Monday, August 12, 2002

Nature III
Antony Trewavas, in the article that serves as an introduction to food issue, grapples inconclusively with the Malthusian scissors:
The lessons of history are clear. Successive lurches in population number have driven the development of new agricultural technologies designed to provide food for growing populations. This process of discovery will continue until there is an abundance of food equally enjoyed by the whole world population. We are far from achieving that at the present time, and there is therefore a constant need to examine the state of current agriculture to see where progress needs to be made. The following collection of articles on 'Food and the future' provides a snapshot of the current state of play....

The benefit of GM technology to the poorest farmers is palpable. To a cotton farmer working on a farm of about a hectare in area, the use of 'Bt' cotton (containing a gene for an insecticide derived from the bacterium Bacillus thuringiensis) has raised income by a quarter, cut costs by a third, and slashed pesticide use by three quarters. There are concerns that the cotton bollworm � the pest whose activity Bt cotton is designed to curb � might evolve resistance to the insecticide, but on-going technological development of other GM lines will almost certainly ameliorate the problem if it emerges.

Antagonism in Europe to GM technology, partly because of concerns about the potential for uncontrolled spread of transgenes into weedy or invasive plants, is likely to subside once the real benefits for the consumer emerge. There is much promise in the concept of designer foods in which 'problem' substances such as gluten or common allergenic proteins are eliminated, and useful secondary products (such as the so-called 'neutra-ceuticals') are boosted....

The deleterious environmental consequences of some kinds of food production are very real. This is clearly evident in fisheries, and incorrectly perceived as such by some in the adoption of GM technology. But nostalgia isn't what it used to be: organic farming, sometimes touted as a panacea, is no more sustainable than the fish-farming that produces high-value smoked salmon to those consumers who can afford it. In the world at large, technological change is � as it always has been � driven by the need to squeeze ever greater yields from the same plot of land. In all such arguments, knowledge is the ultimate decider, balanced as usual by economic considerations. Whatever the outcome, the decisions we make now could have repercussions for millennia.

Even though this naturally pisses me off, I would like to make two points as rationally as possible:
1. It is simply nonsensical to suggest that population growth will stop when there is "an abundance of food enjoyed by the whole world population." Precisely the opposite is self-evidently true.
2. It is disingenuous at best to suggest that opposition to GM food is the product of nostalgia for a hunter-gatherer lifestyle. This is simply an evasion of the issue.
3. Sorry, one more thing: how can you simply state in the final paragraph of an article in a peer-reviewed scientific journal that it is incorrect to perceive GM technology as deleterious [tortured diction follows original] without ever having demonstrated this?

[Antony Trewavas, "Malthus foiled again and again," Nature 418, 668-670 (2002).]

Update 8/19: Here is his gracious response to my email:

