An Edible History of Humanity

by Tom Standage

  Research carried out in the village of Manupur, in the Indian Punjab, illustrates how the demographic transition has manifested itself on the ground. In 1970, men in the village all said that they wanted as many sons as possible. But when researchers returned to the village in 1982, following the introduction of green-revolution crops, fewer than 20 percent of men said that they wanted three or more sons, and contraceptives were being widely used. “These rapid changes in family size preference and contraceptive practice are indications that the demographic transition will continue, if not accelerate, in rural areas experiencing the green revolution,” the researchers concluded. Similarly, Bangladeshi women had an average of seven children in 1981. Following the widespread adoption of green-revolution technologies in the 1980s and the rapid expansion of the country’s textiles industry in the 1990s, however, that figure has fallen to an average of two or three.

  The world will face new challenges as its population shrinks—not least the difficulty of looking after an infirm and aging population, which is already a concern in developed countries where the fertility rate has fallen. But the peak of world population may now be in sight. Once the population starts to decline, worries about population growth outstripping food supply may start to seem rather old-fashioned. A flood of bestselling books will no doubt warn of the dangers of the coming population implosion. But the ghost of Malthus will finally have been laid to rest.

  PROBLEMS WITH THE GREEN REVOLUTION

  New technologies often have unforeseen consequences, and the technologies of the green revolution are no exception. High-yield seed varieties, which require artificial fertilizers, other agricultural chemicals, and large amounts of water, have caused environmental problems in many parts of the world. Nitrogen-laden runoff from agricultural land has created “dead zones” in some coastal areas, stimulating the growth of algae and weeds and reducing the amount of oxygen in the water and thereby affecting fish and shellfish populations. In some cases high-yield varieties proved to be less resistant than traditional varieties to pests or diseases. This necessitated a greater use of pesticides, overuse of which can contaminate the soil and harm beneficial insects and other wildlife, reducing biodiversity. Pesticides can also cause health problems for farm workers. According to the World Health Organization, pesticides cause around one million cases of acute unintentional poisoning a year and are also involved in around two million suicide attempts, leading to some 220,000 deaths a year. (The availability of pesticides has made pesticide poisoning the most widespread method of suicide in the developing world.) A further worry is the depletion of water supplies. In the Punjab, the cradle of India’s green revolution, for example, the proliferation of millions of tube wells caused the water table to fall by more than fifteen feet between 1993 and 2003 alone, and many farmers now have insufficient water to irrigate their crops.

  Much can be done to mitigate these problems, however. More frugal and precise application of fertilizer can reduce runoff without affecting yields. Fertilizer intensity has in fact been declining in recent years in some developed countries. In the United States, maize yields have increased from 42 kilograms per kilogram of fertilizer in 1980 to 57 kilograms in 2000. Similar improvements have been achieved with wheat in Britain and rice in Japan. But in many developing countries fertilizer is heavily subsidized by governments, discouraging more efficient use. More can also be done to reduce the unnecessary use of pesticides and minimize harmful side effects. During the rollout of the green revolution, farmers were instructed that the use of pesticides was a necessary component of “modern” agriculture, which resulted in overuse. Some farmers were told to apply pesticides according to a calendar, whether or not such applications were necessary. The use of pesticides is now flat or declining, and biological pest-control techniques are being promoted in conjunction with chemicals, making the best use of both traditional and modern practices. This hybrid approach, called “integrated pest management,” can reduce the use of pesticides by 50 percent for vegetable crops. In some cases it can eliminate the need for pesticides altogether in rice production, according to the United Nations’ Food and Agricultural Organization.

