Arizona Joins Multi-State Lawsuit Against EPA Over Climate Rules

Mar 23, 2026, 2:19 AM

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Arizona is one of more than two dozen states, counties, and cities suing the Trump administration for rescinding the Endangerment Finding, a crucial scientific basis that allowed the Environmental Protection Agency (EPA) to impose limits on carbon pollution. The lawsuit, filed in the US Court of Appeals for the District of Columbia, challenges the legality of the EPA's decision, which critics argue undermines decades of scientific research on climate change.

The Endangerment Finding was established following a 2007 US Supreme Court ruling, which confirmed that the EPA has the authority to regulate greenhouse gases that pose a threat to public health. In February, the Trump administration announced its plan to eliminate this finding, claiming it would reduce regulations and lower energy costs. However, opponents of the decision, including Arizona Attorney General Kris Mayes, argue that it prioritizes the fossil fuel industry's profits over public health and environmental protections.

"On the day we file this lawsuit, much of Arizona is under an extreme heat warning due to an unprecedented early heat wave that has spiked temperatures over 20 degrees above normal," Mayes stated, emphasizing the real-world impacts of climate change on Arizonans. The attorney general highlighted that hundreds of residents die each year due to heat exposure, which is exacerbated by carbon pollution.

The coalition, which includes attorneys general from states such as California, New Mexico, and New York, argues that the EPA's rollback is not just a regulatory change but an illegal action that violates established scientific consensus and Supreme Court precedent. Massachusetts Attorney General Andrea Joy Campbell, who is leading the lawsuit, stated, "Climate change is real, and it's already affecting our residents and our economy." She emphasized the need for the federal government to adhere to legal and scientific obligations to protect public health.

Critics of the EPA's actions, including environmental advocates, express fears that the rollback will have disastrous consequences for vulnerable populations, particularly in states like Arizona that are already experiencing extreme weather events. Pita Juarez, an Arizona field organizer for Moms Clean Air Force, described the decision as "reckless," warning that it will have devastating consequences for future generations.

The implications of rescinding the Endangerment Finding extend beyond public health, potentially disrupting the regulatory landscape established over the past 15 years. The EPA's decision to eliminate existing and future federal greenhouse gas standards for vehicles may lead to significant increases in greenhouse gas emissions, which could result in severe economic and environmental repercussions.

As the lawsuit progresses, Arizona's legal team is considering various strategies to challenge the federal government's decision. Kirsten Engel, chief of the environmental protection unit in the Arizona Attorney General's Office, indicated that all options are on the table to respond to the EPA's actions. Meanwhile, the state is grappling with the immediate effects of climate change, as rising temperatures pose serious risks to outdoor laborers and agricultural workers.

In response to the ongoing climate crisis, Arizona continues to seek measures to protect its residents and address the impacts of extreme heat. The state's Workplace Heat Safety Task Force has recommended guidelines for employers to ensure worker safety during high temperatures. However, critics argue that these guidelines lack necessary enforcement mechanisms to ensure compliance, raising concerns about worker protections amid escalating climate threats.

The multi-state lawsuit against the EPA signifies a critical moment in the ongoing battle over climate policy in the United States. As states like Arizona take a stand against the rollback of vital regulations, the outcome of this legal challenge could have far-reaching implications for environmental protections and public health in the face of climate change.

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