On Election Night, as the country tuned in to the news networks to watch results pour in, Bill Nye, America’s most-endearing science teacher watched with John Logsdon, the world’s pre-eminent authority on space policy and history. The two are very different men of science. Nye taught a generation of children about gravity by tossing a computer off the roof of a building; Logsdon was a member of NASA’s advisory board. Both were equally disturbed by what they saw.

“[John] and his wife and I watched it together and it was troubling. Pennsylvania . . .” Nye said recently, before trailing off, his head shaking.

In a new documentary, Bill Nye: Science Guy, filmmakers Jason Sussberg and David Alvarado examine the circumstances that transformed the beloved host of Bill Nye the Science Guy, which ran on PBS from 1993 to 1998, into arguably the country’s most vocal and recognizable face of climate-change activism. Since the show shuttered at the end of the millennium, Nye has channeled his eccentric energy and trademark cheekiness into battling the anti-science community, from Tucker Carlson live on Fox News (the video has nearly 2 million views on YouTube) to creationist Ken Ham, in a televised debate at the Creation Museum in Kentucky.

Nye, looking every bit the zany science teacher in thematic bow tie and blazer, made an appearance at Monday night’s New York screening of the documentary at Scandinavia House, where he spoke to Vanity Fair about the intersection of his work with the political sphere. As Nye insists, “I didn’t make climate change political—the climate deniers did.”

Asked if he considered his work as political activism, he drew an important distinction: “Science is political. We want it to not be partisan. You’ve got to allocate the NASA budget, the defense budget, the Department of Agriculture budget, the E.P.A. budget—and that’s going to be political.” The danger, said Nye, comes “when policy is made based on an ideology rather than a real, demonstrable need.”

Nye, who has reckoned with trenchant anti-intellectualism in America throughout his career, points to a real, demonstrable need for critical thinkers. Why the dearth? Nye blames the traditional energy sector: “anti-intellectualism is really fueled (pun intended) by the fossil-fuel industry. They have introduced the idea that scientific uncertainty, plus or minus such and such percent, is the same as doubt about the whole thing, plus or minus 100 percent. That’s just wrong.” According to Nye, this injection of doubt has given climate deniers a platform to espouse anti-scientific thinking in Congress: the fossil-fuel industry “has actually hired the same people that worked on introducing doubt about the carcinogenic effects of cigarettes. Some of the same people who are elderly now are still fighting the same denial fight, and it’s not in anyone’s best interest. But maybe this film will nudge some people.”

Much of the documentary, set to be released on Friday in New York, looks at Nye’s immersion in the scientific community. He was appointed C.E.O. of the Planetary Society, a space-exploration nonprofit co-founded by astronomer Carl Sagan in 1980, and works with Neil DeGrasse Tyson, who is also a board member of the Society and a friend of Nye’s.

A curious aspect of Nye’s career, one that gets explored in the film, is that although he surrounds himself by and studied with such experts, he is not one of them himself. Nye holds no advanced degrees—just a B.S. in mechanical engineering from Cornell. The role he has carved stems from his ability to bridge the expansive gap between science and media.

“Here’s the interesting thing to me right now. Space exploration brings together very disparate political views,” he told V.F. “Conservatives and progressives both support space exploration, so as C.E.O. of the Planetary Society, I do not lobby. Instead, I try to present arguments for exploring space . . . man! There are people in Congress who are very scientifically engaged but still deny the science of climate change. It’s a really surprising time.”

Asked how he would evaluate the success of his mission, Nye says the ball is now in millennials’ court: “It needs another 10 years. The people who got excited about science watching the old show have to become the captains of industry. They have not become 45 years old. I deliberately did this; I came of age when they were taking solar panels off the roof of the White House, saying we don’t need to teach the metric system in U.S. schools. I wanted to affect the future . . . So it looks like it’s been effective, but we need another 10 years.”