I believe the White house has refused to acknowledge a link between emissions and rising temperatures. Their one of the few countries on the planet to do this, if i'm not mistaken, and one of the few to not sign on to Kyoto.
Edit:
Just watching "The Hour" and they were talking about this story, and they had David Suzuki on who is a prominent Canadian environmentalist, and he eluded to the fact that it has become apparent that the position the US took on Kyoto was influenced by Exxon.
Read the story here:
http://www.guardian.co.uk/climatechange ... 46,00.html
He also said that since Russia has ratified Kyoto, there are only 2 industrialized countries in the world who haven't signed it. US and Australia. Now that Russia has signed, Kyoto is now international law.
I respect Dr. Suzuki very much. He is great to hear speek. If you ever get a chance, listen to him. He's got a lot to say.