A rooftop solar system in Brooklyn installed with support from the U.S. Department of Energy and New York City. DOE

Mayors from 233 U.S. cities, representing more than 51 million Americans in 46 states and territories, have released a joint letter voicing their opposition of the Trump administration’s efforts to repeal the Clean Power Plan, arguing that the reversal would “put our citizens at risk and harm our efforts to address the urgent threat of climate change.”

Signatories of the letter, sent directly to Environmental Protection Agency Administrator Scott Pruitt, include mayors from states such as Florida, Pennsylvania, Ohio, Texas, and Michigan. They point to the increasing frequency and intensity of extreme weather events impacting communities across the United States, from severe storms to heat waves. They also cite the growing cost of responding to and preparing for these disasters, as well as for sea level rise.

The annual cost of coastal storm damage is expect to reach $35 billion by the 2030s, and coastal property valued at up to $106 billion could be flooded by 2050, according to a report by the Risky Business Project, which analyzes the economic impacts of climate change in the U.S.

The Trump administration has made reversing the Clean Power Plan, which limits greenhouse gas emissions from power plants, a key goal in their effort to rollback U.S. environmental regulations. The EPA officially moved to repeal the plan in October 2017 and is in the process of hearing public input on the reversal.

“Not only are climate change impacts felt locally — our communities are also where climate change adaptation and mitigation efforts are being implemented,” the collective letter says. “But the legal authority of cities and other municipalities generally extends only as far as their state governments and federal law allow, and as a result, our local efforts to address climate change are highly sensitive to national policies like the Clean Power Plan, which shape markets, steer state action, and have large direct impacts on nationwide emissions.”

For more on how states and local communities are taking action on climate change, click here.