ISSUES

Feeding the five billion
New agricultural techniques can keep hunger at bay Well-fed Luddites on a field trip

SHRIMPS are messy creatures. When scrubbed, shelled and served with lime leaves and lemon grass in a hot Thai tom yam koong soup, they taste wonderful. But while alive, they excrete large amounts of toxic sludge.

On Thai shrimp farms, the traditional way of dealing with this sludge is to toss it in the nearest river. Land used for shrimp farming soon becomes polluted and unusable, so shrimp farmers keep cutting down fresh forest to build new shrimp pools. Since farmed shrimps live in their own waste, they often fall sick. So farmers stuff them with antibiotics, which could end up in your tom yam koong.

Fortunately, there is a technological fix. Bio Solutions, a Thai firm, has developed a pill containing bacteria that eat shrimp excrement. Throw the pill in the pool, and the bacteria multiply until they run out of food. Then they obligingly starve to death, in a tidy, biodegradable way. If Asia is going to feed itself, says Charles Liu, the president of Bio Solutions, agricultural biotechnology has to be part of the answer. That is what you would expect him to say - but he has a point.

Predictions that people would multiply beyond their capacity to feed themselves, like those Thai bacteria, have repeatedly been proved wrong. In 1798, Thomas Malthus foretold famine just as farm yields were taking off. To his credit, he later admitted that he was wrong. Not so Paul Ehrlich, an American biologist who wrote in 1969: The battle to feed humanity is over. In the 1970s hundreds of millions of people will starve to death. They didn't.

The world's population grew much as expected, but food output more than kept pace. During the 1960s and 70s, a green revolution swept the developing world. Millions of farmers started using higher-yielding hybrid seeds, chemical fertilisers, pesticides and weed-killers. The results were remarkable. For example, Mr Ehrlich had predicted that by the mid-1970s, India would be so obviously beyond hope that America would stop sending food aid. Yet by 1990, India was exporting surplus grain. Chinese rice farmers, using similar techniques, raised production by two-thirds between 1970 and 1995. By one estimate, the green revolution saved a billion people from starvation.

There were some side-effects. Governments subsidised the new chemicals,
which encouraged their over-use. This damaged the environment in many
parts of the developing world. But the main worry about the green revolution is that it has run out of steam. There are still areas - mainly in Africa - where its techniques have yet to be tried (see table 1, next page). But in most of the developing world, the gains in productivity from it are tailing off.

Globally, 800m people are still malnourished. Heavily subsidised farmers in rich countries produce enough surplus food to feed the hungry, but not at a price the hungry can afford. Even if the rich world's surplus were simply given to the poor, this would not solve the problem. Most poor people earn their living from agriculture, so a deluge of free food would destroy their livelihoods. The only answer to world hunger is to improve the productivity of farmers in poor countries.

This will be difficult. The developing world's population is growing fast, but the amount of land available for cultivation is not. To feed the 2 billion new mouths expected by 2025, new ways must be found to squeeze more calories out of each hectare. But then more people means not just more stomachs to fill, but also more brains to figure out how to fill them.

There are plenty of good ideas available. The most powerful is biotechnology, and especially genetic modification (GM). It is a young science: biologists first found ways of manipulating recombinant DNA in the early 1970s. The first commercially available genetically modified organism (GMO) appeared a mere five years ago. Supporters of GM expect it to end world hunger. Opponents fear it may poison us all. It is worth stepping back for a moment to consider the evidence.

For and against GMOs

Farmers have been manipulating genomes since long before they knew about genes. For thousands of years, they sought to transfer desirable traits from one plant species to another by cross-breeding: this was how wild grasses were turned into wheat. They also selectively bred animals to make them fatter and tastier: this was how wild boars became pigs.

GM aims to achieve similar results, but faster. It typically takes 8-12 years to produce a better plant by cross-breeding. But if scientists can isolate a gene in one species that is associated with, say, the ability to grow in salty soil, they can sometimes transfer it directly into the genetic code of another species, without spending years crossing successive generations.

GM is more precise than cross-breeding, too. As any parent knows, sexual reproduction is unpredictable. The union of a brilliant woman and an athletic man does not always produce a brilliant and athletic child. In plants, as in people, some traits are inherited, others are not. At least in theory, GM solves this problem by transferring only the gene associated with the trait that the farmer wants.

The final advantage of GM is that it allows the transfer of traits between unrelated species. You cannot cross-breed cacti with corn, but you can take a cactus gene that promotes drought resistance and put it in a corn plant.

So far, scientists have produced GM crops that are more resistant to viruses and insects, and more tolerant of herbicides. In the future, GM could fill the world's larders with high-protein cereals, vegetables with extra vitamins, and all manner of cheaper, tastier and more nutritious foods than we currently enjoy. Researchers at Cornell University in America have even created bananas that contain a vaccine for hepatitis B. A single banana chip inoculates a child for one-fifteenth of the price of an injection, and with fewer tears.

