An Iowa State University professor is hesitant to blame the recent severe weather in Iowa on global warming, but does predict more intense and frequent rainstorms in the future, combined with hotter days and nights. William Gutowski, a professor of geological and atmospheric sciences, says the planet will only get hotter because of human-made greenhouse gases.
"We may have individual years that may be somewhat cooler, just like this past winter was somewhat cooler than some of our previous winters in recent years, but the overall long-term trend is there and I think the science is very clear on that that we can expect that warming trend is going to continue," Gutowski said. As the climate warms, Gutowski says there’s little doubt that strong downpours of rain will increase as well.
"With any single extreme event you can’t say that it was definitely caused by global warming, but what you can say is that the likelihood of certain types of extreme weather – such as strong rainfall – are going to increase in a warming climate," Gutowski said. A number of cities and towns in Iowa have received more than 10 inches of rainfall this month.
The National Weather Service says that’s about six inches above normal. "When we get into things like precipitation – that is a noisier process, much more localized – it’s much harder to directly pinpoint those changes exactly to human behavior," Gutowski said. "Although, there have been some changes that are consistent with what we think increased greenhouse gasses have caused." Gutowski is one of the lead authors on a newly published government report about global warming.