(More alliteration for you.) What we've got here is a failure to communicate. I ran into this back in the day when I was foolish enough to dive into the Intelligent Design debate. I would end up arguing with very smart believers in orthodox neo-Darwinism, and they would keep giving me implications of their theory as if they were evidence for its truth.
The same happens when I (again, foolishly) try to show why the climate change consensus is not as airtight as its strongest advocates assert. For example, the consensus currently says that if you double CO2 concentrations, the long-run equilibrium (i.e. after all feedbacks play out) effect on the global temperature will be about 3C. (They give a range, but 3C is best point guess.) And then this estimate of the earth's "climate sensitivity" is the basis for the projections about the optimal carbon tax, why we need to take immediate action, etc.
Now as you know, there are PhDs in the relevant fields who challenge this consensus view. They say there are serious flaws in the official story. I'm not going to go over their claims here, except this one: If you look at the observational record, so far the historical "transient" (not long-run equilibrium) response to increased CO2 has been much less than the consensus estimates. I.e., just looking at how much CO2 has increased since 1880, and seeing that global temperatures have gone up only 0.7C so far, you get a very low observed sensitivity.
Now there are two main "consensus" responses to this point. First, there are other things going on besides more CO2 (and other GHGs) being pumped into the atmosphere. E.g. industrial emissions also put aerosols up there, which may have had a cooling effect and so masked what would have been greater warming in the 1970s. Second, the 3C best guess is a long-run, equilibrium concept; 120 years is not enough for all the feedbacks to work through the system.
OK everyone got that? The cutting edge models are consistent with the observed trends, but the skeptics' point is that thus far, we haven't actually seen the alarming degree of warming in response to CO2 emissions. So they're saying it lends credibility to their point of view, that these models are bunk, and that people who keep claiming that the models have been "verified" are probably misleading the public with those claims.
Now let's focus in on "PI"'s response to this challenge, in the comments of a MarginalRevolution thread (and if you read our exchange, you'll see he is very sharp, so I'm not picking on a blowhard here):
BOB: "empirical observations THUS FAR have not demonstrated this high sensitivity"
PI: Again, that's misleading. You can't note that the transient response is smaller than the equilibrium response and claim this is evidence against high sensitivity; the transient response is ALWAYS smaller, no matter what the sensitivity. You can equally well say that empirical observations THUS FAR have not demonstrated or even favored low sensitivity. Indeed, from the shape of the estimated climate sensitivity probability distributions, it's been easier to observationally disfavor low sensitivities than high ones.
The fact is that the two are difficult to distinguish from each other at this point, given the limited length of observations, the until-recently small accumulations of excess CO2, the uncertain response time of the system, and the uncertain forcings. We EXPECT low and high sensitivities to give similar responses in these circumstances. The observations so far exclude sensitivities lower than 2 C with high probability, and sensitivities greater than 5 C with somewhat less high probability, but beyond that it's really difficult to say more.
Everyone catch that? The observed 0.7C warming over the last 125 years rules out the 2C estimates more than the 5C estimates of climate sensitivity. (To be clear, the observed forcings have been less than what a doubling of CO2 would have produced; I'm not saying the consensus "ought to have" yielded an observed warming of 3C.)
To put it in other words, I am pointing to the low observed warming as evidence that the models are fundamentally misguided, and PI's response is that no, according to the models, the models are just fine. Yes, that's true, in the model, the model is correct. But we didn't need to look at the data to make that point.
Gene, I am sure my good friends are going to have at me with this topic of climate change, so if you feel inclined please post other examples of this mistake in the comments. I.e., cases where very knowledgeable experts in a field can't step outside their orthodoxy in order to deal with critics who are asking for evidence that their worldview is correct. Basically, scientists who do the same thing as a fundamentalist citing gospel passages when asked to prove the authority of scripture.