“For a successful technology, reality must take precedence over public relations, for Nature cannot be fooled.”

Richard Feynman


FULL HOUSE- Reassessing the earths population carrying capacity

by Lester R. Brown and Hall Kane


Over the next 40 years, the world will face massive grain deficits in Africa, the Indian subcontinent, and China if populations grow as projected, the Worldwatch Institute, a Washington, D.C.-based environmental research institute, said in a study released today.

The new book, “Full House: Reassessing the Earth’s Population Carrying Capacity,” by Lester R. Brown and Hal Kane, shows that the projected import deficits will dwarf exportable supplies, setting up fierce competition among importing countries and driving up world grain prices.

The authors present data showing that the world is moving into a new era. They observe that “From mid-century until recently, projected increases in the world fish catch and grain output were simple extrapolations of past trends. The past was a reliable guide to the future. But in a world of limits, this is changing.”

This study, funded by the Wallace Genetic Foundation, the Turner Foundation, and the McBride Family Fund, contains the first world food projections to take into account the recent leveling off in the world fish catch, the spreading scarcity of irrigation water in major food-producing regions, the projected heavy loss of cropland to industrialization in Asia, and the diminishing response of crop varieties to additional fertilizer use.

These projections are for business as usual. They assume that population growth will continue on the medium-growth trajectory, producer prices will remain at the level of the early nineties, and soil erosion will continue.

The authors conclude that “food supply is the most immediate constraint on the earth’s population carrying capacity.” They note that “the food sector is the first where human demands are colliding with some of the earth’s limits: the capacity of oceanic fisheries to supply fish, the availability of fertile new land to plow, and the ability of the hydrological cycle to supply irrigation water.”

The continuously rising demand for food is also pressing against the capacity of crop varieties to respond to ever greater applications of fertilizer. As the yield response of available wheat, rice, and corn varieties to additional fertilizer diminishes, the rise in grain yield per hectare is slowing in all major grain-producing regions. With biotechnology neither providing nor promising any dramatic breakthrough in raising yields, there is little hope for restoring rapid growth in food output.

“The impact of these collisions will reverberate throughout the economy,” say the authors. “Many knew that this time would eventually come, but because no one knew exactly when or how it would happen, the food prospect was widely debated. Now the constraints that are emerging simultaneously to slow the growth in food production are clearly visible.”

“Full House” compares food and population projections for the next 40 years with the trends of the last 40 years. For example, between 1950 and 1990 the world added 2.8 billion people, an average of 70 million a year. But between 1990 and 2030, it is projected to add 3.6 billion, or 90 million a year.

For developing countries, the population gains ahead are potentially overwhelming. Nigeria, which gained 55 million people from 1950 to 1990, is projected to add 191 million people during the next four decades. Ethiopia, which can no longer feed itself even when rainfall is good, is projected to add 106 million people by 2030—more than three times as many as during the last 40 years. Iran faces increases of a similar magnitude.

Pakistan will add nearly three times as many people in the next four decades as during the last four. Bangladesh and Egypt will each add almost twice as many people. The largest absolute increase is slated for India: 590 million. China is second with 490 million.

Such population growth in a finite ecosystem raises questions about the earth’s carrying capacity: How long can the earth’s natural support systems sustain such growth? How many people can the earth support at a given level of consumption?

Whereas the seafood catch increased by 78 million tons from 1950 (22 million tons) to 1989 (100 million tons), the authors are not counting on any growth in the catch from 1990 to 2030. Marine biologists at the Food and Agriculture Organization report that all 17 of the major oceanic fisheries are being fished at or beyond capacity. Nine are in a state of decline.

With grain output, the world added 1.15 billion tons between 1950 and 1990, but with business-as-usual projections, the authors see the world adding only 369 million tons over the next four decades. To put this in historical perspective, the annual increase from 1950 to 1984 was 30 million tons.

Between 1984 and 1992, it dropped to 12 million tons. And these projections show it dropping further—to 9 million tons between now and 2030.

If this production scenario materializes and if population rises to 8.9 billion in 2030 as projected, the grain supply per person for the world as a whole will drop to 240 kilograms, just 20 percent above the current consumption level in India of 200 kilograms.

The projected world grain harvest of 2.1 billion tons in 2030 could satisfy populations of different sizes, depending on consumption levels. At the U.S. consumption level of 800 kilograms per person per year, a harvest of 2 billion tons would sustain 2.5 billion people. At the Italian consumption level of 400 kilograms, it could support 5 billion, roughly the 1990 world population. And at the Indian level of 200 kilograms, this harvest would support 10 billion people. Although many people aspire to the U.S. diet, population growth is foreclosing that option for much of humanity.

Since 1984, grain output per person has fallen roughly 1 percent per year. Since 1989, the seafood catch per person has fallen by 2 percent per year. At a time when U.N. estimates show nearly 900 million people are already hungry, the prospect of further declines in food consumption is not a pleasant prospect. Even now, the food needs of the 90 million added each year can be satisfied only by reducing consumption among those already here.

Brown and Kane say that “With fishers and farmers no longer able to expand output fast enough to keep up with population growth, it is time to reassess population policy. New information on the carrying capacity of both land and oceanic food systems argues for a basic rethinking of national population policies, an accelerated international response to fill unmet family planning needs, and a recasting of development strategies to address the underlying causes of high fertility.”

In April 1994, the United Nations Population Fund, the U.N. agency responsible for population and family planning, put forth a bold proposal to stabilize world population at 7.8 billion by the year 2050. Among other things, the plan calls for quadrupling funding for international family planning assistance programs, pushing the total to $4.4 billion by 2000.

The program is broad-based, involving changes in the role of women and the expansion of family planning services to include both the 120 million couples who want to use family planning services but cannot get them and an additional 230 million couples who would need to plan their families if population is to stabilize at the 7.8 billion level.

The Fund’s World Plan of Action calls for providing universal primary education for both girls and boys and making secondary education available to at least half of all girls. If implemented, this program would move the world onto a low-growth demographic path where population would rise from today’s 5.5 billion to 7.27 billion in 2015 and stabilize at 7.8 billion in 2050.

In addition to the proposed increase in expenditures on family planning and primary education, Full House includes recommended expenditures on reforestation, soil conservation, and agricultural and forestry research, rounding out a global food security budget. Starting at $24 billion in 1996, the total budget increases to nearly $60 billion in the year 2000, then levels off. The expenditures on agricultural research would entail an abrupt reversal of the decline underway in the last few years.

With the rise in grain yields now slowing and the yield of oceanic fisheries and rangelands unlikely to increase much, if at all, there is an urgent need for national assessments of carrying capacity. Otherwise, there is a real risk that countries will blindly overrun their ability to grow food, developing massive deficits that will collectively exceed the world’s exportable supplies.

Simultaneously there is a need for a global assessment of the long-term food prospect; otherwise, countries facing import deficits will not know whether there will be enough exports to cover them.

The authors conclude that “food security will replace military security as the principal preoccupation of national governments in the years ahead. Despite tight budgets,” they say, “the resources are available to reverse the deteriorating relationship between ourselves and the natural systems and resources on which we depend. Even though the Cold War is over, 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.”

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. –END–

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