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  • 标题:Running out of loaves and fishes - global resources
  • 作者:Lester R. Brown
  • 期刊名称:Humanist
  • 印刷版ISSN:0018-7399
  • 电子版ISSN:2163-3576
  • 出版年度:1994
  • 卷号:Nov-Dec 1994
  • 出版社:American Humanist Association

Running out of loaves and fishes - global resources

Lester R. Brown

This article is adapted from the Worldwatch Institute's Full House: Reassessing the Earth's Population Carrying Capacity, which was prepared for distribution at the Third United Nations Population Conference held recently in Cairo. (For complete details substantiating the positions taken in this article, see Full House.)

As the 90s unfold, the world is entering a new era, which it is far more difficult to expand food Many knew that this time would eventually that at some point the limits of the earth's natural systems, the cumulative effects of environmental degradation on cropland productivity, and the shrinking backlog of yield-raising technologies would slow the record growth in food production of recent decades. Now we can see that several constraints are emerging simultaneously to slow the growth in food production.

After nearly four decades of unprecedented expansion in both land-based and oceanic food supplies, the world is experiencing a massive loss of momentum. Between 1950 and 1984, world grain production expanded 2.6-fold, outstripping population growth by a wide margin and raising the grain harvested per person by 40 percent. Growth in the world fish catch was even more spectacular--a 4.6-fold increase between 1950 and 1989, which doubled seafood consumption per person. Together, these developments reduced hunger and malnutrition throughout the world, offering hope that these biblical scourges would one day be eliminated.

But in recent years, these trends suddenly have been reversed. After expanding at a rate of 3 percent a year from 1950 to 1984, the growth in grain production has slowed abruptly, rising at scarcely 1 percent annually from 1984 until 1993. As a result, grain production per person fell 12 percent during this time.

With the fish catch, it is not merely a slowing of growth but a limit imposed by nature. In 1989, the fish catch (including small contributions from inland catch and aquaculture) reached 100 million tons. After achieving this level, believed to be close to the maximum that oceanic fisheries can sustain, the catch has fluctuated between 96 million and 98 million tons. As a result, the 1993 per capita seafood catch was 9 percent below that of 1988. Marine biologists at the U.N. Food and Agriculture Organization report that the 17 major oceanic fisheries are all now being fished at or beyond capacity and that nine are in a state of decline.

The world's rangelands, a major source of animal protein, are also under excessive pressure. The language use to describe them is similar to that used for fisheries: they are being grazed at or beyond capacity on every continent. This means that rangeland production of beef and mutton may not increase much, if at all, in the future. Here, too, availability per person will decline indefinitely as population grows.

With both fisheries and rangelands being pressed to the limits of their carrying capacity, future growth in food demand can be satisfied only by expanding output from croplands. The growth in demand for food that until recently was satisfied by three food systems must now all be satisfied by one.

From mid-century until recently, grain output projections were for the most part simple extrapolations of trends. The past was a reliable guide to the future. But in a world of limits, this is changing. In projecting food supply trends now, at least six new constraints need to be taken into account:

1. The backlog of unused agricultural technology is shrinking, leaving the more progressive farmers fewer agronomic options for expanding food output. 2. Growing human demands are pressing against the limits of fisheries to supply seafood and of rangelands to supply beef, mutton, and milk. 3. Demands for water are pressing against the limits of the hydrological cycle to supply irrigation water in key food, growing regions. 4. In many countries, the use of additional fertilizer on currently available crop varieties has little or no effect on yields. 5. Countries that are already densely populated when they begin to industrialize risk losing cropland at a rate that exceeds the rise in land productivity, initiating a long-term decline in food production. 6. Social disintegration, often fed by rapid population growth and environmental degradation, is undermining many national governments and their efforts to expand food production.

First, in terms of agricultural technology, the contrast between mid-century and today could not be more striking. When the 1950s began, a great deal of technology was waiting to be used. Except for irrigation, which goes back several thousand years, all the basic advances were made between 1840 and 1940. Justus von Liebig had discovered in 1847 that all the nutrients taken from the soil by crops could be replaced in mineral form. Gregor Mendel's work establishing the basic principles of heredity, which laid the groundwork for future crop breeding advances, was done in the 1860s. Hybrid corn varieties were commercialized in the United States during the 1920s. And the dwarfing of wheat and rice plants in Japan to boost fertilizer responsiveness dates back a century.

