STOPPING AT TWO
Chapter 10. Stabilizing Population by Reducing Fertility
Lester R. Brown, Eco-Economy: Building an Economy for the Earth
(W.W. Norton & Co., NY: 2001).
You do not need to be a mathematician to
understand that there is no long-term alternative to having only
two children per couple, the number needed for replacement. Joel
Cohen, population analyst at Rockefeller University, makes this
point rather effectively. He notes that if the 1990 population growth
rates in various regions had continued until 2150, there would be
694 billion people in the world. This compares with 6.1 billion
people today. "No way," says Cohen. "Not enough water falls from
the sky to satisfy the needs of such a vast human population."47
The basic arithmetic is not new. We have always known that a seemingly
innocuous growth of 3 percent a year, a rate that has been common
in many developing countries, would lead to a 20-fold increase in
one century and a 400-fold increase in two centuries. Saudi Arabia
today has 20 million people and a population that is expanding at
this rate. If this were to continue throughout this century, it
would have 440 million people in 2100more
than the current population of North America.
Or look at Nigeria, also growing at roughly 3 percent a year. A
century from now, Nigeria's 114 million people would total 2.46
billion. Considering that all of Africa is supporting 800 million
today, it is impossible to visualize 2.46 billion people in Nigeria
alone. It is hard to argue with Cohen's basic point that the only
viable long-term option is two children per couple. A population
that is growing, however slowly, will eventually overwhelm its life-support
systems. Conversely, a population that is declining, however slowly,
will eventually disappear.
The growth in world population over the last half-century is sufficiently
recent that we are still struggling to understand what it means.
We may intuitively understand that a 20-fold increase in a century
is not possible, but we have yet to come to terms with the reasons
why. For some threats to our future we have designed response systems.
For example, an outbreak of a deadly infectious disease such as
the Ebola virus sets off programmed responses to contain and eradicate
it. This response involves the World Health Organization, the U.S.
Centers for Disease Control and Prevention, and the appropriate
agencies in the government of the county affected. And if the currency
of a country like Indonesia or Russia collapses, the international
monetary system is programmed to respond to that threat. Such is
not the case when population growth crosses key support system thresholds.
When the water use of a growing population surpasses the sustainable
yield of an aquifer and the water table starts to fall, there is
no alarm system that triggers a response in the councils of government.
As a result, the gap between the demand for water and the sustainable
yield of the aquifer widens. Each year, the drop in the aquifer
is greater than the year before, setting the stage for an eventual
dramatic reduction in the water supply as an aquifer is depleted
and the amount pumped out is reduced to the recharge level. If overpumping
is extensive, the drop in water supply could be traumatic, disrupting
food production.
Unfortunately, no one regularly measures the water table level under
the North China Plain, the Punjab in India, or the southern Great
Plains of the United States, announcing when overpumping begins,
how much water is left, and when the aquifer will be depleted. As
a result, instead of societies planning for a soft landing by bringing
the demand for water into balance with sustainable yield, they keep
going until the inevitable crash occurs.
Societies with water demands surpassing the sustainable yield of
the aquifers and desiring more water per person in the future will
have to consider the possibility of reducing population size, a
trend already under way in some European countries. This means shifting
not to a two-child family, but to a one-child family.
In countries where rural populations continue to grow and holdings
are divided among the children in each generation, the land per
family eventually shrinks to the point where survival is threatened.
Halting the fragmentation that is creating a nightmarish situation
in many rural communities in Africa and Asia depends either on moving
quickly to replacement-level fertility or accepting massive rural-urban
migration.
