By Cass R. Sunstein
Harvard University Press / 340 pages / $24.95
Natural and man-made disasters, it seems, are everywhere. They come from terrorists and tsunamis. Waiting in the wings are anthrax, aerosols, asteroids, avian influenza, and Arctic ice floes. Each of them presents a "worst-case scenario:" a low-probability event that could do disastrous - and irreversible - damage to life as we know it.
When risks have potentially catastrophic consequences - and reliable judgments cannot be made about probability - what steps should be taken to prevent them? Cass Sunstein, a professor of jurisprudence at the University of Chicago, addresses these questions in Worst-Case Scenarios. Using climate change as his case study, he sheds light as well on terrorism, the depletion of the ozone layer, cell phones and genetic modification of food.
The book is technical and theoretical. At times, Sunstein resembles a refugee from a Home for the Incurably Sociological. His "thought experiments" seem distant from real-world applications. And his prescriptions, such as the Catastrophic Harm Precautionary Principle, are, by his own admission, "lamentably vague."
But even if it's short on satisfactory solutions, Worst-Case Scenarios is an important and timely book.
Sunstein demonstrates that Americans tend to give undue attention to worst-case scenarios or pay no attention to them at all. Politicians and the public tend to believe that what happened in the recent past is the best guide to the future. When a "salient event" (like Sept. 11) occurs, the perpetrator has a clear identity (like Osama bin Laden), and "worst-case entrepreneurs" heighten anxiety, Americans are far more likely to support aggressive - and expensive - policies. Conversely, when the threat (like climate change) is not vivid, substantial costs must be incurred immediately and a catastrophe has not occurred and won't occur on "the watch" of any elected official, support for regulatory action is hard to muster.
Nor have policy-makers given sufficient weight to the possibility that removing one worst-case scenario opens the door to others. Fixated on weapons of mass destruction and mushroom clouds in Manhattan, President Bush invaded Iraq, positing a best-case scenario for the aftermath of the war. By 2007 the costs of war and occupation, estimated at more than a trillion dollars, dwarfed expected outlays for the Kyoto Protocol on greenhouse gases. Iraq was becoming a failed state and a haven for terrorists. Worst-case scenarios - regional instability, civil war between Sunni and Shia, and a dominant Iran, armed with nuclear weapons - proliferated.
Although he does not endorse Vice President Dick Cheney's now-notorious One Percent Doctrine, which treats a remote possibility of terrorism as a certainty "in terms of our response," Sunstein believes we have a moral obligation, even when we can't calculate the odds, to remove potentially catastrophic threats. The Principle of Inter-generational Neutrality, he writes, is the best place to start: The inhabitants of Presentville should consider their own interests as no more compelling than those of their imperiled descendants.
This Principle still raises the question of how much to spend - and on what. As Sunstein seems to acknowledge, all cost-benefit analyses seem little more than guesswork. And even the most careful approach includes subjective judgments about the "discount" on current value (including the Statistical Value of a Human Life, which is set at $6.1 million), which ensures that the present generation will not be required to make excessive sacrifices; and a redistribution of resources from the wealthy to the poor and from post-industrial states to developing nations - a deal-breaker for the Kyoto Protocol.
In the real world, alas, the response to catastrophic threats is unlikely to be rational or consistent. As long as "worst-case entrepreneurs" control the flow of information, Americans may well continue to oscillate between two poles, apathy and panicked over-reaction, under-spending and over-spending. Can anyone imagine a worse-case scenario?
Glenn C. Altschuler is the Thomas and Dorothy Litwin professor of American studies at Cornell University.
"How do human beings and their governments approach worst-case scenarios? Do they tend to neglect them or do they give them excessive weight? Whatever we actually do, how should we deal with the unlikely risks of catastrophe?"