Conservatives are weirdos. And part of their weirdness is that everything has to be filtered through their preferred storyline, and some specific side-effect of what is being discussed is far more important than the overall intent of what is being discussed. And so if they're in negotiations in something and don't have all the cards, it pisses them off and they take the attitude that you're unfairly screwing them over. Not because you did anything against them, but simply that they don't know how to negotiate if they aren't in the position to put the screws to you. That's really their only move.
And so I suspect that helps explain Bush's juvenile "world’s biggest polluter" fist-pumping grin. He's not really proud of being a polluter, but rather, he thinks this whole debate is just a big power play to screw America and doesn't like that he's trapped into it. To him, this isn't about Global Warming or pollution or any other direct thing like that. This is about other countries trying to screw America and him not being able to do anything about it. Not that he's doing this for America's, but merely that he doesn't like that he's being pressured on this.
But it's not just Bush. This is a big reason conservatives hate acknowledging Global Warming. I'm not referring to the conservative riff-raff, who hate Global Warming because that's what they're told to do. But the bigwigs largely hate it because it can put them in a bad spot. For these people, the main focus on every issue is "How is this screwing me over and how can I get it to screw over the other guy." And that's pretty much it. And until they figure out a way to screw over Global Warming at the negotiation table, they'll be content with just screwing all of the rest of us over instead.