Last month, the Environmental Protection Agency carried out one of its biggest climate-related reversals, a move guaranteed to be challenged in court. That lawsuit has finally dropped.

On his first day back at the White House, President Donald Trump vowed to roll back “burdensome and ideologically motivated” energy-related regulations. Since then, agencies have wiped out numerous rules, including California’s stricter vehicle-emission regulations.

Perhaps the most sweeping action taken by any agency is EPA’s decision to withdraw a foundational finding. That document, the 2009 endangerment finding, has served as the basis for some of the biggest vehicle emission regulations over the past 15 years.

Created by the EPA per a Supreme Court order, the endangerment finding determined that greenhouse gases pose a danger to public health and welfare. It is the legal basis for regulating greenhouse gas emissions from vehicles. That includes the Phase 3 heavy-duty trucks rule, which requires that 25% of sleeper-cab tractors be zero-direct-emission vehicles by 2032.

Without the endangerment finding, the federal government cannot regulate greenhouse gas emission from vehicles.

Trucking stakeholders applauded EPA’s decision to rescind it. The Owner-Operator Independent Drivers Association said it would put trucking “back on track.”

“Small-business truckers make up 96% of trucking and could be regulated out of existence if the current standards were to be implemented,” OOIDA President Todd Spencer said. “Mom-and-pop trucking businesses would be suffocated by the sheer cost and operational challenges of effectively mandating zero-emission trucks. Vehicle reliability and affordability are top priorities for OOIDA members, and we have yet to see proof that electric commercial motor vehicles are a practical option for most trucking businesses considering the price tag and lack of charging infrastructure. We commend EPA Administrator Zeldin on his realistic approach to emissions regulations.”

Opposition to rescinding the endangerment was loud. The proposed rule received more than 570,000 comments, most of which were opposed. Legal challenges were inevitable.

On Thursday, March 19, a coalition of states, counties and cities filed a petition for review, asking the District of Columbia Circuit Court to determine whether rescinding the endangerment finding was unlawful.

Led by Massachusetts, the challenge is joined by 24 states and 10 cities and counties.

“Climate change is real, and it’s already affecting our residents and our economy,” Massachusetts Attorney General Andrea Joy Campbell said. “When the federal government abandons the law and the science, everyday people suffer the consequences. As a mom, I want my boys – and every child in our state – to grow up breathing clean air and playing safely outdoors. Massachusetts has long led the way in protecting our communities from the dangers of greenhouse gas emissions and we are proud to stand up once again to lead this fight for our future.”

This marks at least the second challenge to the endangerment finding. On the day the final rule was published, more than a dozen health and environmental groups filed a petition. The two petitions are expected to be consolidated.

Truck OEMs staying the course

In the meantime, truck manufacturers have told Land Line that withdrawing the endangerment finding will not significantly alter their plans.

Paccar told Land Line that the new policy will not affect its operations “because we have a strong economic incentive to continuously improve the fuel efficiency of our trucks.”

Daimler Trucks North America said it appreciates the added flexibility. However, the new rule does not change the EPA’s 2027 NOx standards, which is what DTNA’s engine development is based on. The manufacturer does not expect legal challenges around the endangerment finding to change anything.

“As the NOx rule remains unchanged, manufacturers have to stay on track for 2027,” DTNA told Land Line. “Legal challenges around the GHG decision may take years to resolve. For us, the priority is providing customers with a product that meets the customers’ business and operational needs.”

While Volvo did not comment on the endangerment finding specifically, the truck maker told Land Line it remains committed to improving fuel efficiency.

“Regardless of regulation, improving fuel efficiency is a powerful way to deliver both customer value and reduced greenhouse gas emissions,” Volvo said. “Our new highway vehicles are the most efficient we’ve ever produced, and we’re committed to continuing our leadership in this area to benefit our customers’ bottom lines and the environment.” LL