Scott Pruitt, Administrator for the Environmental Protection Agency (EPA), announced today that he had made a "final determination" to revise current vehicle emissions standards for model year 2022-2025 vehicles. Pruitt did not specify any new standards at this time; instead, he stated that he would start a joint rulemaking process with the National Highway Traffic Safety Administration (NHTSA), which manages a parallel set of rules called the Corporate Average Fuel Economy (or CAFE) standards.

The current emissions standards were approved by the Obama-era EPA in December 2016 , two years ahead of time and just before the Trump administration took office. The standards had been years in the making, requiring research and discussions between policymakers and auto industry representatives. But at the change of leadership, the auto industry seized on an opportunity to roll back regulations that would cost it money. The industry also appealed to Trump to limit greenhouse gas (GHG) emission standards. Pruitt opened a public-comment period on revising the emissions standards last summer

The stricter rules would have been beneficial from a climate change perspective. According to the Energy Information Agency, keeping the EPA's fuel economy rules in place would have resulted in 1.2 million fewer barrels of gasoline consumed per day in 2025 than in 2017. Without knowing how Pruitt will revise the emissions standards, it's unclear how his plan will compare to the previous one, but it will likely result in fewer barrels of gasoline saved per day.

There's also the issue of cost: Obama's EPA determined that car buyers would save money over the life of their cars because they would need to purchase less fuel to operate the cars. Trump's EPA says that the regulations would make it more expensive for automakers to build emissions-compliant cars and that the price would get passed on to consumers. Rescinding the regulations, the administration figured, would keep the initial cost of a car down.

Still, according to the the International Council on Clean Transportation (ICCT), the cost of implementing the emissions has been overstated, in some cases by as much as 40 percent, given how quickly the costs of efficient engines, transmissions, accessories, and tires have come down.

Although auto manufacturers have resisted EPA standards that would push the theoretical miles-per-gallon rate above 50, their suppliers are not quite so keen to let go of an opportunity to sell new parts and technology. The Motor and Equipment Manufacturers Association said in a statement: "Our goal is to ensure that the US is a leader in technologies that meet light-duty fuel economy and emission standards here and around the globe while providing affordable vehicles to the consumer.”

The Auto Alliance, whose members include Ford, GM, FCA, Mazda, Toyota, and Volvo, among others, applauded Pruitt's announcement and said "This was the right decision, and we support the administration for pursuing a data-driven effort and a single national program as it works to finalize future standards. We appreciate that the administration is working to find a way to both increase fuel economy standards and keep new vehicles affordable to more Americans."

California in the crosshairs

Interestingly, Pruitt's announcement also called out California, which has enjoyed a waiver allowing it to set its own emissions standards through the California Air Resources Board (CARB) since the 1960s when the state experienced dramatic smog levels. CARB has been able to set emissions standards stricter than the EPA's, and the EPA's press release today mentioned that the state's waiver "is still being reexamined by EPA under Administrator Pruitt's leadership."

In a statement, Pruitt claimed: "Cooperative federalism doesn't mean that one state can dictate standards for the rest of the country... It is in America's best interest to have a national standard, and we look forward to partnering with all states, including California, as we work to finalize that standard."

California Air Resources Board Chair Mary D. Nichols responded with a statement of her own, saying, "This is a politically motivated effort to weaken clean-vehicle standards with no documentation, evidence, or law to back up that decision. This is not a technical assessment; it is a move to demolish the nation's clean-car program. EPA's action, if implemented, will worsen people's health with degraded air quality and undermine regulatory certainty for automakers."

Nichols added, "California will not weaken its nationally accepted clean-car standards, and automakers will continue to meet those higher standards, bringing better gas mileage and less pollution for everyone.”