Despite recent declines in population growth rates, the world's population today is 5.2 billion (International Insitute for Environment and Development and World Resources Institute, 1987) and is expected to continue to grow rapidly. This increasing population is one of the factors affecting trends in greenhouse gas emissions. The more people there are in the world, the greater is the demand put on resources to provide food, energy, clothing, and shelter for them. All these activities necessarily involve emissions of greenhouse gases.
Income growth also affects greenhouse gas emissions. As income per capita grows, the demand for goods also grows, particularly for such goods as health and education services, transportation, and housing.
Most nations in the world have policies to reduce population growth rates, and all seek to achieve rapid growth in income per capita (and other development objectives such as improvements in health). The interests of greenhouse gas emission policy are well served by the first objective but would appear to be in conflict with the second. This chapter explores the greenhouse gas implications of slowing population growth and the nature of this apparent conflict of objectives.
Both the global population and the population growth rate have been increasing rapidly over the past few centuries. The world population of 0.25 billion in A.D. 1 doubled by 1650. Two hundred years later, in 1850, it had doubled again to about 1.1 billion. By 1930, world population stood at 2 billion; it reached 4 billion by 1975 and is 5.2 billion today. Despite recent declines in the growth rate (International Institute for Environment
and Development and World Resources Institute, 1987), world population is expected to continue to increase rapidly. According to the United Nations, the population at the end of this century will be about 6.25 billion, and by 2025 about 8.5 billion. United Nations estimates indicate that population will stabilize at 10 billion perhaps a century from now.
The U.N. Population Fund considers this projection optimistic, because the projection assumes that fertility rates in the developing world will decrease by one-third in the next 30 to 40 years. This, in turn, assumes that the number of women using family planning in the developing countries will increase from its present level of 45 percent to 58 percent by 2000 and to 71 percent (the current level in industrialized countries) by 2025; it also assumes that contraceptive effectiveness will be as high as it is today in developed countries. If this decrease in fertility rates does not occur, U.N. estimates show population approaching 10 billion by 2025 and eventually stabilizing at 14 billion (Sadik, 1989).
Current World Bank estimates put the world population at 10 billion by 2025, stabilizing at approximately 11.5 billion early in the twenty-first century (Bulatao et al., 1989a,b,c,d).
As the population increases, the distribution of the world's population also changes. Africa is growing much faster than the rest of the world, at over 3 percent annually, as opposed to only 1.9 percent for Asia. Although Africa trails Asia, Europe, the former USSR, and the Americas in population today, by the year 2000 it will be second in size only to Asia. This growth is occurring in spite of the fact that population growth in Africa is affected disproportionately by the AIDS epidemic. In addition, many family planning programs in Africa have been established later than similar programs in Asia. Today, Asia contains 58.3 percent of the world's population; Europe and the former USSR contain 15.9 percent; the Americas contain 13.8 percent; Africa contains 11.5 percent; and Oceania, 0.5 percent. By 2020, World Bank estimates show Asia at 58.2 percent, Africa at 18.9 percent, the Americas at 12.4 percent, Europe and the former USSR at 10.1 percent, and Oceania at 0.5 percent (Bulatao et al., 1989a,b,c,d).
Current emission patterns show that industrialized countries are emitting much higher quantities of greenhouse gases per capita (and in total) than less developed countries (LDCs). As LDCs become more industrialized, their per capita emissions are expected to increase. Furthermore, according to current population projections, LDCs will account for an ever-increasing share of the world's population. At present, 77 percent of the world's population lives in the LDCs. Bulatao et al. (1989a,b,c,d) project that LDCs will make up 84 percent of the world's population by 2025 and 88 percent by 2100. According to the U.N. Population Fund, if current rates of growth in energy consumption and population continue, LDCs will be emitting four times as much greenhouse gas in 2025 as industrialized countries.
Population Programs as an Emission Control Method
There appears to be a general consensus that the only feasible and ethically acceptable way to reduce population growth is to achieve reduced fertility rates (Lapham and Simmons, 1987). Reducing fertility rates, however, is complex and depends on a number of factors. Fertility rates tend to slow as more education is provided for girls and as the status of women in the society improves. As noted by Repetto (1985),
New aspirations and alternatives for women are especially important. There is overwhelming evidence that increased education, increased participation in the economy outside the home, increased control over finances, and increased status within the home are all associated with lower fertility, because they either delay marriage or lower marital fertility or both. No other change exerts a more powerful and predictable influence over the pace of fertility decline.
