From the AP’s “More Tornados from Global Warming?”:
A deadly tornado hit suburban Oklahoma City on Monday. A quick look at some basic facts:
Q. Is global warming to blame?
A. You can’t blame a single weather event on global warming. In any case, scientists just don’t know whether there will be more or fewer twisters as global warming increases. Tornadoes arise from very local conditions, and so they’re not as influenced by climate change as much as larger weather systems like hurricanes and nor’easters. They’re not easy to incorporate in the large computer simulations scientists use to gauge the impact of global warming.
And when scientists ponder the key weather ingredients that lead to twisters, there’s still no clear answer about whether to expect more or fewer twisters. Some scientists theorize that the jet stream is changing because sea ice in the Arctic is shrinking. And the jet stream pattern drives weather in the Northern Hemisphere.