In an item on his Future of Capitalism blog yesterday, Ira Stoll pointed out that observations show the frequency and intensity of tornadoes and extreme weather do not show increases. He got a response in his comments section from Bill McKibben himself. As Stoll says,
It links to the Climate Progress blog of the Center for American Progress Action Fund, which acknowledges that “the tornado-warming link is more tenuous” than other evidence on climate and extreme weather. The piece also acknowledges, “‘Today’ weatherman Al Roker appears to have gone beyond the data with his suggestion that ‘climate change’ is bringing tornadoes to urban areas, although, admittedly, it is a brief clip and it’s not exactly clear what he is saying.”
In a roundabout way, McKibben is admitting that he is wrong — although following the links McKibben cites leads you to a banquet of circular reasoning, with assertions that if extreme weather is increasing, there are a number of theories that would link this hypothetical increase to a hypothetical increase in global temperatures.