Clarification On How to Better Examine Evidence Relating to Rare Extreme Weather Events in a Changed Climate
This was not the article I was planning on writing just next, but it appears that I must elaborate on some things I referred to in passing, lest they be misunderstood.
I certainly don’t advocate that “analysis of extreme weather events starts with the built in assumption that climate change has made it worse” as has been alleged. Quite to the contrary, I am suggesting we approach the Disaster Tango afresh, in such a way as to engage skeptics and consensus supporters alike, provided they are reasonable and rational about it.
Imagine you are reasonably well versed in science, probably an applied science like dentistry or mechanical engineering. You are professional and proud of your skills. And you look into this “global warming” business, and most of the writing on it seems like polarized nonsense. But though you see dubious arguments everywhere the allegedly consensus claims seem extreme to you, and you start to fall into the “skeptic” camp and gravitating to some theory of what is going on that casts significant blame on the key scientists in the field. And you start to enjoy mocking them.
A lot of climate scientists find falling into this position unimaginable. But I don’t. There but for the Grace of God go I.
And a lot of political types, especially journalists and people focused on elections, find this group irrelevant, unimportant. They make a lot of noise, they give cover to recalcitrant politicians, but they haven’t enough influence to matter.
I disagree. I think having a core of intelligent people not getting it is fundamentally a problem in a democracy We have to find a way to reach, if not the core group of celebrated malcontents and their sleazy professional eggers-on, the many intelligent people they are constantly recruiting.
So let’s for the sake of argument adopt the point of view of a skeptical recruit. Your position in the Disaster Tango is that claims are made linking every weather disaster without exception and even the occasional tsunami to climate change, that it is ridiculous, and that RPJr and Marty Hoerling among others have convincingly shown that there is little evidence of any trends to increased disasters, and that any concerns are at most ones for a distant future that can gradually adapt in any case.
But you, the skeptic, note that there are people who seem otherwise rational, who stubbornly resist this evidence. You want to win them over. Therefore, what you should be doing is looking at the totality of weird events, and try to determine whether they are getting weirder in any way that might be considered alarming. This seems like a question that can be addressed objectively enough that any person of good will would be convinced. And if, after all, the question is decided against you on the basis of sound reasoning, you would endeavor to the sort of person who would be convinced by it.
Now take your skeptic hat off.
We believe that there is no point in discussing mitigation yes/no anymore – that action is overdue and that contemplated action, while welcome, appears so far to be inadequate. Further, we can see that past commitments have mostly been ignored or fudged.
So we don’t know whether it is worth taking a great deal of trouble to investigate the global tendency of weird events. We know that if they haven’t taken off already they are about to with a vengeance. We can see the cracks in Nature starting to spread and slip. We don’t need no stinking proof anymore, and anyone who can’t see the risk is being amazingly obtuse.
If the bad guys trick the public with nonsense, we have to be better at influencing the public with near-sense. There’s no time to do better, we don’t have the troops on the ground to address every bit of crackpottery anyone comes up with. We should ignore all the dentists and engineers who make a hobby of tormenting this year’s target scientist.
Yeah, I could easily imagine going there too. Some of my best friends are there.
But look, let’s for the sake of argument assume that’s true. Let’s assume we don’t have the resources to address to bottomless arguments with stubborn Dunning-Kruger cases. What should we be putting our brain cells to?
Well, we are beyond the point where we can avoid the adaptation question. (I heard on NPR this week that people are moving fish up hills, on by one, trekking them up thousands of feet in little plastic bags to isolated ponds, in the hope that their species can find a cooler spot to which they are better suited.)
Adaptation will be expensive, and we need to plan for it. To plan for adaptation, we need a better handle on what we are adapting to. Early especially weird severe events which would be very unlikely in an unchanged climate are a sort of canary in coal mine, but we don’t really have a handle on it. So the prognosis for severe outlier events is something worth thinking about even if we don’t care about convincing the skeptic crowd.
So though I wanted to keep you in suspense for a while, and continue to think about how this ought to work, it appears necessary in the light of what I will charitably call misunderstanding, for me to summarize where I am heading as I see it now. I reserve the right to make modifications and even retractions as I investigate further, but this is my thinking as it stands.
1) We acknowledge that humans have changed the composition of the atmosphere measurably. This has changed the climate, whether to a tiny or large amount is to be determined, to some extent by this endeavor among others.
2) Since the human contribution is nonzero, all events, and especially all severe outlier events, take place in a changed environment. For present purposes, we do not assume whether this change is benign or malign, nor whether it is so far minimal or already overwhelming.
3) Both for defending the mitigation proposition and for calibrating the adaptation costs, it is worth keeping a close watch on whether extreme events of various sorts are indeed increasing in frequency or severity. Ideally we would also like to know if they are changing in geographic distribution.
4) Attempts at yes/no attributions of individual events to anthropogenic forcing or partial attribution by regressing against climate model output are misleading because they are inappropriate tools for rare events.
5) Attempts at yes/no attributions of individual events are also particularly counterproductive, as they exacerbate polarization and reduce the field for reasoned, nuanced discourse. Science-driven policy conversation should always seek continuous rather than binary-valued measures because it leaves room for ambiguity and allows for incremental progress and consensus-building.
6) This is more controversial, but I’d say partial attribution methods typically overvalue and misuse GCMs. (Ironic, huh?) In any case they low-ball attribution systematically. To take an extreme example, if at any point in space the model has the wrong sign for a trend, the partial attribution method will assign any event, no matter how bizarre, a negative percentage of anthropogenic contribution.
7) Recurrence times are problematic in interesting ways, but potentially offer a quantitative approach to the severe event problem by allowing various potentially fruitful ways to aggregate events over very large time and space scales, so we can reason about them effectively.
8) This does not appear to have been done. One of the key problems is global availability and inhomogeneity of data, especially regarding extremes of precipitation and drought. This leaves plenty for citizen scientists to work on in many countries.
9) Looking at temperature events can make use of remote observation datasets, so rolling up our sleeves and thinking about how to go about classifying and collating outlier events in temperature could start quickly.
I note that there is no role for GCMs in this research program, so we don’t have to try to explain to skeptics what GCMs are for and what they are not for, which has not been a winning proposition so far, to say the least.
I hope this helps clarify matters. I am certainly NOT advocating looking away from the evidence. I am advocating sounder ways of looking at the evidence, such that the currently dull Disaster Tango gains a few more interesting steps.