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.