DES MOINES, Iowa (AP) — This year's drought is consistent with predictions that global climate change would bring about weather extremes including more frequent droughts, said a report released Monday.

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.

Patrick Michaels, director of the Center for the Study of Science at the Washington-based conservative think tank Cato Institute, said there's no evidence global warming contributed to this summer's drought. He doesn't deny that global warming is real and that man-made pollutants may contribute to it, but says it has a very small impact overall.

Michaels said the scientists who signed on to the report are "nibbling around the edges" with their recommendations that Americans use more renewable energy sources, such as wind power and ethanol, and build homes to be more efficient. He says any action the United States takes wouldn't be that effective because China and India are emitting increasing amounts of pollutants that contribute to global warming.

The Iowa scientists said they're statement is not one of gloom and doom, but meant to indicate investments can be made now to slow the economic impact of weather extremes and to help communities adapt to the changes.

One scientist who helped draft the report, Dave Courard-Hauri, chairman of environmental science and policy program at Drake University, said continuing to deny the connection between increased storm volatility and a warming climate helps no one.

"We gain nothing if we act as if there's uncertainty where there's not or that there is significant division among scientists regarding the causes of climate change," he said.