By Barney Jopson in Washington

Dec. 7, 2016

Donald Trump has signalled his intent to undo Barack Obama’s efforts to curb climate change by choosing as his chief environmental regulator a conservative state law enforcer who is battling to overturn the president’s legacy.

Scott Pruitt, Oklahoma’s attorney-general, has been selected to lead the Environmental Protection Agency, as the president-elect turns to a man who, like himself, has questioned the science of climate change, the Trump team said.

If confirmed by the Senate he would be catapulted from the US’s oil-producing heartland to the centre of global policymaking on climate change, a position from which green groups worry he would wreck progress to stem carbon emissions.

Mr Pruitt, 48, has railed against the EPA for meddling in state affairs and played a leading role in a lawsuit that has frozen the centrepiece of Mr Obama’s climate policy pending a court judgment.

His nomination sparked a fierce reaction from the left. Senator Jeff Merkley said he would turn the EPA into the “Polluter Protection Agency” and Eric Schneiderman, New York attorney-general, called him a “dangerous and unqualified choice”.

The EPA has played a central role in devising Mr Obama’s Clean Power Plan rules to cut emissions from the power sector, which are the bedrock of the president’s commitments in the Paris climate accord.

Mr Trump has called global warming a “hoax” and threatened to ditch the Paris accord. His victory rocked international policymakers who have looked to the US for leadership on action against climate change.

Mr Pruitt’s confirmation would put him in an extraordinary position at the head of an agency whose modus operandi he has condemned, branding it a rogue operator that is overstepping its authority by bossing around states in an interview with the Financial Times last year.

“What we see with the current EPA approach is almost an attitude that the states are a mere vessel of federal will,” he said in 2015, explaining the motivation for the climate change lawsuit. “What the EPA is trying to achieve through regulatory rulemaking [is] unlawful.”

Environmental groups including the League of Conservation Voters condemned Mr Pruitt as a “climate denier” and ally of the oil industry, citing a 2014 New York Times report that said energy lobbyists had drafted letters for Mr Pruitt to send to the federal government on environmental issues.

Mr Pruitt’s re-election campaign in 2014 was chaired by Harold Hamm, the billionaire chief executive of shale producer Continental Resources and an energy adviser to Mr Trump.

In his 2015 interview with the FT, Mr Pruitt said he had been compelled to fight Mr Obama’s plans because they infringed on states’ rights as enshrined in the law, not because of any beliefs about climate change.

Humanity’s contribution to global warming was “subject to considerable debate”. But when told that 97 per cent of scientists endorsed the idea that humans had caused climate change, he said: “Where does that fit with the statutory framework? That’s not material at all. So that’s why I don’t focus on it.”

Mr Pruitt said it was “fanciful” to think that renewable energy could entirely take the place of fossil fuels.

But he bristled at the suggestion that if left to its own devices, Oklahoma might do nothing to cut carbon emissions, noting that the state already generated about 15 per cent of its electricity from wind.

“We drink the water, we breathe the air here in Oklahoma. To think that we don’t care about that, and somehow are being led to sacrifice those things is . . . not accurate,” he said.

“It’s a paternalism that’s exercised by DC to say: ‘We know best, you cannot take care of yourselves’.”

Contrary to the hopes of some Republicans and the fears of some Democrats, it will not be possible for Mr Trump’s EPA to scrap the Obama era’s key climate change regulations quickly.

Thomas Lorenzen, a partner at the law firm Crowell & Moring who argued for Mr Pruitt’s side in a September hearing on the climate lawsuit, said: “Undoing the Clean Power Plan or the clean water rule or any of the other big-ticket items will require significant effort.”

Certain parts of the statute, including the 1970 Clean Air Act, required administrations engaged in rulemaking to explain the legal basis for their actions, put forward supporting facts, take on public comments and then respond to them, he said.

Such a process could take months if not years. It would probably get bogged down in lawsuits from left-leaning groups arguing that the Trump administration was not fulfilling a legal obligation to curb the effects of climate change on public health.

“The Clean Power Plan generated over 3m public comments and you could anticipate that a rule to withdraw or revise it would generate the same number of comments,” Mr Lorenzen said.

Earlier this week Al Gore, the former vice-president and advocate of action on climate change, visited Mr Trump for a meeting that was reportedly facilitated by his daughter Ivanka.