Pennsylvania Gov. Josh Shapiro’s administration has joined a lawsuit challenging the Trump administration for repealing environmental rules that treated greenhouse gases as a public health threat.
“Pollution puts people’s health at risk, makes severe weather worse, threatens our farmer’s crops, and makes health care more expensive,” Shapiro said in the March 19 announcement. “By trying to roll back protections that keep pollution out of the air we breathe, the Trump Administration is once again throwing science out the window.”
Under President Donald Trump, officials in the U.S. Environmental Protection Agency have ended the endangerment finding, a longstanding rule that deemed six greenhouse gases, including carbon dioxide and methane, a risk to “both the public health and the public welfare of current and future generations.”
The finding formed the basis for federal regulation of greenhouse gas emissions from cars and power plants, and environmental groups say its February repeal will reverse progress on pollution controls. The Trump administration argues that scrapping the rule will give Americans greater consumer choice and will alleviate $1.3 trillion in hidden regulatory costs.
The commonwealth is the nation’s fourth-highest source of greenhouse gas emissions, and in a September 2025 letter to the EPA, Pennsylvania officials expressed concern about the negative health impacts of ozone pollution in the Philadelphia region.
They also wrote that climate change exposes the Keystone State to higher temperatures and increased risk of landslides, flooding and diseases.
Massachusetts and California are leading the legal action against the Trump administration, and 22 states including Pennsylvania are backing it.
