Contrary to what you may have been led to believe, Bill Nye the "science guy" is not a scientist. He is a "science educator" (whatever that means) and more pertinently, a media celebrity. He makes a lot of declarations about things like global warming, and presents his opinions as if they're coming from someone with authority and credibility. But he is not a scientist and doesn't really have the credentials to present his claims as an authority.
William Happer, by contrast, is a scientist. He's a physicist at Princeton University. He knows that global warmism is based on alarmism and faulty models. And he's not afraid to say so, even though Nye wants very badly for him to shut up and, in fact, demands that he do so:
