The “Argumentum ad Timorem” and the Failure of Climate Models

Fellow netizen LM reminds me about Mark Buchanan’s “Thesis” op-ed in Nature Physics: “Less reticence on nonlinear climate change” (May 2007, Vol. 3, p. 291). A few extracts:

“…There are so many factors involved [in global climate] that no one can be absolutely sure […]
[Computational models] always seem open to legitimate criticism given the number of parameters they contain […]
The latest and biggest model may be ‘the best’, in some sense, but that doesn’t mean it is any good […]
What we shouldn’t be reticent about are the inherent dangers of strongly disturbing a highly nonlinear system that we’re not close to understanding, and on which our lives depend. We may not know the future, but we can have confidence that it won’t unfold gradually and predictably. There will probably be plenty of surprises, driven by instabilities and positive feedbacks. Precaution would seem very well-advised.”

(by the way: a trip to the local Library and a few days of wait for that magazine to be delivered there are in order…nice to see how “Nature” opts for the milking of $32 out of its readers rather than the free and full dissemination of articles on an issue about which they claim “time is running out“…)

Buchanan’s point is as interesting as it is flawed. And it is interesting because it can be used:

1. to argue that climate skeptics have been right all along: climate models are no good, and
2. to illustrate yet another example of out-and-out catastrophism, taking “change” as synonym of “bad”, and
3. to elucidate the flawed reasoning behind appeals to fight Climate Change in the name of the Precautionary Principle, with the Argumentum ad Timorem of accepting AGW as a given, out of fear for its consequences.

BYE-BYE MODELS
Wittingly or otherwise, Buchanan is suggesting that all the work done to model the global climate has been futile at best:

1. Models have inherently flawed results “no one can be absolutely sure” of (actually, that’s an euphemism). We can’t even tell if the best model is “any good”
2. Model have brought us nowhere in our quest to grasp the evolution of climate, “a highly nonlinear system that we’re not close to understanding”
3. Models can’t tell us much or anything at all about the future they purport to be describing. We can only have confidence in the fact that “there will probably be plenty of surprises”

No need to spend millions of dollars to figure out the above: even RealClimate acknowledges that climate models are “scenarios” and not “predictions”. It is not just a matter of building more powerful computers: no model will ever be able to take into consideration a future volcanic eruption, for example, as the actual start and end dates cannot be fathomed in advance by any computer we can dream of.

Everything considered, in Buchanan’s view models become a big waste of time, and of money, with the situation made all the worse as models are what politicians refer as predictive tools, when trying to conjure up ways to prevent a climate catastrophe.

Climate skeptics, wondering for years what the value could be in a multidecadal computer simulation with no chance of direct verification, truly may feel vindicated.

CHANGE IS ALWAYS BAD (DON’T TELL OBAMA)
Buchanan takes it for granted that climatic reactions will always be bad. And he brings his reasoning to its logical conclusion:

[…] Talk of a catastrophic shutdown of the North Atlantic Conveyor, or of possible ‘runaway’ global warming, isn’t irresponsible hysteria; it’s plausible speculation that is consistent with everything we know about nonlinear sysems. […]

Cue troublemaking “instabilities” and ominous “positive feedbacks”.

Yet, if we can only expect that in the future “there will probably be plenty of surprises”, why wouldn’t positive surprises be just as likely to happen as negative ones? For example: a more benign global climate, more rain in the deserts, fewer/weaker hurricanes, etc etc.

It’s exactly because we do not understand the climate, that everything and anything can happen in the short-, medium- and long-term.

FLAWED REASONING BEHIND THE ARGUMENTUM AD TIMOREM
Upon casual reading, models appear pretty much irrelevant in Buchanan’s description: the real point of climate change worry is not the uncertain stuff the models indicate, rather that we shouldn’t be “strongly disturbing” the climate because we do not know how it might react. That’s a good example of the Precautionary Principle: don’t do it if you have the remotest chance of hurting/killing some human (or animal) in the process.

And it’s also an “Argumentum Ad Timorem”, a reasoning based on fear: don’t touch anything, it might break!

In other words, Buchanan recommends precaution in face of admitted, abject ignorance and outright fear of what could happen. Note how the phraseology implies that Homo Sapiens is an extraneous body to the rest of the Biosphere. Quadrillions of microorganisms can “breathe” in and out as they please, yet it’s the animal called human that is singled out as the Strong Disturbance.

And how can we define what “strongly disturbing” means, in order to avoid doing that? After all there are many ways in which we (as individuals, and as a species) interact with the highly nonlinear system we live in. It’s not just CO2 emissions: people cut trees, replant forests, build roads, turn on stoves, cover green fields with industrial estates. One feels that unless the human race is trimmed down to 10,000 or less by tomorrow, we are bound to be “strongly disturbing”, whatever we do. Alternatively, by opting for voluntarily holding one’s breath, again we can stop disturbing (within a few minutes) whatever we have been disturbing so far.

Often, the Precautionary Principle appears as unassailable as it is paralyzing. But there is a way out, in matters of Climate Change.

In fact: why is Buchanan worried about CO2 emissions? Because climate models suggest that emissions may lead to changes in global climate. But at the same time, those same models are not good enough to make Buchanan limit his worrying.

With an understanding far from complete, and little clue on how the system will actually evolve, Buchanan finds himself fearing any “strong disturbing” of a system that we have been living with for thousands of years. Hence the Argumentum ad Timorem, whose actual source is in the models, not in the “disturbing”. Like a cancer test reporting too many false positives, worrisome-yet-too-uncertain models are less than useless: they are dis-useful: effectively, harmful.

Remove the models, and the very bases for the Precautionary Principle and the Argumentum ad Timorem go with them. And didn’t we show a few lines back, that climate models are a big waste of time, and of money?

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