Pompeo has questioned the scientific consensus that human activity is changing the climate, and he has strongly opposed the Paris Agreement, a pact among nearly 200 nations to address climate change.

He told Congress last year during his Senate confirmation hearing for the CIA post that the notion of climate change as a top national security threat was “ignorant, dangerous and absolutely unbelievable.”

Tillerson, despite his decades-long career in the oil industry — a major contributor to planet-warming pollution — holds that rising global temperatures spurred by human activity pose significant risks.

The change in leadership at the State Department all but cements an increasingly hard-line opposition to the idea of climate change at the highest levels of the U.S. government. Tillerson’s departure follows the resignation announcement last week of Gary Cohn, the president’s top economic adviser, and the departure last month of George David Banks, a senior adviser to the president on international energy issues. All three had argued to keep the United States in the Paris agreement.

With the three departures, “the moderating forces on climate change within the administration are all but gone, the ones that matter,” said Sarah Ladislaw, an energy analyst at the Center for Strategic and International Studies, a Washington-based think tank.

Pompeo, a Tea Party Republican from Kansas, won praise Tuesday from those who deny the human influence on the climate. President Donald Trump announced Tillerson’s departure in a tweet on Tuesday.

“He’s a great climate skeptic and he’s not going to be in favor of the Paris treaty as Tillerson was. I think it’s awesome,” said Steven J. Milloy, who runs a website, JunkScience.com, aimed at undermining climate science and who worked on the Environmental Protection Agency transition team for the Trump administration. “The administration seems to be shedding its Paris climate supporters.”

A State Department official did not respond to a request for comment. A spokesman at the CIA declined to comment.

Last year, Tillerson stood as a lonely voice in the administration’s inner circle urging Trump not to withdraw from the Paris Agreement, which calls for every country in the world to put forth plans to cut emissions that contribute to warming. Tillerson’s efforts were unsuccessful, and Trump announced the United States would go it alone as the only nation not party to the accord.

The United States cannot formally withdraw until 2020, and Trump has since made conflicting statements about whether he might reconsider his decision. In a recent interview, Banks said he believed the president remained open to rejoining the deal. But others have noted that Trump appears to be hardening against it, at least in his public remarks.

“We knocked out the Paris climate accord. Would have been a disaster. Would have been a disaster for our country,” Trump told the Conservative Political Action Conference in Washington last month, calling it a “totally disastrous, job-killing” agreement.

As a Kansas member of the House of Representatives, Pompeo called the Paris Agreement a “costly burden” to America. He has also questioned the scientific consensus that human activity is causing the planet to warm to dangerous levels.

“There are scientists who think lots of different things about climate change,” Pompeo said in a 2013 interview on C-Span. “There’s some who think we’re warming, there’s some who think we’re cooling, there’s some who think that the last 16 years have shown a pretty stable climate environment.”

Asked again about the science during his CIA confirmation hearing last year, he replied that he stood by his past statements. He also said that, “Frankly, as the director of CIA, I would prefer today not to get into the details of the climate debate and science.”

Pompeo’s top funder during his years in Congress was Koch Industries, the petroleum and chemicals conglomerate owned by billionaire brothers Charles G. and David H. Koch, who have lobbied for rollbacks in environmental regulation and other libertarian causes.

Pompeo took $375,000 from Koch Industries between 2009 and 2017 and almost $1.2 million from oil and gas companies overall, according to data from the Center for Responsive Politics, making him one of the top recipients of oil money in the House of Representatives.

In the 1990s, the Kochs’ venture capital arm also invested in an aeronautics company Pompeo started, and later sold, in Wichita, Kansas, which is also home to Koch Industries.

In Congress, Pompeo backed changes that would benefit the Kochs’ business interests, including eliminating funding for a nationwide registry of greenhouse gas polluters. He also frequently accused the Obama administration of having a “radical climate agenda.”

Since taking the helm of the CIA, though, Pompeo has not spoken publicly about climate change. The agency did help put forward a Worldwide Threat Assessment of the U.S. Intelligence Community that states that climate change contributes to national security threats.

“I can only hope that in the year of being CIA director, some of that information has found its way up to him,” said Andrew Light, a former State Department climate change negotiator under President Barack Obama. Light said he did not believe Pompeo was coming to his new role with an “ax to grind” against climate change, but said it was also not likely to be on his agenda.

If he is confirmed by the Senate, Pompeo will shape the State Department’s negotiating position at a key United Nations climate change meeting this year in Poland, where nations are expected to discuss their plans for curbing greenhouse gas emissions.

This article originally appeared in The New York Times.