I see you're still taking the NYT as gospel.
The report said no such thing. The report used qualifiers such as likely and mostly when it said that global warming may be caused by humans. It further stated, repeatedly, that that conclusion is preliminary and subject to change. This is basically the same position that the president took a year ago.
The report further stated that there will be no policy change.
After the Chicken Littles were hit in the head by an acorn (the report) and ran around screaming, "The sky is falling, the sky is falling," Bush was asked about it and he referred to the report as having been done by the burocracy and emphatically stated, in no uncertain terms, that Kyoto is out of the question.