World Food Supply

I

Introduction

World Food Supply, quantity of food, including food stored from previous years, available for people to consume at any given time. Obtaining enough food is an important concern for every nation in the world, and in some countries food shortage is an extremely serious problem. Worldwide, about 840 million people, or about 14 percent of the total population, do not have adequate food. These people suffer from undernutrition, a condition of nutrient deficiency that causes general weakness and fatigue, stymies mental and physical development in children, and makes people susceptible to potentially fatal diseases such as dysentery, whooping cough, and tuberculosis. The majority of the world’s undernourished people live in China, India, Africa, and Latin America.

Creating an adequate world food supply poses two challenges. The first is to provide enough food to meet the needs of the earth’s expanding population, without destroying natural resources needed to continue producing food. The second challenge is to ensure food security—that is, to make sure all people have access to enough food to live active, healthy lives. Just producing enough food does not guarantee that the people who need it are able to get it. If people do not have enough money to buy food—or to buy the land, seeds, and tools to grow food—or if natural or human-made disasters such as drought or war prevent them from getting food, then people are at risk for undernutrition even when there is an adequate food supply. In industrialized countries, poverty typically prevents people from obtaining food; in developing countries, the circumstances that cause food insecurity include poverty, low crop yields, and unproductive economic policies.

II

Factors Affecting Food Production

The number of farmers worldwide has been decreasing since the 1950s as farmers migrate to cities to find other work. Some of the factors that compel farmers to move to cities are the need for a better income, the inability of small farms to compete with larger farms, and the takeover of farms for development of industry or roads. Fewer farmers and the loss of knowledge—passed down through generations of farming families—about the most productive agricultural practices for a region affect the variety, quality, and quantity of food produced.

Food production also requires water, arable land (land that can grow crops), some form of energy, such as petroleum, to run tractors and other farm equipment, and the human and animal labor needed to till the land. These vital resources are distributed unevenly around the world, and many have been depleted or damaged by modern agricultural techniques. Scientists estimate that since 1945, about 17 percent of the earth's vegetated surface, or 2 billion hectares (4.9 billion acres) have been degraded, or made less productive, by human mismanagement. Poor agricultural practices, such as overgrazing, plowing vulnerable soils, overfertilizing, and irrigation without proper drainage, have degraded about 552 million hectares (13.6 million acres), 38 percent of the world’s total cultivated area.

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Water, essential for growth of all crops, is the natural resource in shortest supply. More than 20 countries lack sufficient water to grow enough food for their people. Over half of these people live in the arid, or dry, regions of Africa and the Middle East, where periodic drought, or extreme water scarcity lasting months or years, contributes to severe food shortages. By the year 2025, if current population trends continue, about 75 percent of Africans will live in regions where water shortages limit food production. The increasing costs of irrigation, the greater fluctuation in drought and floods anticipated with global climate change, and population growth are all pushing in the direction of more pressure on water resources.

The primary culprit for water depletion is irrigation, the artificial application of water for crops that makes unproductive lands fertile. Too much irrigation depletes fresh water supplies, seriously damages the environment, and wreaks havoc on human populations. The Aral Sea in Uzbekistan, for example, was once the world’s fourth largest inland lake. Its water volume has dropped over 80 percent since the 1960s because the rivers that flow into the sea have been diverted to irrigate farmlands and cotton plantations. As a result, all of the 24 fish species native to the Aral Sea have disappeared, and the once-thriving fishing villages, now miles from the shore, are ghost towns. The low water level in the sea concentrates salts and toxic chemicals from pesticides, which accumulate on the dry lake bottom. The wind blows the toxic mix over the surrounding farmlands, destroying cropland, poisoning the drinking water, and creating serious health problems among the population. Severe environmental deterioration from improper irrigation threatens ecosystems near other irrigated croplands, including croplands near the Colorado River in the United States and the Ganges River in India.

