If you want to be an honest and constructive participant in public debate, it’s important to acknowledge evidence that you didn’t expect and that doesn’t seem to fit your understanding of the world. Ideas are complicated, and there really is no such thing as a beautiful theory slain by a single brute fact. But over time a theory can be rendered ugly by too many pesky stinging facts that don’t fit. And in our case we acknowledged in March that Arctic sea ice was at its lowest level in a decade, the opposite of the situation a year earlier, when we pointed out that it was at a 20-year high and a lot of alarmists, instead of going oh that’s weird, didn’t see that coming, proceeded to throw a fit at us. So what will they make of the fact that, after a slow spring, the ice is staging a comeback, having actually tied the decadal high over the weekend before falling very slightly behind 2023 and 2024 at time of writing while still exceeding every other year since 2016? Does it prove we’re no-good rotten something-or-others again? Or that the ice is part of a plot? Or that too many climate alarmists aren’t the kind of people who admit their theory could be doubted by people with working hearts and minds? As historian John Lukacs has pointedly observed “People do not have ideas. They choose them.” And it’s important to do so with a balanced mix of bold determination and cautious humility.

Theories are complicated things because the world is complicated. As Willard van Orman Quine famously wrote (OK, it’s famous with us), any comprehensive view of how the world works in any field, including science:

“is like a field of force whose boundary conditions are experience. A conflict with experience at the periphery occasions readjustments in the interior of the field. Truth values have to be redistributed over some of our statements. Reevaluation of some statements entails reevaluation of others, because of their logical interconnections – the logical laws being in turn simply certain further statements of the system… Having reevaluated one statement we must reevaluate some others, which may be statements logically connected with the first – or may be statements of logical connections themselves. But the total field is so underdetermined by its boundary conditions, experience, that there is much latitude of choice as to what statements to reevaluate in the light of any single contrary experience.”

This statement is not a call to relativism, a declaration that truth is unobtainable or can be anything we like. It is a caution that to establish or rebut a theory is a complicated business including both rigour with respect to facts and logic and a certain intuitive sensitivity to when the internal tensions involved in keeping the boundary intact have become suspiciously or intolerably high.

The world is complicated and so are many things in it. Including Arctic ice. We did point out in March that if Javier Vinós is correct in his Winter Gatekeeper hypothesis challenging the Enhanced CO2 orthodoxy, then the Arctic warming isn’t proof of a warming planet but a cause of a cooling one. But we also said, and say again, that just because we find this theory appealing, partly because of its compatibility with others we think are on balance supported by the evidence, doesn’t mean it’s true and certainly doesn’t mean that anyone who mounts an informed challenge must be a fool, a rogue or both.

On the contrary, it’s something that requires investigation, with skeptical minds probing the logic and the evidence. But not closed minds shouting it down or scorning to acknowledge its existence.

The same is true of a point we made more recently about Arctic ice and specifically what we know about it. Climate alarmists are very fond of the modern satellite data record beginning in 1979 for two reasons, one much better than the other.

The good reason is that this data is better than anything collected before. It is more comprehensive and more precise and both are good things.

The bad reason is that it seems to show a dramatic decline in Arctic ice which is compatible with other ideas they think are on balance supported by the evidence. (Or, less creditably, think are proven by the “settled science” and only rogues or fools could question them.) But while other data sets going back further aren’t as good, we really do want a longer-term perspective on the behaviour of Arctic ice and whether it exhibits cyclical patterns of which a decline from 1979 through around 2010 might be a natural component, since the idea here is to separate the “signal” of human influence from the “noise” of natural variability if, indeed, there is such a signal to be found through honest and rigorous research.

The trouble here for their theory is that in fact it seems that Arctic ice was a lot lower in the early 1970s than in 1979 or indeed today. Which if true surely puts the kibosh on the notion that it’s melting at all, dealing a mortal blow to any claim that we’re melting it.

There’s no sin in being attached to ideas that seem to you to work. If we abandoned every hypothesis in the face of the first unexpected detail, we’d never be able to think at all. But there is a problem with being so attached to ideas that we can’t see or won’t acknowledge such details. In another famous passage, this time from historian John Lukacz (and again famous is a word here meaning we think it’s cool, not that everybody knows it), in which he explains that having rejected first naive objectivity and then radical relativism he concluded that:

“it is possible (and there exist, fortunately, examples of it) for a historian or a scientist or, indeed, for any thinking man to present evidences, from a proper employment of sources, that are contrary to his prejudices, or to his politics, or indeed to the inclinations of his mind. Whenever this happens, it manifests in his decision to present (which usually means: not to exclude) evidences not supporting his ideas or theses. Something – not merely by the external material evidence, but something internal and spiritual – compels him to do so. I prefer not to name this kind of intellectual (and moral) probity ‘objective’ (or even ‘detached’). ‘Objectivity’ is a method: I prefer the word honesty, which is something else (and more) than a method: within it there resides at least a modicum of humility (and in history, being the knowledge that human beings have of other human beings, even a spark of understanding, of a human empathy).”

When it comes to Arctic ice, we were surprised to see it at a low for the decade early this spring and we said so. We also weren’t sure what it meant and we said it as well. But now that it’s rebounding, will alarmists admit they were surprised and don’t know what it means? Because if not, they have a mental and a moral problem.