EPA administrator Scott Pruitt said yesterday the agency plans to modify rules limiting carbon-dioxide emissions for light-duty vehicles in model years 2022 through 2025.

The agency, he said, had reached a determination that the limits put in place in 2012 under the Obama administration were “not appropriate and should be revised."

The standards it had set—agreed to in 2012 by virtually every automaker, the EPA and NHTSA, and the powerful California Air Resources Board—were "too high," he said.

DON'T MISS: EPA staffers told how to downplay climate change in leaked memo

Automakers had requested the standards be modified or delayed to account for increased sales of less-efficient utility vehicles and trucks, which continue to displace passenger cars in U.S. vehicle sales.

Pruitt gave no indication of what new rules would be proposed, saying only that the EPA (which issues rules on tailpipe emissions) will launch a new rulemaking process and work with the NHTSA (which regulates fuel economy) to develop a single set of national standards.

He was scheduled to do a public announcement Tuesday morning at Pohanka Chevrolet in Virginia, a dealership run by Geoff Pohanka, an outspoken climate-science denier who (until Tuesday evening) operated a website dedicated to the proposition that the earth is in fact cooling.

EPA administrator Scott Pruitt [photo from 2014]

EPA administrator Scott Pruitt [photo from 2014]

That event was abruptly canceled Monday, with varying reasons given.

Some reports indicated EPA staff were anxious about the possibility of protests, while The New York Times attributed the cancellation to pressure from Chevrolet dealers who didn't want their brand associated with the rollback.

The event was ultimately held at EPA headquarters in the Rachel Carson Green Room, ironically named after the famed environmental activist who drew attention to the damage wrought by the insecticide DDT.

CHECK OUT: EPA to ease emission limits, reports say, setting up clash with California

Pruitt took no questions from the press after he read his statement.

After going through more than a dozen news stories on the announcement, along with twice that number of press releases from activist groups on both sides, here's our summary of what we think you should know.

(1) Nothing has changed, yet.

All Pruitt has done so far is announced that the agency doesn't think its current standards are appropriate. That kicks off a lengthy and detailed process of investigation and rulemaking that will take quite some time.

The White House, Washington, D.C. [Creative Commons license by dcjohn]

The White House, Washington, D.C. [Creative Commons license by dcjohn]

Meanwhile, emission limits for the 2019, 2020, and 2021 model years continue unchanged. Automakers have already invested tens or hundreds of millions of dollars into vehicle designs, tooling, and equipment to meet those standards.

And even for the 2022-2025 standards, neither Pruitt nor Trump can get standards changed without going through hearings, rulemaking, public comment, and so forth.

As The New York Times noted in a late March news story on the EPA's anticipated revisions:

Even at the federal level, the president’s announcement alone will not be enough to immediately roll back emissions standards, a process expected to take more than a year of legal and regulatory reviews by the E.P.A. and the Transportation Department.

The Trump administration would then need to propose its own replacement fuel-economy standards.

Elaine Chao

Elaine Chao

(2) The EPA and NHTSA will work together to loosen and revise rules

President Trump appointed both EPA administrator Scott Pruitt and Secretary of Transportation Elaine Chao.

Chao and her staff are reported to be working with the EPA to ensure that corporate average fuel-economy rules for 2022-2025 light vehicles are loosened in concert with the EPA emission limits.

The two agencies have to coordinate their rulemaking because CO2 emitted is directly proportional to fuel consumed, so CAFE and emission limits must be aligned to avoid automakers having to deal with inconsistent rules applying to the same fuel use.

Chrome exhaust pipe

Chrome exhaust pipe

(3) No details of any proposed new rules have been released ...

It's noteworthy that while Pruitt said in several ways that he didn't like the current standards, he didn't say anything about what he proposed to replace them with.

Or even if he believes standards should continue to exist in any form.

As attorney general of Oklahoma, Pruitt sued the agency he now runs more than a dozen times (largely unsuccessfully) to prevent it from enforcing emission rules applying to the state's powerful fossil-fuel industry.

It's not outside the realm of possibility that instead of adjusting, delaying, or freezing the current standards, Pruitt could attempt to roll them back significantly or even do away with carbon-dioxide limits altogether.

While a Supreme Court decision more than 10 years ago ruled that the EPA not only could, but must, regulate CO2, Pruitt has denied, derided, and downplaying accepted climate science.

If the head of the agency charged with protecting the U.S. from pollution in our air, land, and water doesn't accept the court ruling that carbon dioxide is a pollutant, anything is possible.

GM Headquarters

GM Headquarters

(4) ... which makes car companies very nervous.

And that, as a more recent New York Times piece makes clear, makes car companies very nervous.

Automakers don't reject climate science, though they do want the linked emission and fuel-economy rules eased, delayed, and tweaked.

