The administration billed the rollback it announced on Thursday, which would also revoke California's authority to set its own strict vehicle emissions rules, as a way to lower auto prices for consumers.
The administration also projects the efficiency rules would drive up the price of cars enough to push some buyers out of the market, leaving them to remain in older vehicles lacking life-saving new technologies like assisted braking and blind spot warning.
"They imply they're going to save people a whole lot of money", Alson told ABC News.
Israeli airforce targets militants in Syrian-held Golan Heights
The Syrian civil war erupted in 2011 and Russian intervention in 2015 helped to turn the tide in Assad's favor. The incident took place on the southern Golan Heights, near the triangle of Syria, Jordan and Israel borders.
California Attorney General Xavier Becerra said on Twitter that "The #Trump Administration has launched a brazen attack, no matter how it is cloaked, on our nation's #CleanCarStandards". "In short, the agencies propose to maintain one national standard - a standard that is set exclusively by the Federal government". California and other states are already suing the EPA.
And while automakers initially asked the Trump administration to loosen fuel economy requirements, this impending legal battle is one they would rather avoid.
California is expected to challenge the withdrawal of the waiver in court. The timeline could then align with the finalization of the fuel efficiency changes, as the proposed rule still needs to work its way through a lengthy public comment process.
What did the White House say?
Fred Krupp, president of the Environmental Defense Fund, called the proposed rule "a massive pileup of bad ideas" that would increase pollution and raise fuel costs for consumers. Under the Obama plan, the fleetwide fuel economy would have risen gradually to roughly 47 mpg by 2025.
White House officials: Russian election meddling is happening again
But Nielsen said US agencies have "seen a willingness and a capability on the part of the Russians" to attack USA election infrastructure.
The proposal itself estimates it could cost tens of thousands of jobs - auto workers who deal with making vehicles more fuel efficient.
It's costly for companies to design and build vehicles for California and states that follow its rules, and a different set for the rest of the country. The new proposal would freeze standards at 2020 levels.
"It means that the federal government will have slightly less control over the kinds of cars and trucks people can buy", Ebell said. It might even cause vehicle prices to stop increasing so rapidly. As a result, the age of the average auto in America is now nearly 12 years old, the highest in US history, according to IHS Markit.
Chart showing EPA fuel-efficiency targets.
"There are compelling reasons for a new rulemaking on fuel economy standards for 2021-2026", said Transportation Secretary Elaine L. Chao.
Trump chief of staff says he will stay at Trump's request
"I am pleased to inform you that I have just named General/Secretary John F Kelly as White House Chief of Staff". Every few months, reports re-emerge about Kelly's dissatisfaction with his job and potential resignation.
Pollution from cars, trucks and other on-road vehicles is the California's single-largest source of greenhouse gas emissions, according to state data. In 1989, aHarvard-Brookings study estimated that the modest 27.5 mile-per-gallon requirement at the time caused a 14 to 27 percent increase in traffic deaths because carmakers downsized vehicles. Adopting these new rules instead of the 2012 figures would have only a minimal effect on global temperature increases by the year 2100 - just three one-thousandths of a degree Celsius - the proposal claims.