At the outset, let’s be quite clear: There is no consensus about dangerous anthropogenic global warming (DAGW)—and there never was. There is not even a consensus on whether human activities, such as burning fossil fuels to produce useful energy, affect global climate significantly. So what’s all this fuss about?
Let’s also be quite clear that science does not work by way of consensus. Science does not progress by appeal to authority; in fact, major scientific advances usually come from outside the consensus; one can cite many classic examples, from Galileo to Einstein. [Another way to phrase this issue: Scientific veracity does not depend on fashionable thinking.] In other words, the very notion of a scientific consensus is unscientific.
The degree of consensus also depends on the way the questions are phrased. For example, we can get 100% consensus if the question is “Do you believe in climate change?” We can get a near-100% consensus if the question is “Do you believe that humans have some effect on the climate?” This latter question also would include also local effects, like urbanization, clearing of forests, agriculture, etc.
So one has to be rather careful and always ask: What is the exact question for which a consensus has been claimed?
Subverting Peer Review
Finally, we should point out that a consensus can be manufactured—even where no consensus exists. For example, it has become very popular to claim that 97% of all publications support AGW. Here the key question to ask is: Which publications and what exactly is the form of support?
Thanks to the revelations of the Climategate e-mails, we now have a more skeptical view about the process which is used to vet publications. We know now that peer-review, once considered by many as the ‘gold-standard,’ can be manipulated—and in fact has been manipulated by a gang of UK and US climate scientists who have been very open about their aim to keep dissenting views from being published. We also know from the same e-mails that editors can be bullied by determined activists.
In any case, the peer-review process can easily be slanted by the editor, who usually selects the reviewers. And some editors misuse their position to advance their personal biases.