These long-standing technologies have been enhanced and modified for wide use through agricultural research and exploited by farmers during the last four decades. Although new technologies continue to appear, none promises to lead to quantum leaps in world food output. The relatively easy gains have been made. Moreover, public funding for international agricultural research has begun to decline. As a result, the more progressive farmers are looking over the shoulders of agricultural scientists seeking new yield-raising technologies--and discovering that they have less and less to offer. The pipeline has not run dry, but the flow has slowed to a trickle.

In Asia, rice yields on maximum-yield experimental plots have not increased for more than two decades. Some countries appear to be "hitting the wall" as their yields approach those on the research plots. Japan reached this point with a rice yield in 1984 at 4.7 tons per hectare, a level it has been unable to top in nine harvests since then. South Korea, with similar growing conditions, may have run into the same barrier in 1988, when its rice yield stopped rising. Indonesia, whose rice yield has increased little since 1988, may be the first tropical rice-growing country to see its yield rise lose momentum. Other countries could hit the wall before the end of this decade.

Farmers and policymakers search in vain for new advances--perhaps from biotechnology--that will lift world food output quickly to a new level. But biotechnology has not produced any yield-raising technologies that will lead to quantum jumps in output, nor do many researchers expect it to. Donald Duvick, for many years the director of research at the Iowa-based Pioneer Hi-Bred International (one of the world's largest seed suppliers), makes this point all too clearly: "No breakthroughs are in sight. Biotechnology, while essential to progress, will not produce sharp upward swings in yield potential except for isolated crops in certain situations."

The productivity of oceanic fisheries and rangelands--both natural systems--is determined by nature. It can be reduced by overfishing and overgrazing or other forms of mismanagement, but once sustainable yield limits are reached, the contribution of these systems to world food supply cannot be expanded. As noted earlier, all oceanic fisheries are being pressed to their limits and beyond. And the decline in fisheries is not limited to developing countries: by early 1994, the United States was experiencing precipitous drops in fishery stocks off the coast of New England, off the West Coast, and in the Gulf of Mexico.

With water--the third constraint--the overpumping that is now so widespread will eventually be curbed to bring it into balance with aquifer recharge. This reduction, combined with the growing diversion of irrigation water to residential and industrial uses, limits the amount of water available to produce food. Where farmers now depend upon fossil aquifers for their irrigation water--in the southern US. Great Plains, for example, or the wheat fields of Saudi Arabia--aquifer depletion means an end to irrigated agriculture. In the United States, where more than a fourth of irrigated cropland is watered by drawing down underground water tables, the downward adjustment in irrigation pumping will be substantial. Major food-producing regions where overpumping is commonplace include the southern Great Plains, India's Punjab, and the North China Plain. For many of the world's farmers, the best hope for more water is from gains in efficiency. Perhaps the most worrisome emerging constraint on food production is the limited capacity of grain varieties to respond to the use of additional fertilizer. In the United States, Western Europe, and Japan, fertilizer use has increased little if at all during the last decade. Using additional amounts on existing crop varieties has little or no effect on yield in these countries. After a tenfold increase in world fertilizer use from 1950 to 1989-from 14 million to 146 million tons--use actually declined in the following four years.

A little-recognized threat to the future world food balance is the heavy loss of cropland that occurs when countries that are already densely populated begin to industrialize. The experience in Japan, South Korea, and Taiwan gives a sense of what to expect. The conversion of grainland to nonfarm uses and to high-value specialty crops has cost Japan 52 percent of its grainland, South Korea 42 percent, and Taiwan 35 percent.

As the loss of land proceeded, it began to override the rise in land productivity, leading to declines in production. From its peak, Japan's grain production has dropped 33 percent, South Korea's has fallen 31 percent, and Taiwan's is down 19 percent. These declines occurred at a time when population growth and rapidly rising incomes were driving up the demand for grain. The result: by 1993 Japan was importing 77 percent of its grain, South Korea was bringing in 68 per, cent, and Taiwan, 74 percent.

Asia's densely populated giants, India and China, are now going through the same stages which led to the extraordinarily heavy dependence on imported grain in the three smaller countries that industrialized earlier. In both, the shrinkage in grainland has begun. It is one thing for Japan, a country of 120 million people, to import 77 percent of its grain; it's quite another if China, with 1.2 billion people, moves in this direction.

