Hurricane Irene, Aug. 27, 2011
The connection between climate change and extreme weather — hurricanes, tornadoes, floods and droughts — is one scientists have struggled with for years. But there's no doubt that 2011 was a memorable year for natural disasters. From the freakish string of tornadoes that hit the Midwest to the ongoing Texas drought to the tropical storms of August, the U.S. was buffeted by extreme weather throughout the year. Fourteen $1 billion–plus natural disasters hit the U.S. in 2011 — an all-time record.
Of course, the cost of a natural disaster isn't a measure just of the strength of a tornado or a hurricane. As population and income grow — and especially, as people and wealth concentrate in vulnerable areas like the coastline — the economic and human toll from any given disaster is likely to increase. Add in climate change, which can put ordinary weather on steroids, and we're going to be facing a future in which the billion-dollar disaster becomes all too common.