The series of weekend tornadoes that ripped through the parts of the US this weekend adds to another stretch of deadly and potentially unprecedented weather disasters that plagued the planet this year. Meteorologists and climate scientists say the latest outbreak is historic.
And as these extreme weather events intensify, occur more often and exacerbate the country’s growing economic toll, science is running to keep up to answer emerging questions of whether climate change is intensifying every single disaster. With this weekend’s tornadoes, climate researchers say it’s too early to determine the link, but the uncertainty doesn’t mean it is unlikely.
In Kentucky, the series of tornadoes uprooted trees, tore down homes and infrastructure, and killed at least 74 people. Gov. Andy Beshear said at a news conference that the tornado event reached a “level of devastation unlike anything I have ever seen,” he said.
Global scientists made clear that weather events, no matter how severe, are occurring against the backdrop of human-caused climate change; nevertheless, it all comes down to discerning how a warming planet is altering weather patterns, including geographical location and frequency, as well as severity.
Scientists say the short-lived scale of tornadoes, coupled with an extremely inconsistent and unreliable historical record, makes connecting outbreaks to long-term, human-caused climate change extremely challenging.
Unlike large-scale and slow-trending weather events such as droughts, floods and hurricanes, scientific research about the link between climate change and tornadoes has not been as robust.
Victor Gensini, a professor at Northern Illinois University and one of the top tornado experts, said the weekend’s outbreak is one of the most remarkable tornado events in US history – and while climate change may have played a part in its violent behavior, it’s not yet clear what that role was.
Think of a pair of dice, he said. On one of the die, you altered the value of five to six, which means it now has two sixes – raising the chances of you rolling the pair of dice and getting the value 12. Although you can’t immediately attribute that value of 12 to the change you made, you just altered the probability of that event occurring.
Gensini said that’s similar to how the climate system now works – the more humans pump greenhouse gases into the atmosphere and change the system, the chances of extreme weather events occurring will amplify.
He points to different ingredients that primed the landscape for the outbreak to happen, such as a late spring, early summer air mass and a strong wind shear.