Iowa’s signature summer humidity is not just an annoyance, it’s a costly reminder that climate change is real and needs to be addressed, a group of Iowa scientists said Wednesday.

Gene Takle, director of Iowa State University’s climate science program told a Statehouse news conference that “absolute humidity” measured by dew-point temperature has increased statewide by 8 percent to 23 percent since 1971. 

Scientists have “good evidence” the rise is due to increased carbon dioxide in the atmosphere that likely will increase in the future, Takle said.

He is one of the architects of the seventh annual Iowa Climate Statement, released with endorsement of endorsement of 190 science faculty, researchers and educators from 39 Iowa colleges and universities.

Takle, a professor of geological and atmospheric sciences in the ISU Department of Agronomy, said the conditions relate to the increase of springtime moisture transported from the Gulf of Mexico that settle along eastern Iowa. That results in higher humidity readings measured across all seasons at all long-term monitoring stations in Iowa.