Sunday, January 25, 2015

Pararationality: Climate Science Edition

"Pararationality" is a term I coined for use in a new course that focuses on arguments that appear to be rational in some sense but that are in fact unsound at best or, what is more typical, invalid at worst. Typically the sorts of arguments that I have in mind have to do with the public reception of scientific work (for example, unreasonable skepticism regarding either the explanatory power of or even scientific status of evolutionary theory, or equally unreasonable attempts to argue for a causal connection between vaccinations and childhood autism), though this is not a necessary condition on the sort of reasoning I have in mind (for example, uninformed views about the nature of probability often lie behind acceptance of certain hypotheses even outside the domain of the sciences). Pararationality is, in some ways, just fallacious reasoning, but with it I intend to pick out those instances of fallacious reasoning that are particularly embedded in our culture in ways that have become remarkable as a social phenomenon.

Lately I've been thinking about the sorts of cases to look at closely in the course, and Facebook, unsurprisingly, has offered some striking examples. Climate science is in the news a lot as well as in Facebook threads not because the research is of poor quality but because the suggestions of some climate scientists regarding public policy have been found unsavory in various political quarters. What is interesting about the case of climate science, however, is the vehemence with which these political sectors have denied that their objections are political. Indeed, almost to a man, they insist that it is not they who are being political about the science, but the researchers, and they go on to argue that the science is flawed and that climate scientists defend their work for political rather than scientific reasons.

I have found a couple of examples of this phenomenon from my own Facebook feed and an examination of them is instructive. Now, Aristotle once remarked (Nicomachean Ethics I.6 1096a14-16) that it is better, indeed our duty, for the sake of maintaining the truth even to destroy what touches us closely, for, while both are dear, piety requires us to honor truth above our friends. With that sentiment in view, therefore, I will not identify the authors of these remarks even while showing the ways in which they stand as illustrative examples of pararationality.

The first example is a remark whose author was so proud of it that he copied it and posted it in more than one place on Facebook, each time in reply to a posting of a graph showing 2014 to be the warmest year on record:
And yet not nearly as warm as it was between the years 1000 and 1300, a period during which human population and prosperity boomed. This was then followed by the Little Ice Age, during which temperatures plummeted, major rivers froze over for months at a time, crops failed, famine raged, and the Black Death killed off a third of the world's population. The Little Ice Age ended only in the middle of the 19th century, so one might say not that we face catastrophic warming, but that we are just getting back to where we ought to be.

Because, morons, climate changes--sometimes quite drastically in a short timespan. It has ALWAYS done this, and it has NOTHING to do with us. We do not cause it, neither can we stop it.

You're puny, humans! Get over yourselves.

The person who wrote this, while not uneducated, is basically an autodidact and, while I admire autodidacticism in general, in this particular instance it highlights the dangers of trying to educate oneself in the absence of anything analogous to peer review. So if we put aside, for a moment, the question of the advisability of referring to genuine experts as "morons" when one has only an undergraduate degree in public policy on which to ground one's own views, there is still plenty here to examine closely.

Let us begin where our author begins, with the claim that it was warmer between the years 1000 and 1300 than in 2014. The first thing to note about this claim is that, to the extent that there is any evidence for it at all, the evidence shows it to be false. By the year 2004 the average global temperature was already much higher than in the 1000-1300 period, and by 2014 the average global temperature was higher still.

As interesting as the mistake about the empirical data is, however, what is even more interesting is the assumption that lies behind the assertion. In order to make comparative claims of the sort that our author wants to make, one would need data collected in relevantly similar ways. But in fact there are no reliable temperature data from the period 1000-1300: what we have instead are estimates based on indirect evidence such as ice cores, tree ring data, and subjective personal reports, none of which are very well documented nor, in the case of the ice cores or the tree ring data, are they collected from analogously relevant locations from around the globe.

Now, it is true that cooling of average temperatures in Europe during the period from roughly 1350 to 1850 has been called the "Little Ice Age", but these effects were not as pronounced around the globe. However, it is fair to say that the evidence for global cooling patterns either during this same time period or shortly thereafter is not nil, so suppose we grant that the temperatures cooled globally during this period. While it is tempting to point out that even today rivers still freeze over for months at a time and crops continue to disappoint, that would be fun but beside the point, since there is a more important claim on the table here. Notice the inference our author wishes to draw from the temperature differential from 1000-1850:
climate changes--sometimes drastically in a short timespan. It has ALWAYS done this, and it has NOTHING to do with us.
This is where the reasoning becomes very bad indeed: our author is asserting the following argument:
In the past, phenomenon X was caused by non-human activity. Therefore, any appearance of phenomenon X will also be caused by non-human activity.
Or, to put it another way, if we were to ask our author, "How do you know that today's changing climate is not due to human activity," his answer would appear to be nothing stronger than "Well, in the past it wasn't due to human activity, so it's not due to human activity now." This is obviously invalid, as Hume famously showed, but it is not even a strong induction. It is worth noting that we actually do have some very good candidates for causal mechanisms involved in both the warm period of 1000-1300 and in the so-called "Little Ice Age", just as we have some very good candidates for the causal mechanisms involved in our own contemporary warming trend. What our author is doing, with something like the appearance of rationality, is suggesting that because climate change in the past was clearly not caused by human activity, we have no rational reason to think that the present climate changes are due to human activity. This ignores the evidence of the causal mechanisms involved in the various climate changes being discussed, and simply assumes that they must always be similar.

