The rules, bemoaned by auto manufacturers, would have reduced carbon dioxide emissions by 540 million metric tons.

gas pump

As expected, EPA Administrator Scott Pruitt on Monday announced plans to “revise” President Obama’s signature fuel-economy rules for cars and trucks, which would have reduced carbon dioxide emissions by 540 million metric tons and reduced oil consumption by 1.2 billion barrels. The rules governed cars and light trucks released during the 2022-2025 model years and would have increased their required fuel economy to more than 50 miles per gallon.

In a press release — which was not posted to the EPA website as of press time and was only distributed to certain members of the media — Pruitt called President Obama’s rules “inappropriate.” Several automakers had vocally opposed the rules, as did Alliance of Automobile Manufacturers, an industry trade group.

Science and environmental groups were quick to blast Pruitt’s plan. “This decision is not based on science,” wrote Dave Cook, senior vehicles analyst with the Union of Concerned Scientists. Pruitt, he wrote, “is overturning thousands of pages of hard evidence, and the consequences will be limiting consumer choice, increasing emissions and undercutting the economy.”

Even EPA officials criticized this week’s action, saying it diminishes the role of science at the agency. “I am concerned that those who provide the technical basis for Administrator Pruitt’s regulatory decision will be ignored or dismissed, and that sound science and engineering may be reassigned to another government agency that lacks the technical expertise,” AFGE Local 3907 President Mark Coryell said in a prepared release. The union represents members who work at the EPA’s National Vehicle and Fuel Emissions Laboratory.

What comes next? The Obama-era emissions standards were part of an agreement with the state of California, which has set its own clean-air and fuel-emission standards higher than the federal government’s. California officials, anticipating this week’s decision, have already been hinting at a legal fight to maintain the standards. New York, meanwhile, could join the fray, as state Attorney General Eric T. Schneiderman today called Pruitt’s actions “illegal,” adding “we stand ready to take legal action to block the Trump administration’s reckless and illegal efforts to reverse these critical standards and the gains we’ve made in ensuring cars are more fuel-efficient and less polluting.”

John R. Platt

is the editor of The Revelator. An award-winning environmental journalist, his work has appeared in Scientific American, Audubon, Motherboard, and numerous other magazines and publications. His “Extinction Countdown” column has run continuously since 2004 and has covered news and science related to more than 1,000 endangered species. He is a member of the Society of Environmental Journalists and the National Association of Science Writers. John lives on the outskirts of Portland, Ore., where he finds himself surrounded by animals and cartoonists.