*Will GM technology feed the world - or destroy farming, and human health, in the name of corporate profit? How can we tell, when the science is up for sale?

Genetically modified crops might once have proved useful. In the early days, in the 1980s, scientists I spoke to in India hoped to transfer genes from groundnuts (which are very resistant to heat and drought) into sorghum, the staple cereal of the Sahel, which is also drought-resistant but succumbs in the worst years. In California, there were advanced plans to produce barley that could thrive in brackish water of the kind that is spreading worldwide in the wake of overzealous irrigation. In Brazil, just a few years ago, I found GM being used to make disease-resistant papaya - which grows everywhere in the tropics and is an instant, free source of succulence, energy and Vitamin A. I was all for it.

Of course, the scientists anticipated snags. The GM plants might develop undesirable traits, possibly hazardous to consumer health, not necessarily in the first generation but down the line. That things could go wrong was evident from some of the early forays into GM livestock, which produced sad monsters. Perhaps the GM plants would escape into ecosystems and become pests - as many a crop has done in the past - but the GM super-crops might prove to be super-pests. Perhaps the
insect-resistant types with built-in insecticide would kill non-target insects, with disastrous knock-on effects.

Nevertheless, the mood I encountered then was optimistic, essentially altruistic, and cautious. There was no need to hurry, because the conventional techniques of the day, properly deployed, could do what needed doing. Today, the world isn't like that: food production is now private enterprise, controlled by corporations and banks. The main purpose of farming is no longer to feed people but to maximise profits, raise GDP and maintain economic growth.

Critically, farming geared to making money differs in all significant ways from farming that is committed to providing good food today and for the future. Farming that feeds people well and sustainably must in general be mixed (many kinds of livestock and crops all interacting). It is complex and labour-intensive. Chemical inputs should be minimised, especially inputs of non-renewables; and, as far as possible, most food should be produced locally. The overall target is to ensure resilience: a steady supply of varied and high-quality crops, even in difficult times.

Cheap food is an illusion

In contrast, farming that is designed to make money must be maximally productive, but at minimum cost. So the systems must be simple: big machines and industrial chemistry instead of husbandry, and the farms on as large a scale as possible and monocultural, with just one crop or one kind of animal. Balanced diets in any one place can therefore be ensured only by mass imports. Labour - usually the most expensive input - must be cut to the bone and then cut again, with the workers paid as little as possible.

Finally, there must be maximal "value-adding" by processing, packaging and contrived exoticism, but above all by turning cheap yet good staples of the kind that have supported the great cuisines into meat for fast food. So we feed half the world's wheat to animals, and 80 per cent of the maize. But if something else should turn up that makes more money than food - for instance, biofuels - we'll grow that instead.

It works, does it not? While the food technologists and retailers have grown rich beyond all dreams of avarice, the masses have had, at least until recently, cheap food: it takes up just 8 per cent of the average Briton's income. Yet cheap food is an illusion. It is made to seem cheap by creative accountancy that ignores the vast quantities of oil needed, the collateral damage to soil, rivers, lakes, forests, wildlife, climate and, indeed, to human life, as well as the most blatant injustice as farmers across the globe are made bankrupt. According to the UN, one billion people now live in urban slums worldwide; and most of the shanty-dwellers are former farmers or their immediate descendants and
dependants. The multinationals assure us there are "alternative industries". No, there aren't. When and if there are alternatives, it may be sensible to encourage people to leave the land. Not until. And
it's a big "if".

As long as GM was part of an economy and a morality that had the well-being of humanity at heart, it had the potential to become what Ivan Illich in the 1970s called "a convivial technology", truly
improving the human lot. As things stand, it merely serves to consolidate the status quo: to strengthen the arm of the corporations, which alone will control the seed and the inputs that the new seed
requires; and to promote all the agro-industrial strategies that are so obviously destructive.

To be sure, the biological risks of GM remain, and should not be underestimated; but given time, and due caution, they could have been minimised. Commerce, however, demands immediate results, such that organic farmers already find it hard to buy feed for their animals that is not made from GM maize or soya. Yet reports that all is safe in the world of GM technology are greatly exaggerated. Nor is it true that it simply replicates the "horizontal" transmission of genes that occurs in the wild, and hence is "natural". Natural genes contain stretches of DNA known as "introns" that modify and regulate their function. Genetic engineers strip out the introns before they transfer them, to make life simpler. The difference could be significant, but we just don't know. I have yet to hear an advocate of GM technology even raise this issue.

Indeed, there has been so much hype and obfuscation in the promotion of GM - Prince Charles's recent warning about the looming environmental disaster aside - that it would be foolish to believe a word of it. Here are three quick examples. We have heard much, of late, of the "golden rice" made by Syngenta. It is fitted with a gene that produces carotene, which is the precursor of Vitamin A - the lack of which is a prime source of blindness among children worldwide. Therefore, Syngenta tells us, golden rice is a good thing - a sentiment echoed subsequently in the media and in the House of Lords by Dick Taverne. But carotene is the yellowish pigment in green leaves (such as spinach) and in all yellow-orange roots and fruits (carrots and papaya among them) and is one of the commonest organic molecules in nature. Poor people do not need handouts from Syngenta. All they need is horticulture - which, before the days of corporate-owned monocultures of commodity crops, they
had.

We are told that GM crops yield more, and that the technology's opponents are irresponsible. Yet yield is rarely what really matters: very few famines in modern history have been caused by an inability to
grow enough food; it has always been secondary to wars and economic breakdown, often caused by the west's destruction of subsistence farming. And anyway, the idea that GM crops can be relied upon to yield more than conventional crops is simply not true. Some GM crops do sometimes yield more than most standard crops in some circumstances and in some years; often they do not. In the long term, we have yet to see. The published results which seem to show that GM crops consistently
outstrip their conventional counterparts are highly selective, with unfavourable results not made public. More and more, we are urged to rely on the "objectivity" and unimpeachable integrity of science. But when science itself is up for sale, there is no court of appeal.

"Feeding People is Easy" by Colin Tudge is published by Pari Publishing (GBP9.99)