The debate about GM food arouses strong emotions and affects important business interests. Let me, therefore, begin by stating some basic personal beliefs. First, I believe our lack of concern for the environment is perhaps the greatest threat to the future of civilised society. Accordingly I have supported Friends of the Earth from the early 1970s until recently. Environmental considerations were also one reason why, with the advantage of residence in central London, I gave up a car in favour of a bicycle more than 25 years ago. Second, I am not a scientist, but I believe the lack of a basic public understanding of science, especially biology, is a serious defect of our culture. Further, I regard the public's growing distrust of scientists and its indifference to scientific evidence, especially in the debate about GM plants, as a trend with dangerous consequences. Lastly, because opponents of GM foods question the integrity of anyone who does not share their views, I should add that I have no connection with any company involved in their production.
GM foods act as a kind of lightning rod for the public malaise with science. Earlier disasters, like thalidomide, undermined confidence in scientific experts. BSE destroyed it altogether. The public, according to a recent poll, now regards scientists as little more trustworthy than politicians. It is only too ready to believe sensational headlines about Frankenstein foods. Attempts at an objective analysis of the risks and benefits involved-by the Royal Society, the Nuffield Council on Bioethics, the House of Lords and House of Commons Select Committees, for example-have been almost totally ignored by the press and have therefore had little impact on public opinion.
Justice and a healthy democracy require rational debate, the testing of evidence and the disregard of rumour and hearsay. Improvements in the condition of man depend on a respect for reason. How could we develop new life-saving drugs without regard for scientific method? The progress of all medicine depends on the careful examination of evidence and due weight being given to the best available expertise.
It is clear that the current public mood is broadly anti-science. Greenpeace and other organisations regard GM crops as so immoral or dangerous that they break the law, invade fields and destroy farmers' property. One recent campaign led to the destruction of GM trees even though the purpose of growing the trees was entirely beneficial to the environment, namely to reduce the use of bleach and energy in the manufacture of paper. The trees were also female and thus unable to produce pollen. No altered genes could have spread to other trees.
Now, it seems, Greenpeace is starting on the road followed by animal rights activists whose bigotry has led them to abandon all concern for the law, life or property. It wants to stop all experiments which are designed to establish what impact GM crops will have on the environment. By their actions they imply that they already know the outcome. As John Beringer, former government adviser on GM foods, has observed: that is the logic of those who burned witches.
Many people-like Prince Charles, who prefers mysticism to science-complain that we are playing God, that it is immoral to interfere with plants by inserting new genes, or that we are acting "against nature" if we insert animal genes into plants by, for example, transferring frost-resistant fish genes into strawberries. If these views are held as a tenet of religious dogma, then by definition they cannot be challenged by reference to evidence.
Some practices are objectionable on moral grounds. To me there is something deeply repellent about the battery farming of chickens. And it always seemed to me prima facie unnatural, in the proper meaning of the word, to turn cows into carnivores-which in the event proved to have harmful consequences. But the objections to GM technology as unnatural are generally based on misinformation.
To start with, it is hard to see what principle is involved which has not been breached centuries ago. All farming is in a sense "unnatural." God told his people to be fruitful and multiply, which is what farmers have done throughout the ages by breeding ever more fruitful crops, including hybrid crops in which genes have been transferred from one plant to another by traditional means. Animals have been transformed by selective breeding. Why is a process viewed as unnatural if it is used in a laboratory, yet natural if it is used on a farm? Is Bt maize unnatural because it contains a Bt gene which kills insects? Why then is it "natural" for organic farmers to spray Bt to kill insects on their "organic" produce, as they do?
As for "breaching the species barrier," for example, by combining fish and strawberry genes, the abhorrence felt seems based on ignorance. It suggests that animals and plants are somehow chemically different. Yet animals and plants have many genes in common. Human beings share 50 per cent of their genes with bananas. What is therefore so objectionable in transferring a stretch of DNA from one cell in a fish to another in a strawberry? (Incidentally, the Chief Rabbi gave evidence to the Nuffield Council that orthodox Judaism had no objections to GM crops; and the Church of Scotland, in its study Engineering Genesis, also gives a balanced account of the arguments about religion, GM technology and nature.)