Although population projections for the world have been available
since the 1950s, remarkably little has been done to analyze the
relationship between the size of current and future populations
and the earth's capacity to satisfy people's needs for basic resources,
such as water and cropland. Demographers who do the projections
have long since abandoned this area as a field of research. In his
1996 book How Many People Can the Earth Support?, Joel Cohen
analyzed the 1992 and 1993 annual meetings of the Population Association
of America, where there were some 200 symposia. Not one of these
panels attempted to analyze the relationship between projected population
growth and the earth's natural resource base.48
The good news is that the world is making progress in achieving
replacement-level fertility. Fifty-four countries have now reduced
average family size to two children or less. (See Table 10-1.) Together
these countries contain 2.5 billion people. Family size in China,
at 1.8 children per couple, is now below the level in the United
States (2.1). Even so, the large number of young people reaching
reproductive age in China means that the population is still expected
to reach 1.49 billion by 2038, before its numbers begin to decline,
dropping to 1.46 billion in 2050. Some countries have seen fertility
drop well below replacement level. For example, Russia's fertility
rate is 1.2 children. As a result of this decline, and a rise in
mortality over the last decade, Russia's population of 144 million
is now declining by 900,000 per year. Other countries where population
is beginning to decline include Bulgaria, the Czech Republic, Italy,
and the Ukraine.49
Despite these trends, the threat of continuing population growth
in more than a hundred developing countries is all too real. Perhaps
the most dangerous educational gap is the lack of understanding
of the relationship between family size, the longer-term population
trajectory, and the future availability of resources per person.
Filling this gap requires projections that link a range of family
sizessay,
two, four, or six childrento
the future availability of land, water, and other basic resources.
Without this information, individuals may simply not understand
the urgency of shifting to smaller families. And of even more concern,
political leaders will not be able to make responsible decisions
on population and related policies, such as investment in family
planning services.
Discussions of future population growth in this chapter use the
U.N. medium projections, those that have world population going
from 6.1 billion at present to 9.3 billion by 2050. There is also
a high projection, which has human numbers approaching 11 billion
by 2050, and a low projection, which has population peaking at 7.9
billion in 2046 and then declining. (See Figure 10-3.)50
This low number assumes that the entire world will quickly move
below replacement-level fertility to 1.7 children per couple. This
is not only achievable, it is the only humane population option.
Otherwise the land and water scarcity that is already increasing
hunger and deaths in some countries could spread to many more.
Achieving this lower figure is the responsibility of national political
leaders, but unless world leadersthe
Secretary-General of the United Nations, the President of the World
Bank, and the President of the United Statesurge
governments and couples everywhere to adopt a goal of two surviving
children per couple, resource constraints will likely lead to economic
decline. The issue today is not whether individual couples can afford
more than two children, but whether the earth can afford for couples
to have more than two children.
Table 10-1. Fertility Levels in Selected
Countries in 2001 |
Country |
Average
Number of Children Per Woman1
|
Population,
Mid-2001
|
|
(number)
|
(million)
|
Countries with Fertility
at or Below Replacement Level2 |
|
|
Russia |
1.2
|
144
|
Italy |
1.2
|
58
|
Japan |
1.3
|
127
|
Germany |
1.3
|
82
|
Poland |
1.4
|
39
|
Australia |
1.7
|
19
|
United Kingdom |
1.7
|
60
|
China |
1.8
|
1,273
|
France |
1.8
|
59
|
United States |
2.1
|
285
|
|
|
|
Countries with Fertility
Above Replacement Level2 |
|
|
Brazil |
2.4
|
172
|
Indonesia |
2.7
|
206
|
India |
3.2
|
1,033
|
Pakistan |
5.6
|
145
|
Tanzania |
5.6
|
36
|
Saudi Arabia |
5.7
|
21
|
Nigeria |
5.8
|
127
|
Ethiopia |
5.9
|
65
|
Dem. Rep. of Congo |
7.0
|
54
|
Yemen |
7.2
|
18
|
|
1The
average number of children born to a woman in her lifetime is
also known as the Total Fertility Rate. 2Replacement-level
fertility is an average of 2.1 children per woman.
Source: Population Reference Bureau, 2001 World Population Data
Sheet, wall chart (Washington, DC: 2001). |
ENDNOTES:
47.
Joel E. Cohen, How Many People Can the Earth Support? (New York:
W.W. Norton & Company, 1996).
48. Ibid.
49. PRB, op. cit. note 27.
50. Figure 10-3 from United Nations, op. cit. note 1.
Copyright
© 2001 Earth Policy Institute
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