WASHINGTON (Reuters) - Several green groups criticized the Trump administration’s choice on Tuesday of CIA Director Mike Pompeo to replace Rex Tillerson as Secretary of State, saying his past skeptical comments about global warming show he is less suited to run U.S. foreign policy about climate change than the former Exxon Mobil CEO.

FILE PHOTO: CIA Director Mike Pompeo speaks at the FDD National Security Summit in Washington, DC, U.S., October 19, 2017. REUTERS/Yuri Gripas/File Photo

Pompeo, who was a Republican congressman from Kansas prior to running the CIA under U.S. President Donald Trump, has been among the biggest critics of efforts to combat global warming by past U.S. administrations, and has questioned the validity of existing climate science - saying it needs to be developed further.

“In this position, (Pompeo) could prove to be dangerous to our national security and the safety of our planet,” said Michael Brune, executive director of the Sierra Club.

Some climate advocates said, however, they hoped the long slate of issues facing the State Department now - from North Korea’s nuclear agenda to intensifying trade disputes - would keep climate change low on Pompeo’s list of priorities should he be confirmed by the Senate.

“Right now, climate change is not going to be a top 10 issue for him,” said Andrew Light, a former adviser to Todd Stern, the U.S. Special Envoy on Climate Change under Obama.

Pompeo is also a top recipient of campaign donations from Koch Industries, having taken over $375,500 from the family-owned energy conglomerate for campaigns going back to 2010, according to data from the Center for Responsive Politics, a transparency watchdog. Koch Industries has donated millions of dollars to efforts opposing climate change regulation.

His background upsets many environmentalists, but dovetails neatly with Trump’s energy agenda to roll back Obama-era climate regulations and support domestic production of coal and crude oil - the fossil fuels that scientists blame for global warming. Trump has repeatedly bashed international efforts to combat climate change, and has at times called global warming a hoax.

Tillerson had also faced stern opposition from environmentalists when he was nominated as Secretary of State, given his years at the helm of one of the world’s biggest oil and gas companies, but he had tried to be a moderating influence on Trump over climate policy during his tenure.

For example, Tillerson advocated continued U.S. cooperation regarding the Paris Climate Agreement, a global deal to fight warming, a battle he lost when Trump announced in June the U.S. intention to withdraw. The State Department has since continued to send delegations to international climate summits, where envoys have been perceived by their foreign counterparts as constructive.

“We’ve gone from Exxon’s CEO to the Koch Brothers’ most loyal lapdog,” said May Boeve, executive director for climate activist group 350.org. Billionaire brothers Charles and David Koch own Koch Industries.

Environmental groups like Greenpeace and the Sierra Club issued similar statements, calling the nomination a potential step backwards.

Koch Industries did not immediately comment, and efforts to reach Pompeo were not successful.

Officials at the White House and the State Department did not immediately comment on whether Pompeo would be expected to update U.S. climate change policy.

“Tillerson was basically hands-off on the issue (of climate change),” said Alden Meyer, director of strategy and policy for the Union of Concerned Scientists. “It is not clear it is going to be any more of a priority for Pompeo.”