A former coal lobbyist is set to take over the helm at the Environmental Protection Agency after EPA administrator Scott Pruitt resigned Thursday amid questions of unethical behavior.

Andrew Wheeler, the former deputy EPA administrator, is unlikely to shift the agency’s course as he steps into his new role as acting chief. In fact, Wheeler’s years working in both the federal government and the private sector mean he could be even more effective than his predecessor.

MORE: Read former EPA chief Scott Pruitt’s full resignation letter

In a tweet announcing Pruitt’s resignation, President Donald Trump made his own expectations clear when he praised the work Pruitt had done at the EPA and announced Wheeler as his replacement.

“Within the Agency Scott has done an excellent job,” Trump tweeted “I have no doubt that Andy will continue on with our great and lasting EPA agenda,” he added.

I have accepted the resignation of Scott Pruitt as the Administrator of the Environmental Protection Agency. Within the Agency Scott has done an outstanding job, and I will always be thankful to him for this. The Senate confirmed Deputy at EPA, Andrew Wheeler, will… — Donald J. Trump (@realDonaldTrump) July 5, 2018

…on Monday assume duties as the acting Administrator of the EPA. I have no doubt that Andy will continue on with our great and lasting EPA agenda. We have made tremendous progress and the future of the EPA is very bright! — Donald J. Trump (@realDonaldTrump) July 5, 2018

In only 1.5 years at the agency, Pruitt has rolled back numerous Obama-era policies. He played a key role in withdrawing the U.S. from the Paris climate accord, endorsed a proposal to repeal the Clean Power Plan, suspended the Clean Water Rule and began a review of the stricter vehicle fuel emissions standards that were set to take effect in 2022.

Matt Dempsey, the managing director of FTI Consulting who worked with Wheeler on the Senate Environment and Public Works Committee, said he fully expects Wheeler will carry out President Trump’s agenda.

“I don’t think there was any question of effectiveness of Scott Pruitt, and I think Andrew [Wheeler] will be in the same lane,” Dempsey said.

In a letter sent to EPA employees obtained by BuzzFeed News, Wheeler said he looks forward to working toward the “collective goal of protecting public health and the environment on behalf of the American people.”

The statement stands in contrast to the first remarks Pruitt made to his staff, which focused on reigning in regulations.

Wheeler has a long history in politics. He worked as a legislative aide on the Senate Committee on Environment and Public Works for several years.

In 2009, he became a lobbyist for the firm Faegre Baker Daniels Consulting. While there, one of his main clients was Murray Energy, the largest privately-held coal mining company in the U.S.

Now Wheeler is back in the public sector, and those years in the federal government may give him an advantage that Pruitt, who spent his career at the state level, never had.

“When you feel like you are being thrown out of the pot and into the frying pan, it’s not cause for enthusiasm.”

“[Wheeler] has the relationships on Capitol Hill,” Dempsey said. The people he worked with “respect him, and I think that will help move the agenda forward and make sure the accomplishments are long lasting.”

That is exactly what many environmental groups fear.

“When you feel like you are being thrown out of the pot and into the frying pan, it’s not cause for enthusiasm,” Natural Resources Defense Council spokesperson Bob Deans told the NewsHour. He said Wheeler is a lobbyist who went “to bat for the very industries he’s now being asked to regulate.”

He was also an aide to Sen. Jim Inhofe, R-Oklahoma, who sits on the Environment and Public Works committee and is known as the Senate’s most vocal climate skeptic. Inhofe authored a book on the subject, titled “The Greatest Hoax: How the Global Warming Conspiracy Threatens Your Future.”

That background made his confirmation process for deputy EPA administrator contentious.

During the hearings, Sen. Jeff Merkley, D-Oregon, pressed Wheeler on whether he believes the science community’s consensus that humans are responsible for climate change.

“I believe man has an impact on the climate, but what is not completely understood is what the impact is,” Wheeler responded.

The Senate confirmed Wheeler in April by a 53-45 vote, mostly along party lines. Sen. Joe Donnelly, D-Indiana, Sen. Heidi Heitkamp, D-North Dakota, and Sen. Joe Manchin, D-West Virginia, were the only Democrats to support Wheeler. All three senators are from coal-producing states and are considered vulnerable in the midterm elections.

READ MORE: All of the ways Scott Pruitt changed energy policy