there is a tightly knit group of individuals who passionately believe in their thesis. However, our perception is that this group has a self-reinforcing feedback mechanism and, moreover, the work has been sufficiently politicized that they can hardly reassess their public positions without losing credibility.What this idea overlooks is that one gets ahead in science not by agreeing with previous work, but by advancing new ideas. The bigger the new idea, and the bigger the old idea that it replaces, the more fame and success accrue to the scientist. Look at famous scientists through history and you won't find a single one that got there by agreeing with the prevailing wisdom.
If you're a member of the so-called "hockey team," you're not going to get much credit or respect from the community if all you do is agree with hockey stick. Rather, an individual scientist will do much, much better if he can show that his competitors' (aka colleagues) work is faulty or biased. And that same individual scientist will do much worse if his or her work is viewed as faulty or biased. This incentive to destroy previous work explains why, in any group of a few scientists, there will be at least two that hate each other.
Scientists are human and all of us have personal biases. But because scientists know that important ideas they advance will be re-tested by other scientists, there is a strong incentive to be careful and conservative in their claims.
People that argue that there's some type of "conspiracy" among climate scientists to increase funding by producing "alarmist" science are either a) a clever advocates trying to obstruct AGW policy by attacking the science or b) someone who doesn't understand science.