I had other plans for this morning, but the article by Rosenbaum and the subsequent discussion are too interesting to ignore (thanks, Matt, for the link). As a climate scientist (30 years of active research in government laboratories and academia and more than 200 peer-reviewed publications), professor, and lecturer on global climate, the subject is of considerable interest and importance to me. I read through the discussion comments and many of them make good points. I apologize if I reiterate a few.

The nature of science. Rosenbaum misunderstands how science progresses, as Thomas Kuhn did before him. Science is akin to building a medieval castle with scientists as masonry workers lying bricks upon bricks, but without a really good blueprint of the entire structure. Very rarely we discover that some underlying bricks are bad and we have to go back and uproot them. Mostly we discover that the bricks are uneven – they do not provide an absolutely true (in the geometric sense) surface upon which we can build further, so we take the time to level the surface and then continue building. Sometimes, a masonry worker has a particularly creative idea that results in a major addition to the existing blueprint. Ideas such as Einstein’s theory of relativity did not negate the previous building based on Newton’s laws, but extended them in new and provocative ways.

Science does progress by consensus. New ideas are introduced and scientists examine and refine them. These ideas coalesce into a theory, which in scientific parlance is simply a testable construct of ideas. In order to be useful, the theory must make predictions and the prediction must be testable. Flat earth theory is testable and found wanting by experiment – any geostationary satellite picture will do. Of course if you persist in denying the existence of satellites, then there isn’t much we can do. Thus scientists agree with the idea of consensus, but note that it is a consensus based on theory and testing, not on the number of votes! This is a critical distinction.

The role of dissent. Dissent within science is not only accepted, but encouraged. There are rules, however. Dissent has to come with scientific research and data and has to be published following the peer-reviewed process. Is this unfair? No more so (and probably less so) than the judicial system. Much of what passes for scientific dissent in the public forum is not dissent to the scientific community – it is half-baked ideas that have not passed through the distillation of careful writing, review, revision and publication.

The voice of authority. Up top I deliberately cited some credentials. I am a “doctor”, but If someone has a serious bodily ailment, he or she would be poorly advised to consult me on the cure and I would be a charlatan where I to offer my opinion on the ailment and suggest that my opinion is just as good as any doctor’s opinion. Our world is complex and we make decisions every day about who speaks with authority. I find it fascinating (and sometimes, I must admit, downright annoying) that there is a cadre of people who are willing to tell society what to think about climate change but have no credentials. Mr. color.less.blue, in commenting on this post, provides a wonderful example. He reports that he is a physicist doing computer modeling and “every month or so … [does] … a quick review of some of the literature concerning the climate debate”. This, of course, allows him to provide us with a succinct overview of greenhouse warming science. Unfortunately for us, his 7 points are somewhere between half-true, wrong and misleading. Authority in science is earned, as is the right to have one’s dissent taken seriously. And before someone starts in with the idea that somehow scientists have this giant conspiracy going to eliminate dissent, let me say that I could be a lot more famous and make a lot more money if I could really prove that greenhouse warming is not occurring and will not occur. Besides, if you actually know any scientists, the idea of getting them to participate collectively in a giant conspiracy is laughable.

The role of reporting. This is really tough. I see no reason to advocate for reporters to stifle dissent. That strikes me as counter-productive. What we do need is for reporters to consider AND name the authority with which people speak. The Climate Debate Daily, for example would be far more useful if the postings included a rating of reliability based on credentials and credibility. We could, after all, do a similar “debate” posting for cancer from smoking or HIV/AIDS or the age of the earth. Would such debate posting really help us understand those issues better? The major problem, of course, is that there are only a handful of reporters with any kind of earth science credentials themselves (Andy Revkin ranks right at the top in my book) so the reporters are unable to separate wheat and chaff (or even identifying wheat in the first place). Thus he said / she said reporting becomes the reporter’s refuge. And then, there is the blogging phenomenon where presentation and obstreperousness seem to count for more than logic and careful analysis.

Global warming and action. Rosenbaum “has no strong position on the matter [anthropogenic global warming”. I wonder why that is. Is it because he deems that matter too unimportant to have a strong position (I have no strong position on wearing socks with sandals) or because he doesn’t think there is enough information available to have a strong position or because he is unwilling to take a strong position because then it might have consequences for his behavior or …? I wonder what would convince Rosenbaum to “believe”. Would it be a carefully considered report by the world’s scientists? Oh, yes we already have that from the IPCC. Would it be a massive collection of peer-reviewed articles spanning decades of research? Ah, but we have that as well. Would it be a well-understood theory of greenhouse gas absorption and climate change? We have that as well. So what does he want? I am reminded constantly of those who continued and continue to smoke in defiance of all the evidence of what it will do. I was one, but eventually had to face up to the facts that the evidence was compelling (although there were still denialists is the early 80’s) and that I needed to do something about my habits. So I invite Rosenbaum to look deep inside and ask what evidence would be sufficient for him to develop a strong opinion on global warming. I suspect that the issue here is not actually about stifling dissent, it is rather about stifling the need for this country to come to grips with an addition problem.