WASHINGTON (Reuters) - The U.S. Environmental Protection Agency is in the early stages of launching a debate about climate change that could air on television – challenging scientists to prove the widespread view that global warming is a serious threat, the head of the agency said.

Environmental Protection Agency Administrator Scott Pruitt speaks during an interview for Reuters at his office in Washington, U.S., July 10, 2017. REUTERS/Yuri Gripas

The move comes as the administration of President Donald Trump seeks to roll back a slew of Obama-era regulations limiting carbon dioxide emissions from fossil fuels, and begins a withdrawal from the Paris Climate Agreement - a global pact to stem planetary warming through emissions cuts.

“There are lots of questions that have not been asked and answered (about climate change),” EPA Administrator Scott Pruitt told Reuters in an interview late on Monday.

“Who better to do that than a group of scientists... getting together and having a robust discussion for all the world to see,” he added without explaining how the scientists would be chosen.

Asked if he thought the debate should be televised, Pruitt said: “I think so. I think so. I mean, I don’t know yet, but you want this to be open to the world. You want this to be on full display. I think the American people would be very interested in consuming that. I think they deserve it.”

Pruitt, one of the most controversial figures in the Trump administration, has repeatedly expressed doubts about climate change – one of the main points of contention in his narrow confirmation by the Senate.

While acknowledging the planet is warming, Pruitt says he questions the gravity of the problem and the need for regulations that require companies to take costly measures to reduce their carbon footprint.

“It is a question about how much we contribute to it. How do we measure that with precision? And by the way, are we on an unsustainable path? And is it causing an existential threat?” he said in the interview.

Since taking up his role at EPA, he has emerged as one of the more prolific Trump cabinet appointees, taking steps to undo more than two dozen regulations, and influencing Trump’s decision to pull the United States from the Paris climate change deal, agreed by nearly 200 countries in 2015.

Pruitt rejected global criticism of the United States for pulling out of the climate deal, which Trump has said would have cost America trillions of dollars without benefit.

“We have nothing to be apologetic about,” Pruitt said. “It was absolutely a decision of courage and fortitude and truly represented an America First strategy with respect to how we are leading on this issue.”

Pruitt said the United States had already cut its carbon output to the lowest levels in nearly 25 years without mandates, thanks mainly to increased use of natural gas - which burns cleaner than coal.

“RED TEAM, BLUE TEAM” TACTICS

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Pruitt said his desire for the agency to host an ongoing climate change debate was inspired by two articles published in April – one in the Wall Street Journal by theoretical physicist Steve Koonin, who served as undersecretary of energy under Obama – and one by conservative columnist Brett Stephens in the New York Times.

Koonin’s article made the case that climate science should use the “red team-blue team” methodology used by the national security community to test assumptions. Stephens’ article criticized claims of complete certainty in climate science, saying that it “traduces the spirit of science.”

Pruitt said scientists should not scoff at the idea of participating in these debates.

“If you’re going to win and if you’re so certain about it, come and do your deal. They shouldn’t be scared of the debate and discussion,” he said.

Pruitt said debate is not necessarily aimed at undermining the 2009 “endangerment finding,” the scientific determination that carbon dioxide harms human health that formed the basis for the Democratic Obama administration’s regulation of greenhouse gases. He said there may be a legal basis to challenge the finding but would prefer Congress weigh in on the matter.

In the interview, Pruitt added that he intended to deal “very aggressively” with automakers that use devices to cheat emissions tests, and would also seek to boost accountability for companies to clean up polluted sites under the Superfund program.

He said EPA was also not ready to decide yet on a change proposed by Trump’s special adviser Carl Icahn to the U.S. biofuels program, that would shift the burden of blending biofuels like ethanol into gasoline away from refiners to companies further down the supply chain.