With Rex Tillerson's firing, President Donald Trump's new choice for Secretary of State—Mike Pompeo, a former Kansas congressman currently serving as director of the CIA—signals a hardening stance against international engagement on climate change.

Pompeo's career in business and politics was tightly intertwined with the oil magnate Koch brothers, and he has shown a deep disregard for climate science and the need to address the climate crisis.

As a congressman, Pompeo said the Paris climate agreement amounted to "bow(ing) down to radical environmentalists," and he blasted President Barack Obama for what Pompeo called a "perverse fixation on achieving his economically harmful environmental agenda" in the 2015 talks.

Pompeo's past statements indicate a far more recalcitrant stance than Tillerson's.

Tillerson, a longtime oil executive, argued that the U.S. should keep a "seat at the table" in global climate change talks and unsuccessfully sought to persuade Trump to stay in the Paris accord. Environmentalists noted the irony that the best advocate of their cause in the Trump administration—albeit never an effective one—was the former CEO of Exxon.

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The Trump White House in recent weeks has lost two other supporters of the Paris accord: National Economic Council Director Gary Cohn and George David Banks, who was a senior director at the NEC and on the National Security Council. Cohn resigned in a rebuke of Trump's steel and aluminum tariffs. Banks, who had clashed with the White House counsel's office over the legalities of the Paris accord, resigned after learning that he would not be granted permanent security clearance because of his past marijuana use.

"In a strange kind of way, [Tillerson's] experience at Exxon dealing with energy and heads of state and climate gave him a deeper understanding of the diplomatic, economic and political dimensions of the issue," said Alden Meyer, director of strategy and policy for the Union of Concerned Scientists. "From what we know, that does not seem to be the case with Pompeo."

Rex Tillerson was the CEO of oil giant Exxon for 10 years before Trump nominated him to be secretary of state. The president fired him a little over a year after he was sworn in. Credit: Alex Wong/Getty Images

As a congressman, Pompeo described the new 2015 Paris climate pact as a "costly burden" to the United States. "Congress must also do all in our power to fight against this damaging climate change proposal and pursue policies that support American energy, create new jobs and power our economy," he said.

During the hearings that led to his confirmation as CIA director last year, Pompeo dodged a direct answer on his views on climate change, but he made clear—as Tillerson did during his own confirmation hearing—that he did not view it as a national security issue.

"I, frankly, as the director of CIA, would prefer today not to get into the details of climate debate and science," he said in response to questions from Sen. Kamala Harris (D-Calif.) "It just seems—my role is going to be so different and unique from that. It is gonna be to work alongside warriors keeping Americans safe."

Meyer predicted that Pompeo will not be able to evade discussing his views on climate change so easily at his next confirmation hearing, before the Senate Foreign Relations committee, which is chaired by retiring Sen. Bob Corker (R-Tenn.).

Pompeo's Koch Brothers Connections

Pompeo, who graduated first in his class at West Point and served in the mechanized cavalry during the Gulf War, earned a law degree at Harvard and built a business career as founder of an aerospace and security firm with an investment from Koch Industries. He later became president of the oilfield services firm Sentry International, which partnered with Koch.

Pompeo was among the Tea Party class that was swept into office in 2010 and helped the Republicans regain control of the U.S. House. The Koch advocacy group Americans for Prosperity was among the right-wing groups that spent tens of thousands of dollars to attack his opponent in the primary and secured him the Republican nomination. Every year after that, the Kansas congressman was the No. 1 recipient of money from the political action committee of Wichita-based Koch Industries, with more than $375,000 in contributions.

Pompeo's close ties to the Koch brothers and his dismal environmental voting record have raised alarm bells with climate advocates. Sierra Club Executive Director Michael Brune said replacing Tillerson with Pompeo amounts to turning "our global diplomatic efforts over from Exxon to the Koch Brothers."

"Every single other world leader accepts climate science, and every single other nation wants to be a part of the Paris Agreement, yet Trump wants to give the stewardship of our international relations to an extremist," Brune said.

Tiernan Sittenfeld, senior vice president of government affairs for the League of Conservation Voters, said that, "with a history of questioning the science of climate change, a close relationship with the polluter Koch brothers and lifetime LCV score of 4 percent, Mike Pompeo has no business becoming the next secretary of state."

Influence Over Future Climate Efforts

If Pompeo is confirmed, one of the big questions is how much attention he will give to climate change at all, given the pressure of addressing upcoming talks with North Korea and the international trade disputes arising in the wake of Trump's tariff decisions, Meyer said.

Meyer, who has more than 30 years of experience as an observer of international climate talks, described Tillerson's approach as akin to "benign neglect."

"He allowed career diplomats to continue to engage on issues that have had bipartisan support in the past, without backing away from the Trump administration's stand," Meyer said. For example, allowing them to argue for greater transparency and reporting, and against the divide between developing and developed nations.

"To me, it's an open question whether Pompeo will continue that, or does he actively try to shift U.S. policy?" Meyer said.

Harvard economist Robert Stavins writes: "Perhaps Mr. Tillerson should be credited for the fact that the State Department has at least remained engaged in the climate change negotiations. ... However, such continued bureaucratic involvement cannot make up for the fact that the U.S. is disengaged at political levels, which must be attributed—at least in part—to Tillerson's ineffectiveness in tilting the president toward a more sensible path on climate change policy."