The newly installed chief of the Environmental Protection Agency says climate change is real — but how much humans are to blame for causing it is up for debate.

“There’s a warming trend — the climate is changing,” Scott Pruitt said on “Fox News Sunday.” “And human activity contributes to that change in some measure. The real issue is how much we contribute to it.”

According to the most recent United Nations “State of the Climate” report led by the National Oceanic and Atmospheric Administration, 2015 was the warmest year on record since at least the mid-to-late 19th century. The study concluded that it is 95 percent likely that more than half of the global temperature increase over the last 75 years is due to human activity.

President Trump has called climate change a hoax perpetrated by China and has claimed that “nobody really knows” if it’s real, despite overwhelming scientific evidence to the contrary.

Pruitt said it is unclear what the administration can do to reduce carbon dioxide emissions.

“You can’t just simply, from the EPA perspective, make that up,” Pruitt said. “You can’t do what [former President Barack Obama] did previously with the Clean Power Plan … to simply reimagine authority.”

Pruitt’s comments came just days after Trump signed an executive order rolling back Obama-era environmental protections intended to combat climate change.

The new administration’s “Energy Independence” order, which Trump signed Tuesday, effectively began the process of dismantling the Clean Power Plan, which limited greenhouse gas emissions from coal-burning power plants and was the centerpiece of Obama’s climate legacy.

Trump presented the controversial executive order as his latest action in a series of steps intended to stimulate the economy and create jobs. Flanked by coal miners and industry executives, Trump criticized what he called “the war on coal,” complete with “job-killing regulations” and “government intrusion.”

“The action I’m taking today will eliminate federal overreach; restore economic freedom; and allow our companies and our workers to thrive, compete, and succeed on a level playing field for the first time in a long time, fellas,” Trump said.

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Environmental groups and progressive lawmakers quickly denounced the order.

“Mr. Trump: You are threatening the lives of our children and grandchildren,” Vermont Sen. Bernie Sanders wrote on Twitter. “We will fight you every step of the way.”

“This is an all-out assault on the protections we need to avert climate catastrophe,” Rhea Suh, president of the Natural Resources Defense Council, said in a statement. “It’s a senseless betrayal of our national interests. And it’s a shortsighted attempt to undermine American clean energy leadership.”

On Sunday, Pruitt also blasted the Paris Agreement — the 2015 global action plan “to avoid dangerous climate change” by limiting the increase in average temperature worldwide to below 2 degrees Celsius — as “a bad deal for this country.”

He also would not confirm whether the United States would remain in the global climate change pact.

“We have done better than anybody in the world at growing an economy and also being a good steward of our environment,” Pruitt said. “We have nothing to be apologetic about.”

— With Michael Walsh contributing reporting

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