In January of this year, a ritual took shape on Capitol Hill, as one Trump nominee after another sat down a Senate committee for their confirmation hearing. The nominee shuffled his papers, greeted the lawmakers, and delivered conciliatory pablum about climate change.

As many soon noticed, these statements were often… surprisingly similar. They seemed to attest more to careful pre-briefing than to some new cross-party consensus. With tremendous reliability, every answer about the issue consisted of two parts. A nominee first recognized the reality of “some” global warming—sounding appropriately grave and concerned about it—before they pivoted to casting doubt on whether humans were behind this warming, or even whether a human influence could ever be known at all.

“Science tells us that the climate is changing and human activity in some manner impacts that change,” said Scott Pruitt, the future administrator of the Environmental Protection Agency. (That’s part one.) “The human ability to measure with precision the extent of that impact is subject to continuing debate and dialogue, as well they should be.” (Part two.)

“The risk of climate change does exist. The increase in greenhouse gas in the atmosphere is having an effect,” said Rex Tillerson, future secretary of state. (Part one.) “Our ability to predict that effect is very limited.” (Part two.)

“I do not believe it is a hoax,” said Ryan Zinke, the future secretary of the interior. (Part one.) “I think where there’s debate on it is what [the human] influence is, what can we do about it.”(Part—well, you know.)

These answers weren’t necessarily true, but they were milder and more reasonable than outright denial. They prompted coverage in The New York Times and The Washington Post, which noted the new position was “more nuanced” and “less urgent” while also noting that it wasn’t, well, correct. As Michael Oppenheimer, a professor of geosciences and international affairs at Princeton University, told the Post: “It sounds like an orchestrated campaign of head-in-the-sand. The scientific consensus is clear: Most of the warming since 1950 is the result of the buildup of the human-made greenhouse gases.”

But even as scientists and some journalists shook their heads, Trump nominees’ statements were amended, and not outright rejected, in the broader public conversation. My own work testifies to that: My headline about Tillerson’s hearing announced that he believes in climate change, even as I corrected what was incorrect about his scientific summary. I also wondered if his kinder, softer line pointed to a “potential shift in the Republican Party’s treatment” of the issue.  

Compare that to what happened last week. On Friday, Scott Pruitt told a CNBC host that he didn’t believe carbon dioxide to be a primary contributor to modern-day climate change. He also said he hoped for more study and debate of the issue.

This is extremely wrong. Decades of research have established that carbon dioxide, emitted by human industrial activities, traps heat in the atmosphere and boosts global temperatures. It is a scientific fact, as surely as the simple pull of gravity or the miracle of photosynthesis is a scientific fact. But if you go back and read Pruitt’s comments from January above, he doesn’t contradict himself.

And yet this time, the public leaped in to correct him. My inbox soon filled up with comments from pastors, politicians, well-known scientists, and former military leaders. So many people called Pruitt’s main telephone number to complain that the EPA had to set up an impromptu call center. And Keith Seitter, the executive director of the American Meteorological Society, wrote a public letter to Pruitt.

“We understand and accept that individuals and institutions both public and private can reach differing conclusions on the decisions and actions to be taken in the face of this reality [of climate change],” Seitter said. “But mischaracterizing the science is not the best starting point for a constructive dialogue.”

“We are not familiar with any scientific institution with relevant subject matter expertise that has reached a different conclusion,” he added.

Then the TV segments started. The Weather Channel packaged a fact-check for television, then fired it off in a tweet retweeted by thousands. “It is simply not true that there is disagreement among scientists,” Carl Parker, a hurricane specialist for the network, told viewers.

Then Al Roker, the Today show host, went on MSNBC to correct Pruitt.

“The fact is, carbon dioxide, one of the greenhouse gases, is responsible for climate change,” he said, sounding his best I’m-not-sad-just-disappointed notes. “There is no credible science or scientist who will tell you the contrary.”

“Look, this is America and you can make whatever statements you want to, but everybody will pretty much agree [on the science],” he added. Roker also prevailed on Pruitt to fund climate research at the agency.

You know what they say: If a long-time host of Macy’s Thanksgiving Day Parade is correcting your science on national television, and you’re the newly appointed head of the EPA, then, well, yikes. By the end of the brouhaha, both Stephen Colbert and the New York Post had covered the meteorology community’s mass rebuttal.

That is all to say: On Friday, for the first time in his national political career, Pruitt played himself. He stepped in it. And why? What did he gain? Previously, he’d been spouting off incorrect statements about climate change—the Times even tepidly labeled him a “denialist”—but it was this untruth that prompted a mass response when the other statements did not. Now, accusations of climate-change denial will dog him for years—in the press, on late-night television, and when he his EPA goes to the courts.

In part, this statement blew up because people notice what comes out of the mouth of from sitting government officials much more than they notice old quotes from government nominees.

It’s also partly because this was a more unambiguously false statement. Most journalists could not quickly update you on the state of the art of human-climate forcing measurement, but they can tell you that carbon dioxide is the main greenhouse gas. Virtually all scientists can do the same.

Part of what happened here has to do with the curious strictures of mainstream journalism about climate change. Most American journalists still aspire to be nonpartisan. But on this one issue, most also know that only one U.S. political party talks about the science in a way that by-and-large conforms to reality. (Mitt Romney and some of the members of his campaign have become notable exceptions.)

Journalists covering climate change are constantly correcting obviously wrong Republican claims. This makes it harder for many to fact check the other, more waffley quotes that waft by. Many are loosely phrased and reasonable-sounding, but they contain little truth content. An example is Pruitt’s line from his confirmation hearing: “The human ability to measure with precision the extent of [the human] impact is subject to continuing debate and dialogue, as well they should be.”

There is some kind of invisible consensus around questions of climate change. Say an obvious untruth and be mocked the world over. Say a non-commital vapidity—which has the same import as an outright lie—and you don’t wind up on Colbert. I suspect that an effect like this exists across politics, but it is surprising to see it so clearly on this one issue, where scientific agreement on reality is so strong.