You really think New York City and London are only a few decades away from being uninhabitable because of climate change? BET ME. Are you a dopey royal who fears that mutant corn is going to kill us all? BET ME. Are you a highly credentialed but sort of sloppy academic who believes that the Western world is headed toward Dickensian social conditions? BET ME.

I anticipate an objection here: “These predictions are free speech, protected by the First Amendment.” Yeah, yeah, yeah — I know how the theory goes: The free exchange of ideas and views leads to a better state of public knowledge, and that is so valuable to a free society that it is worth bearing the costs of all the lies, ignorance, Cosmopolitan articles, superstition, and malfeasance that are also protected by the First Amendment. Areopagitica and all that. Well, screw John Milton — I have it on the excellent authority of Harry Reid and all the other Democrats in the Senate that freedom of speech applies only when Congress believes that it is consistent with the public good, and that we can restrict — with prison time, if necessary — attempts by irresponsible or self-interested parties to influence public-policy debates. If there’s a public-interest defense of Matt Yglesias’s predictions — “I wanted to once again take the opportunity to lay down a marker and say once again that Obamacare implementation is going to be a huge political success” — or Nancy Pelosi’s — “Everybody will have lower rates, better quality care, and better access” — it is far from obvious what that is. Pelosi clearly is motivated by craven political self-interest, while Yglesias is motivated by the magical goblins in his head, but there’s a good case that both should have been sanctioned for such fantastical tomfoolery.