Like water, arable land is another disappearing agricultural resource. The amount of arable land per person has been shrinking since 1981. An estimated 8 million hectares (20 million acres) of farmland is replaced each year by homes, shopping centers, industries, and roads built to accommodate growing populations. Modern farming practices also contribute to the decline of arable land by causing the wearing away, or erosion, of topsoil, the upper layer of soil that provides the nutrients plants need. Erosion leaves only nutrient-poor subsoil, which cannot support plants.

Farming techniques, particularly irrigation, also contribute to salinization, the accumulation of salt in soils. Salinization stunts plant growth, decreasing harvests and eventually making soils unusable. According to the Food and Agriculture Organization (FAO) of the United Nations (UN), salinization has degraded an estimated 7 to 10 percent of the world’s 250 million hectares (618 million acres) of irrigated lands.

Modern farming techniques depend on extensive use of fossil fuels—oil, gasoline, and natural gas—for a variety of tasks. Fuels are needed to operate machines for plowing, planting, and harvesting, to make fertilizers and pesticides, and to build irrigation systems. After food is harvested, energy from fossil fuels is used to transport and process food. Although fossil fuel supplies are ample for the near future, they cannot last forever. Also, extensive use of fossil fuels damages the environment, contributing to air, soil, and water pollution, ozone depletion (see Ozone Layer), and global warming.

III

Factors Affecting Food Security

The world’s population is now 6.7 billion people and is projected to reach 8 billion by the year 2025. Food production must keep pace with the increasing number of people living on the planet. Since 1960, world food production has grown faster than population, mainly because of the green revolution, the effort to increase and diversify crop yields in agriculturally less advanced regions of the world. Introduction of irrigation, fertilizers, pesticides, and new seed varieties resulted in increased yields of rice, wheat, and corn in many countries. In most countries, however, added water and fertilizer do not increase yields as much as in the past, and in the future, food production may not match population growth.

Although controlling population growth rate is important for achieving food security, a low population growth rate does not guarantee food security, nor does a high growth rate create food insecurity. China has a low population growth rate of 0.6 percent, but 11 percent of its people are undernourished. China’s food security problem is caused in part by poverty—17 percent survive on less than U.S.$1 per day. Food security is also threatened by the rapid loss of arable land as cities expand. In Haiti, the population growth rate of 2.5 percent is also low, yet 49 percent of the population is undernourished. Lack of food security in Haiti is caused by extreme poverty, largely the result of two centuries of military dictatorships, which have neglected development of agriculture, schools, health care, and transportation.

Population growth negatively affects food security only when other food-related variables are impaired. For instance, a country may not have enough water or arable land to support more people, or agricultural techniques may not produce enough food for a growing population. Food availability depends on physical access—that is, adequate markets, sound highways, reliable vehicles to transport food, and storage facilities. A lack of any one of these items can cause a food crisis. War and political strife also disrupt access to food, resulting in famines and temporary food shortages. In 1992, for example, at the height of the wars of Yugoslav succession, 4 million people in Bosnia-Herzegovina and 3 million refugees in Croatia were without food.

Grain, or cereal, production plays a significant role in the world’s food security. Grains such as rice, wheat, and corn provide about 50 percent of the calories people consume each day. Grain supplies may be threatened, however, by the world’s reliance on a small number of crop varieties. Throughout history, farmers planted many varieties of rice, wheat, corn, millet, and other grains, selected for how well they grew in local soils, how they withstood local insects and diseases, and how they adapted to the climate. In the 20th century, however, most of these regional varieties have been replaced by new varieties of rice, wheat, and corn that produce more grain but are vulnerable to unpredictable diseases or insect infestations. For example, in the early 1970s a disease called Southern corn leaf blight destroyed 15 percent of the corn crop in the United States, and eliminated almost the entire corn crop in areas of Illinois and Indiana. To provide a stable food supply, agriculture needs diverse crop varieties so that the failure of one or two crops is less likely to cause famine.

