State officials filed a strongly worded declaration challenging the Trump administration’s efforts to roll back greenhouse-gas and mileage standards that were imposed during the Obama presidency.

“We oppose any weakening, for any model year,” read the statement submitted with federal officials by the California Attorney General’s Office and the California Air Resources Board.

The state’s filing, submitted to the U.S. Environmental Protection Agency and the National Highway Traffic Safety Administration, represents the latest chapter in a battle that has been escalating for months. The Trump administration, responding to pleas from the automobile industry, said it would reconsider standards requiring that new cars sold between 2021 and 2025 reduce greenhouse gas emissions by about one-third. Those same rules would raise average fuel mileage by roughly 40 percent, to 50.8 miles per gallon by 2025.

“We are going to ensure that any regulations we have protect and defend your jobs, your factories, we’re going to be fair,” Trump said in March at a rally of autoworkers in Ypsilanti, Mich.

California officials said relaxing the standards would worsen climate change and cited “the latest scientific analyses” suggesting that global warming worsened the effects of Hurricanes Harvey, Irma and Maria.

“We cannot allow this to happen. The need is too great,” read the state’s filing, authored by Air Resources Board Executive Officer Richard Corey and David Zonana, supervising deputy attorney general.

Ordinarily, mileage and pollution standards are set by the federal government. But California has a good deal of muscle in how the rules are made. The federal Clean Air Act allows the state to impose rules that are stronger than the federal government’s, if California can get permission from the U.S. EPA. The law also allows other states to adopt California’s rules as their own.

The fight between California and Trump has put automakers in an awkward spot. While they favor easier restrictions on mileage and carbon, they don’t want to wind up building cars to two sets of standards: one for California and the 12 other states that adopted California’s stance on greenhouse gases, and one for every other state. That would be prohibitively expensive.

“Harmonization between the federal and California programs must be maintained,” the Association of Global Automakers said in its filing this week with the EPA and the highway safety agency.

President Donald Trump meets with EPA Administrator Scott Pruitt, Michigan Gov. Rick Snyder and General Motors CEO Mary Barra after announcing in March he would consider relaxing rules on tailpipe greenhouse gas emissions. California is resisting those efforts.
President Donald Trump meets with EPA Administrator Scott Pruitt, Michigan Gov. Rick Snyder and General Motors CEO Mary Barra after announcing in March he would consider relaxing rules on tailpipe greenhouse gas emissions. California is resisting those efforts. Evan Vucci Associated Press file
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