Two years ago, at an event convened by the conservative Federalist Society, Oklahoma Attorney General Scott Pruitt joked about a competition of sorts he had going with the Texas attorney general over the Environmental Protection Agency.

“When I came into office, I think he had roughly 13 lawsuits against the EPA,” Pruitt told the audience. “I’m trying to catch up — we only have, I think, six or seven.”

Pruitt indeed spent much of his tenure as state attorney general attacking the federal agency he now is nominated to head, going so far as to describe himself as “a leading advocate against the EPA’s activist agenda.” Along the way, he spearheaded a coalition of state attorneys general in their legal challenge to EPA’s Clean Power Plan, Obama’s key policy aimed at reducing U.S. greenhouse gas emissions from the electricity sector. He also sued over the EPA’s attempts to curtail the emissions of methane, a powerful greenhouse gas, from the oil and gas sector.

But should the 48-year-old lawyer end up at the helm of the EPA, he is likely to find himself on the receiving end of a cascade of litigation from environmental and public health groups intent on protecting Obama-era antipollution measures and ensuring that the agency lives up to its mission of safeguarding the air Americans breathe and the water they drink.

“We definitely plan to fight any rollback or any attacks on our bedrock environmental laws. We think that the courts will be the last line of defense if advocacy doesn’t work,” said Lisa Garcia, vice president of litigation for Earthjustice, which employs more than 100 lawyers across the country.

Though President-elect Donald Trump and Pruitt are intent on pulling back the EPA’s authority and putting more power in the hands of states, Garcia noted that key environmental laws such as the Clean Air Act and Clean Water Act were passed with bipartisan support and require the agency to enforce violations that put Americans at risk.

“We’re ready to make sure these laws are adhered to and that the EPA follows its obligations and its mission,” she said. “We’re ready for that fight.”

Pruitt himself seems prepared for just such a fight.

“The greatest opportunity that we have heading into this new administration…is to provide certainty to business industries across this country,” he said in an interview last month with radio host John Catsimatidis. “When you look at the EPA, and the role that it’s played over the last several years, there’s going to be substantial change in that agency. There’s going to be a regulatory rollback.”

When it comes to reversing the Obama administration’s environmental policies and substantially altering the EPA’s reach, Pruitt “can do a fair amount,” said Tom McGarity, a law professor at the University of Texas at Austin who focuses on environmental and regulatory law. “He will be moving against institutional inertia, no question about that, but the civil servants in EPA are going to try to do what the boss tells them to do.”

A key factor will be whether Pruitt appoints high-level staff who know the agency well and are able to get his mandates carried out. But, McGarity added, he will be less successful if he fails to change the institution from within and merely attacks it — as he has done during his tenure in Oklahoma. A case in point: Ronald Reagan’s controversial EPA administrator during his first term.

“The last time we had somebody who really came in with a mandate to turn things around was . . . Anne Gorsuch, and she really wasn’t able to do it because she was fairly arrogant about it,” McGarity said. “She made some very bad appointments and, ultimately, wound up in a lot of scandal.”

David Doniger, a lawyer at the Natural Resources Defense Council, said that while Pruitt’s appointment puts the environmental community very much on the defensive, the detailed nature of the process that the EPA must follow to create new regulations, or reverse existing ones, makes it difficult to roll back much of what the Obama administration has done. It also provides opportunities for green groups to resist in the courts.

“We are going to be vigilant about making sure that every step in the administrative process is respected, and if they try to shortcut things — by suspending regulations, suspending public health safeguards without due process — we will take them to court right away,” Doniger said.

Before Pruitt can set about the work of scaling back both the EPA and Obama environmental regulations that he has called harmful to U.S. businesses, he first has to get through the Senate confirmation process. While the Republican majority probably will assure his confirmation, he’s certain to face criticism and harsh questioning from Democratic lawmakers, who have denounced him as a mouthpiece of the fossil fuel industry and yet another potential Trump Cabinet member who has questioned the scientific consensus around climate change.

“This is a full-fledged environmental emergency,” Sen. Brian Schatz (D-Hawaii) said on a call with reporters Thursday. Schatz pledged a pitched confirmation fight and promised that colleagues who support Pruitt will have to explain themselves when it comes to the science of climate change. “This is going to be a litmus test for every member of the Senate who claims not to be a denier.”

Of course, those who share Pruitt’s long-held views about federal government overreach have welcomed his appointment.

Sen. James M. Inhofe, the Oklahoma Republican who has long cast doubt on climate-change science, wrote on Facebook that Pruitt “has demonstrated that he is an expert on environmental laws and a champion of states’ roles in implementing those laws.” Greg Abbott, former Texas attorney general and now the governor, tweeted that “Pruitt is excellent choice for EPA. He & I teamed up on many lawsuits against the EPA. He’ll bring needed change.”

On that spring day in 2014, Pruitt himself made no secret of his disdain for the EPA’s approach to regulation.

“This dictatorial attitude, that says so long as you agree with us then everything is kosher and everything is okay, is exactly the opposite of what Congress has said repeatedly [is] the role of the states,” he said. “The states have a meaningful role. It’s not an administrative role. The states are not a vessel to carry out the desires of EPA. The states are actually there to make important decisions, balancing factors between industry and consumers and meeting the obligations of air and water quality in their respective states.”

Read more at Energy & Environment:

Yes, Trump met with Al Gore. But his transition tells a very different climate change story

It’s likely Earth’s hottest year on record — and some people are already talking about global cooling

Indonesia just made a huge move to protect the climate

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