Page 220 - Environment: The Science Behind the Stories

World TAbLe 8.2 Total Fertility rates for Major
More developed regions continental regions
Less developed regions rEgIoN ToTAl fErTIlITy rATE (Tfr)
Least developed countries
Global population Africa 4.7
Australia and South Pacific 2.5
3.5 8 Latin America and Caribbean 2.2
7
3.0
Population growth rate (percent) 2.0 5 Global population (billions of people) with good sanitation, effective health care, and reliable
Asia
2.2
North America
1.9
6
2.5
Europe
1.6
Data from Population Reference Bureau, 2012. 2012 World popula-
tion data sheet.
4
1.5
3
1.0
2
0.5
0.0
lives. As a result, over the past 50 years the life expectancy
for the average person has increased from 46 to 70 years
–0.5 1 food supplies, more people than ever before are living long
0
as the global death rate has dropped from 20 deaths per
1950 1960 1970 1980 1990 2000 2010 2015
Year 1000 people to 8 deaths per 1000 people. Strictly speaking,
life expectancy is the average number of years that an indi-
Figure 8.15 The annual growth rate of the global human
population peaked in the late 1960s and has declined since vidual in a particular age group is likely to continue to live,
then. Growth rates of developed nations have fallen since 1950, but often people use this term to refer to the average num-
whereas those of developing nations have fallen since the global ber of years a person can expect to live from birth. Much
peak in the late 1960s. For the world’s least developed nations, of the increase in life expectancy is due to reduced rates
growth rates began to fall in the 1990s. Although growth rates are of infant mortality. Societies going through these changes
declining, global population size is still growing about the same are generally those that have undergone urbanization and
amount each year, because smaller percentage increases of ever- industrialization and have generated personal wealth for
larger numbers produce roughly equivalent additional amounts. their citizens.
Data from Population Division of the Department of Economic and Social Affairs To make sense of these trends, demographers devel-
of the United Nations Secretariat, 2011. World population prospects: The 2010 oped a concept called the demographic transition. This is
revision. http://esa.un.org/wpp. © United Nations, 2011. Data updates for a model of economic and cultural change first proposed
2011–2012 from Population Reference Bureau, 2011 and 2012 World population in the 1940s and 1950s by demographer Frank Notestein
data sheets. Global population in 2015 is projected.
to explain the declining death rates and birth rates that
have occurred in Western nations as they industrialized.
equals a TFR of 2.1. (Two children replace the mother and Notestein believed nations move from a stable pre-industrial
father, and the extra 0.1 accounts for the risk of a child dying state of high birth and death rates to a stable post-industrial
before reaching reproductive age.) If the TFR drops below 2.1, state of low birth and death rates (Figure 8.16). Industri-
population size (in the absence of immigration) will shrink. alization, he proposed, causes these rates to fall by first
Factors such as industrialization, improved women’s decreasing mortality and then lessening the need for large
rights, and quality health care have driven TFR downward families. Parents thereafter choose to invest in quality of
in many nations in recent years. All these factors have come life rather than quantity of children. Because death rates
together in Europe, where TFR has dropped from 2.6 to 1.6 in fall before birth rates fall, a period of net population growth
the past half-century. Nearly every European nation now has results. Thus, under the demographic transition model,
a fertility rate below the replacement level, and populations population growth is seen as a temporary phenomenon that
are declining in 16 of 45 European nations. In 2012, Europe’s occurs as societies move from one stage of development
overall annual rate of natural increase (also called the natural to another.
rate of population change)—change due to birth and death
rates alone, excluding migration—was between 0.0% and
0.1%. Worldwide by 2012, 92 countries had fallen below the
replacement fertility of 2.1. These countries make up roughly WEIGHING THE ISSUES CHAPTER 8 • Hum A n Po P ul AT i on
half of the world’s population and include China (with a TFR CONSEQUENCES OF LOW FERTILITy? In the United States,
of 1.5). TAbLe 8.2 shows TFRs of major continental regions. Canada, and almost every European nation, the total fertility
rate is now at or below the replacement fertility rate (although
Many nations are experiencing some of these nations are still growing because of immigra-
tion). What economic or social consequences do you think
the demographic transition might result from below-replacement fertility rates? Would you
rather live in a society with a growing population, a shrinking
Many nations with lowered birth rates and TFRs are expe- population, or a stable population? Why?
riencing a common set of interrelated changes. In countries 219

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