This Week With George Stephenapolous:

STEPHANOPOULOS: So what is the responsible way? That’s my question. What is the Republican plan to deal with carbon emissions, which every major scientific organization has said is contributing to climate change?

BOEHNER: George, the idea that carbon dioxide is a carcinogen that is harmful to our environment is almost comical. Every time we exhale, we exhale carbon dioxide. Every cow in the world, you know, when they do what they do, you’ve got more carbon dioxide.

Boehner has just demonstrated why he is in no position to be an opponent of efforts to address climate change.

Because to be an opponent of something, you have to at least be on the same playing field.

Carbon dioxide is a carcinogen?  He's right when he says CO2 is not a carcinogen, but that has NOTHING to do with global warming.  It's a non sequitor from left field. 

But carbon dioxide, in high levels, contributes to the destabilization of the planet’s climate.  And it does kill.  (Anyone remember Apollo 13 and the part where they had to replace the scrubber?  That's because the old one was broke, forcing the astronauts to be living in an environment full of their own CO2 emissions).

Then Boehner says, "Every cow in the world, you know, when they do what they do, you’ve got more carbon dioxide."

Uh… no.  Cow farts do not consist of carbon dioxide.  And if John Boehner thinks that cow farts are no different from human exhalation, he is more than welcome to lift the tail of a cow and put that theory to the test.  I'll even provide the stool for him to sit on.

No, bovine flatulence is actually methane, and yes, it does genuinely contribute to global warming, albeit not on the same scale as industrial activity.

But the larger point here is that you can't do much to address the global warming issue properly in the face of powerful politicians as ignorant as Boehner.