These people think you're stupid: A bunch of academics in Iowa suggest that CO2 has caused intense rainfall to "occur five times more often than in our previous history"

Iowa Scientists: Climate Change Is Affecting Iowa, Candidates Should Acknowledge Climate Science - Iowa Climate Advocates

Changes in rainfall patterns and other climate indicators have emerged as the latest and potentially the most serious challenge to Iowans' lives and livelihoods. Subtle changes in climate can have large effects on agriculture, making it a sensitive indicator of climate change. Statewide data show changes in temperature, precipitation, and humidity over the last forty years affecting Iowa's producers. In recent decades a longer growing season, more precipitation, and lack of extreme high daytime temperatures have contributed to improved crop yields in our State. But the accompanying increase in extreme rainfall events, higher humidity, and higher nighttime temperatures have required costly adaptations. 

Like its farmers, Iowa's cities and rural communities, which provide our infrastructure, educational opportunities, and cultural amenities, also have felt the effects of a changing climate. Over the last 40 years intense rainfall has occurred about five times more often than in our previous history.

Flashback:  In Iowa, some farmers see changing climate | Harvest Public Media

only 10 percent of farmers said they believe climate change is caused mostly by human activities