James Lacis, a colleague of Jim Hansen at NASA GISS and not an AGW skeptic, has very strong words for the the executive summary of the IPCC AR4 report:
There is no scientific merit to be found in the Executive Summary. The presentation sounds like something put together by Greenpeace activists and their legal department. The points being made are made arbitrarily with legal sounding caveats without having established any foundation or basis in fact. The Executive Summary seems to be a political statement that is only designed to annoy greenhouse skeptics. Wasn’t the IPCC Assessment Report intended to be a scientific document that would merit solid backing from the climate science community – instead of forcing many climate scientists into having to agree with greenhouse skeptic criticisms that this is indeed a report with a clear and obvious political agenda. Attribution can not happen until understanding has been clearly demonstrated. Once the facts of climate change have been established and understood, attribution will become self-evident to all. The Executive Summary as it stands is beyond redemption and should simply be deleted.