Provision of health services may also be key to slowing population growth. Urbanization and industrialization have also been linked to decreased fertility rates (Johnson and Lee, 1987; National Research Council, 1987; Gillespie et al., 1989).
The provision of family planning services is another important policy variable in achieving reduced fertility. ''Most countries that have experienced rapid fertility declines have made vigorous efforts to bring modern means of birth control within reach of the entire population and have brought social and economic change and opportunities to the large majority of the population," notes Repetto (1985).
Lapham and Mauldin (1987) reviewed literature on factors effecting a lowering of fertility. They conclude that socioeconomic status and family planning program efforts work together. Countries that rank high on both generally have higher contraceptive prevalence and greater fertility decrease than countries than rank well on just one or the other. Nevertheless, the existence of family planning programs, which increase the availability of contraceptives, results in greater contraceptive use.
Perhaps the most relevant (although most aggregate) evidence in support of the proposition that the "demographic transition" (from high to low fertility rates) is closely related to economic and social development is to be gleaned from the experience of the past 30 years. Virtually all of the countries in the world today that have not achieved a significant reduction of population growth rates over the past 30 years also cannot be said to have achieved a development transition to modern economic growth. Conversely, almost all countries that have achieved some degree of demographic transition in the past 30 years have also achieved rapid economic growth. The highly successful cases of economic development have attained relatively
complete demographic transitions in a very short period of time. Several other economies in Latin America (Colombia, Brazil, Mexico, and Costa Rica) and Southeast Asia (Thailand, Indonesia, and Malaysia) have also achieved significant demographic transitions while attaining development objectives.
In contrast, the economies in southern Asia (e.g., India, Bangladesh, and Pakistan) have not fully achieved large reductions in fertility rates, despite substantial family planning program investments. Countries in sub-Saharan Africa have achieved some reductions in fertility from the extraordinarily high levels of a few years ago, but fertility rates remain high.
Microstudies of population program effectiveness generally support these aggregate observations. Women in very low income economies usually express a desire for large families and thus have little interest in contraception. When education levels and employment opportunities for women improve, women demand contraceptive services, including sterilization. The effectiveness of contraceptive use increases as well (Schultz, 1988).
In those countries where the demographic transition is not under way, family planning programs generally reach only a small proportion of the population. They do serve an educational role, and they do reduce births. However, without the associated economic change they cannot achieve large impacts on fertility rates.
Family planning services are often provided both by public health systems and by private suppliers. When the development-based demand conditions for contraception improve, public and private suppliers of contraceptives and contraceptive information find expanded markets. There is also a related demand for better health care and nutrition, and programs providing these services become highly effective. (These programs are also effective in countries not yet entering the demographic transition.)
Thus population control options exist in countries not achieving economic growth development, but they probably cannot produce large changes and initiate a large demographic transition unless economic development takes place. When development does occur, the demographic transition can be very rapid, as demonstrated by Taiwan, Singapore, Hong Kong, and South Korea.
This interaction or complementarity between economic and social change and the demand for and effectiveness of population programs has two implications for greenhouse gas policy. The first is that the effectiveness of a population program is itself limited by economic and social conditions. The second is that this interaction effectively removes much of the apparent conflict between the objectives of reduced population growth and increased per capita income. It is not a practical option to achieve a major reduction in population growth without some increase in per capita income. Indeed, there is some evidence not only that population programs are more effective
when incomes grow but also that such programs themselves induce income growth.
The analysis of population programs as a mitigation option has two parts. The first, as discussed above, is an examination of the apparent conflict between greenhouse gas concerns and income growth. The second is a calculation of the greenhouse gas emission reduction associated with a reduction in births.
This attempt to determine the actual impact of population policies on greenhouse gas emissions begins with a question. Would a country that failed to achieve a demographic transition and also failed to achieve economic growth emit more greenhouse gases over the next century than a country that achieved a demographic transition and economic growth as well?
