Expert Voices

Rolling back emissions standards, EPA threatens state leadership on climate

Traffic backs up on an exit from Highway 101 on May 1, 2018, in Larkspur, California.
Highway 101 in Larkspur, California. Photo: Justin Sullivan via Getty Images

On April 2, the EPA issued its final determination to roll back the federal greenhouse gas (GHG) vehicle emissions standards, one of the most effective policies for reducing carbon pollution. The Obama administration enacted the policy with auto industry support in 2009, but the EPA has now called the standards for model years 2022–2025 “not appropriate."

Why it matters: The Trump administration may freeze air pollution standards at 2020 levels and limit states’ authority to enforce more stringent ones, sparking a familiar legal battle with leading states and making it more difficult for them to meet pollution reduction goals.