Hansen said the exact opposite in 1999
Empirical evidence does not lend much support to the notion that climate is headed precipitately toward more extreme heat and drought. The drought of 1999 covered a smaller area than the 1988 drought, when the Mississippi almost dried up. And 1988 was a temporary inconvenience as compared with repeated droughts during the 1930s “Dust Bowl” that caused an exodus from the prairies, as chronicled in Steinbeck’s Grapes of Wrath. NASA GISS: Science Briefs: Whither U.S. Climate?
There is no indication that droughts are getting worse. In 1934, 80% of the US was simultaneously experiencing drought. 190001-201202.gif (650×534)
Over the past decade, extreme drought has plummeted in the US.
So what evidence caused him to change his mind?