Over the past eight years, the Environmental Protection Agency has become the main US agency in charge of tackling climate change, issuing a slew of regulations to curtail emissions of carbon dioxide — a key greenhouse gas heating up the planet.
So it’s a big deal that Scott Pruitt, President Trump’s new EPA head, now openly dismisses basic climate science. On CNBC last week, Pruitt said: "I think that measuring with precision human activity on the climate is something very challenging to do, and there's tremendous disagreement about the degree of impact, so no, I would not agree that [carbon dioxide is] a primary contributor to the global warming that we see.” (This is wrong: there’s ample evidence that human CO2 emissions are a primary contributor.)
Pruitt’s comments, while stunning, weren’t totally unexpected. He’s been hinting for a while now that he doesn’t think global warming is a problem and plans to roll back as many Obama-era EPA climate policies as possible. But in light of this CNBC interview, it’s worth rehashing what he can — and can’t — do to put these views into practice:
1) The EPA is still required to regulate CO2 — and Pruitt can’t easily undo that
The Clean Air Act, largely written by Congress in the 1970s, requires the EPA to regulate air pollutants that threaten public health or welfare. While lawmakers didn’t have climate change in mind when they drafted the law, they defined “air pollutant” broadly, so that the law could accommodate new environmental threats over time.
In 2007, the Supreme Court ruled that the law’s “capacious definition” could apply to greenhouse gases like carbon dioxide too, assuming there was evidence that these gases endangered public health or welfare. In response, the EPA in 2009 issued what’s known as the “endangerment finding,” a formal review of the hundreds and hundreds of scientific studies showing that rising greenhouse gas emissions would cause deadly heat waves, raise sea levels, hurt agriculture, and more.
With that finding in place, the EPA was now legally obligated to regulate CO2 through various Clean Air Act programs (though it had some discretion on how). Obama’s EPA began by setting ambitious new fuel economy standards for cars and light trucks. Then it issued CO2 standards for new power plants, making it impossible to build coal plants that don’t bury their emissions underground. Then it crafted the Clean Power Plan to regulate CO2 from existing plants. Then came fuel efficiency standards for heavy-duty trucks, regulations around methane emissions from oil and gas operations, and more.
These rules would all vanish if the EPA ever revoked its endangerment finding. And, given Pruitt’s comments on CNBC, he’d no doubt prefer this outcome. The hitch is that this is very, very, very difficult to do.
To overturn the endangerment finding, Pruitt would need to go through a formal rulemaking process, crafting a fresh analysis showing that CO2 isn’t a threat after all — and explaining in persuasive detail why the EPA’s previous analysis was wrong. He’d need to solicit public comment and prove to the courts that this new finding is on solid factual ground. And, seeing as how virtually the entire scientific establishment disagrees with Pruitt’s views on CO2, this would be an extraordinarily tough sell.
“[The endangerment finding] has a voluminous scientific foundation behind it,” Jody Freeman, a Harvard law school professor and former climate adviser to Obama, told me earlier this year. “The Trump administration couldn’t just come in and say nope, no more endangerment! There’s almost no chance that would be upheld, because you cannot ignore this record.”
Indeed, Pruitt’s comments on CNBC might even hurt any effort at repeal. Opponents could point to them in court as evidence that EPA’s new conclusion was being driven by the administrator’s unfounded views on science rather than careful analysis. “The comment could come to haunt Administrator Pruitt in court in the same way that the ‘Muslim ban’ comment has haunted President Trump in recent rulings,” says Richard Revesz, a law professor at New York University.
It would also be difficult for Pruitt to convince EPA’s career scientists to rewrite the finding — after all, many of them crafted the original version. “I think that would be a management challenge,” Jeffrey Holmstead, a top EPA official in the George W. Bush administration, told me recently. “You would be asking people to do something that is objectionable to them, that is inconsistent with their view on their science. I don’t want to say it’s impossible, but it’s a lot harder than saying we want to move in a new policy direction.”
Some conservatives want Pruitt to try to attack the endangerment finding anyway. But Pruitt himself has sounded reluctant at times to take on this uphill battle. During his Senate confirmation hearing, he acknowledged that the endangerment finding was “the law of the land” and that “there is nothing that I know that will cause a review at this point.”