Pointing out that it is not a good argument to claim that different causal mechanisms cannot bring about similar effects may seem like shooting fish in a bucket, but this argument is not at all rare, and one finds all sorts of variations on the theme of "the climate has always been changing, it was never due to human activity before, therefore it isn't due to human activity now". To the extent that the proponents of this view bother to address the empirical data regarding causation at all, they do so incompetently, because, of course, they are not experts in climate science themselves, they are simply annoyed at those climate scientists who are trying to tell us what to do about this situation.

A slightly different approach is taken by those who, knowing they are not experts in climate science, nevertheless see themselves as experts in history and, thus, qualified to make assertions about science on the basis of their interpretation of the history of it. This leads to a different sort of pararationality. The following quotation comes from someone who is responding to a story from New York Magazine in which Jonathan Chait, in something of a snit, argued that "climate science denialism" ought to exclude someone from holding pubic office. Putting aside, for a moment, the foot-shooting aspects of that suggestion, let's take a look at what my friend said about it:
So whenever there is a scientific consensus on issues like eugenics (or say abortion where the medical community assures us that the fetus in no way merits protection) then that should just trump democracy? Why even hold elections at all ... just have examinations that scan for right thinking?Oh - and the scientific consensus in psychology used to be that homosexuality was a sickness (and might one day be that religious belief is also a kind of illness).... One of the things I found fascinating when doing research on eugenics was the degree to which so many people were so absolutely certain of the scientific consensus that they did all sorts of horrible things AND labeled as dogmatic religiously inspired sentimentality any opposition to their policies.
The author of this bit is not directly challenging the claims of climate science in this particular quotation, but I use it as an example for two reasons. First, it is a good example of pararationality. Second, the very same author has, on numerous occasions, expressed deep skepticism about the claims of climate science, so perhaps our author makes these comments partly for personal reasons in reaction to Chait's ridiculous suggestion.

The principle argument here has to do with the notion of a "scientific consensus", which our author contrasts with democratic ideals regarding social policy. There are two principle flaws with this, both of which bear examining. One is the mistaken notion of science involved in comparing the present state of climate science with that of eugenics in the early 20th century, the other is the attempt to suggest an inference based on an analogical comparison of the scientific community and the democratic polity.

First, regarding the scientific question. While it is often tempting to point out the arrogance of scientists who think they know everything and are happy to tell you so, one must avoid conflating this feature of the scientific community with the actual work they do. So while it is true that some contemporary climate scientists are, indeed, just as big assholes as early 20th century eugenicists, this is irrelevant to the question of the comparable worth of the work being done by contemporary climate scientists and early 20th century eugenicists. For one thing, in the 1920s and 1930s genetics in general was still in its infancy, but climate science is well established and is not at all controversial among scientists generally, which is not something that could be said about eugenics as an offshoot of genetics. There was never any consensus about causal connections between genetics and human worth or behavior, but there is a consensus about a very well understood set of causal mechanisms regarding climate change, so comparison of the two cases is at best a false analogy but at worst, and sadly more likely, a kind of ignoratio elenchi.

One might add that, while there are certainly plenty of medical professionals who do not oppose abortion, the claim that "the medical community assures us that the fetus in no way merits protection" is simply false, and indeed is something of an insult to the many medical professionals who oppose abortion in the strongest possible terms. To treat the "medical community" as something monolithic and easily described in a slogan or two is not even pararational, it is simply ad hominem and fallacious.

Second, when one accepts democratic ideals as the best sort of social polity one is making a very different sort of normative move than one makes when one accepts a scientific consensus about a scientific problem. In a democracy, everyone is treated as though capable of governing, whether or not they are so in reality. But in science, not everyone is endowed with the same expertise regarding scientific questions. While it is true that, in a democracy, we cannot force the general public to act in any specific way on a particular finding of the scientific community, it does not follow from this that the general public is in any position to reject those findings as "not good science". Granted, our present author does not say precisely that in this particular quote, I only mention it because he has made similar suggestions elsewhere, and indeed it is not an uncommon version of this very same argument to point out that as long as there are one or two people who work in scientific areas who do not accept the general consensus, then there isn't really any consensus at all. The desire seems to be to excuse one's refusal for taking a particular course of action not by saying that one does not wish to act in that way but rather by accusing the scientific community of trying to put one over on us and force us to act in a way contrary to what we desire. It almost seems that, in arguing this way, the proponents of this view are admitting that, if the science is right, we really ought to do something. So let's pretend that the people who are doing the science don't know what they're doing, or are politically biased, or are morons.

I once had an argument with a very well-educated woman about evolutionary theory. Her education, however, was in English literature, not biology, so I was perplexed when, to my query as to why she rejected it, her answer was "I just don't buy it." In short, she didn't have anything to propose in its place, nor did she have any particular argument against it--she just didn't "buy it", as though scientific evidence is some sort of commodity that we may either buy or leave on the shelf for some other poor sap to fall for and take home. While I don't agree with Chait's proposal, I do think there is a problem with scientific literacy in our country, and that is unfortunate.