Except on the night of the White House Correspondents' Dinner:
THE PRESIDENT: The science is clear. Nine of the ten hottest years ever came in the last decade.
LUTHER: Now, I’m not a scientist, but I do know how to count to 10. (Laughter.)
THE PRESIDENT: Rising seas, more violent storms.
LUTHER: We’ve got mosquitos. Sweaty people on the train, stinking it up. It’s just nasty. (Laughter.)
THE PRESIDENT: I mean, look at what’s happening right now. Every serious scientist says we need to act. The Pentagon says it’s a national security risk. Miami floods on a sunny day, and instead of doing anything about it, we’ve got elected officials throwing snowballs in the Senate!
LUTHER: Okay, Mr. President. Okay, I think they’ve got it, bro.
THE PRESIDENT: It is crazy! What about our kids? What kind of stupid, shortsighted, irresponsible bull — (Laughter and applause.)
LUTHER: Wow! Hey! (Applause.)
THE PRESIDENT: What?!
LUTHER: All due respect, sir. You don’t need an anger translator. (Laughter.) You need counseling.
So the joke here was that Obama is so angry about the Republican Party's climate denialism that he even managed to scare his anger translator. This isn't a joke. It's just Obama's opinion, delivered with a fury that's rarely allowed in American politics.
Read these sentences again: "Every serious scientist says we need to act. The Pentagon says it's a national security risk. Miami floods on a sunny day, and instead of doing anything about it, we've got elected officials throwing snowballs in the Senate!" Is there a single one of them that you think Obama doesn't believe? He gets right up to the first syllable of calling it "bullshit." But since he said it at the White House Correspondents' Dinner, he can just say he's kidding, even though everyone knows he's not kidding in the least.