Genetic modification is a new technique rather than a dramatic new development. It is worth quoting from the admirably thorough report of the Nuffield Council on Bioethics, published in May 1999 by a group including representatives of the Green Alliance: "Conventional plant breeding techniques rely on the repeated crossing of closely related plants and the selection of those showing the most desirable characteristics. Genetic modification enables more rapid introduction of desired characteristics. Once the genes for the desired traits have been identified, they can be spliced directly into plant cells... The immediate products of such plant transformations go through a series of extensive trials. They are grown initially in closed greenhouses, then in isolated field lots, before further testing in a variety of crops and climates, in exactly the same way as the products of conventional plant breeding. All novel crops... have to satisfy certain standards before they are released. GM crops do not have a short cut to the market."
When reading this summary of what genetic modification involves, I wonder why it arouses such opposition. It becomes even harder to understand when you consider that between 1986 and 1997 about 25,000 transgenic crop field trials were conducted on more than 60 crops in 45 different countries involving ten different traits. No adverse effects on food safety or the environment have been found.
The fact that this new technology offers no more than a more rapid (and accurate) way of solving old problems and has not yet been found to have adverse effects does not mean that there is no need for special regulatory measures of control or that adverse effects may not be possible. Because it acts more rapidly, GM technology may in itself create new pressures on the environment or may exacerbate existing harmful trends. What then are the potential risks? And how do these compare with potential benefits?
Until the pusztai controversy, there was little public concern in Britain about the safety of GM food. Few products were on the British market: mainly tomato paste and various soya bean products. GM tomato paste seemed to be outselling conventional brands, largely because it was cheaper. In the US, genetically modified tomatoes appear to be popular because they are seen to be of higher quality, last longer and taste better. Americans seem to have no fears about GM foods because they have faith in their Food and Drugs Administration, which has expressed no reservations about declaring GM products such as soya and maize as fit to eat.
Arpad Pusztai, who claimed that GM potatoes had harmed rats, is one of the main sources of the present public disquiet. I can only say that his conclusions deserve little weight. He started on the wrong foot by going public on television before his experiments were complete. The Rowett Research Institute, which employed him and which had no special axe to grind, criticised him for doing so and rejected his conclusions. The Royal Society conducted the most authoritative study of his work and found that it was "flawed in many aspects of design, execution and analysis, and that no conclusions should be drawn from it." The view of many experts was that his paper in the Lancet should not have been published at all-indeed, unusually, the editor commented that the reason for publication was to bring Pusztai's study into the open; it did not imply the Lancet's endorsement of its findings. Again, it is noteworthy that the Lancet paper omits claims Pusztai made in the original television broadcast, that GM potatoes could stunt rats' growth and impair their immune systems. The House of Commons Select Committee also found that, in his evidence to them, Pusztai contradicted his previous statements.
As for other evidence about the safety of GM foods, the Nuffield report was clear. It stated: "We have not been able to find any evidence of harm." The Health and Safety executive had earlier concluded, after 20 years of scrutiny, that GM food technology is one of the safest yet developed. GM soya has been eaten for several years by hundreds of millions of people in the US and Europe with no ill effects. Yet public opinion, stirred up by the press, Greenpeace and, most depressingly, the Consumer Association, all mainly on the basis of Pusztai's work, has compelled the supermarkets to take GM foods off their shelves. In all likelihood, conventional foods, which have not had the same thorough testing, are less safe.
Modern farming methods have brought great benefits. They have given us food which is cheaper, safer, more nutritious and more varied than our ancestors could ever have hoped to eat. But intensive farming, and its extensive use of chemicals, has also caused a loss of biodiversity. Herbicides and pesticides have reduced the numbers of grey partridge by more than half by destroying the weeds which feed the insects which feed their chicks. Removal of field margins and hedgerows has also taken its toll. There are fewer sparrows, skylarks and reed bunting. If we make farming even more efficient through GM technology, will we not accelerate this damage to our wildlife?
Further, is there a danger that pest or herbicide- resistant crops will infect weeds and make them uncontrollable, by developing "superweeds" which are herbicide- or pest-resistant? We already have to live with a series of natural disasters like the spread of knotweed and rhododendrons. Alarmists argue that this is just the start. Will GM crops cross-pollinate and transfer their genes to wild species or non-GM plants? Will they contaminate organic produce, for which public demand seems to be increasing so fast that our organic farmers cannot keep up?
According to the Royal Society study, all depends on the species of crop and where it is grown. In some cases, such as maize or potatoes, there are no wild relatives in Britain to which a transfer of inserted genes can occur. In some crops, transfers of some genes are bound to occur-in the case of oilseed rape, for example, which has many wild relatives. But gene transfers from GM crops are likely to be at exactly the same level as from conventional crops. Transfers from disease and pest-resistant crops grown conventionally have happened for many years and have not created any special problems. Gene transfers from hybrid crops are unlikely to survive because such crops are not used to breed for the next generation.
