When the Prez formulates and implements policy, it is important that it be based on sound science. Otherwise, it won't withstand a legal challenge. He can't just say: this is what I think about climate change, therefore I am going to do such and such. The sources of the science have to be recognized by the courts.
Although the EPA Climate report contains some phrases that none of us like, it also contains the "natural variability" phrase. The National Acadamy of Science Climate Report also contains that phrase. The NAS report is the authority that Bush has used thus far and I would certainly not speculate as to which report Bush might rely more, or less, on in developing policy. I will remind you that when Bush developed his Klamath Basin water policies earlier this year, he relied exclusively on NAS and ignored all reports created by federal agencies. It is not likely that he will totally abandon the NAS Climate Report. It is also not likely that he will sign Kyoto.
As one of the more strident Bush detractors, you fail to comprehend that Bush is pro business and in favor of States' rights/local control. Whatever set of numbers he has to work with, he will always be that way and his policy will reflect that.