Notwithstanding the similarities, the Montreal Protocol has proved a stunning success, and the Kyoto Protocol has largely failed. The contrasting outcomes are best explained by reference to the radically different approaches taken by the United States-by far the most significant contributor, per capita, to both ozone depletion and climate change. It is tempting to attribute those different approaches to the political convictions of the relevant administrations. But the Reagan administration, which pressed for the Montreal Protocol, was hardly known for its aggressive pursuit of environmental protection, and the Senate showed no interest in the Kyoto Protocol during the Clinton administration. The American posture, and hence the fate of the two protocols, was largely determined by perceived benefits and costs.
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The real problem with the Precautionary Principle, thus understood, is that it offers no guidance-not that it is wrong, but that it forbids all courses of action, including regulation. Taken seriously, it is paralyzing, banning the very steps that it simultaneously requires. If you accepted the strong version, you would not be able to get through a single day, because every action, including inaction, would be forbidden by the principle by which you were attempting to live. You would be banned from going to work; you would be banned from staying at home; you would be banned from taking medications; you would be banned from neglecting to take medications. The same point holds for governments that try to follow the Precautionary Principle.
In some cases, serious precautions would actually run afoul of the Precautionary Principle. Consider the “drug lag,” produced whenever the government takes a highly precautionary approach to the introduction of new medicines and drugs onto the market. If a government insists on this approach, it will protect people against harms from inadequately tested drugs, in a way that fits well with the goal of precaution. But it will also prevent people from receiving potential benefits from those very drugs-and hence subject people to serious risks that they would not otherwise face. Is it “precautionary” to require extensive premarket testing, or to do the opposite? In 2006, 50,000 dogs were slaughtered in China, and the slaughter was defended as a precautionary step against the spread of rabies. But the slaughter itself caused a serious harm to many animals, and it inflicted psychological harms on many dog-owners, and even physical injuries on those whose pets were clubbed to death during walks. Is it so clear that the Precautionary Principle justified the slaughter? And even if the Precautionary Principle could be applied, was the slaughter really justified?
Or consider the case of DDT, often banned or regulated in the interest of reducing risks to birds and human beings. The problem with such bans is that, in poor nations, they eliminate what appears to be the most effective way of combating malaria. For this reason, they significantly undermine public health. DDT may well be the best method for combating serious health risks in many countries. With respect to DDT, precautionary steps are both mandated and forbidden by the idea of precaution in its strong forms. To know what to do, we need to identify the probability and magnitude of the harms created and prevented by DDT-not to insist on precaution as such.
Similar issues are raised by the continuing debate over whether certain antidepressants impose a (small) risk of breast cancer. A precautionary approach might seem to argue against the use of these drugs because of their carcinogenic potential. But the failure to use those antidepressants might well impose risks of its own, certainly psychological and possibly even physical (because psychological ailments are sometimes associated with physical ones as well). Or consider the decision by the Soviet Union to evacuate and relocate more than 270,000 people in response to the risk of adverse effects from the Chernobyl fallout. It is hardly clear that on balance this massive relocation project was justified on health grounds: “A comparison ought to have been made between the psychological and medical burdens of this measure (anxiety, psychosomatic diseases, depression and suicides) and the harm that may have been prevented.” More generally, a sensible government might want to ignore the small risks associated with low levels of radiation, on the ground that precautionary responses are likely to cause fear that outweighs any health benefits from those responses—and fear is not good for your health.
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It has become standard to say that some nations are more precautionary, and more concerned about worst-case scenarios, than are others. European countries, for example, are said to be more precautionary than the United States. If the argument thus far is correct, this conclusion is utterly implausible. First, it is implausible empirically. Some nations take strong precautions against some risks, but no nation takes precautions against every risk. As we have seen, the United States has followed a kind of Precautionary Principle with respect to ozone depletion, and certainly with respect to terrorism, but not for climate change or genetic modification of food. The United Kingdom was not particularly focused on the worst-case scenarios associated with ozone depletion; but it closely attends to those scenarios in the context of climate change. France is not precautionary with respect to nuclear power, and it followed no strong Precautionary Principle with respect to Saddam Hussein. But on many issues of health and safety, France takes aggressive precautionary measures. No nation is precautionary in general; costly precautions are inevitably taken against only those hazards that seem especially salient or insistent.
More (#3) from Worst-Case Scenarios:
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Similar issues are raised by the continuing debate over whether certain antidepressants impose a (small) risk of breast cancer. A precautionary approach might seem to argue against the use of these drugs because of their carcinogenic potential. But the failure to use those antidepressants might well impose risks of its own, certainly psychological and possibly even physical (because psychological ailments are sometimes associated with physical ones as well). Or consider the decision by the Soviet Union to evacuate and relocate more than 270,000 people in response to the risk of adverse effects from the Chernobyl fallout. It is hardly clear that on balance this massive relocation project was justified on health grounds: “A comparison ought to have been made between the psychological and medical burdens of this measure (anxiety, psychosomatic diseases, depression and suicides) and the harm that may have been prevented.” More generally, a sensible government might want to ignore the small risks associated with low levels of radiation, on the ground that precautionary responses are likely to cause fear that outweighs any health benefits from those responses—and fear is not good for your health.
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