To address this question, the panel has chosen to analyze the actual experiences of developing economies over the past 25 to 30 years.
The World Bank's annual World Development Report (World Bank, 1989) classifies developing countries as low income (excluding China and India), lower-middle income, and upper-middle income. The newly industrialized economics (NIEs) are middle-income (South Korea, Brazil) or high-income (Singapore, Hong Kong) countries.
By utilizing these categories of actual economic growth experience and projected population growth rates, the scenarios for population, per capita income, CO2 emissions, and the family planning effect are computed and reported in Table 26.1. Each group of countries is indexed to 1.00 in 1990. Thus numbers reported for the years 2020, 2050, and 2100 are multiples of the 1990 base. For a more detailed explanation of the procedures used to derive Table 26.1, see Appendix N.
According to this analysis, the apparent conflict between economic development programs and greenhouse gas concerns is not an actual conflict. Countries that are able to achieve rapid economic growth (NIEs) also achieve earlier and more rapid population declines. After a century, these countries will not have emitted substantially more greenhouse gases than countries that remain poor. Thus support of both population and economic development programs is not self-defeating from a greenhouse gas mitigation standpoint. However, it is important to note that countries experiencing rapid economic growth will need greenhouse gas mitigation programs similar to those needed for developed countries.
Barriers to Implementation
The experience of demographic change in the twentieth century indicates that large-scale economic, institutional, and social changes accompanyand may causedeclining birth rates. The institutional changes include
TABLE 26.1 Relationship Between Population and Greenhouse Gas Emissions
social insurance, so that parents need not rely on their descendants for material support in old age. Changes in the status of women also appear to be influential in the decisions of women to limit family size. Government policies to guarantee the material support of the elderly connect to a wide range of fundamental policy issues, including the evolution of the macro-economy and the labor force. For matters of this scale, political will is an indispensable element of policy formulation. Similarly, the reverberations of changes in family size and the status of women are too large to be set aside in policy design. These matters of national interest are central to the international discussion of population.
Accordingly, although specific policy alternatives abound in areas such as tax treatment of children and provision for the costs of child-rearing, including education and health care, uncertainties remain as to the nature of the most successful strategies for population policy. Within the United States, the controversy surrounding abortion as a means of controlling family size has complicated discussions of a national population policy and the demographic components of U.S. foreign policy.
A National Research Council (1987) study noted that those countries that have had unusually effective family planning programs have put significant personnel and resources into them. Availability of resources appears to be a necessary precondition for family planning program effectiveness. Yet less than 1.5 percent of the total international development assistance goes into population programs. The United States provided about $227.1 million in population assistance in 1988, that is, about 2.2 percent of the total U.S. development assistance that year (Population Crisis Committee, 1990).
Survey data have shown that a substantial demand for limiting and spacing births remains unmet by current family planning programs (Gillespie et al., 1989; Repetto, 1985). It would appear that the current annual worldwide expenditure of $3.2 billion for contraceptives is insufficient to meet demand in the LDCs. Gillespie et al. (1989) estimate that at least an additional $250 million each year over the next 20 years will be required to meet minimum LDC demand. The Population Crisis Committee (1990) estimates that expenditures must reach $10 billion per year by 2000 to slow population growth substantially.
Increasing availability of contraceptives where they are demanded and the concomitant reduction in fertility rates could help to hold down overall greenhouse gas emissions at a relatively inexpensive cost per ton of CO2. It would be prudent for the United States to consider increasing funding for voluntary family planning services for LDCs requesting such assistance. For example, U.S. funding for the U.N. Population Fund could be restored,
or U.S. Agency for International Development (AID) funds for population programs could be increased.
Other Benefits and Costs
Slowing population growth may well lead to less stress on the environment. In reviewing research on population growth and economic development, a National Research Council (1986) report concluded that slower population growth is likely to lead to a reduced rate of degradation of renewable common-property resources such as air, water, forests, land, and species of plants and animals. As discussed above, it should also be noted that population reduction programs may themselves have income consequences.
