As someone who grew up in semi-tropical south Louisiana, I didn’t think Iowa had anything to teach me about humidity. I was wrong.
Iowa, of course, is the most corn-centric of the states. Last year, cornfields made up more than a third of its total landmass. And with corn comes corn sweat.
Like other plants, corn releases water vapor from its leaves — “evapotranspiration” is the scientific term. During peak growing season, an acre of corn can release as much as 4,000 gallons of water vapor every day. In 2021, there were 12.5 million acres of corn growing in Iowa.
Corn sweat can exacerbate problems caused by humidity, but it’s not the biggest humidity-related problem Iowa is facing. Climate change is.
“The rise in ‘absolute humidity’ (moisture in the air) is likely to become the most pervasive factor in climate change across the state,” according to the 2017 Iowa Climate Statement, endorsed by 190 scientists, researchers and educators from 39 of the state’s colleges and universities.
In Dubuque, absolute humidity during springtime increased 23 percent between 1970 and 2017, and increases in “humidity have been measured across the Midwest and in Iowa across all seasons and at all long-term monitoring stations.”
Humidity makes it harder for humans and other animals to cool off and accelerates corrosion of metal and the warping and rotting of wood. It also aggravates some of Iowa’s worst agriculture problems as “increased warm-season humidity leads to increased rainfall, extreme rain events, water-logged soils during planting season, soil erosion, and runoff of chemicals to waterways,” the statement said.
Addressing the increasing humidity means addressing climate change, and until that’s done, Iowans will have to keep sweating, just like the corn.
This article was originally published in Little Village issue 304.
