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26
Population
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.
Recent Trends
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
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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.
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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
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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
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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 accompany—and may cause—declining birth rates.
The institutional changes include
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Representative terms from entire chapter:
greenhouse gas
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TABLE 26.1 Relationship Between Population and Greenhouse
Gas Emissions
Low-Income Economies
Lower-Middle-Income Economies
Upper-Middle-Income Economies
Newly Industrialized Economies
Population
(2.6)
(2.1)
(1.7)
(0.8)
1990
1.0
1.0
1.0
1.0
2020
2.16
1.87
1.66
1.27
2050
4.03
3.10
2.10
1.61
2100
9.36
4.62
3.12
1.61
Per capita income
(1.5)
(2.2)
(2.9)
(6.2)
1990
1.0
1.0
1.0
1.0
2020
1.56
1.92
2.35
6.07
2050
2.43
3.69
5.54
14.31
2100
5.11
10.95
23.14
59.75
CO2 emissions,
annual
1990
1.0
1.0
1.0
1.0
2020
3.37
3.59
3.90
6.17
2050
9.79
11.44
11.63
16.12
2100
47.83
40.47
67.06
57.71
CO2 emissions,
cumulated
1990
1.0
1.0
1.0
1.0
2020
65.5
68.8
73.5
107.5
2050
262.9
294.3
306.4
441.3
2100
1,703.4
1,591
2,271
2,286
Family planning effect (base = CO2 emission, cumulated)
1990
2020
0.20
0.56
0.49
1.34
2050
2.94
3.43
6.54
7.01
2100
58.71
51.90
34.65
89.09
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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.
Policy Options
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,
Page 421
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.
Conclusions
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).
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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.
References
Bulatao, R. A., E. Bos, P. W. Stephens, and M. T. Vu. 1989a.
Africa Region Population Projections: 1989–90 Edition. World
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Bulatao, R. A., E. Bos, P. W. Stephens, and M. T. Vu. 1989b.
Asia Region Population Projections: 1989–90 Edition. World
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Bulatao, R. A., E. Bos, P. W. Stephens, and M. T. Vu. 1989c.
Europe, Middle East, and Africa (EMN) Region Population
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