Back when the Climategate affair first hit the news, head of the Intergovernmental Panel on Climate Change Rajendra Pachauri angrily defended the IPCC's Fourth Assessment Report (4AR) by asserting that it had been rigorously peer-reviewed. As the Guardian quoted Pachauri:

"The processes in the IPCC are so robust, so inclusive, that even if an author or two has a particular bias it is completely unlikely that bias will find its way into the IPCC report," he said.

"Every single comment that an expert reviewer provides has to be answered either by acceptance of the comment, or if it is not accepted, the reasons have to be clearly specified. So I think it is a very transparent, a very comprehensive process which insures that even if someone wants to leave out a piece of peer reviewed literature there is virtually no possibility of that happening."

The Daily Telegraph is reporting that claims of rigorous peer-review may have been exaggerated:

... a new study put this claim to the test. A team of 40 researchers from 12 countries, led by a Canadian analyst Donna Laframboise, checked out every one of the 18,531 scientific sources cited in the mammoth 2007 report. Astonishingly, they found that nearly a third of them – 5,587 – were not peer-reviewed at all, but came from newspaper articles, student theses, even propaganda leaflets and press releases put out by green activists and lobby groups.

The group auditing the 4AR references was organized by Canadian global warming skeptic Donna Laframboise. You can find the report here and judge its accuracy for yourself.