Thursday, July 29, 2010

"Climate change" 1 - it's the uncertainty, stupid

In an earlier post, I'd expressed the hope that we were starting to see the winding down of "climate change", at least as a political hot button, and I see others are still of that opinion, in particular Shika Dalmia of Forbes ("The Death of the Global Warming Movement") and Paul Krugman of the NY Times (in a hilariously titled column, "Who Cooked the Planet?"). But then you get Tyler Cowan, of all people, endorsing a carbon tax because, oh, who knows, it might do something, and we need to tax something anyway, and.... Sigh.   

Having gotten into a couple of online debates in comments recently, though, (see this post, and this) it seemed to me worthwhile to summarize my general position here, and say why attempts at major policy decisions aimed at curbing carbon emissions are not a good idea -- not now, and probably not ever.

First, this has nothing to do with any skepticism regarding AGW -- though I should perhaps say it has almost  nothing to do with such skepticism, since a critical approach to any such claim is both rational and in the best traditions of science, and since any new evidence that AGW is not occurring would of course undermine attempts to mitigate it. But, on the whole, and despite the despicable behaviors of some climatologists revealed by Climategate, I think it's likely that AGW is a reality.

Second, this has nothing to do with how hard or complex it might be to get concerted global action to make the huge cuts in carbon emissions necessary to have any significant impact on AGW, given the above likelihood. It's not the difficulty, it's the uncertainty. When making policy decisions that are a) known to have serious immediate costs in themselves, but b) not known how successful or effective they might be, over an extended time period of 1 or 2 centuries, and c) not known how they might compare with even present policy alternatives not to mention others that might show up in the years before any significant effects of policy could be felt -- then "Just do something" is not a good motto. "First do no harm" is a better one.

The point here is that it's not just one source or level of uncertainty, but rather a concatenation of uncertainties, which when joined together reveal just how deeply irrational the "just do something" frenzy has been":
  • First, of course, there's the lingering uncertainty regarding the warming trend itself. As I've said, despite Climategate and the "hide the decline" embarrassments, it still seems this is likely. The only point here is that there are numerous instances in the history of science where something that seemed highly likely, even obvious, at one point, turned out to be wrong -- and it's important to stay open to the possibility that this too may be wrong.
  • Second, given the likelihood that there is a warming trend, there's also some remaining uncertainty around whether or not it's caused, or caused primarily, by human activity. Again, it looks as though this is also quite likely at this point, though there are certainly additional sources of uncertainty introduced here -- we're starting to see the problem when levels of uncertainty are stacked on top of one another.
Here's where the serious layers of guess-work begin:
  • Third, given the above two likelihoods, there is considerable uncertainty surrounding the costs of this warming -- or even whether, balancing gains against costs, including the costs of adaptation, the result of a warmer world would not be a net positive (fewer deaths from cold, vast new areas of arable land, etc.) One reason the whole issue so often looks like fabricated alarmism is just the fact that you almost never hear even the possibility of any gains from warming, as though somehow the world is only now at some magical Goldilocks level of perfect temperature.
  • Fourth, even if we knew the costs of warming, or even just knew that it would be a net negative -- i.e., that anything warmer must be worse -- there is a huge uncertainty around the costs and likelihood of success of any particular strategy of mitigation, costs and probabilities that would need to be added to the balance sheet before we could assess the cost/benefit of the strategy. This too has been largely ignored, as warmist believers have focused on only the most immediate, short-term objectives of carbon emission reduction, as in Kyoto. Those alone have significant economic impact, but everyone understands, even if they rarely speak it, that such objectives in themselves will have only a negligible impact on climate change a century or two from now -- the only thing that has the remotest chance of an impact would be massive emission reductions, even as most of the world is still trying to industrialize. Such reductions could only be realized by the most wrenching economic interventions, which would in turn have a serious impact on the chances of such policies ever being sustainable in the long time frames necessary.  And likelihood of success is particularly important here because if the strategy fails it simply adds -- perhaps greatly -- to the overall costs of the warming itself.
And the greatest source of uncertainty of all...
  • Fifth, even if we could convince ourselves that we've got some sort of even approximate handle on the overall cost-benefit of both the warming and the chosen mitigation strategy, the very time frames involved here introduce insuperable uncertainties. To see why, consider just a range of 40 years -- enough to take us just to mid-century going forward, or to 1970 looking backward. That's not long in this case, where the anthropogenic warming is typically considered over a range of from one to two centuries, but, looking back, it's enough to take us into another world so far as environmental issues are concerned. In 1970, if climate was considered at all, it was as a source of worry about an approaching Ice Age; there was going to be a "Great Die-Off" in the 1980's that would kill 4 billion people; metal and mineral resources, not to mention oil, would be used up by the year 2000; survivors would be wearing gas masks in cities; etc. Needless to say, things look different now. Not only that, but in 1970 there were no cell phones, no digital cameras, no Internet, no personal computers, and little hint that any of that might be coming and might change the world and our sense of what's possible -- just 40 years ago. If, just 40 years from now, we find our sense of the world and its possibilities changed to a similar degree, then global economic/climatic engineering projects now will almost certainly look as antiquated and silly as those apocalyptic predictions of 40 years ago. In particular, possibilities of carbon capture and sequestration that are even now being looked at seriously -- see, e.g., "Washing Carbon out of the Air", Scientific American, June/10 -- may make it possible to reduce atmospheric carbon to below industrial levels much more quickly, cheaply, efficiently, and effectively, than any such politically and diplomatically fragile global emission-reduction schemes. 
So, in the context of such a stack of uncertainties, the recent media and political push to "Just do something!" seems much more a kind of over-excited fad, or one of those "end times" apoclyptic hysterias that occasionally sweep through whole populations, like a cultural contagion, rather than anything based on the actual science of climate change itself. In the next post, I'll look at these more irrational influences. But in the meantime, I'll end this one by noting again, as I said at the start, that it seems as though more and more people are already shaking themselves awake from this fixation, and many are starting to feel that maybe they've been had. Or so we can only hope.

UPDATE: next post in this series.

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