It was a bright warm day in March, and while the clocks weren’t quite striking thirteen, something was awry. Scott Pruitt, the new chief of the U.S. Environmental Protection Agency, was rejecting the international scientific consensus about human-caused global warming.

He did it, actually, about when the clocks were striking nine Thursday morning, in an appearance on CNBC’s morning news program, Squawk Box.

“Do you believe that it’s been proven that CO2 is the primary control knob on climate?” asked Joe Kernen, a host on the show.

“No,” said Pruitt. “I believe 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.”

“We need to continue the review and analysis,” he added.

This is wrong. There is not “tremendous disagreement” about Kernen’s question. Pruitt’s claim runs so counter to the findings of the international scientific community, to the conclusions of the U.S. government, and even to the marketing materials of the oil-and-gas industry that it is difficult to label it anything but a falsehood.

The scientific evidence on this question—does carbon dioxide, as emitted by human activity, cause climate change?—has been available for decades. Since the late 1970s, climate scientists have suggested that the accumulation of carbon dioxide in the atmosphere might cause global warming. In 1995, the Intergovernmental Panel on Climate Change, an international group of thousands of the world’s climate scientists, announced that the “balance of evidence” suggested that this had caused ongoing global warming.

This conclusion only strengthened throughout the 2000s. By 2013, the Intergovernmental Panel on Climate Change announced that there was at least a 95 percent chance that CO₂ was causing global warming.

Two branches of the U.S. government have also come to this conclusion. In 2007, the Supreme Court announced in a major decision that:

A well-documented rise in global temperatures has coincided with a significant increase in the concentration of carbon dioxide in the atmosphere. Respected scientists believe the two trends are related.

In 2009, the EPA formally agreed, announcing that carbon dioxide and five other greenhouse gases endangered public health and welfare by causing global warming.

Even the oil companies, who stand to be most harmed by the regulation of greenhouse gases, have come to accept the science. In its official statement on climate change, Exxon Mobil says: “The risk of climate change is clear and the risk warrants action. Increasing carbon emissions in the atmosphere are having a warming effect.”

In its own page on climate change, Shell says: “In order to prosper while tackling climate change, society needs to provide much more energy for a growing global population while finding ways to emit much less CO2.”

Pruitt has previously vacillated on some of these questions. Early last year, he cast doubt on the human origins of climate change, writing in the National Review that “scientists continue to disagree about the degree and extent of global warming and its connection to the actions of mankind.”

Speaking to Congress in January, he moderated those views—somewhat. “Science tells us that the climate is changing and human activity in some manner impacts that change,” he said. “The human ability to measure with precision the extent of that impact is subject to continuing debate and dialogue, as well they should be.”

As I noted at the time, this was a carefully crafted line: It seemed to recognize the reality of climate change while undermining the research methods that scientists used to discover it. It remained out of step with scientific consensus, though, because human activity doesn’t just “impact” contemporary global warming “in some manner.” It is the cause of this climate change. You could even call carbon dioxide and other greenhouse gases the “primary control knob” of the modern-day climate as Kernen did.

Already, the Sierra Club has called for Pruitt to resign, alleging that he misled Congress in his testimony about global warming. Some senior U.S. climate and atmospheric scientists have joined their call.

In my view, there are more clear cut cases of Pruitt giving false information to Congress: During his hearing, for instance, he told senators that he never used his private email address while conducting state business, even though an Oklahoma City FOX station later revealed that he did.

But it hardly matters, because now there will be a great public fight over Pruitt’s comments, and partisans across the country will be asked to take sides. Pruitt’s claim runs so counter to the long-standing, hard-won scientific understanding of the issue that it is not improper to call him a climate-change denier. This won’t be hyperbole: The evidence that CO₂ alters the planet’s climate is as critical to the idea of global warming as the evidence showing the planet to be warming in the first place.

“Pruitt has demonstrated that he is unqualified to run the EPA or any agency,” said Kevin Trenberth, a senior scientist at the National Center for Atmospheric Research, in a statement responding to Pruitt’s Squawk Box appearance. “There is no doubt whatsoever that the planet is warming and it is primarily due to increased carbon dioxide in the atmosphere from burning of fossil fuels.”

And yet, few minds are likely to change as a result of this debate. Many Americans will hear Pruitt’s comments at the same time they hear the scientific community’s response. They will assume that both groups mean well—that their new public servant isn’t lying to them—and they will grasp for a false truth somewhere between the two statements. These Americans will come to assume that there is some debate about climate change, some moderate position between those who say the world is warming and those who say otherwise.

These Americans will be intelligent, good-faith, savvy consumers of media—yet they will have been successfully misled. The moderate position between the truth and a falsehood is still a falsehood. It's still incorrect to believe, as Pruitt does, that there is "tremendous disagreement" about these issues. The long, grinding fight to convince the public of the reality of global warming will be set back once again.