This New York Times column is the second time I've read the eminent climate scientist claim that the 2011 Texas drought was due to global warming/climate change.
And, he's wrong.
Now, global warming and climate, in all likelihood, exacerbated a drought that was going to happen anyway. And, yes, this was the worst one-year drought in state history.
But, that drought was going to happen anyway, due to La Niña. Which Hansen ignores. (As he does the fact that the multi-year drought of the 1950s, so far, remains the worst on record.)
If he had said "exacerbates," I wouldn't be venting. Because his concerns in the column, such as about tar sands oil, are good and valid. But, you've got to have sound science to make sound scientific arguments.
And, in this case he doesn't.
Update: In this Time story, Hansen says why he makes his claim. That said, a three-sigma, as the story notes, is only about an 80 percent probability. That's why I'd prefer that he had said global warming exacerbated a La Niña, rather than it did his alone.
Beyond that, as I have noted elsewhere, we only have about 100 years of scientific weather measurement in much of the U.S., so we don't really have much precision yet on talking about "100-year evertns" on climate.
Update 2: Per Andrew Revkin, I see that some climate change professionals also worry Hansen may be overstating his case, though they seem to be making overstatements themselves. For example, contra Martin Hoerling, I, like Hansen, have heard about the possible rainfall decrease in the southern Great Plains and the Southwest. That said, until Hansen can get to the four-sigma level, he's overstating things.