Scott Pruitt, who on Thursday resigned as administrator of the Environmental Protection Agency, was a firm favourite of Donald Trump. But Pruitt was plagued by scandal and faltered in carrying out the president’s agenda of peeling back clean air and water regulations. His replacement is likely to be far more adept.

While Pruitt was a bête noire to environmentalists, for his zeal in targeting Obama-era rules and his dismissal of climate science, his attempts at deregulation were regularly framed as rushed and clumsy as they floundered in the courts.

Andrew Wheeler, Pruitt’s replacement at least in the interim, could be a more effective weapon for Trump. A consummate Washington insider and a former coal lobbyist, he will likely approach his work with the same ideology as Pruitt but without the flamboyance and ethical scandals – which may be a more frightening prospect for those dismayed with the Trump administration’s attitude to the environment.

“Pruitt’s agenda was really Trump’s agenda and I think Andrew is as fully committed to advancing it as Pruitt was,” Myron Ebell, who led the EPA transition team for Trump and has known Wheeler for two decades, told the Guardian.

“He knows much more about managing the agency and the technical side of the environmental statutes that EPA is charged with enforcing than Pruitt. Undoing [Barack] Obama’s regulatory onslaught at EPA is a key part of the president’s economic revival agenda, and therefore Wheeler will be a point man for Trump just as Pruitt was.”

For opponents of the president, the prospect is a daunting one. “Scott Pruitt was the most scandal-plagued cabinet member in an administration rife with corruption,” said Christy Goldfuss, an environment advisor to Obama who is now at the Center for American Progress. “There is no reason to believe that Wheeler will fix the problems left behind and put children’s health ahead of his industry friends.”

Confirmed by the Senate as deputy EPA administrator in April, Wheeler is well versed in the machinations of the federal government. He spent four years at the EPA’s office of pollution prevention in the Bush and Clinton administrators before working for Senator James Inhofe, an Oklahoma Republican whose vocal rejection of climate change science involved theatrics such as bringing a snowball on to the Senate floor.

Wheeler then became a lobbyist at Faegre Baker Daniels, where he represented Murray Energy, a major coal company, until August 2017. The firm put to Trump a wish list of environmental rollbacks; Wheeler helped in its attempts to fight limits on toxic emissions such as mercury.

While working for Marco Rubio’s presidential campaign in February 2016, Wheeler wrote a now-deleted Facebook post in which he called Trump a “PR person” and “a bully”, which he said should “alone should disqualify him from the White House”.

That has not hindered his rise in the Trump administration. Shortly after his nomination in October, Wheeler sent an email to Ryan Jackson, Pruitt’s chief of staff, with a link to an article by the satirical website the Onion that was headlined: “EPA Promotes Pulsating Black Sludge to Deputy Director.”

“Welcome, pulsating black sludge,” Jackson responded, in emails released under freedom of information laws. “I guess I’m going to have to get the cleaning crews to come in more often.”

Wheeler insisted he didn’t want Pruitt’s job. “I could have put my hat in the ring for the administrator,” he said in June. “I wasn’t interested in that. I am still not interested in that.”

Now that he is in the role he said he didn’t covet, he will be tasked with completing the job of dismantling environmental and climate regulations. Pruitt went about it enthusiastically but ran into legal action launched by states such as New York and California, as well as environmental groups.

Pruitt’s attempt to halt restrictions on emissions of methane, a powerful greenhouse gas, was stymied by the courts, as were proposed delays to stricter limits of lead in paint and hazy ozone in urban areas.

Trump’s EPA has also had difficulty in coming up with robust reasons why fuel efficiency rules for cars should be watered down, or what will replace the clean power plan, given that the agency is legally obliged to force down greenhouse gas emissions.

Wheeler, with his knowledge of the rule-making process, will help manage such reversals while avoiding headlines over $1,500 fountain pens, Trump Hotel mattresses or Chick-fil-A franchises.

“He is low key and likes to keep a low profile,” Ebell said. “He may have to do more public speaking than he wants to.”

A senior EPA official who did not wish to be named said: “I think it will be night and day with Wheeler, or at least night and late afternoon. He will talk to us. He’s a human being, not a politician.”

Wheeler is likely to maintain Pruitt’s close ties to industry, however. Under Trump, the fossil fuel industry has wielded unusual influence over the agency that supposedly regulates it and beleaguered staff fret that its public health mission is at risk of being buried.

“Pruitt’s removal is just the first step in restoring a strong EPA that gets back to its mission to protect public health and our environment,” said Carol Browner, a long-serving EPA chief in Bill Clinton’s administration. “Congress must ensure the next EPA administrator is not another industry insider.”