I keep saying, from time to time, that I am a sceptic, not just about the imagined catastrophe awaiting us through anthropogenic global warming, or ‘climate change’, but about other statements and about theories in general. In terms of daily life, of course, I ‘take for granted’ all sorts of things that others might be sceptical about. I have found no need yet to be sceptical about them, or I don’t think it matters. I don’t, for example, care much one way or the other about fats of various kinds. I’ll eat butter or margarine, without worrying about the consequences.
What is it to be sceptical about something? My own meaning is that where I am not sure about something I think is important, and can’t reasonably be sure, I am sceptical about claims. That doesn’t mean I think it’s wrong, whatever it is; it is simply that I am not in a position to make a proper judgment. Some other person or organisation may be sure, but that is no real help to me. I need to make up my own mind about it, and for the moment I can’t. Therefore I don’t accept the proposition, at least for the moment. Quine would call it the state of ‘suspended judgment’, one of non-belief rather than of disbelief.
I came across a neat little series of thoughts on the issue of scepticism on the Fabius Maximus website, and that prompted this essay. Much of it comes from a man whose name I didn’t know, but who is credited with the immortal line: ‘extraordinary claims require extraordinary proof’, though there are earlier versions of it from Laplace and David Hume. His name is Marcello Truzzi, and he was once a Professor of Sociology at Eastern Michigan University, where I was once offered a senior job. I was tempted, as an Australian might especially be, at thought of working at EMU, but I went elsewhere. Truzzi was famous for being prepared to investigate the ‘paranormal’, and the claims of protosciences (most of the natural sciences before the mid 19th century) and of pseudosciences (alchemy, for example).
He summed up his position like this:
In science, the burden of proof falls upon the claimant; and the more extraordinary a claim, the heavier is the burden of proof demanded. The true skeptic takes an agnostic position, one that says the claim is not proved rather than disproved. He asserts that the claimant has not borne the burden of proof and that science must continue to build its cognitive map of reality without incorporating the extraordinary claim as a new “fact”. Since the true skeptic does not assert a claim, he has no burden to prove anything. He just goes on using the established theories of “conventional science” as usual. But if a critic asserts that there is evidence for disproof, that he has a negative hypothesis … he is making a claim and therefore also has to bear a burden of proof. (Marcello Truzzi, ‘On Pseudo-Skepticism’, Zetetic Scholar, 12/13, pp3-4, 1987)
Now I like that way of setting things out. I think it is where I am, and where I have been, too. It helps me with the argument with Stephen Mosher that was the subject of a recent essay. I entered this debating arena ten or more years ago by saying that I was an ‘agnostic’, and that I was prepared to accept what I now call the ‘orthodox’ AGW or ‘climate change’ proposition if the argument and data were good enough. As time has passed the data and argument look weaker rather than stronger, but I am still open to persuasion.
Someone else (James H. Hyslop) has called scepticism ‘critical ignorance’, and I like that too: Hyslop adds Open-mindedness is the only scepticism that can claim immunity from prejudice. (The link is in the Truzzi article.) Here is Truzzi again.
Evidence is, then, a matter of degree, and not having enough results in a claimant’s not satisfying the burden of proof. It does not mean disconfirmation of the claim. The proof is insubstantial, and the claim is unaccepted rather than refuted. The claimant is, in effect, told either to give up or go back to find stronger evidence and arguments for a possible later day in the court of science. As a practical matter, an unproved fact is a non-fact.
There is a lot of Popper and Khun in all this, which Truzzi concedes, but the Truzzi essay is well worth reading by those who think of themselves as ‘sceptics’, because he brings all of the various insights into a clear and sensible summary.
Let me deal with one of the familiar red herrings in the scepticism business, about which I have written in the past. You are diagnosed with cancer. Are you sceptical when you hear what the specialist(s) say(s)? Now I have been diagnosed with cancer, and treated for it, and that was 24 years ago, and I am still here. I wasn’t at all sceptical on that occasion. I knew something about the condition, and I knew also that the science was by no means fully developed (we are still searching for a ‘cure for cancer’). Therefore at best there were probabilities, and there were risks.
In the case of ‘climate science’, which I would term a ‘protoscience’ rather than a ‘pseudoscience’, the science is not at all well developed, much less so than in the medical science to do with cancer. I am sceptical of the claims that carbon dioxide is the control knob of our climate, that increasing carbon dioxide in the atmosphere is bound to be bad for us over a human lifetime or two, and that carbon taxes and emissions trading schemes can do anything of any consequence about climate.
Here there is abundant data and argument, and from my perspective, and I think from that of any educated and informed person, those data and the general argument do not powerfully support the AGW orthodoxy. That could change, and I once wrote a piece about what would be necessary for me to change my perspective (and cannot find it). There would need, for example, to be unequivocal evidence that ‘climate sensitivity’ was at the very high end of the IPCC’s range — 4.5, perhaps. But it increasingly looks as though climate sensitivity has a value of around 1, or a little higher. If that is the case, then we do not have a problem with global temperature in the foreseeable future.
I am also sceptical that anyone will do anything to change the orthodoxy, either, which is a bit sad. Wegener’s theory of ‘continental drift’ was pooh-poohed by geologists almost everywhere, but a generation later (after his death) was resurrected as ‘plate tectonics’, and is now accepted as good theory. It may take a generation before ‘climate change’ theory is finally buried, at least in the form that humans are responsible for global climate. We’ll have something else to worry about by then, and I won’t be writing posts like this — or at all!