The EPA’s Final Auto Emission Rules Are Out

The Biden administration announced final new emissions standards for cars on Wednesday, significantly curtailing both the carbon dioxide and the toxic soot and chemicals that spew from the tailpipes of the nation’s light- and medium-duty vehicles.

With that, Biden is checking off one of the two most important pieces of unfinished climate business he has left on his first term to-do list. The rules tighten pollution limits gradually over six years, beginning in 2027. In concert with other Biden policies including consumer tax credits for electric vehicles purchases, initiatives to build out charging infrastructure, and support for domestic manufacturing, the standards will help accelerate the transition to electric vehicles that is already well underway.

Transportation is responsible for more planet-warming emissions than any other part of the U.S. economy. To get the country on the path of reaching net zero emissions by 2050, as Biden has set out to do, curbing car emissions is unavoidable.

When the rules were originally proposed last year, we wrote that they would “roughly halve carbon pollution from America’s massive car and truck fleet, the world’s third largest, within a decade.” That’s still broadly the case, even though the final version features one big change: Automakers will now have more time to cut emissions from their fleets. They will still have to achieve the same standard in 2032 as what was originally proposed, but they can transition to it more slowly.

Ahead of the official release, senior administration officials downplayed the significance of the slower rollout. They argued that giving automakers, dealers, and labor unions more time in the near-term would make for a sturdier rule, and that the cumulative emissions benefits of the final standard converge with the original proposal. At a White House event on Wednesday, members of the president’s climate team built on that message, framing the new rules not as a government mandate but rather as a tool to give consumers more of what they already want. “We are witnessing a technological revolution driven by the markets,” Environmental Protection Agency administrator Michael Regan proclaimed.

Also speaking at the event was John Bozzella, head of the Alliance for Automotive Innovation, which represents most U.S. automakers, including the Big Three. Bozzella praised the administration for heeding the industry’s concerns over the original proposal’s rapid phase-in and said the new rules were “much improved” from what had initially been proposed. “Pace matters to automakers,” he said. “It certainly matters to consumers.”

The full rule was released mid-day Wednesday, and we’re digging through it to find out exactly what else has changed. But here’s what we know so far.

What do the rules say?

The rules strengthen greenhouse gas emission limits, in terms of grams of CO2 per mile, that automakers will have to adhere to, on average, across their product lines. They also tighten limits on dangerous pollutants, including particulate matter — the tiny bits that make up soot — and nitrogen oxides.

This chart shows how the cuts in the final rule compare to those proposed in the draft rule. The version released last April required automakers to make steeper reductions to carbon emissions in the first three years, while the final rule allows for a more gradual reduction.

Will the rules ban gas-powered cars?

No. They are what’s called technology-neutral standards, meaning that automakers have options for how to comply with them. Since automakers have to meet the emissions targets on average across their fleets, rather than for each vehicle, it’s likely they’ll produce a range of options in 2032, including plug-in hybrids, regular hybrids, and even some gas cars with improved efficiency — though their fleets will probably have a much higher proportion of EVs than they do now.

While that generally hasn’t changed from the preliminary rule, the Biden administration’s messaging around it has.

When it released the initial proposal, the EPA emphasized that the least-cost path to achieving the standards would be for about two-thirds of new vehicles sold in 2032 to be electric. Although this was just one potential scenario, it was widely interpreted as a target or even a mandate — particularly by Biden’s political opponents .

On Tuesday, administration officials said that the two-thirds finding had been based on limited data. The EPA now estimates that EVs may make up anywhere between 30% and 56% of new light-duty sales from model years 2030 to 2032.

How much carbon pollution will the rules avoid?

By 2032, the light-duty fleet on offer from automakers will emit half as much carbon as vehicles on the market in 2026.

The EPA estimates that these rules will avoid 7.2 billion metric tons of carbon from 2027 to 2055, which accounts for the vehicles’ full lifetime on the road. That’s slightly less than the 7.3 billion metric tons the initial proposal would have avoided.

How will the rules affect new car-buyers?

The rules will change the mix of vehicles sold by automakers, encouraging dealers to sell more hybrid, plug-in hybrid, and battery electric vehicles. They’re also expected to save Americans roughly $62 billion in fuel costs and avoided maintenance costs, since the EPA assumes that EVs are still cheaper to operate and maintain. On average, a consumer will save about $6,000 over the lifetime of a 2032 vehicle compared to one sold in 2026, according to the agency.

The tailpipe rule will likely increase the cost of building each vehicle, which could translate into higher prices for consumers. However, state and federal tax incentives — as well as the cheaper cost of operating and fueling EVs — will offset that increase.

How will the rules affect people who don’t own a car — or who don’t plan to buy one soon?

The rules are projected to deliver major health and environmental benefits to the public. The EPA estimates they will produce $37 billion in benefits from improved public health and climate mitigation, including avoided hospitalizations and premature deaths.

This is what the EPA was created to do — use the best available science to protect human health and the environment. But even after decades of improvements in air quality, there is still a lot of room for improvement. More than one third of the population still live in places with unhealthy levels of ozone or particulate pollution, according to The American Lung Association’s most recent “ state of the air ” report. The risks are deeply unequal, with people of color making up half of those exposed. The report also noted that climate change is making it harder to protect people, as heat, drought, and wildfires increasingly lead to spikes in these pollutants. Altogether, ozone and particulate matter are responsible for more than 60,000 premature deaths annually, according to the Health Effects Institute , a nonprofit, independent research organization funded by the EPA and automakers.

How is the Biden administration selling the rule?

Officials stressed that EV sales are already shattering analyst predictions , prices are dropping, and product availability is growing. They see this rule as part of a larger ecosystem of policies — including those in the Inflation Reduction Act, the Bipartisan Infrastructure Law, and the CHIPS and Science Act — that are revitalizing American manufacturing and creating jobs while also contributing to the global fight against climate change. The EPA’s press release notes that companies have announced more than $160 billion in domestic clean vehicle manufacturing, and that the auto manufacturing sector as a whole has added more than 100,000 jobs since Biden took office.

The administration is also, perhaps less loudly, selling the pollution standards as a path to freedom from fossil fuels. During the press call Tuesday, a senior administration official said the rules would enable consumers to break loose from the oil industry’s grip on how we get around and how much it costs us.

What happens next?

The new rules kick in for cars in model year 2027, which will go on sale in 2026 and are being designed right now. Although the Biden administration has suggested that the new rules have won the support of the car industry — including automakers, labor unions, and dealerships — it could still face a court challenge from attorneys general in Republican-controlled states. Republican officials have repeatedly sued to block the Biden administration’s climate policies.

It’s unclear how the Supreme Court would respond to such a challenge. Although the Court has long backed the EPA’s ability to limit climate pollution from cars and trucks, its hard-right majority has recently rolled back what were once thought to be bedrock environmental laws. In this term alone, the Court seems likely to restrict the EPA’s ability to regulate toxic air pollution while sweeping away a central legal doctrine of environmental regulation.

Editor’s note: This story has been updated to reflect the White House event announcing the new rules.

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