For the past decade, Fox News has been a haven for climate change denialism, shielding viewers from the evidence that humans are causing global temperatures to rise. Perhaps no other news outlet has done as much to harden the view, among conservatives, that global warming is a fiction.

But on Thursday, just a few minutes before President Donald Trump’s announcement that the United States would back out of a major international climate agreement, Fox did something startling and utterly off brand.

Viewers tuning in to watch the president’s speech saw anchor Shepard Smith lecturing them that climate change was not, in fact, a hoax:

Climate change is real and our activities do contribute to it. As the New York Times reports today, scientific studies show if the world's carbon emissions continue unchecked, atmospheric temperatures will continue to rise. The planet will not just be hotter but also suffer from rising sea levels, more powerful storms, droughts that lead to food shortages and extreme conditions. Supporters of the accord argue it's the right thing to do for the environment, and for people — future generations.

On the matter of climate change, Smith has been one of the few dissenting voices at Fox News. In 2014, he stirred up a minor controversy when he declared, on air: “Climate change — it is real. The science is true.”

Trump’s Paris speech Thursday fell squarely in the middle of Smith’s 3 pm show, which gave the anchor a chance to remind his conservative viewers about the scientific consensus on climate change.

Smith’s forceful acknowledgement of the science is startling only in the context of Fox News, a channel that has long been blamed for perpetuating right-wing ignorance of the science on global warming. In 2011, researchers from American, George Mason, and Yale universities found that Fox News programs overwhelmingly rejected or ignored the scientific evidence on climate change, and promoted a false sense of balance by favoring guests who denied the planet was heating up.

“Notably, Fox also provided substantially more coverage on climate change than the other two networks, thereby amplifying doubt about global warming within the cable news landscape,” the researchers write.

People who already doubt climate change are much more likely to watch Fox News, of course, but there’s evidence that Fox News, in turn, has suppressed public recognition of global warming.

Studies have shown that many climate deniers are not incorrigible, but in fact are surprisingly open to new viewpoints. A recent experiment from Yale University researchers Sander van der Linden and Anthony Leiserowitz, and George Mason’s Edward Maibach found that simply telling people “97% of climate scientists have concluded that human-caused global warming is happening” is enough to increase their confidence that climate change is real.

What’s more, both liberals and conservatives shifted their views equally after learning this fact. Even people who were avid watchers of Fox News became more receptive to the idea of man-made global warming, suggesting that at least some climate skeptics are simply misinformed, not willfully oblivious.

Part of the problem is that the American media has done a bad job of explaining climate science. According to the survey, only a quarter of liberals and only 5 percent of conservatives were aware that more than 90 percent of climate scientists believe climate change is real and that it is caused by people. The widespread “public confusion and doubt about the state of scientific agreement has limited action on global warming for decades,” the researchers argue.

As this issue becomes more and more politicized, one fear is that it will be harder to change people’s minds. Over the past 20 years, Democrats have become more confident that humans are causing global warming, while Republicans have become more skeptical. This reflects, in part, how politicians and pundits have increasingly turned climate skepticism into a matter of political identity.

Making fun of liberals is now the default mode for how the conservative media covers climate change. Just this week, “Celebs Freak Over Trump’s Paris Agreement Exit” was the headline of an article on the alt-right website Breitbart. And on Fox News Thursday morning, one host asked: “Why is climate change the religion of the left?”

“I think precisely because it is so meaningless,” the guest replied.

These kinds of conversations avoid discussing the actual science in favor of scoring partisan points. Which makes it all the more surprising when, on occasion, a Fox News anchor does relay the facts about climate change, as Smith did Thursday. Fox News has done much over the years to perpetuate climate denialism, but if the studies are to be believed, there still may be a window for people like Smith to nudge Republicans toward accepting the reality of global warming.

Though, judging by the nasty reception Smith received on Twitter yesterday afternoon, that window may fast be closing.

“Anyone who insists that FOX is right-wing totally disregards Shepard Smith. He is a reliable lefty STOOGE,” one said, shortly after Smith delivered his climate change monologue on Thursday. Someone else complained, “Holy Crud, @ShepNewsTeam went full tin foil hat at 3pm.”

“Please just report the news,” another added. “We don't need Shepard Smith telling us how things are.”