Research and Development
The links between population growth and greenhouse gas emissions are not fully understood. While some researchers indicate that increased population growth will result in increased greenhouse gas emissions, others feel that a reduction in population will result in increased greenhouse gas emissions as the per capita income of the population increases. A better understanding of the links among population growth, economic growth, and greenhouse gas emissions would aid decision makers in their determination of whether family planning is a worthwhile policy to pursue with regard to greenhouse warming.
The world population is growing rapidly. If there is not a significant reduction in fertility rates, the population may reach 14 billion before stabilizing.
The National Research Council (1986) report noted that reducing fertility would produce at every subsequent point slower population growth and smaller population size. Both World Bank and U.N. population projections show that the sooner fertility rates are reduced, the smaller the world population will be at stabilization.
The links between population growth and greenhouse emissions are complex and not well understood. However, at any given rate of greenhouse gas emissions per capita, a smaller population will mean less total emissions, as well as less stress on the environment in general. For example, at any given level of per capita emissions in 2025, the U.N. low population projection would involve 11 percent less total emissions than the medium projection, and 24 percent less than the high population projection (Sadik, 1990).
Greenhouse gas mitigation is thus well served by well-designed family planning, health, and education programs. It is furthered by broader economic development programs if they complement population reduction programs and enable earlier and more complete demographic transition.
Bulatao, R. A., E. Bos, P. W. Stephens, and M. T. Vu. 1989a. Africa Region Population Projections: 1989–90 Edition. World Bank Staff Working Paper WPS 330. Washington, D.C.: World Bank.
Bulatao, R. A., E. Bos, P. W. Stephens, and M. T. Vu. 1989b. Asia Region Population Projections: 1989–90 Edition. World Bank Staff Working Paper WPS 331. Washington, D.C.: World Bank.
Bulatao, R. A., E. Bos, P. W. Stephens, and M. T. Vu. 1989c. Europe, Middle East, and Africa (EMN) Region Population Projections: 1989–90 Edition. World Bank Staff Working Paper WPS 328. Washington, D.C.: World Bank.
Bulatao, R. A., E. Bos, P. W. Stephens, and M. T. Vu. 1989d. Latin America and the Caribbean (LAC) Region Population Projections: 1989–90 Edition. World Bank Staff Working Paper WPS 329. Washington, D.C.: World Bank.
Gillespie, D. G., H. E. Cross, J. G. Crowley, and S. R. Radloff. 1989. Financing the delivery of contraceptives: The challenge of the next twenty years. In The Demographic and Programmatic Consequences of Contraceptive Innovation, S. Segal, A. Tsui, and S. Rogers, eds. New York: Plenum.
International Institute for Environment and Development and World Resources Institute. 1987. World Resources 1987. New York: Basic Books.
Johnson, D. G., and R. D. Lee, eds. 1987. Population Growth and Economic Development: Issues and Evidence. Madison: University of Wisconsin Press.
Lapham, R. J., and W. P. Mauldin. 1987. The effects of family planning on fertility: Research findings. In Organizing for Effective Family Planning Programs, R. J. Lapham and G. B. Simmons, eds. Washington, D.C.: National Academy Press.
Lapham, R. J., and G. B. Simmons. 1987. Overview and framework. In Organizing for Effective Family Planning Programs, R. J. Lapham and G. B. Simmons, eds. Washington, D.C.: National Academy Press.
National Research Council. 1986. Population Growth and Economic Development: Policy Questions. Washington, D.C.: National Academy Press.
National Research Council. 1987. Organizing for Effective Family Planning Programs. Washington, D.C.: National Academy Press.
Population Crisis Committee. 1990. 1990 Report on Progress Towards Population Stabilization. Washington, D.C.: Population Crisis Committee.
Repetto, R. 1985. Population, resource pressures, and poverty. In The Global Possible, R. Repetto, ed. New Haven, Conn.: Yale University Press.
Sadik, N. 1989. The State of World Population 1989. New York: United Nations Population Fund.
Sadik, N. 1990. The State of World Population 1990. New York: United Nations Population Fund.
Schultz, T. P. 1988. Population programs: Measuring their impact on fertility. Journal of Policy Modeling 10:1.
World Bank. 1989. 1989 World Development Report. Washington, D.C.: World Bank.