After a deadly night of extreme weather, questions of whether climate change is intensifying tornadoes are beginning to emerge.

But research about the connection between the climate crisis and tornadoes is not as robust as other extreme weather, like drought, floods and hurricanes. 

The short and small scale of tornadoes, coupled with an extremely inconsistent and unreliable historical record, makes linking outbreaks to long-term, human-caused climate change extremely challenging. 

Victor Gensini, a professor at Northern Illinois University and one of the top tornado experts, said last night’s outbreak is one of the most remarkable tornado events in US history — and while climate change may have played a role, it’s not yet clear what that role was.

“But when you start putting a lot of these events together, and you start looking at them in the aggregate sense, the statistics are pretty clear that not only has there sort of been a change — a shift, if you will — of where the greatest tornado frequency is happening,” Gensini told CNN. “But these events are becoming perhaps stronger, more frequent and also more variable.”

Jennifer Marlon, a climate scientist at the Yale School of Environment, told CNN it’s early to say what the connection is in last night’s outbreak, but there are “some really important signatures that suggest that this very well may be linked to climate change,” and that scientists are “observing changes in the outbreaks, not just the severity of individual outbreaks and tornadoes, but also quiet periods."

For example, if any of last night’s tornadoes are rated EF-5 (estimated winds of 260 mph or greater), it would end a streak of 3,126 days since the last EF-5, which is the longest stretch without since the records began in 1950. The last EF-5 tornado was the Moore, Oklahoma, tornado on May 20, 2013.

Some studies also indicate climate change could be contributing to an eastward shift in tornado alley, for instance, resulting in more tornadoes occurring in the more heavily populated states east of the Mississippi river, such as this tornado outbreak.

But Gensini said one thing is certain: regardless of climate change, these types of tornado disasters will continue to worsen as humans alter the landscape and build larger, more sprawling cities.

“We have more assets and more targets for the severe storms to hit,” he said. “So even if you take climate change out of the equation, which is very likely to make the problem worse, we still have this issue of human and societal vulnerability.”