Dear Max Excuse the shortness of this as I have returned to 400 emails from holiday.question 1 The population is predicted to peak at 9-10 billion by 2050. Population expansion and growth is a complex area but we do understand that wealth constrains population growth, most specifically careers for women keep families smaller than they could be. However every parent will want the best rightly so for his/ her child and that includes an abundance of food. 2. I think you should read the article in the insight series on Chinese agriculture and see how the benefits of GM crops are experienced by the poorest farmers. While you are right to be sceptical of large global companies offering you various things global companies are not the only people producing crops of considerable value to many people. GM vaccines for example and the development of virus resistant crops in Africa. I do not agree with the word genetic pollution. All crops contain genes in very large numbers and always have done. Much of what you eat has been irradiated top induce mutations usually for pest resistance and the mutations are extensive and largely not understood. Use of ordinary mutations that arise serendipitously and are used in crop breeding are no more than natural GM. The whole of the green revolution was based on one such mutation. Is that genetic pollution? 3. The current GM crops offer the potential of reductions in use of pesticides and for herbicide resistant crops the use of no plough agriculture. Measurements in the UK have shown that no plough agriculture reduces fossil fuel use to one third that of organic farming (global warming benefit), it conserves carbon in the soil reduces soil rerosion to negligible levels and cuts nitrate run off by 50%. All of these parameters are superior to organic agriculture which ploughs to eliminate weeds because of failure to use innocuous herbicides like glyphosate. That is why I say it is incorrently perceived by some to be damaging, when in fact it is the opposite. Finally I would have preferred that GM had been used as in the green revolution, crops developed in universites like mine and then given to those in need. It has not happened that way but knowledge is power particularly for farmers in the developing and third world and we should use our knowledge to benefit them. Thus I defend GM vigorously because knowledge is our unique biological characteristic and responsible use fo knowledge has placed our societies in the happy but imperfect state they currently enjoy.Sorry I don't have more time kind regards Tony
And my lengthy reply:
Dear Professor Trewavas, I want to thank you very much for your reasoned reply to my email -- it must have been very strenuous to reply intelligently to all the mail generated by the Nature article, and I do appreciate the effort expended. You will excuse me if I feel compelled to reply, understanding that you may not have comparable leisure. I have, in fact, been reading more of the literature on the subject, including Huang's et al. article on Chinese Bt cotton. That study seemed problematic to me because the true cost of the cotton is obscured by both subsidized seeds and artificial price controls on the cotton market. Since the extra value, whatever it is, is captured by the farmers, I would of course agree that the technology is beneficial, especially when coupled with the reduction in pesticide use. I would note here that US results are more equivocal, as summarized in Shoemaker, et al., "Economic Issues in Agricultural Biotechnology," ERS Agriculture Information Bulletin No. 762, March 2001, though they generally include increased yield and reduced pesticides. I have not seen comparably detailed data for food crops (largely because, as noted by Huang et al., these have neither been developed nor deployed as rapidly as cash crops). I do remain skeptical of the perceived need to increase food production, both because the current food shortage is caused by distribution not production (as Conway and Toeniessen noted in an article from Nature 402 included on the "Food and the Future" website), and because the the underlying Malthusian logic does not seem to have been disproven: namely that an elastic food supply will simply lead to further population growth -- and not to a higher quality of life for an arbitrarily fixed number of people. I do not see how projections of a levelling-off in population growth based on age structure represent more than a temporary lull, assuming the continued elasticity of the food supply. Let me also respond to the loaded issue of genetic "pollution," which I believe I originally surrounded with inverted commas to indicate its problematic nature. Without adopting an alarmist position that the transfer of GM genes is somehow polluting, or dangerous, it is surely at the very least undesirable for these genes to transfer to the wild forebears of our domesticated crops, as this has the potential to drastically reduce biodiversity. I understand that there are severe methodological problems with Quist and Chapela's infamous Nature paper, but to my knowledge no one has disputed that they did indeed find the GM CaMV gene in wild Oaxacan Maize. As I understand it, this event has the potential to eliminate an important source of further crop improvement, even ignoring the intrinsic desirability of preserving existing maize variability. When this gene transfer crosses the species barrier, it raises further ethical issues that I am not competent to pronounce on, but I believe need to be taken seriously. I am not sure that other effects, including the inevitable inefficacy of Bt can be so casually dismissed. And finally, the transfer of these genes presents GM food crops to the world as a fait accompli, without our consent. While I have no fears about the safety of RR corn, I may soon have no choice but to eat it. That is antidemocratic and dangerous. In closing, I certainly agree with you that this is important science, which should be continued in the public and the private sector. Knowledge is, as you say, part of being human, and the reason why more of us are not starving, or mad from ergotism, or from eating dirt. but in my (so far cursory) review of the scientific literature, "consumer objections" are frequently presented as an incidental obstacle to the advancement of science. I would suggest, on the contrary, that what people want to eat should be the goal of this research. What matters to me about food is quality and flavor, not ease of processing or glyphosate tolerance. This is a position that 800 million people do not have the luxury of adopting, but it is no less valid. Instead of ensuring a miserable existence for more people, I would like to see scientists figure out how to improve the quality of life for all of us. Thank you again for taking the time to reply. Sincerely, Max


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