Further complicating efforts to achieve an acceptable balance between food and people is the social disintegration occurring in many parts of the world. In a landmark article in the February 1994 Atlantic entitled "The Coming Anarchy," writer and political analyst Robert Kaplan observed that unprecedented population growth and environmental degradation were driving people from the countryside into cities and across national borders at a record rate, This, in turn, he reasoned, was leading to social disintegration and political fragmentation. In parts of Africa, he argues, nation-states no longer exist in any meaningful sense. In their place are fragmented tribal and ethnic groups.

The sequence of events that leads to environmental degradation is all too familiar to environmentalists. It begins when the firewood demands of a growing population exceed the sustainable yield of local forests, leading to deforestation. As firewood becomes scarce, cow dung and crop residues are burned for fuel, depriving the land of nutrients and organic matter. Livestock numbers expand more or less apace with the human population, eventually exceeding grazing capacity. The combination of deforestation and overgrazing increase rainfall runoff and soil erosion, simultaneously reducing aquifer recharge and soil fertility. No longer able to feed themselves, people become environmental refugees, heading for the nearest city or food relief center.

Crop reports for African countries now regularly cite weather and civil disorder as the key variables affecting harvest prospects. Not only is agricultural progress difficult, under these circumstances even providing food aid can be a challenge. In Somalia, getting food to the starving in late 1992 required a U.N. peacekeeping force and military expenditures that probably cost 10 times as much as the food that was distributed.

As political fragmentation and instability spread, national governments can no longer provide the physical and economic infrastructure for development. Countries in this category include Afghanistan, Haiti, Liberia, Sierra Leone, and Somalia. To the extent that nation=states become dysfunctional, the prospects for humanely slowing population growth, for reversing environmental degradation, and for systematically expanding food production are diminished.

The six limits or constraints briefly discussed here have emerged rather recently. In many cases, they were not anticipated. All available projections of world fertilizer use made during the 1980s, for example, showed growth continuing smoothly through the remainder of the century and into the next. Few analysts anticipated the scale of water scarcity that is unfolding in large parts of the world. Many assumed that the agricultural research establishment could continue to chum out new technologies that would rapidly raise crop yields for the indefinite future. And few have even asked the question of what happens if China starts losing cropland as fast as Japan has during the last few decades. Other negative influences, such as various forms of environmental degradation, also exist, but they have emerged more gradually. Among those which affect food production more directly are soil erosion, the waterlogging and salting of irrigated land, and air pollution. For example, a substantial share of the world's cropland is losing topsoil at a rate that exceeds natural soil formation. On newly cleared land that is steeply sloping, soil losses can lead to cropland abandonment in a matter of years. In other situations, the loss is slow and has a measurable effect on land productivity only over many decades.

Until recently, concerns about the earth's capacity to feed ever-growing numbers of people adequately was con, fined largely to the environmental and population communities and a few scientists. During the 1990s, however, these issues are arousing the concerns of the mainstream scientific community. In early 1992, the U.S. National Academy of Sciences and the Royal Society of London issued a report that began: "If current predictions of population growth prove accurate and patterns of human activity on the planet remain unchanged, science and technology may not be able to pre, vent either irreversible degradation of the environment or continued poverty for much of the world."

It was a remarkable statement--an admission that science and technology can no longer ensure a better future unless population growth slows quickly and the economy is restructured. This abandonment of the technological optimism that has permeated so much of the twentieth century by two of the world's leading scientific bodies represents a major shift--though perhaps not a surprising one, given the deteriorating state of this planet. That they chose to issue a joint statement, their first ever, reflects the deepening concern about the future within the mainstream scientific community.

Later that same year, the Union of Concerned Scientists issued a "World Scientists Warning to Humanity" signed by some 1,600 of the world's leading scientists, including 102 Nobel Prize winners. It observes that the continuation of destructive human activities "may so alter the living world that it will be unable to sustain life in the manner that we know." The scientists warned: "A great change in our stewardship of the earth and the life on it is required, if vast human misery is to be avoided and our global home on this planet is not to be irretrievably mutilated."

And in November 1993, representatives of 56 national science academies convened in New Delhi, India, to discuss the population issue. At the end of their conference, they issued a statement in which they urged the world to move toward zero population growth during the lifetimes of their children.