  Similarly, there is plenty of scope for improvements in water use. Far more attention is now being paid to aquifer management, for example, and to the deployment of rainwater harvesting and storage systems, and of more water-efficient irrigation systems such as drip-irrigation technology (which also reduces nitrogen runoff). Clearly defined water rights that can be traded by farmers can also encourage more sensible use of water, by encouraging farmers to concentrate on the most appropriate crops. It seems odd to grow water-intensive crops such as potatoes in Israel, oranges in Egypt, cotton in Australia, and rice in California, for example, when all of these crops could be grown more cheaply and efficiently elsewhere. And in the Punjab, the provision of free electricity to farmers, along with subsidies for growing rice, a water-intensive crop, encouraged farmers to leave their water pumps running continuously. In recent years, growing concern about the scarcity of water for agriculture—it has even been called the “oil of the twenty-first century”—has prompted policymakers to pay greater attention to the development of sensible water policies.

  The environmental problems associated with high-yield farming must also be weighed against its unseen environmental benefits, in the form of damage to ecosystems that would otherwise have been done in order to increase food production. High-yield varieties have enabled food production to multiply with only a marginal increase in land use. Asia’s cereal production doubled between 1970 and 1995, for example, but the total area cultivated with cereals increased by just 4 percent. Globally, the figures are even more striking. Norman Borlaug has pointed out that world output of cereal grains tripled between 1950 and 2000, but the area used for cereal cultivation increased by only 10 percent. Without green-revolution technologies, he contends, there would either have been mass starvation, or enormous amounts of virgin land (such as forests) would have had to have been taken under cultivation.

  Many critics of the green revolution advocate a return to traditional, or organic, agricultural techniques that do not rely on chemical fertilizers and pesticides. This would reduce both the direct environmental impact of agriculture (in the form of nitrogen runoff and pesticide use) and its indirect impact (since the production of chemical fertilizer is an energy-intensive process that consumes natural gas and contribtues to climate change). But farming without the use of chemical fertilizers produces lower yields, so more land is then needed to provide the same amount of food. Studies have found that organic production of wheat, maize, and potatoes, for example, requires two or three times as much land as conventional production. Global agriculture in 1900, using almost no chemical fertilizer, supported about 1.6 billion people on an area of about 850 million hectares (2.1 billion acres), according to the University of Manitoba’s Vaclav Smil, an expert on the nitrogen cycle. Farming using fertilizer-free (that is, organic) methods on today’s 1,500 million hectares (3.7 billion acres) would support only 3.2 billion people on mostly vegetarian diets, he estimates, or half of today’s global population.

  That said, the use of fertilizer in the developed world could be reduced while still providing enough food to provide adequate nutrition, despite the fall in yields. That is because rich countries produce more food than they need, in part because paying subsidies to farmers encourages overproduction. The excess allows for unnecessarily protein-rich diets (resulting in rising levels of obesity in rich countries) and large exportable surpluses. So there is scope to switch some food production to less chemically intensive methods, such as organic farming. The situation in the developing world is very different, however. In rich countries, chemical fertilizer supplies only about 45 percent of the nitrogen applied to fields. But in poorer countries it supplies as much as 80 percent. It is the use of fertilizer that makes the difference between inadequate and adequate nutrition, and in many developing countries the supply of dietary prote
in remains inadequate even so.

  By the late 1990s, 75 percent of all nitrogen being applied to crops in China was coming from chemical fertilizers. Since 90 percent of the protein consumed by Chinese is homegrown, this means that two thirds of the nitrogen in China’s food comes from the Haber-Bosch process. Traditional methods, such as planting nitrogen-fixing legumes or using animal manure, simply cannot supply as much nitrogen per hectare. In many other populous developing countries, the level of food production now exceeds the level that could be produced by traditional, fertilizer-free methods. There may be scope to reduce the amount of fertilizer used by more precise application, but it is difficult to see how it can be eliminated altogether without reducing food output.

  There are no easy answers. Both conventional and organic farming have environmental costs and benefits. During the twentieth century mankind became dependent on artificial nitrogen, and turning back the clock is not an option. Chemically intensive agriculture has undesirable environmental side effects, and more effort is undoubtedly needed to mitigate them. But the consequences to humanity of abandoning the green revolution would surely be far worse.

