It’s peculiar that Judith Curry is criticizing the IPCC and climate community for understressing uncertainty. It’s something one can imagine from the Wattses and McIntyres with their narrow focus on data, but it’s incomprehensible from a member of the community.
It’s hard to avoid this thought popping up as I watch the Schneider Symposium; probably over half the speakers have talked at length about uncertainty, and how to treat it in interfacing with the public and the policy sector. This includes a few high level IPCC muckety-muck types.
An interesting aspect that several have agreed upon is that the word “uncertainty” carries unfortunate semiotics; the public perceives “uncertainty” as meaning “confusion”. A comment from the audience, after much talk about how to communicate the range of plausible outcomes, noted that the new draft AMS statement on climate change eschews the word “uncertainty” entirely, even though the prior statement used it many times. I was astonished to hear this greeted by general applause and enthusiasm!
I heard one speaker suggest turning it upside-down and talking about “certainty” as a quantitative measure, which makes little sense. The right word to use is “confidence“, which in fact means exactly the same thing as “uncertainty” technically, despite appearing as its exact opposite in informal speech!
But the idea that this isn’t something the community struggles with is nonsensical.
Turning the word upside-down to call the “uncertainty range” the “confidence interval” may not help the basic battle against agnotology. The forces of confusion keep insisting that action is counterindicated because uncertainty is broad. As I’ve always said, this is complete nonsense. The greater the uncertainty, the greater the need for a vigorous response. It’s palpable but unstated in most of the sessions. People look at the uncertainties and are mostly concerned about cataclysms, not about false negatives. Schneider was quoted explicitly making the case that a false negative is far more dangerous than a false positive in this matter.
But it’s a matter which is easy to distort. And so, those inclined to inaction stress uncertainty. This is odd enough. But then they criticize a community that is plainly obsessed with uncertainty of ignoring it!
We can use the actuarial concept of risk very nicely. Risk is cost-weighted probability. The risk spectrum in the climate matter is dominated by worst cases, not by best cases. And that is why uncertainty is not your friend. And if you advocate inaction, it is not your ally.