(Nederlandse versie hier)
A meteorologist and a chemist were discussing the cause of the unexpected isoprene concentrations at a forest site (isoprene is an organic compound emitted by trees). The meteorologist thought it was most likely caused by some specific boundary layer dynamics, whereas the chemist thought that perhaps some unexpected chemical reaction was taking place. What did I learn from witnessing this discussion?
Everybody has a natural tendency to think along familiar lines. And to a certain extent, it makes sense: If you’re much more familiar with meteorology than with chemistry, then of course most explanations you can come up with are meteorological in nature. And as long as you are fair in weighing your thoughts and specific evidence alongside those coming from other disciplines, then there’s no problem. By discussing the relative merits of different explanations, you can hopefully come to a conclusion (dare I say “consensus”) as to what is most likely the case, taking all evidence into account.
Problems may arise when you downplay explanations coming from other relevant disciplines, being all too sure that the explanation is to be found within the realms of your specialty. If in doing so you ignore evidence to the contrary, chances are you’re in denial.
The theory of continental drift was rejected by some influential geologists in the early 20th century. In an excellent presentation, Oreskes sais of one of them, Bowie, that he did so “wholly on the basis of geodetic evidence (from his own specialty), and ignored the large body of data from various other geological specialties that independently argued in favor of continental drift.” She goes on to say that “we all gravitate towards certain kinds of evidence and arguments, and they tend to be the ones with which we are most familiar.”
This “professional deformation” of favoring familiar lines of evidence, while ignoring that from other disciplines, is also happening in the climate debate: Examples abound of meteorologists who point to the chaotic nature of weather and turbulence, of geologists who point to massive climate changes in the past, of astronomers or solar physicists who point to the sun as the main driver of climate change, etc. Such claims are often so called half-truths.
These are all specialties that are related to the broad field of climate science, and as such they often make very useful contributions to the field. But some individual scientists make strong and contrarian claims about climate change, rooted in their own specialty, while ignoring the vast body of data and evidence from various other disciplines that independently argue in favor of the scientific consensus. That’s a red flag for taking their opinions on climate science with a grain of salt, even though they may be perfectly capable and honest scientists in their specialty. A multidisciplinary view is not everyone’s cup of tea.
The feeling of being the new Galileo, the misunderstood underdog fighting “the scientific establishment”, may be an important psychological drive for “skeptical” scientists. This feeling is amplified by a big fan-club cheering them on from the sideline (in the popular media).
In addition to the explanation given by Oreskes above, I think that many people tend to gravitate towards the kinds of evidence of which we like the perceived consequences best. With continental drift nobody besides geologists could care less what scientific consensus would be reached, but that’s a different story with global warming. Those who are afraid of the solution (predicting economic doom) find an easy way out, psychologically speaking, by ignoring or denying the problem, e.g. by holding on to even the flimsiest piece of evidence to the contrary. They are more of the “anything-but-CO2” kind, and they constitute the fan-club mentioned above.
Btw, the meteorologist was most likely correct, as I could show with a 1 dimensional box model.