The Dust Bowl — the seven-year drought that devastated large swathes of US prairie land in the 1930s — was the worst prolonged environmental disaster recorded for the country. But a study of the American Southwest’s more distant climatic past reveals that the catastrophic drought was a mere dry spell compared to the ‘mega-droughts’ that were recurring long before humans began to settle the continent.
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.
Hansen : http://www.giss.nasa.gov/
The 350 ppm drought was nothing like the 310 ppm drought, which was nothing like the 280 ppm drought. Maybe we need more CO2 to eliminate droughts completely?