Heavy traffic moves along Interstate 395 in Washington, D.C. Transportation is the nation’s leading source of greenhouse gas emissions, and the District of Columbia and many states have adopted California’s strict rules to cut emissions. But President-elect Donald Trump is expected to challenge long-standing waivers that allow those states to exceed federal standards. (Drew Angerer/Getty Images)

By Alex Brown, on Newsfromthestates.com

Blue states are bracing for a battle with the Trump administration over their authority to limit tailpipe emissions, a showdown that will have major repercussions on the types of cars and trucks sold to American drivers.

All sides expect President-elect Donald Trump to try to revoke states’ authority to adopt California’s strict rules on the pollution spewed by vehicles.

Many states’ efforts to fight climate change hinge on a federal process that allows them to adopt stringent regulations for transportation, the country’s largest source of greenhouse gas emissions.

This long-standing waiver authority allows California — and the dozen or so states that follow its lead — to apply rules that go beyond federal limits and cover everything from specific pollutants to sales of certain vehicles. The states following the stricter California standards make up a significant portion of the U.S. auto market and exert major leverage over the cars that are offered to American consumers.

“It becomes a de facto national standard,” said Ethan Elkind, director of the climate program at the Center for Law, Energy & the Environment at the UC Berkeley School of Law. “The combined might of California and those other states is pretty significant.”

During his first term, Trump attempted to revoke California’s waiver authority, an action many states challenged as unlawful. The effort to deny the waivers was tied up in legal challenges until President Joe Biden took office. This time, Trump will have a “much more cohesive plan” to block state efforts to clean up their cars and trucks, Elkind said.

California is urging the U.S. Environmental Protection Agency to finalize several pending waivers before Trump returns to the White House. Officials in blue states are preparing to defend their authority in court should Trump seek to revoke the waivers. And attorneys general in some red states are pushing to end the waivers altogether — mounting a legal challenge to California’s power to set its own rules.

“Without [California’s waiver authority], we would probably be a decade or more behind where we are today in terms of the U.S. automotive market,” said Mary Nichols, former chair of the California Air Resources Board, the agency that issues the state’s auto regulations. “In terms of reaching our climate goals, it’s essential.”

Nichols now serves as the distinguished counsel for the Emmett Institute on Climate Change and the Environment at the UCLA School of Law.

State efforts

When Congress enacted federal air quality laws in the 1960s, it gave California the authority to go above and beyond national standards because it was the only state to already have passed its own auto emissions rules. The state’s geography, with mountains that trap harmful pollution in heavily populated areas, also contributed to California’s unique status. Over 50-plus years, the state has received more than 100 waivers from the feds covering everything from particulate matter to catalytic converters to “check engine” lights.

The EPA allows other states to adopt the regulations set by California. Seventeen other states and the District of Columbia have adopted some portion of California’s regulations — representing 40% of the light-duty vehicle market and more than 25% of the heavy-duty market.

“These waivers are a really important part of our strategy to reduce emissions in line with what climate science tells us what we need to do,” said Joel Creswell, climate pollution reduction program manager with the Washington State Department of Ecology. “They’re also really important for our air quality near road communities.”