Did you know? China is planting a belt of trees to protect land from the expanding Gobi Desert. This Great Green Wall is projected to extend some 4,480 kilometers (2,800 miles), stretching from outer Beijing through Inner Mongolia (Nei Monggol). Unfortunately, recent pressures to expand food production appear to have slowed this tree planting initiative. For more information view the text and data in Chapter 8 of Plan B 4.0: Mobilizing to Save Civilization.
Chapter 10. Stabilizing Population by Reducing Fertility: Breaking out or Breaking Down
Today we find ourselves in a demographically divided world, one where national projections of population growth vary more widely than at any time in history. In most European countries and Japan, population has stabilized or is declining; but in others, such as Ethiopia, Pakistan, and Saudi Arabia, population is projected to double or even triple before stabilizing.
Demographers use a three-stage model to understand how population growth rates change over time as modernization proceeds. In the first stage, birth and death rates are both high, resulting in little or no population growth. In the second stage, death rates fall while birth rates remain high, leading to rapid growth. In the third stage, birth rates fall to a low level, balancing low death rates and again leading to population stability while offering greater possibilities for comfort and dignity than in stage one. It is assumed that countries will progress from stage one to stage three.3
Today there are no countries in stage one; all are either in stage two or stage three. However, instead of progressing steadily forward toward stage three as expected, some countries are falling back toward stage one as the historical fall in death rates is reversed, leading the world into a new demographic era. If countries do not break out of the middle stage of the demographic transition in a matter of decades, rapid population growth will eventually overwhelm natural systems, leading to economic decline and forcing societies back into stage one as mortality rises. Over the long term, there is no middle ground. Countries either break out or break down. Unfortunately, a number of countries, mostly in Africa, are showing signs of breaking down.
For the first time since China's great famine claimed 30 million lives in 1959-61, world population growth is being slowed by rising death rates. (See Figure 10-1.) Although rapid population growth continues in scores of countries, the world is beginning to divide into two parts: one where population growth is slowing as fertility falls, and another where population growth is slowing as mortality rises. One way or the other, population growth will slow. That rising death rates from AIDS have already reduced the projected population for 2050 by more than 150 million represents a failure of our political institutions unmatched since the outbreak of World War II.4
The world is starting to reap the consequences of past neglect of the population issue. The two regions where death rates either are already rising or are likely to do so are sub-Saharan Africa and the Indian subcontinent, which together contain 1.9 billion people--nearly one third of humanity. Without clearly defined government strategies in countries with rapid population growth to lower birth rates quickly and a commitment by the international community to support them, one third of humanity could slide into a demographic black hole.
After nearly half a century of continuous population growth, the demand in many countries for food, water, and forest products is simply outrunning the capacity of local life-support systems. In addition, the ever growing number of young people who need health care and education is exceeding the availability of these services. If birth rates do not come down soon, these natural systems and social services are likely to deteriorate to the point where death rates will rise.
But what will cause death rates to go up in individual countries? Will it be starvation? An outbreak of disease? War? Social disintegration? At some point as population pressures build, governments are simply overwhelmed and are not able to respond to new threats. There are now three clearly identifiable threats that either are already pushing death rates up or have the potential to do so—the HIV epidemic, aquifer depletion, and land hunger.
Of these three, the HIV epidemic is the first to spiral out of control in developing countries. The epidemic should be seen for what it is: an international emergency of epic proportions, one that could claim more lives in the early part of this century than World War II did in the last one. In sub-Saharan Africa, HIV infection rates are soaring, already affecting one fifth to one third or more of adults in Botswana, Namibia, South Africa, Zambia, and Zimbabwe.5
Barring a medical miracle, many African countries will lose a fifth or more of their adult populations to AIDS by the end of this decade. To find a precedent for such a potentially devastating loss of life from an infectious disease, we have to go back to the decimation of New World Indian communities by the introduction of smallpox in the sixteenth century or to the Bubonic plague that claimed roughly a third of Europe's population during the fourteenth century.6
Ominously, the virus has also established a foothold in the Indian subcontinent. With 3.7 million adults now HIV-positive, India is home to more infected individuals than any other nation except South Africa. And with the infection rate among India's adults at roughly 1 percent—a critical threshold for potentially rapid spread--the epidemic threatens to engulf the country if the government does not move quickly to check it. The virus is also spreading rapidly in Myanmar, Cambodia, and China.7
One consequence of continuing population growth is potentially life-threatening water shortages. If rapid population growth continues indefinitely, the demand for water eventually exceeds the sustainable yield of aquifers. The result is excessive water withdrawals and falling water tables. (See Chapter 2.) Since 40 percent of the world's food comes from irrigated land, water shortages can quickly translate into food shortages.8
Dozens of developing countries face acute water shortages, but none illustrate the threat better than India, whose population—expanding by 18 million a year—has already surpassed 1 billion. New estimates for India indicate that in some areas water withdrawals are now double the rate of aquifer recharge. As a result, water tables are falling by 1 meter or more per year over parts of the country. Overpumping today means water supply cutbacks tomorrow, a serious matter where half of the harvest comes from irrigated land.9
The International Water Management Institute estimates that aquifer depletion and the resulting cutbacks in irrigation water could override technology gains, reducing the grain harvest in water-short regions of India. In a country where 53 percent of all children are already malnourished and underweight, a shrinking harvest could increase hunger-related deaths, adding to the 6 million worldwide who die each year from hunger and malnutrition. In contrast to AIDS, which takes a heavy toll among young adults, hunger claims mostly infants and children.10
The third threat hanging over the future of countries with rapid population growth is land hunger. Once cropland per person shrinks to a certain point, people can no longer feed themselves and they either turn to imported food or go hungry. The risk is that countries will not be able to afford the imported food or that food simply will not be available if world import needs exceed exportable supplies.
