The Financial Times reports:
And even if there were a more concerted trend, there is little understanding of exactly how global warming affects tornadoes.
A warmer climate may mean there is more moisture in the atmosphere and therefore more thunderstorms and tornadoes, says Richard Betts, head of climate impacts at the UK’s Met Office. “But on the other hand, you might get changes in high-level winds which could decrease tornadoes. So it literally could be either way. We don’t know.”