Nearly 200 science faculty from 26 colleges and universities across Iowa endorsed the 15th annual Iowa Climate Statement, which warns of higher insurance costs due to climate change.
The scientists pointed to data showing the number of inflation-adjusted billion-dollar disasters in the region, including in Iowa, more than doubled in the last four decades.
"Insurance, obviously, is a way that we spread costs of private risks in our society … but with climate change increasing risks from extreme events, that cost will increase for all of us," Dave Courard-Hauri, professor of environmental science and sustainability at Drake University, said during a news conference Monday.
Bill Gutowski, professor emeritus of meteorology at Iowa State University, summarized decades of research linking the burning of fossil fuels to increased greenhouse gases in the atmosphere, which trap heat.
Earth's 10 hottest years on record have all occurred in the last decade, with 2024 topping the list.
Gutowski explained a warmer atmosphere holds more moisture, contributing to longer periods between rainfall events followed by heavier bursts of rain.
The number of extreme precipitation days in the Midwest has increased by around 45% since the 1950s. Downpours can lead to more flooding and erosion.
"Moreover, when that water condenses [in the atmosphere], it adds energy in the form of heat to those storms, which can make them stronger, especially the severe weather storms we experience in late spring to early summer and which often cause substantial damage," Gutowski said.
Climate change is also linked to more large hail events in the Midwest. Courard-Hauri said hailstorms are one of the major reasons why insurance rates have increased in Iowa. He added that many insurers have reduced their coverage of roofing.
"As insurance costs become prohibitive or as companies choose not to insure in areas of high risk, the entire housing market can experience ripple effects," Courard-Hauri said.
Peter Thorne, professor of occupational and environmental health at the University of Iowa, said the insurance industry faces higher costs for labor, building materials and reinsurance — the industry that backs-up insurance companies.
But all these expenses are "amplified by climate change," Thorne said. Insurance companies use advanced climate models "to align their rates and anticipated losses across their customer pool."
Beyond homeowners' insurance, Thorne said farmers are particularly vulnerable to extreme weather events exacerbated by climate change and insurance costs.
Federal crop insurance premiums hit $15.8 billion in 2024. Taxpayer dollars subsidized $9.8 billion.
"It's important to recognize that crop insurance only supports losses of crops that are in the field, so farmers have to purchase additional insurance to protect against other losses due to severe weather, such as damage to equipment, structures and stored grain," Thorne said.
2025 Iowa Climate Statement recommendations
The scientists said stronger building standards in Iowa could help protect structures and their owners against extreme weather events. They pointed to the International Residential Code and FORTIFIED construction standards as examples.
"The building standards and codes that made a lot of sense 20 years ago may not be sufficiently protective," Courard-Hauri said.
Thorne said new building standards could include specific types of shingles and requirements for attaching roofs to protect structures from stronger wind and hail.
These changes would need to happen through the state Legislature, according to Emma Stapleton, research assistant professor of internal medicine at the University of Iowa. She added that homeowners can explore potential incentives through their insurance companies.
"Some policies do give you green update coverages, where you can rebuild or replace the damaged parts of your house with environmentally friendly materials," Stapleton said. "But you do want to ask your insurance agent and look up your policy online and see if you can take advantage of some of those discounts."
The scientists underscored that long-term solutions to rising insurance costs require quickly shifting away from fossil fuels to renewable energy, including wind and solar. Federal policies can speed up or hinder this transition, they said.
Since 2011, Iowa researchers and educators have produced annual statements describing impacts from climate change in the state and ways Iowa can address and adapt to those changes.
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