Between 1950 and 1990, the world added 2.8 billion people--an average of 70 million a year. But between 1990 and and 2030, the world is projected to add 3.6 billion, or 90 million a year. Even more troubling, nearly all this increase is projected for the developing countries, where life-support systems are already deteriorating. Such population growth in a finite ecosystem raises questions about the earth's carrying capacity. Will the earth's natural support systems sustain such growth in, definitely? How many people can the earth support at a given level of consumption?

Indeed, at the international level, our projections suggest that the population-driven environmental deterioration/political disintegration scenario described by Robert Kaplan is not only possible; it is likely in a business-as-usual world. But it is not inevitable. This future can be averted if our security is redefined and if we recognize that food scarcity, not military aggression, is the principal threat to our future. This would lead to a massive reordering of priorities--giving top place to filling the family-planning gap; to attacking the underlying causes of high fertility, such as illiteracy and poverty; to protecting soil and water resources; and to raising investment in agriculture.

The need now is for world leaders to seize the initiative for a bold new effort similar to the Marshall Plan launched in 1947. When the United States announced this plan to rebuild war-torn economies, including adversary and ally alike, it changed the way governments think about war and particularly its aftermath. The traditional "pillage and plunder" approach had been replaced by "rebuild and restore." It redefined the behavior expected of countries after a war, setting the stage for an era of unprecedented international cooperation.

Only the United Nations can manage an effort to reverse the environmental degradation of the planet. The United Nations has distinguished itself with the boldness of its initiatives on several occasions. For example, the World Health Organization led the highly successfully effort to eradicate smallpox, literally banishing this age-old plague from the face of the earth. A decade ago, UNICEF launched a highly successful worldwide program to immunize all the world's children. And most recently, UNFPA has outlined a comprehensive strategy to stabilize population by 2050.

Even as these steps are being taken, there is a need for a detailed assessment of the earth's population carrying capacity. Such a study could be done by the United Nations or by a member government. Once completed, this study could be used to refine both international and national strategies. Without such an assessment, it is very difficult for national governments to have a clear sense of what, for example, the world's food market will be in the decades a

It cannot be argued that resources are not available to reverse the deteriorating relationship between ourselves and the natural systems and resources upon which we depend. Despite the end of the cold war, the world is still spending close to $700 billion for military purposes, much of it designed to deal with threats that have long since disappeared.

If national security is defined to address the threats facing the world in the mid-1990s, it will lead to a massive redirection of resources. To cite just one specific example, the US. government spends $30 billion a year on military intelligence. UNFPA, the lead agency in the effort to stabilize world population, has an annual budget of $240 million. If continuing population growth is the threat to political stability that we believe it is, then having a U.N. Population Fund budget that is less than 1 percent of the US. military intelligence budget is indefensible.

Seldom has the world faced an unfolding emergency whose dimensions are as clear as the growing imbalance between food and people. The new information on the earth's carrying capacity brings with it a responsibility to educate and to act that, until recently, did not exist. A massive global environmental education effort--one in which the communications media is heavily involved--may be the only way to bring about the needed transformation in the time available.

If the world is to move off the path of potential deterioration and decline onto one that is environmentally sustainable, there is a need for leadership. The United Nations can and should play the lead role. But if the United States does not step forward and strongly support it, it is unlikely that the United Nations will be able to do it, particularly given the preoccupation of the secretary general with day-to-day peace, keeping crises.

There is a dangerous perception today that the world is adrift, with no clear sense of where to go or how to get there. The loss of hope associated with this situation, particularly among those already caught in the deterioration/decline scenario, is dangerous and can be destructive. The investments we can make in such things as family planning, tree planting, and literacy can help restore hope, giving people a sense that the future can be better. But whether it is or not is up to us.

The measure of individuals or nations is whether they respond to the great issues of their time. For our generation, the challenge is to reverse the deteriorating food situation, achieving a balance between people and food that is both humane and sustainable. And this, in turn, depends on reversing the deteriorating relationship between ourselves, currently increasing by 90 million per year, and the natural systems and resources upon which we depend.

Lester R. Brown, a 1991 Humanist of the Year, is president of the Worldwatch Institute, a Private, nonprofit environmental research organization in Washington, D.C.

Hal Kane is a research associate at the Worldwatch Institute and a principal author of the institute's annual Vital Signs: The Trends That Are Shaping Our Future.

COPYRIGHT 1994 American Humanist Association
COPYRIGHT 2004 Gale Group

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