Further, the vast majority of trials have not disclosed evidence of increased harm to wildlife. From those 25,000 field trials of various kinds over the past 12 years, there have been only isolated reports, mainly from laboratory studies, of harmful effects of particular genetic transfers on lacewings, ladybirds and Monarch butterflies. Even these reports did not, as opponents of GM crops claimed, establish that harmful effects have been proved.
No one argues that no possible harm to the environment can result from GM crops. But to call for a stop on all development, or a moratorium on trials, is to disregard the weight of evidence and to surrender to alarmism. Already public concern has forced the government into promising that no GM crops will be grown commercially for three years. There would not be rational grounds for making further concessions, even if there were few countervailing benefits from GM crops. In fact, the potential benefits are huge.
At present, the consumer is scarcely aware of any benefits from GM foods. In fact there are actual benefits to the public, but they are indirect mainly affecting the environment, not consumers. Producing GM tomatoes uses less energy and water. Most of the evidence about the widespread use of herbicide-tolerant crops in the US suggests that it decreases the use of herbicides because crops have to be sprayed less frequently and less intensively. Pest-resistant cotton has reduced the use of pesticides on cotton crops in the US by up to two thirds. There are many other examples of benefits already achieved, but there is no doubt that future promise, rather than actual achievement, is the main attraction of GM crops.
The scope of these future benefits is almost unlimited because we do not yet know the limits of what can be achieved. But we do know that genetic modification can increase yields substantially, by making plants resistant to pests and disease, by enabling them to come to maturity more quickly, by enhancing their resistance to drought, heat or cold and controlling their salt tolerance so that crops can be grown in arid parts of the world where they cannot grow today. It should also become possible to fix nitrogen in the roots of wheat, to eliminate the need for fertiliser. With a reduction in the use of chemicals the pollution of ground water would be commensurately reduced. GM crops can make a huge contribution to the campaign against disease as well as hunger. One example is the engineering of vitamin A, as well as a heavy dose of iron, into a rice plant. This would greatly increase a child's resistance to diarrhoea and save the lives of millions of children who die from vitamin A deficiency every year. Iron deficiency affects some 3.7 billion people, mainly women, leaving them weakened by anaemia. There is also huge potential for using GM crops to produce vaccines and to contribute to the control of pollution.
The more reasonable critics of GM crops do not deny this potential, but nevertheless advance a number of counter-arguments as to why GM crops are not needed. The first is that we do not need higher yields. There is no shortage of food in the world, they say, we just need a better system for distributing the food grown by conventional methods.
But the fact is that we have failed to solve for at least a century the problem of distribution. And even if Africa's hungry millions could be fed on surplus American or European food, what would be the effect on local agriculture and therefore local employment? Africa and many parts of Asia are desperately in need of more efficient agriculture, not increased dependence on other countries.
In a July issue of Nature, an eloquent plea for the development of GM crops in Africa was made by Florence Wambugu, the director of the International Service for the Acquisition of Agrobiotech Applications in Nairobi. She cited many examples of the potential gain to African agriculture from the new technology, for example in fighting the maize streak virus which can cause total loss of the maize crop in parts of Africa and the development of transgenic varieties of sweet potatoes which are resistant to a virus that can reduce yields by 20-80 per cent. Moreover, she wrote, the new technology can offer "'packaged technology in the seed,' which ensures technology benefits without changing local cultural practices."
And what are the alternative hopes of more food for the hungry? The green revolution is slowing. In the 1970s it increased cereal production by 3 per cent a year; between 1983 and 1993, by only 1.3 per cent. Moreover, there are serious disadvantages in relying on conventional crops for increased yields. More use of marginal land decreases returns and increases environmental damage. Increased irrigation faces increased urban competition for ever scarcer water supplies and it lowers water tables. Conventional breeders already face falling water tables, new pest strains and micro-nutrient exhaustion. The best hope in places like Africa may lie in the increased use of fertilisers or other chemicals. Even if poor farmers can afford these, which they mostly cannot, is this what self-righteous environmentalists want to promote? Or do they not care about the 900m people who suffer from malnutrition?
A more substantial objection is that the present emphasis of GM research is not on developing new crops needed by the developing world, but on more profitable products for the developed world, which has less need of them. The charge is valid. Less than one tenth of the 25,000 field trials already mentioned were in developing countries. The same criticism applies to the development of new drugs. Overwhelmingly these are drugs to cure the diseases of the comparatively rich. Research on malaria, for example, a disease which kills over 1m children a year in Africa alone, is left to the public sector, which spends a tiny fraction of the amount spent by the private sector. Profits for the private sector depend on drugs to cure diseases common in rich countries, like obesity and Alzheimer's disease. The multinational biotechnology companies exist to make profits and most of these are not made in developing countries.
