Iowa scientists: Drought a sign of climate change

The Iowa Climate Statement updates the 2010 report, reflecting the year's lingering drought and the belief that it signifies what many scientists have predicted — increasing instability in weather patterns will lead to extremes during both wet and dry years.

Iowa has experienced such extremes in recent years; in 2008, flooding caused an estimated $10 billion in damage, making it the worst disaster in the state's history.

More broadly, this year's drought brought about parched croplands, reducing corn yields across the nation's Grain Belt, from South Dakota to Indiana. And last month's Superstorm Sandy — a combination of a hurricane, a wintry storm and a blast of arctic air — devastated parts of the Eastern seaboard and killed more than 100 people.

The report was signed by 138 scientists and researchers from 27 Iowa colleges and universities. They said they wanted to release the updated report now while the drought is still fresh in the public's mind.

"The drought is sort of a teachable moment," said Jerry Schnoor, co-director of the Center for Global and Regional Environmental Research at the University of Iowa.

The scientists are careful to avoid saying any single extreme weather incident is directly caused by global warming, saying too many factors are at play when it comes to weather. But, they did say increasingly volatile weather patterns have been predicted by scientists who study global warming.