  A SECOND GREEN REVOLUTION?

  Between January 2007 and April 2008, after several years of stable prices, wheat prices abruptly doubled, rice prices tripled, and maize prices increased 50 percent. For the first time since the early 1970s, food riots erupted in several countries simultaneously. In Haiti the prime minister was forced to resign by crowds of protesters chanting “We’re hungry!” Two dozen people died in food riots in Cameroon. The president of Egypt mobilized the army and told soldiers to start baking bread. In the Philippines, a new law was introduced making the hoarding of rice punishable by life imprisonment. After years in which farmers and development specialists had lamented the low prices of staple foods, the era of cheap food seemed to have abruptly come to an end. In many respects the origins of this food crisis can be traced back to the consequences of the green revolution.

  One consequence was that governments and aid agencies lost interest in agriculture as a means of promoting development. According to the World Bank, the proportion of “official development assistance” spent on agriculture fell from 18 percent in 1979 to 3.5 percent in 2004. There were several reasons for this shift, according to the World Bank’s 2008 World Development Report. To some extent it seemed that the food problem had been solved. There were food gluts in North America and Europe, and low international prices for staple foods, the result of both green-revolution technologies and subsidies to farmers in the developed world. As a result, donors lost their enthusiasm for funding agricultural projects in the developing world. Waning investment by governments in agricultural research, starting in the 1990s, meant that growth in yields slowed.

  Farmers and environmental groups in developed countries also convinced donors to reduce funding for agricultural development in the developing world. The farmers regarded developing countries as valuable export markets, and did not want their governments to fund potential competitors. And environmental groups highlighted the pollution caused by chemically intensive agriculture, and managed to discredit the green revolution in the eyes of many donors. In the 1980s, when Norman Borlaug began a campaign to extend the green revolution to Africa, where it had had little impact, he found that attitudes were changing. Environmental lobby groups had persuaded the World Bank and the Ford Foundation that promoting the use of chemical fertilizers in Africa was a bad idea.

  The emergence of the Chinese and Indian middle classes, who could afford to eat more meat-rich, Western-style diets, increased demand for cereal grains for use as animal feed, raising prices. And the diversion of food crops into biofuel production also increased prices, though exactly how much impact this had on world prices is uncertain. Higher oil prices also contributed to higher food prices, by increasing production and transport costs and by raising the price of fertilizer (since the price of natural gas, from which fertilizer is made, is pegged to the price of oil). In short, although the supply of food continued to grow, the rate of growth declined (to 1 to 2 percent a year since the mid-1990s) and was unable to keep pace with the growth in demand (at around 2 percent a year). Tellingly, India started importing wheat again in 2006. Like many countries, India also banned the export of many foodstuffs in an effort to maintain supplies for the domestic population. Such export bans further increased international food prices, by reducing the amount of food available on global markets.

  If nothing else, the food crisis has put agriculture back on the international development agenda, after years of neglect. In the short term, the appropriate response to the crisis is a rapid increase in humanitarian food aid. Policies promoting biofuels made from food crops must also be reconsidered. But in the medium term, shipping large quantities of food from rich to poor countries makes things worse, because it undermines the market for local producers. The long-term answer is to embark upon a new effort to increase agricultural production in the developing world, by placing renewed emphasis on agricultural research and the development of new seed varieties, investment in the rural infrastructure needed to support farmers, greater access to credit, the introduction of new crop-insurance schemes, and so on. All of this may sound rather familiar, because it is, in essence, a call for a second “green revolution.”

  Inevitably, this has revived the arguments about the pros and cons of the original green revolution. Some advocates of a second green revolution emphasize the potential of genetically modified seeds, now under development, that produce their own pesticides or are designed to make more efficient use of water and fertilizer. (This has been referred to as a “doubly green revolution.”) Advocates of organic farming, meanwhile, regard the food crisis as an ideal opportunity to promote greater use of organic methods, particularly in Africa where yields are low. In much of Africa, raising yields even to the level of pre-fertilizer agriculture in other countries would be a valuable achievement.

