollable wildfire burned it to cinders.
In July, China’s Henan province saw more than a year’s worth of rainfall in just three days; more than 300 people died in the flooding. That same month, torrential rains killed nearly 200 people in Germany, Belgium and the Netherlands, with entire villages washed out by flooding rivers. Meanwhile, some of the largest wildfires California has ever seen burned out of control.
In August, heat and wildfires plagued the Mediterranean region, wreaking terrible destruction in Algeria, Greece and Turkey. And later that month, Hurricane Ida struck Louisiana as a powerful Category 4 storm then moved northeast, dumping biblical torrents of rain that trapped and drowned Brooklynites in their basement apartments.
In October, South Sudan saw its worst flooding in at least 60 years. And the next month, poor British Columbia, reeling from the summer, bore the brunt of a massive “atmospheric river” rainstorm that caused floods and landslides.
Until fairly recently, this sort of list had to be followed by the disclaimer that no individual weather event could be conclusively blamed on climate change. Recently, however, a consortium of leading climate scientists called World Weather Attribution has been applying rigorous methods to determine whether some events can indeed be attributed to the overall warming of the planet.
For example, WWA looked at whether increasing hunger in Madagascar was being caused by drought, which was, in turn, being caused by climate change. The scientists concluded the answer was no. The increased food insecurity is being mainly caused by “factors other than climate change,” WWA said.
But WWA found that Western Europe’s flooding was “made more likely” by climate change. It declared that the heat wave in the Pacific Northwest would have been “virtually impossible” without human-induced climate change.
Tornadoes are more difficult to pin down with scientific rigor than heat waves or hurricanes. A study published last month in the climate science journal Earth’s Future concluded that the frequency of atmospheric conditions conducive to severe thunderstorms and tornadoes can be expected to increase between 5 percent and 20 percent for every 1.8 degrees Fahrenheit of warming. The most dramatic impact, according to the study, should be in the higher latitudes of the Northern Hemisphere. Keep in mind that 1.8 degrees Fahrenheit is about the temperature rise Earth has experienced already.
That perhaps adds another piece of circumstantial evidence: In the past, December tornadoes had been more of a Deep South phenomenon. To have storms cause such death and destruction in such places as Kentucky and Illinois this late in the year is almost unheard of.
No smoking gun proves climate change played a role in the tornadoes that destroyed a 275-mile swath of the nation’s heartland. But there is a lot of haze and a strong whiff of gunpowder.
We should remember that climate is nothing but weather over long periods of time. And we should take this year’s brutal events as an urgent warning. By continuing to spew heat-trapping carbon dioxide and other greenhouse gases into the atmosphere, we’re daring nature to do its worst. I fear the consequences are just beginning.