They fear that a wholesale abolition of emission standards, paired with NHTSA action to eliminate or severely roll back corporate average fuel-economy requirements, would generate enormously bad publicity that would land squarely at their doorstep.

Environmental protection, it turns out, polls really well pretty much across the board among U.S. voters—which is why Pruitt has started to pitch the idea of looser emission limits as a way to cut the costs of new vehicles.

(5) However, rule-making requires actual science.

The Environmental Protection Agency is required to base its regulatory proposals on scientific data.

While Pruitt and many of his appointees deny the accepted climate science or suggest mankind's role in global warming is up for debate, that point of view will undoubtedly be challenged if it creeps into the supporting documents for loosened standards.

Flooded car in parking lot. Photo via Flickr user waitscm/CC2.0

Flooded car in parking lot. Photo via Flickr user waitscm/CC2.0

The agency will also have to prove that the existing emissions regulations, which vary depending on vehicle footprint specifically to account for buyer shifts among segments, cannot be met at an acceptable cost by current and projected automotive technology.

In other words, the agency can't unilaterally change rules adopted through a science-based process: It has to prove its case.

(6) The changes will likely be justified on the grounds of affordability.

The concept of making vehicles more affordable for real American buyers has suddenly become an EPA talking point.

That talking point was echoed yesterday by Ford, the AAA, and the National Automobile Dealers Association, among other parties.

Chrome exhaust pipe

Chrome exhaust pipe

It seemed a curious argument to make on the same day as record auto sales were reported with the average transaction price per vehicle close to its all-time high: $35,825 last month, according to Kelley Blue Book.

Nonetheless, expect further headlines and statements from Trump administration officials about the need to permit higher emissions in future years than under the current rules so American families can continue to buy new cars.

A new vehicle today represents a higher proportion of the average U.S. income than it did in 1975, but that encompasses greater safety, higher performance, far more features, and generally larger, faster, and plusher vehicles. (They also last far longer and for more miles than they did in 1975.)

The cost of emission controls are likely just a small fraction of the price increase.

A variant of the affordability argument, by the way, is the one suggesting that pricier new cars keep higher-emitting old cars on the roads longer, which is bad for the environment.

We look forward to independent analyses of the data and the modeling that the agency will use to support the affordability assertions.

(7) Pruitt clearly wants to end the California waiver.

The EPA administrator has said numerous times that no one state should be allowed to set national policy, nor to hold the rest of the country hostage to its particular demands.

Environmentalists, industry analysts, and California officials all interpret those comments to indicate that Pruitt is preparing to attack the "California waiver," the latest in a series of waivers granted over 45 years to the state that pioneered clean-air legislation before the EPA even existed.

California Air Resources Board chair Mary Nichols (via Twitter)

California Air Resources Board chair Mary Nichols (via Twitter)

Last July, Pruitt told lawmakers at an EPA budget hearing, "Currently, the waiver is not under review."

Most observers suggest that is no longer the case.

(8) But California will fight back, aggressively.

The current governor of California, Jerry Brown, was the state's attorney general when it prevailed in court against a sustained attempt by the George W. Bush administration to rein in California and substitute lower fuel-economy standards.

On Monday, Brown called the EPA’s decision a “cynical and meretricious abuse of power [that] will poison our air and jeopardize the health of all Americans.”

At the end of February, the state's current attorney general, Xavier Becerra, called Pruitt's statement that the EPA does not intend to let California set the agenda for national emission limits on vehicles just "veiled threats" that were "par for the course" from the Trump Administration

Becerra underscored the need for a scientific basis to support any changes to emission rules, noting it is "pretty clear there is a lot of evidence behind the standards, and it would be tough to simply say you can roll them back."

The state's stricter standards have "proven effective," he noted, suggesting the state wants "to make sure we are making progress, not going backwards."

National Plug-In Day 2012: San Francisco, with 60 Nissan Leafs in front of the Golden Gate Bridge

National Plug-In Day 2012: San Francisco, with 60 Nissan Leafs in front of the Golden Gate Bridge

That translates to a declaration of war, meaning that whatever the EPA proposes, the state will fight aggressively to maintain the right to set its own standards.

If standards for California stay put while national rules loosen, that could require automakers to sell one mix of vehicles to a third of new-car buyers in more than a dozen states, and a different mix to the rest of the country.

That's what auto companies fear, which is why they are staying mum on the California waiver beyond anodyne statements to the effect that a single set of standards is a good thing.

Green Car Reports respectfully reminds its readers that the scientific validity of climate change is not a topic for debate in our comments. We ask that any comments by climate-change denialists be flagged for moderation. We also ask that political discussions be restricted to the topic of the article they follow. Thank you in advance for helping us keep our comments on topic, civil, respectful, family-friendly, and fact-based.