  Clearly, any new green revolution should take into account the lessons learned since the 1960s. There are many new techniques to draw upon that can improve yields while minimizing environmental problems. Some are low-tech, such as burying precisely measured pellets of fertilizer to minimize runoff, or using particular beetles and spiders to keep pests at bay. Seeds can be coated with fungicides or pesticides directly, reducing the need to spray chemicals. And a particularly promising approach is “conservation agriculture” (also known as “no till” or “conservation tillage” farming), a set of techniques developed since the 1970s that minimize the tilling of the soil, or even eliminate it altogether.

  Farmers practicing conservation agriculture leave crop residues on their fields after harvest, rather than plowing them in or burning them off. Cover crops are then planted to protect the soil. (Planting legumes as cover crops helps to increase soil nitrogen.) In the spring, the cover crop and any weeds are either killed using a herbicide, or chopped up on the surface using special machinery. Planting of the main crop is then done using machines that guide seeds into slots in the soil below the protective layer of residue. All this helps to reduce soil erosion, since covered, unplowed soil is less likely to be washed or blown away. Water is used more efficiently because the soil’s ability to hold water increases, and less water is lost to runoff or evaporation. Conservation agriculture also saves fuel and reduces energy consumption, since about half as many passes over the field using machinery are required. Less fertilizer is usually needed because less nitrogen is lost to the environment; this also reduces nitrogen pollution of waterways. Conservation agriculture is most widely used in North and South America, where it was first developed, but it still accounts for only a small proportion (around 6 percent) of cultivated land worldwide, so there is much potential to expand its use.

  It is possible that new genetically modified seeds will deliver on their promise of more efficient nitrogen uptake and water use. New seeds are also being engineered to grow in soils that are too salty for traditional va
rieties. The development of such seeds will take several more years, and it is too early to say how successful they will be. It is certainly overstating the case to suggest that genetic modification is a “silver bullet” that will fix the world’s various food problems. But it would be foolish to rule out its use altogether. At the same time, there may be organic techniques that can be more widely applied, particularly when it comes to biological pest control and growing crops in arid areas. Some studies show that organic methods may produce higher yields for some crops in dry conditions, for example.

  To ensure an adequate supply of food as the world population heads toward its peak and climate change shifts long-established patterns of agriculture, it will be necessary to assemble the largest possible toolbox of agricultural techniques. Different methods will be the most appropriate in different regions. It may make sense to grow staple crops using chemically intensive methods in some parts of the world, and to trade them for specialist crops grown using traditional methods elsewhere, for example. It is far too simplistic to suggest that the world faces a choice between organic fundamentalism on the one hand and blind faith in biotechnology on the other. The future of food production, and of mankind, surely lies in the wide and fertile middle ground in between.

  EPILOGUE

  INGREDIENTS OF THE FUTURE

  There is no feast which does not come to an end.

  —CHINESE PROVERB

  On a remote island in the Arctic circle, seven hundred miles from the North Pole, an incongruous concrete wedge protrudes from the snow on the side of a mountain. Reflective steel, mirrors, and prisms, built into an aperture on its outside face, reflect the polar light during the summer months, making the building gleam like a gem set into the landscape. In the dark of the winter it glows with an eerie white, green, and turquoise light from two hundred optical fibers, ensuring that the building remains visible for miles around. Behind its heavy steel entrance doors, a reinforced-concrete tunnel extends 125 meters (410 feet) into the bedrock. And behind another set of doors and two airlocks are three vaults, each 27 meters long, 6 meters tall, and 10 meters wide (89 by 20 by 33 feet). These vaults will not store gold, works of art, secret blueprints, or high-tech weaponry. Instead they will store something far more valuable—something that is arguably mankind’s greatest treasure. The vaults will be filled with billions of seeds.