On the Dash:
- Regulatory uncertainty around emissions standards may continue as legal challenges progress.
- Policy shifts have already accelerated automaker focus on gas-powered vehicles over EVs.
- Future administrations’ ability to regulate vehicle emissions could be significantly affected.
Michigan has joined a coalition of 24 states in suing the Trump administration over its decision to revoke the legal foundation of major U.S. climate regulations, including greenhouse gas rules governing the auto industry. The lawsuit, filed Thursday in the U.S. Court of Appeals for the D.C. Circuit, also includes 10 cities and counties, none of which are based in Michigan.
At the center of the challenge is the 2009 endangerment finding, established under former President Barack Obama, which enabled the Environmental Protection Agency to regulate emissions from motor vehicles and power plants. The EPA finalized a rule in February repealing that finding, effectively eliminating existing federal regulations on climate pollutants from vehicles. President Donald Trump described the action as “the single largest deregulatory action in American history.”
Michigan Attorney General Dana Nessel criticized the move, stating the rescission “poses an immediate danger to Michigan’s environment and economy.” She pointed to impacts such as wildfire smoke, disruptions to winter tourism, and challenges for farmers who depend on stable seasonal conditions. Nessel said she is challenging the repeal to ensure the EPA fulfills its responsibility to protect public health.
The outcome of the lawsuit is not expected to immediately alter current federal policy but could shape how future administrations regulate vehicle emissions. The policy shift has already influenced automakers, with the Detroit Three reallocating resources away from plug-in vehicles toward gas-powered models, which remain more profitable in the U.S. market.
The EPA defended its decision, citing legal analysis following recent Supreme Court rulings, including Loper Bright Enterprises v. Raimondo and West Virginia v. EPA, and arguing that the Clean Air Act does not authorize regulation of vehicle emissions for global climate change purposes.
The lawsuit follows two similar legal challenges filed Feb. 18 by environmental, health and youth advocacy groups.