To ensure food security, an adequate diet must include not only calories but the full range of nutrients that humans need (see Human Nutrition). Of particular importance is protein, which is essential for muscles, bones, the antibodies that prevent infection, and the many enzymes that regulate all of the body’s systems. Grains, beans, and seeds are common sources of protein in developing countries, while meat, milk, cheese, and eggs are more likely to be consumed in industrialized countries, and by the newly wealthy in developing countries. The demand for these products is high, despite the inefficient use of land required to produce them. To raise chickens and pigs, it takes an estimated 2 to 4 kg (5 to 9 lb) of grain to produce 1 kg (2.2 lb) of meat, and for cows raised in feedlots, the figure is an estimated 7 kg (15 lb) of grain per 1 kg (2.2 lb) of meat. In contrast, direct consumption of grain by humans is far more efficient.

Reliance on fish as a protein source varies widely. Although fish provide only an estimated 6.5 percent of the animal protein consumed in North America, in Africa the figure is an estimated 21 percent, and in Japan, North and South Korea, and China, 22 percent. In regions where fish supply a significant percent of the protein, people’s protein source is threatened by the continuous decline in quality and quantity of fish caught in all parts of the world.

In 2002, about 70 percent of marine fish stocks were being harvested faster than they could reproduce, according to a report by the United Nations Environment Program (UNEP). UNEP also noted that major changes were needed in the use and management of marine fisheries to avoid the commercial extinction of many fisheries. “Fishing fleets are venturing farther from their home ports, off the continental shelves and into deeper waters to meet the global demand for fish,” the report noted. “Consequently, fish are being captured from stocks which were previously unexploited and the long-term viability of a number of species may be jeopardized.” See also Fisheries.

In contrast, fish farming, or aquaculture, is expanding rapidly, especially in developing countries, where it holds the promise of improved food security. Between 1970 and 2000, aquaculture increased from 3.9 percent to 27.3 percent of the total volume of fish raised or captured. Salmon, scallops, and shrimp are among the most popular species for aquaculture. Fisheries exports earn more money worldwide than sugar, coffee, tea, and cocoa combined, crops traditionally raised for export by developing countries.

Crops grown for sale to other countries also influence food security. Export crops can include staple foods, such as rice, or luxury foods, such as strawberries. Export sales provide income for farmers, enabling them to purchase food, and exports help a nation reduce debt owed to other countries for imports. Some countries, however, grow so many crops for export that not enough food is grown for domestic consumption. In Colombia, for example, coffee sold to other countries supplies about 10 percent of the country’s export income, and coffee farms occupy an estimated 25 percent of the arable land, an estimated 1 million hectares (2.4 million acres) that could be used for food crops needed at home. Export crops are widely planted in other Latin American countries and in African countries, which in addition to coffee, provide most of the world supply of cacao (cocoa beans), peanuts, cloves and sisal, a plant from which rope is made.

To ensure food security in times of low crop yields, natural disasters, or famine, nations must use stored foods. Global cereal reserves, also known as world carryover stocks, are an indicator of world food security. Grain stores reached a historic high in 1988, sufficient to feed the world for 100 days. By the beginning of the 21st century, however, stores had dropped to their lowest level in 20 years. The decrease in grain stores resulted from cutbacks in grain production in Europe and the United States, lower yields due to regional weather problems, and soil erosion resulting from poor farming practices. As yields have decreased, many countries have dipped deeper into carryover stocks to feed their growing populations.

Countries that cannot grow or buy enough food to feed their people, or experience natural disaster or political disruption, are dependent on food aid from wealthier countries. In 1992, 16.9 million metric tons of food were distributed to countries in need. However, in 1996, global food aid fell to about 6 million metric tons of food, and during the first few years of the 21st century, annual aid stood at about 10 million metric tons. The decline in food aid coupled with an increase in natural and political disasters has caused international aid organizations to shift their priorities from long-term agricultural development to crisis intervention and helping refugees survive emergency shortages.

IV

Food Supply in Different Regions of the World

People in different regions of the world have vastly different food supplies and nutritional states. Much of this difference is caused by poverty. The availability and condition of natural resources for food production, the political system, and national economic policies—including international trade arrangements—also affect the number of people suffering from undernutrition in each region.

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