But that is not an argument against GM crops, but against their current application. A whole raft of policies could be introduced, from incentives for companies to help developing countries, to strict controls to prevent a handful of companies establishing a narrow oligopoly through restrictive patents. Of course there is a need for a strict regulatory regime-both for the science and the economics of GM food-but those are separate issues from judging the balance of risks and benefits implicit in GM technology. A rational assessment must conclude that potential benefits hugely outweigh potential risks.
In the end, should we not apply the precautionary principle, which says that it is better to be safe than sorry, that we may have no evidence of actual harm but should proceed no further until GM crops are proved positively safe? There are two answers. First, it is almost impossible positively to prove absence of harm, as opposed to showing no evidence of harm. If absence of harm had to be proved positively before food was declared safe to eat, we would all starve to death. Second, how cautious we should be depends on the current state of our knowledge. If very little was known about GM crops, even a suspicion of harmful effects might deter us from starting field trials. But plenty of research has already been done which suggests that the effects of GM crops on the environment are likely to be no different than the effects of conventional crops.
It is further argued that even if public opinion is wrong, it must be respected. Clearly if the public votes to ban GM crops by electing a government pledged to do so, the issue is decided. And most people would agree that consumers must be free to choose, with proper labelling of GM content. However, it is absurd to claim that the public is always right. Public opinion can hardly be the arbiter of scientific truth. Prevailing opinion once decreed that the sun moved round the earth; but on the whole people now accept Galileo's view that the earth goes round the sun. Nor is there a moral imperative to accept public opinion. Parliament has consistently voted against hanging despite poll evidence that public opinion strongly favours it. MPs vote against hanging because, inter alia, the evidence shows that capital punishment does not reduce the number of murders.
In the case of scientific judgments there is a special problem-a conflict of cultures. It is not only that scientists are concerned with the pursuit of truth whereas the newspapers are primarily concerned with increasing circulation; but also that the press deals in absolutes. It needs clarity, not qualifications. Scientists are often blamed for qualifying any public statement they make. In the biological sciences there are seldom, if ever, any absolutes. They cannot say food is absolutely "safe" and that there is absolutely "no risk." They are concerned that what they say is accurate, which means that statements must be qualified, not dogmatic. Often the qualification is the only thing reported. The possibility of risk is a more exciting headline than the probability of safety.
Further, there will always be some scientists who can be found to disagree. Dissenters may be right. But as the evidence piles up it becomes possible to distinguish the cranks from the serious challengers of orthodoxy. Peter Duesberg received huge publicity for his claim that there was no link between HIV and Aids. Now even the press has recognised him as a crank. We must look at the weight of evidence. The evidence does not support Pusztai's claims. But they make more exciting headlines.
Perhaps the most formidable opponents of GM crops are Greenpeace and Friends of the Earth, who have huge memberships and influence, and who now seem, sadly, to have moved decisively into the anti-science camp. It is often argued that evidence from company scientists must be discounted because companies have to make profits. Of course this should make us look carefully at company claims, although it does not mean that they are necessarily false, or that scientists who work for biotechnology companies have no concern for humankind. However, we should examine equally sceptically claims by Greenpeace and Friends of the Earth, many of whose causes are worthy causes, but who have a vested interest in scare headlines which increase membership. Both are now causing harm to the environment because their activities are preventing the development of a technology which is vital to its protection.
How can reason prevail? In time, no doubt, opinion will change if the benefits to consumers of cheaper and better GM food can be clearly demonstrated. So far the benefits have been to the environment, farmers and companies. But scientists themselves must make a bigger contribution to educating the public. I know of several who have vowed to give no more interviews, after experiencing a monstrous distortion of their views. They have a duty to continue to present their case in public. It should be possible to phrase comments so that distortion is minimised.
We should recognise that in its anti-science dogmatism, Greenpeace is becoming the British equivalent of the religious right in the US. Our anti-GM campaigners have much in common with the creationists. In both countries, public opinion seems friendly to the anti-science cause (more than 100m Americans are said to believe that Genesis is literally true). But the Achilles heel of these environmentalist groups is the vital role GM technology has to play in a sustainable world. They can be beaten in argument with moral conviction. Indeed, provided there is effective testing and regulation, a rational person who cares about our environment and about feeding the world's hungry should passionately support the cause of GM crops.