Among the larger countries where shrinking cropland per person threatens future food security are Ethiopia, Nigeria, and Pakistan, all countries with weak family planning programs. As Nigeria's population goes from 114 million today to a projected 278 million in 2050, its grainland per person will shrink from 0.16 hectares to 0.06 hectares. Pakistan's projected growth from 141 million today to 344 million by 2050 will reduce its grainland per person from 0.09 hectares at present to 0.04 hectares—scarcely the size of a tennis court. Countries where this number has shrunk to 0.03 hectares, such as Japan, South Korea, and Taiwan, import 70 percent or more of their grain.11
The threats from HIV, aquifer depletion, and shrinking cropland are not new or unexpected. We have known for more than a decade that AIDS could decimate human populations if it were not controlled. In each of the last 18 years, the number of new HIV infections has risen. Of the 58 million infected by the year 2000, 22 million people have died. In the absence of a low-cost cure, nearly all the remaining 36 million will die by 2010. It is hard to believe, given our advanced medical knowledge, that a controllable disease could devastate human populations in so many countries.12
Similarly, it is hard to imagine that falling water tables, which may prove an even greater threat to future economic progress and political stability, could be so widely ignored. The arithmetic of emerging water shortages is not difficult. A growing population with a water supply that is essentially fixed by nature means that the water per person will diminish over time, eventually dropping below the level needed to meet basic needs for drinking water, food production, and sanitation.
The same holds true for cropland per person. The mystery is not in the arithmetic. That is straightforward. The mystery is in our failure to respond to the threats associated with continuing population growth.
3. Lester R. Brown, Gary Gardner, and Brian Halweil, Beyond Malthus (New York: W.W. Norton & Company, 1999), pp. 112-13.
4. Figure 10-1 from U.S. Bureau of the Census, International Data Base, electronic database, Suitland, MD, updated 10 May 2000.
5. Joint United Nations Programme on HIV/AIDS (UNAIDS), Report on the Global HIV/AIDS Epidemic (Geneva: June 2000).
6. William H. McNeill, Plagues and Peoples (New York: Anchor Press/Doubleday, 1976).
7. UNAIDS, op. cit. note 5.
8. Sandra Postel, Pillar of Sand (New York: W.W. Norton & Company, 1999), p. 5.
9. David Seckler, David Molden, and Randolph Barker, Water Scarcity in the 21st Century, IWMI Water Brief 1 (Colombo, Sri Lanka: International Water Management Institute (IWMI), July 1998).
10. Irrigation cutbacks from ibid., and from Randolph Barker and Barbara van Koppen, Water Scarcity and Poverty, IWMI Water Brief 3 (Colombo, Sri Lanka: IWMI, 1999), p. 3; estimates of child malnutrition and underweight in United Nations Administrative Committee on Coordination, Sub-Committee on Nutrition (UN ACC/SCN) in collaboration with International Food Policy Research Institute, Fourth Report on the World Nutrition Situation (Geneva: January 2000), pp. 94-96; annual deaths worldwide from Brown, Gardner, and Halweil, op. cit. note 3.
11. Cropland from U.S. Department of Agriculture (USDA), Production, Supply, and Distribution, electronic database, Washington, DC, updated May 2001.
12. UNAIDS, AIDS Epidemic Update (Geneva: UNAIDS/WHO, December 2000), p. 3.
Copyright © 2001 Earth Policy Institute