The head of the Environmental Protection Agency (EPA) said Thursday that he does not believe carbon dioxide is a “primary contributor” to climate change.

“I think that measuring with precision human activity on the climate is something very challenging to do and there’s tremendous disagreement about the degree of impact. So no, I would not agree that it’s a primary contributor to the global warming that we see,” Scott Pruitt Edward (Scott) Scott PruittJuan Williams: Swamp creature at the White House Science protections must be enforceable Conspicuous by their absence from the Republican Convention MORE said on CNBC Thursday morning from an oil industry conference in Houston, where he plans to speak.

“But we don’t know that yet ... we need to continue the debate and continue the review and the analysis,” Pruitt continued.

CNBC host Joe Kernen had asked Pruitt if he believes that carbon dioxide is the “primary control knob” in global warming.

ADVERTISEMENT

Pruitt’s position is in contradiction with the agency he runs, which concluded in 2009 that greenhouse gas emissions "threaten the public health and welfare of current and future generations" because they cause warming.

He is also in disagreement with the scientific consensus among researchers who have studied the issue and agree that carbon dioxide and other greenhouse gases, emitted primarily by burning fossil fuels and other human activity, are the main cause of climate change in recent decades.

Pruitt said in his January Senate confirmation hearing that be believes the climate change is real and humans contribute to it, but the degree of human impact is “subject to continuing debate."

Environmentalists have labeled Pruitt a “climate denier” despite his position that climate change is real, since he does not agree with the consensus about the contribution of human activity.

President Trump has previously called climate change a “hoax.” Both Trump and Pruitt say they plan to undo all of Obama’s major climate regulations, including the Clean Power Plan, which limited carbon emissions from power plants.

His CNBC comments could hint that Pruitt wants to reconsider the EPA’s 2009 “endangerment finding,” in which it concluded that greenhouse gases harm public health and welfare and should be regulated.

The finding is the backbone of the Obama administration’s climate regulations, since it obligates the EPA to regulate emissions if it finds it necessary to do so. When Pruitt was Oklahoma’s attorney general, he unsuccessfully sued to have it overturned.

But he told the Senate Environment and Public Works Committee that the endangerment finding, and the 2007 Supreme Court decision that ruled that the EPA could regulate greenhouse gases, are “the law of the land."