Brian Williams: Is Global Warming to Blame for Tornadoes?

“This has been one of the most active, deadly tornado seasons in a long time....I talked to three people, casual conversation today, all of them smart, saying, ‘I don’t know, we must be doing something to our Earth.’ So once and for all, what’s going on?”
— NBC Nightly News anchor Brian Williams to NBC WeatherPlus meteorologist Bill Karins, May 12, 2008. Karins discounted global warming as a cause.