Scott Pruitt, the nation’s top environmental official, strongly rejected the established science of climate change on Thursday, outraging scientists, environmentalists, and even his immediate predecessors at the Environmental Protection Agency.

“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,” Pruitt, the newly installed EPA administrator, said on the CNBC program “Squawk Box.”

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

His comments represented a startling statement for an official so high in the U.S. government, putting him at odds not only with other countries around the globe but also with the official scientific findings of the agency he now leads. President Donald Trump in the past has called the notion of human-fueled climate change a hoax. Other cabinet members, including Secretary of Energy Rick Perry, have questioned the scientific basis for combating global warming.

But Pruitt’s attempt to sow scientific doubt where little exists alarmed environmental advocates, scientists and former EPA officials, who fear he plans to use such views to attack Obama-era regulations aimed at reining in pollution from the burning of coal and other fossil fuels.

“The world of science is about empirical evidence, not beliefs,” Gina McCarthy, the EPA’s most recent administrator, said in a statement. “When it comes to climate change, the evidence is robust and overwhelmingly clear that the cost of inaction is unacceptably high. Preventing the greatest consequences of climate change is imperative to the health and well-being of all of us who call Earth home.”

She added, “I cannot imagine what additional information the Administrator might want from scientists for him to understand that.”

A BACKLASH

Pruitt’s climate change comments resulted in instant headlines. As criticism mounted, White House press secretary Sean Spicer batted back a question about Pruitt’s comments from a reporter who cited Pruitt’s words and how they contradict the scientific consensus on climate change.

“That’s a snippet of what Administrator Pruitt said,” said Spicer. “I don’t think we know conclusively, this is what we know.”

Pruitt, who was visiting the energy industry conference CERAWeek in Houston, waded into related controversial topics during his CNBC interview. He questioned whether it was EPA’s role to regulate carbon dioxide emissions — something undertaken through the agency’s Clean Power Plan, the Obama administration’s most significant policy to combat climate change — and challenged the Paris agreement on climate change.

“Nowhere in the equation has Congress spoken,” said Pruitt on whether his agency is obligated to regulate carbon dioxide. “The legislative branch has not addressed this issue at all. It’s a very fundamental question to say, ‘Are the tools in the toolbox available to the EPA to address this issue of CO2, as the court had recognized in 2007, with it being a pollutant?’ ”

(Pruitt was apparently referring to the 2007 Supreme Court decision in Massachusetts v. EPA, in which the court ruled that “harms associated with climate change are serious and well recognized” and that the EPA had been “arbitrary and capricious” in failing to issue a determination on whether greenhouse gases endanger public health .

The remarks appeared to fundamentally call into question whether the EPA has a role in the regulation of greenhouse gases that drive global warming, including carbon dioxide and methane. Last week, Pruitt’s agency withdrew an agency request to oil and gas companies to report on their equipment and its methane emissions, which could have laid the groundwork for tighter regulations.

Pruitt also dismissed the international Paris climate agreement, which the Obama administration helped lead and which was joined by nearly 200 countries in late 2015, as a “bad deal” for the United States.

“It’s one thing to be talking about CO2 internationally,” Pruitt said. “But when you front-load your costs, as we endeavored to do in that agreement, and then China and India back-loaded their costs for 2030 and beyond, that’s not good for America. That’s not an America first type of approach.”

INTERNATIONAL CONSENSUS

On the science of climate change, Pruitt’s statements fly in the face of an international scientific consensus, which has concluded that it is “extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century.” They also contradict the very website of the agency that Pruitt heads.

The EPA’s “Climate Change” website states: “Recent climate changes, however, cannot be explained by natural causes alone. Research indicates that natural causes do not explain most observed warming, especially warming since the mid-20thcentury. Rather, it is extremely likely that human activities have been the dominant cause of that warming.”

Pruitt spoke with CNBC amidst growing anticipation that the Trump administration will soon begin a formal rollback of President Barack Obama’s Clean Power Plan, an EPA policy capping emissions from electricity generating stations, such as coal-fired power plants.

Pruitt himself sued the EPA over the Clean Power Plan in his previous role as the attorney general of Oklahoma – one of many

lawsuits that he filed against the agency. Others were over mercury and air pollution, the agency’s attempts to regulate pollution of waterways, and methane emissions from oil and gas facilities.

The EPA chief has made several statements that are similar to the present one, perhaps, but not so strongly worded.

In his Senate confirmation hearing, meanwhile, he stated that “the climate is changing, and human activity contributes to that in some manner.”

Another of Pruitt’s predecessors also commented on the science of climate change in the context of his remarks.

“The time for debate on climate change has passed,” Lisa Jackson, Obama’s first EPA administrator and now vice president of Environment, Policy and Social Initiatives at Apple, told the Post.

“Certainty is what business needs,” said Jackson. “And relying on science is something that we do every single day. So now if we’re going to question science, I think it has an impact on more than just some federal rules, or some law, it has a huge impact on human health, the environment, and our economy.”