Wednesday, December 5, 2007

Posner's Catastrophe: Risk and Response

This is not really a review but just a record of my impressions. It was a little surreal to read a conservative judge's review of movies like Armageddon, The Day After Tomorrow, and Matrix. Surreal but pleasant. It was also a little surreal to hear him discuss the possibility of a strangelet disaster and gray goo. Ultimately, his view of catastrophe (complete annihilation of the human race or something of the same magnitude) is not the same as my idea of a catastrophe (e.g. Katrina, earthquakes) possibly because these are already written somewhere else. However, he sometimes switches between human extinction with just extinction of Americans and its a little confusing and inconsistent.

He does take on issues such as abrupt climate change rather than gradual climate change which he views not as a catastrophe but something that we can adapt to. If I'm reading him correctly he advocates that we take action now even though the probability of an abrupt climate change is remote (small probabilities of extremely large losses). So he is not in the same camp as those who propose cap-and-trade and/or small hikes on gasoline. He proposes a large tax on emissions rather than on fossil fuels to induce innovation in cleaner fuels and carbon sequestration technology.

Not surprisingly, given his background, he advocates using cost benefit analysis as a guide not because it is problematic but because it is hard to put numbers on probabilities and costs. CBA in his view is a way to focus on the issues and to think through them. Rather than to dismiss CBA by saying the cost is infinite or we should not use any discounting, CBA forces a disciplined approach to whether we should undertake any measures to counter the possibility of a catastrophe or to not fund a project because of the possibility of a catastrophe. His analysis indicates that Brookhaven's Relativistic Heavy Ion Collider should not have been built. He also goes through CBA exercises with numbers as examples. This is refreshing since he also debates the value of the numbers being used as in, "I plucked this number out of the air".

This was also the first time I've read a critique on the uncertainty in measuring species and biological diversity (estimates of the number of species) and the rate of extinction. The end notes (I would have preferred footnotes) were a wealth of information on this and other disaster scenarios.

Some interesting passages:
Conservatives seize on the existence of doubt about the magnitude or causality of global warming to oppose emission controls, while liberals seize on doubt concerning the likelihood of bioterrorism to oppose limitations on granting visas to foreigners to do research on lethal pathogens. In neither case is the existence of doubt a valid ground for rejecting expert opinion. Doubt properly is an input into analysis rather than a substitute for analysis. [Fred] Singer's basic error is to suppose that the only rational response to the existence of doubt is to conduct research aimed at dispelling it. (p. 57)

Not only is there no census of species, but it is infeasible to conduct one, because many species, especially those in danger of extinction, have minute populations and restricted habitats, often in hard-to-reach places. As a result, we do not know how many of the species that are not being conserved will become extinct unless heroic mesausres are taken to preserve their habitats. If we take a strictly anthropocentric view of catastrophic risks, eschewing philosophical questions, we must ask what exactly humankind loses by extinctions. Maybe nothing beyond the charm of the unusual life forms if extinctions are considered one by one; what is worrisome from the point of view of this book is the unknown consequences of mass extinctions. (p. 65)

I stopped noting these after the first chapter (which is probably the best chapter out of the four chapter of the book). Chapter 3 on CBA is interesting as well not only in his attempt to apply it but in his simultaneous critique of his attempts.

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