In American Thinker, IPCC ‘s Bogus Evidence for Global Warming by S. Fred Singer:
In spite of much effort, the IPCC has never succeeded in demonstrating that climate change is significantly affected by human activities — and in particular, by the emission of greenhouse gases. Over the last 25 years, their supporting arguments have shifted drastically — and are shown to be worthless. It appears more than likely that climate change is controlled by variations in solar magnetic activity and by periodic changes in ocean circulation.
The Mission of the IPCC seems more inclined to confirming a view than discovery. The answers you get depend largely on the questions you ask.