Climate change threatens Midwest infrastructure, report says.

The Midwest is safe from hurricanes and drought-driven wildfires. But that does not mean the region and its roads and bridges are free from the threat of climate change, a new study warns.

Higher temperatures and unusually heavy rain events in the Midwest spell trouble for transportation and infrastructure systems, according to a study released Tuesday by the Midwest Economic Policy Institute. The group is a division of the Illinois Economic Policy Institute, a nonpartisan think tank whose members include representatives from the construction industry and labor unions.

“Rising temperatures and the likelihood of more storms and flooding reduce the lifespan of roads and bridges, could cause railways to buckle, and threaten above-ground energy facilities and transmission lines,” said study author Mary Craighead, transportation policy analyst with the Illinois Economic Policy Institute, in a statement. “Without critical maintenance and modernization of these systems, everything from freight and commuter routes to our region’s overall economic value as a net distributor of electricity could be jeopardized.”

The report noted that the region’s average air temperature has risen by 4.5 degrees since 1980. The Midwest also has seen more electricity outages, a 27 percent increase in the number of “very heavy precipitation days” between 1958 and 2007, a reduction in Great Lakes ice coverage and more frequent freeze-thaw cycles — all of which can affect roads, bridges and other infrastructure.

Metra has reported that extreme weather has taken a toll on its budget. Officials for the suburban rail service have cited weather conditions, such as this year’s flooding in Lake County and very hot days that can cause track misalignment, as part of the cause of increased worker overtime. The CTA also has reported having to inspect for “sun kinks” on rail tracks during hot days.

The institute study notes that increased heat can reduce the life of asphalt and add stress to expansion joints for bridges and highways. Flooding also can weaken structural supports for bridges, promote deterioration of soil that supports roads, tunnels and bridges and increase a buildup of sediment in waterway channels. More frequent freeze-thaw cycles add stress to pavement, which can cause potholes. Droughts, such as the one that hit the Midwest in 2012, can hurt water traffic.

The study concludes that infrastructure is “grossly underfunded” to meet the maintenance and growth needs of the nation. Even without accounting for adaptations for climate change, the funding gap between needs and revenues between 2016 and 2025 is over $2 trillion for national infrastructure systems, the study said, citing the American Society of Civil Engineers.

The study recommended that local, state and federal governments take action to help minimize the effects of weather in the future on transportation and electricity systems.

The administration of President Donald Trump, who has said that he disagrees with the scientific consensus that humans play a role in changing the climate, has rescinded Obama administration requirements that federal infrastructure construction account for climate change and sea-level change.

“I think it’s incredibly unfortunate that we’re still having this debate over climate change to begin with,” Craighead said in an interview. “We’ve seen it happening, scientists have told us it is happening and we need to move forward.”

Some state and local governments have taken their own action on climate change. Minnesota and Michigan lead the region in adequately preparing their systems for climate change, the study said. The study also gave credit to the Illinois Department of Transportation, along with the transportation departments in Michigan, Ohio and Minnesota, in pursuing programs to manage assets and identify vulnerabilities in response to climate change.

The Chicago Department of Transportation said it looks at climate change as a factor in the planning process, spokesman Mike Claffey said. For example, in its study of improvements for North Lake Shore Drive, the city plans to address the potential effects of more severe weather by strengthening shoreline protection and upgrading stormwater management, for instance, Claffey said.

Another step governments can take is to consider changes to design standards for infrastructure to account for worsening heat and flooding, Craighead said. She said new infrastructure must stand up to future use.

“When we do get money for infrastructure and we’re investing in it, we need to make sure climate change factors are taken into account,” Craighead said.

mwisniewski@chicagotribune.com

Twitter @marywizchicago