In my last note, I took on Allègre and his co-authors of the infamous “sixteen concerned scientists” op-ed for not being experts in climate science. When Kevin Trenberth answered Allègre and friends’ op-ed, he stated just that. The Wall Street Journal published various letters, one of them condemning Trenberth for making an “argument from authority” (this letter also claims that the op-ed made valid points —one would be hard pressed to find one). The irony, here, is that the argument from authority was made by Allègre and friends, relying on their academic credentials to claim that they, themselves, are experts in climate sciences.
Admittedly, I am far from being an expert in climate sciences: I have been trained as a biologist. But here’s the catch: because I am not an expert in climate sciences, I rely on the opinion of experts on this particular matter. I particularly examine whether, on a given topic there is a consensus, or lack thereof. Contrary to what the letters to the editors mentioned above, this is by no means relying on an argument of authority. Rather, it is about recognizing that today, with science being specialized as it is, and with the amount of knowledge available, one has no other choice than to rely on what scientists of a particular field are saying about their field and the state of the science concerning a problem in this field. Someone who claims to be an expert in all sciences simply because he or she holds a PhD in one discipline is likely to be a snake oil salesman (or woman). And the media would do well to recognize that, as this kind of people usually enjoy a warm welcome on late-night shows. It is impossible, as of today, to know and to understand every bit of science, every method of every sciences. In fact, it is already hard enough to keep up with methods in one particular science. Take biology, for example. Setting aside all branches like zoology and systematics, we are still left with a vast array of techniques: patch-clamp, chromatin immunoprecipitation, co-immunoprecipitation, various types of pulldowns, fluorescence and immuno-fluorescence, biacore®, etc… To name but a few. Some of these techniques are difficult to master, and keeping up with them, learning some new ones (not to mention being up-to-date with the literature of your discipline) is hard enough. Hence, when one pretends to be an expert in climate science while he is a geochemist or a biochemist, I usually smell a rat. That’s why I don’t claim to be an expert in climate sciences: I’m not. I, however, know how science is evaluated in their fields: it is done in the same way whether you talk about physics, biology, climate sciences… The reviewing process is comparable in every natural science. And, together with the consensus on climate change, this is what gives me confidence that, when climate scientists say that the Earth is warming, there is a strong probability that, indeed, the Earth is warming. Now, people often say that sciences advance thanks to “geniuses” who help to make huge leaps forward and that these geniuses work against the Zeitgeist of their discipline. The former isn’t entirely true: no scientific work comes to existence ex nihilo. A particular work is always based on previous discoveries (big or small) from fellow scientists. Darwin and Wallace didn’t devise the theory of evolution merely by observing animals, they also looked at the geological record. And even after having published his famous book, Darwin admitted (in fact he basically sent an appeal in his book) to scientists that they should look for more evidence, there was some things he couldn’t grasp: the technology of the time would simply not allow it. Nowadays, evidence to support evolution is here in the plenty. Because scores of biologists tested Darwin and Wallace hypothesis, and because new discoveries strengthened the notion that evolution is occurring… There are examples of lone scientists being right against a whole scientific community: the story of Wegener is paradigmatic. His hypothesis of continental drifting was not taken seriously until the 1950s, and it was only fully accepted in the 1970s. Then again, while Darwin and Wallace did provide some evidence and explanation on how evolution might occur, Wegener was only able to present evidence (fossil of the same species present on various continents, for example), he couldn’t build an hypothesis about how this continental drifting happened. He couldn’t : the technology wasn’t there to provide an answer to that problem. Once however, it became available, and geologists around the world tested Wegener’s hypothesis. Results confirmed it, hence geologists accepted that continental drifting is occurring and from an hypothesis, it became a theory. They where sceptical about it only because no mechanism could explain how continents are drifting, once they were convinced that they found one, however, continental drifting made it into the core, established knowledge of geologists (in France, his theory is taught from high school).This is my point: science is a conservative process and scientists are reluctant to accept any hypothesis without any evidence, let alone throw away an entire body of knowledge without any good reason to do so. They are hard to budge, but if you provide any evidence, not to mention a credible mechanical explanation (goddidit won’t do), they will.This is the contrary of an argument taken from authority: this is an argument taken from facts. And, unless you are able to provide evidence that an entire scientific community is wrong, this community isn’t likely to change its views. Climate sciences provide evidence that the Earth is warming, and they provide a mechanism. Climate change deniers, not unlike creationists, have not provided anything of substance to back their claims. That is why they are not considered seriously, and because both creationists and climate change deniers are not about science but about ideology, they resort to slander, martyr postures, conspiracy theories and other propaganda ploys to back their claims.