First, Oreskes could well be meassuring a politically induced artifact. That is, with 90% of all climate science funding coming from the US federal government, alternative explanations are crowded out. This notion is supported by Colorado State University climatologist William Grey’s complaint in the late 90s about his inability to gain funding for his arguable more important hurricane prediction program.

Second, her methods are flawed and misleading. The fact that this paper was published without methodological details sthrengthens this possibility. A cns news story from December 7th raises this criticism in a story detailing a critic of the Oreskes’ Science paper by social anthropologist Benny Peiser:

http://www.cnsnews.com/Nation/Archive/200412/NAT20041207a.html
[P]eiser, a senior lecturer in Social Anthropology & Sport Sociology at Liverpool John Moores University and the editor of of CCNet (Cambridge Conference Network) webzine, labeled Oreskes’ essay a “disturbing article.

“Whatever happened to the countless research papers published in the last ten years in peer-reviewed journals that show that temperatures were generally higher during the Medieval Warm Period than today, that solar variability is most likely to be the key driver of any significant climate change and that the methods used in climate modeling are highly questionable?” Peiser asked.

“Given the countless papers published in the peer-reviewed literature over the last ten years that implicitly or explicitly disagree with the hypothesis of anthropogenic global warming, one can only conclude that all of these were simply excluded from the [Science Magazine] review. That’s how it arrived at a 100 percent consensus!” he added.

According to Peiser, Oreskes’ assertion that there is a 100 percent consensus about the issue is not backed by science.

“Even [former Soviet dictator Joseph] Stalin himself did not take consensus politics to such extremes,” Peiser explained. “In the Soviet Union the official ‘participation rate’ was never higher than 98-99 percent.

“So how did the results published in Science achieve a 100 percent level of conformity? Regrettably, the article does not include any reference to the [unpublished?] study itself, let alone the methodology on which the research was based. This makes it difficult to check how Oreskes arrived at the truly miraculous results,” he added.

-Orson Olson, University of London

Dr Z doesn’t seem to either edit or contribute to the IPCC at all, so I’m not sure how seriously she should be taken.

In spite his extremist politics, Mark Lynas seems to get the science right.

Although they are clearly operating in their own interests, there is a body of peer-reviewed research they direct one to that offers a counterpoint to the (admittedly generally-held) view on climate change.