Against these actual and potential benefits must be set the potential dangers. Shifting genes between different species could create health risks. For example, soyabeans given brazil nut genes have been found to express brazil nut proteins of the sort that might trigger allergic reactions. Soyabeans are used in thousands of food products, so if the problem had not been spotted this could have made life hazardous for people with nut allergies.

GM crops may also cause environmental problems. Their pollen might blow
into fields of ordinary crops and fertilise them. There is no evidence that this has happened so far, but it is possible, with unknown effects. Also, crops genetically modified to repel pests might spur the evolution of super-pests or poison other species. Laboratory tests have shown that butterfly larvae are harmed when fed the pollen of plants genetically modified to express a toxin called Bacillus thuringiensis (Bt), which protects corn from corn borers and cotton from boll worms.

All these risks are rather speculative. As with any new technology, it is impossible ever to prove conclusively that GM foods are safe. It is essential to test GM products carefully before releasing them, and to keep monitoring them afterwards. But so far, there is no evidence that GM crops hurt either humans or the environment. Americans have been munching modified corn and soyabeans for six years without discernible harm. And so far it looks as though GM crops actually help protect the environment, by reducing the need for chemical pesticides.

Last year, about 44m hectares of transgenic crops were planted, more than 20 times the area in 1996. Most of these fields, however, were in North America. Developing countries have yet to see much benefit from GM technology. But that could change. Among poor countries, the most enthusiastic adopter of GM technology has been China, where the government frets about food security. In 1997-99, China gave 26 commercial approvals for GM crops, including transgenic peppers, tomatoes, rice and cotton. The most commercially successful of these has been Bt cotton.

Cotton-chomping boll worms have grown resistant to pesticides. In 1992, these worms destroyed the entire cotton crop in some parts of China, ruining large numbers of farmers and bankrupting textile factories. So when Monsanto, a big American biotech firm, started selling boll-worm-resistant Bt cotton seeds, the Chinese government snapped them up. But cotton now covers half a million hectares of Chinese soil. Production costs have fallen by 14%, despite the hefty price that Monsanto charges for its seeds. Chinese scientists are now working on their own GMOs, and have already produced at least four new versions of Bt cotton.

The Chinese example is hopeful, but not unambiguously so. One reason that China's government was able to embrace GM technology is that the country is a dictatorship. Dissident voices are silenced or ignored. A few democracies, such as America, Canada and Argentina, have taken to GM food. But in Europe, although regulators say that GM products are safe, an energetic campaign by non-governmental organisations (NGOs) has convinced consumers that they are not, and dissuaded supermarkets from stocking them. Through the Internet, the campaign has spread to the developing world.

India, like China, has lots of poor rural folk who must somehow be fed. Anything that raises rural incomes is likely to help. Indian field trials found that Bt cotton produced 40% more fibre than ordinary cotton, with five fewer chemical sprays for each crop. For a typical small farmer with five hectares, this would save $50 per season, a huge sum by local standards. The farmer would also inhale less pesticide. Despite these findings, the Indian government refuses to permit the commercial planting of Bt cotton, largely because of pressure from NGOs. Protesters have invaded field trials and burned GM crops. Some even blocked the delivery of American food aid to cyclone victims, arguing that it probably
contained GM products.

Some poor countries hesitate to plant GMOs for fear of upsetting Europeans. NGOs claim that GM crops may contaminate neighbouring fields with their pollen. It would be a short step to call for a boycott of all the food exports, modified and unmodified, of countries where GMOs are widely grown. Even for developing countries that allow GM crops to be planted only in isolated plots for research purposes, the risk of a boycott remains. The peasants who live near research centres often notice how good the new crops are and steal the seeds.

Unlike the techniques of the green revolution, GM technology was largely developed by private companies. In the eyes of many, this made it suspect, but such suspicion is largely misplaced. The profit motive gives companies a strong incentive not to poison their customers. But it gives them no incentive to cater for people who cannot afford their products. Better versions of poor people's staples, such as millet, sorghum and cassava, will probably appear only if governments pay for some of the research, but the current hysteria about GMOs makes this politically difficult. When the UNDP recently suggested that GM technology could help the poor, it was met with howls of outrage.

The many ways of fighting hunger

GM is not the only weapon in the war on hunger. Democracy is important too: famines usually occur only in dictatorships. And other technologies too can produce impressive results: using less controversial biotechnology, the UNDP and the Japanese government recently produced a high-yielding hybrid rice that grows faster and contains more protein than ordinary varieties. But battles are easier to win if you have many weapons at your disposal. To remove the most powerful one from the arsenal seems unwise.

For the poor, GM appeared at an awkward time. After several people in
Britain died of what was almost certainly a human version of mad-cow disease, Europeans lost faith in their governments' ability to keep dangerous food off their plates. Since people in rich countries rarely go hungry, they were not wildly excited about the promise of cheap and abundant food. Perhaps they will change their minds when scientists create better rather than simply cheaper foods: cholesterol-free bacon, perhaps.

But in the meantime, it is sad that the priorities of the well-fed few should make it harder for the world's hungry billions to feed themselves.

Courtesy The Economist November 10, 2001