Illinois Farmers Insurance Co. is suing Chicago for failing to prevent flooding related to climate change in what experts say could be a landmark case that accelerates local efforts to grapple with the impacts of climbing temperatures.

The insurance company filed nine class-action lawsuits last month alleging that dozens of Chicago-area municipalities are responsible for the damage caused by a two-day downpour last year in April. The company claims that local officials are aware that climate change is causing heavier rainfalls but failed to prevent sewage backups in more than 600 homes by draining water from the region's system of tunnels and retention basins before the storm.

Farmers is asking to be reimbursed for the claims it paid to homeowners who sometimes saw geysers of sewage ruin basement walls, floors and furniture. The company says it also paid policyholders for lost income, the cost of evacuations and other damages related to declining property values. But some analysts say that Farmers likely has a bigger prize in mind.

The company, which is a subsidiary of global giant Zurich Insurance Group, could be positioning itself to avoid future losses nationwide from claims linked to floods, sea-level rise and even lawsuits against its corporate policyholders that emit greenhouse gases, said Andrew Logan, an insurance expert with Ceres.

In 2012, a different Zurich subsidiary, Steadfast Insurance Co., won another high-profile climate fight: Steadfast fought a claim submitted by its policyholder AES Corp., an electric utility, stemming from a lawsuit by Kivalina, Alaska, that accused AES of contributing to climate change by emitting carbon dioxide. The Virginia Supreme Court ruled that Steadfast wasn't liable for AES's pollution.

When viewed together, Zurich's two climate cases might represent a broader strategy to insulate itself from climate losses, Logan said. The company protected itself from corporate claims related to emissions with the Steadfast case; now it seems to be separating itself from municipal losses in Illinois.

"I guess if you're an insurer that's really worried about the scale of liability that you might face from climate change, this would be a pretty smart way to begin to put up some walls around yourself," Logan said. "The dollars at stake [in the Illinois case] are much smaller than the precedent that's being set."

…A book-length analysis of the legal challenges faced by insurers notes that the industry's climate expertise related to natural catastrophes, climate science and adaptation resembles its level of knowledge around asbestos. One of the authors is Lindene Patton, Zurich's climate expert in North America.

"This could lead to claims against insurers arising out of their particularized knowledge of any of these issues," says the book, titled Climate Change and Insurance.

Similarly, the lawsuit by Farmers uses the climate assertions by local officials to show that they knew about the risks of a warmer and wetter atmosphere but didn't do enough to avoid damage. The suit points to the Chicago Climate Action Plan as evidence that the city is aware of the dangers.

"The defendant knew or should have known that climate change in Cook County has resulted in greater rain fall [sic] volume, greater rainfall intensity and greater rainfall duration than pre-1970 rainfall history evidenced, resulting in greater stormwater runoff," the lawsuit says.