So unless Congress wants to rewrite the Clean Air Act — a move that would face a potential filibuster in the Senate — the EPA will likely preserve its authority to regulate CO2, no matter what Pruitt says on television. The real question is whether Pruitt can revise the actual policies this authority has wrought.
2) But Pruitt can still try to scale back specific Obama policies — like the Clean Power Plan or vehicle rules
Even if the EPA is broadly required to regulate CO2, the law offers a fair bit of flexibility in how the agency actually does it. So if Pruitt wants to pare back some of Obama’s climate policies, he can — though he’s still relatively constrained by the law.
For instance, under Section 202 of the Clean Air Act, the EPA is required to regulate greenhouse gases from new motor vehicles (so long as there’s evidence that they endanger public health). But the law doesn’t say precisely how — only that the EPA has to pursue the “greatest degree of emission reductions achievable” while weighing cost, available technologies, and safety.
Obama’s EPA used this language to propose ambitious fuel economy standards for new cars and light trucks — by 2025, new passenger vehicles would average about 36 miles per gallon on the road, up from 25 mpg today. But these standards haven’t yet been finalized for the 2022-’25 period, and Pruitt reportedly plans to reconsider them and presumably weaken them. While he obviously couldn’t just abolish the standards entirely, there’s a fair bit of leeway to make them less stringent, as long as he justifies the changes in court.
The same goes for Obama’s Clean Power Plan, which aims to reduce CO2 emissions from existing power plants 32 percent below 2005 levels by 2030. Trump has long promised to roll back this policy, and Pruitt has a few options for doing so. He could try to argue that the EPA has no authority to regulate CO2 from existing power plants because it already regulates mercury emissions from those same plants. (This argument would solely apply to existing power plants, not other sources, and it’s legally risky.) Or Pruitt’s EPA could try to revamp the Clean Power Plan to make it much narrower and require utilities to do far less.
Many legal observers think this is Pruitt’s most likely strategy: He won’t question that the EPA can regulate CO2. He’ll just argue that Obama’s specific rules were much too aggressive and need to be scaled back. And while this isn’t easy — he still has to follow careful legal procedure and may get thwarted by legal challenges — the Clean Air Act offers him more room to maneuver here.
3) Pruitt could also delay any new climate rules indefinitely
In theory, the EPA is supposed to do a lot more to regulate CO2 than it’s already doing. The Clean Air Act obliges the agency to regulate air pollutants from other major sectors as well: chemical plants, cement plants, refineries, airplanes, and so on. And, as we’ve seen, this now applies to greenhouse gases too.
But there’s not really a hard timetable for issuing new climate rules for these sectors, and Pruitt will likely want to delay any action here indefinitely. And, legal experts say, he’ll have some latitude to do so.
Here’s one relevant precedent: Back in 2010, environmental groups sued Obama’s EPA for not regulating methane emissions from underground coal mines, as it’s in principle now supposed to do under the Clean Air Act. In response, the agency said it was looking into the issue but simply didn’t have the resources to craft new regulations on every single sector at once. And the DC Circuit Court ultimately sided with the EPA, deferring to the agency’s explanation of how best to allocate scarce resources.
Holmstead suspects that Pruitt’s EPA will take a similar tack. “If the EPA has a duty to regulate but no clear deadlines, then courts have typically been reluctant to overrule EPA’s explanation of what priorities they pursue.” So Pruitt might argue that his agency is consumed with other business and simply doesn’t have the bandwidth to issue new climate rules right now.
4) A new president could take the EPA in a different direction on climate
One final point here is that Pruitt’s influence over the EPA’s climate policy could well prove temporary. So long as the agency maintains its authority to regulate greenhouse gases, a new president could come in after Trump and pursue much more ambitious climate policies. That’s what happens when climate policy is left largely in the hands of the EPA — it can change with the whims of the executive branch.
So, for instance, a new president in 2020 or 2024 might try to pursue more stringent fuel economy standards for the post-2025 period; a newer, stronger version of the Clean Power Plan; and additional rules on refineries, industrial plants, and more. The biggest obstacles here will likely be the courts, which will presumably be far more skeptical of climate action after four to eight years of Trump appointments.
In the end, Pruitt’s biggest impact might be in delaying aggressive climate action at a time when there’s already so little room left to avoid drastic temperature increases. He seems confident this is nothing to fret about. The rest of the world, not so much.