Friday, November 10, 2006

Global Hot Air, Pt 2

My friend JR recently emailed me on this subject again, specifically regarding the Stern report. The Stern report is a document prepared by a senior British civil servant. It's been a while since I've written about it, and there were a couple of extra points I wanted to mention. So I decided to share them with you, my multitude legions of loyal readers.

1. Regarding important or controversial issues, when people have a legitimate case to make, they usually make it. If they don't, they tend to bring up side-issue distractions. For that reason, we should be very suspicious regarding disparagement of oil companies. In the big scheme of things, it's just not relevant. And the fact that it's as central to environmentalist activism as it is, should make us wonder that there's really no there there.

2. A scientific consensus on something, is often not particularly relevant and doesn't necessarily mean the underlying assertions are true. This is a little bit different than when I wrote there was no scientific consensus behind certain aspects of global warming, and probably more important. Like a lot of things, global warming in toto is a complex issue, but is also very simple in many ways. In particular, there are many parts of it which are not too complicated for a reasonably intelligent person to think through themselves.

And so it is with the Stern report. (Truth be told, we really shouldn't take the Stern report as a statement of scientific consensus. But JR cited it that way, so I'll just let that go for now.) As the editors of The Business Online point out*,
the Stern report makes no allowance for interest in evaluating cost. This is ridiculous, to the point where anybody should be able to see it. Millions of Americans own their residences, and the size of the check they write to the mortgage company every month is largely a function of the interest rate on the loan.

Or consider that the main case for global warming is the fact that scientists haven't been able to make any reasonably accurate atmospheric model without it. That's substantial evidence, but it's not necessarily conclusive. It depends on the quality of atmospheric models in circulation. We certainly don't need a scientific consensus to tell us the difference between software that works and software that doesn't. And atmospheric models are notoriously unreliable, the Windows95 of that corner of the world.

3. Like many other things, the case for global warming depends on looking at our current state and trends and extrapolating them far into the future. And in that context, derived quantities are in general less reliable than directly observed ones. Inaccuracies in the fundamental data are compounded the more analysis done on it, especially in this case where the inaccuracies are large in comparison to the phenomena they are supposed to measure. More concretely, there are substantial concerns about the quality of atmospheric data behind the global warming case. Ie, questions about how many tenths of a degree the earth has warmed over the last decade, how many fractions of a millimeter sea level has risen, how many parts per million CO2 is in the atmosphere. There are boiling debates about the heat-island effect and methodological controversies about data gathering, etc, that I don't have the time or patience too wade into to deeply. We should just allow that for the moment they are significant in their own right, but more importantly they illustrate that speculations about cause, effect, adaptability etc. are more haphazard than the existence of the underlying phenomenon.


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