Make plans on the hoof

十二月 21, 2000

Whether it is GM food or the office Christmas party, the precautionary principle sounds like a rational approach. But Gary Comstock, professor and cowboy, finds that things are not that simple.

As a 13-year-old, I won my dream job, wrangling horses at Honey Rock Camp in northern Wisconsin. The image I cultivated for myself was the weathered cowboy astride Chief or Big Red, dispensing nuggets to awestruck young rider wannabes. But I was, as they say in Texas, all hat.

"Be careful!" was the best advice I could muster.

Only after years of experience in a western saddle would I have the skills to size up various riders and advise them properly on a case-by-case basis. "You should slouch more against the cantle and get the balls of your feet on the stirrups." "You need to thrust your heels in front of your knees and down toward the animal's front hooves." "You! Roll your hips in rhythm with the animal, and stay away from the horn." "You, stay alert for sudden changes of direction."

Only after years of experience with hundreds of different riders would I realise that my earlier generic advice, well intentioned though it was, had been of absolutely no use to anyone. As an older cowboy once remarked, I might as well have been saying, "Go crazy!" Both pieces of advice were equally useless in making good decisions about how to behave on a horse.

Now, as mad cow disease grips the European imagination, concerned observers transfer fears to genetically modified foods, advising: "Take precaution!" Is this a valuable observation that can guide specific public policy decisions, or well-intentioned but ultimately unhelpful advice?

As formulated in the 1992 Rio Declaration on Environment and Development, the precautionary principle states that "Ilack of full scientific certainty shall not be used as a reason for postponing cost-effective measures to prevent environmental degradation."

The precautionary approach has led many countries to declare a moratorium on genetically modified crops on the supposition that developing them might lead to environmental degradation. The countries are correct that this is an implication of the principle. But is it the only implication?

Suppose global warming intensifies and comes, as some now darkly predict, to interfere dramatically with food production and distribution. Massive dislocations in international trade and corresponding political power follow global food shortages, affecting all regions and nations. In desperate attempts to feed themselves, billions begin to pillage game animals, clear-cut forests to plant crops, cultivate previously non-productive lands, apply fertilisers and pesticides at higher than recommended rates, kill and eat endangered and previously non-endangered species.

Perhaps not a likely scenario, but not entirely implausible either. GM crops could help to prevent it, by providing hardier versions of traditional lines capable of growing in drought conditions, in saline soils, under unusual climactic stresses in previously temperate zones, or in zones in which we have no prior agronomic experience.

On the supposition that we might need the tools of genetic engineering to avert future episodes of crushing human attacks on what Aldo Leopold called "the land", the precautionary principle requires that we develop GM crops. Yes, we lack full scientific certainty that developing such crops will prevent environmental degradation. True, we do not know what the final financial price of its research and development will be. But if GM technology were to help save the land, few would not deem that price cost-effective. So, according to the precautionary principle, lack of full scientific certainty that GM crops will prevent environmental degradation shall not be used as a reason for postponing this potentially cost-effective measure.

The precautionary principle commits us to each of the following propositions: 1. We must not develop GM crops.

2. We must develop GM crops.

As 1 and 2 are plainly contradictory, however, defenders of the principle should explain why its implications are not incoherent.

Much more helpful than the precautionary principle would be detailed case-by-case recommendations crafted on the basis of a wide review of non-industry-sponsored field tests, conducted by objective scientists expert in the construction and interpretation of ecological and medical data. Without such a basis for judging this use acceptable and that use unacceptable, we may as well advise people in the GM area to go crazy. It would be just as helpful as "Take precaution!"

Gary Comstock is coordinator of the bioethics programme and professor of philosophy and religious studies at Iowa State University. His book, Vexing Nature? On the Ethical Case against Agricultural Biotechnology (Kluwer), tells the story of how he changed his mind about the moral acceptability of GM foods.

www.public.iastate.edu/~comstock/homepage.html

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