Demographers for the United Nations calculated that on October 12, 1999, the global population reached six billion. This event renewed interest in long-standing debates concerning population growth and heightened disagreements over the necessity and advisability of governments’ pursuing efforts to reduce fertility and growth rates.
Changes in population size and composition are driven by three demographic processes: fertility, mortality, and migration. Global population growth is determined by natural increase (the difference between numbers of births and numbers of deaths). All reliable scientific sources agree that, give or take a few years, it took from the dawn of humankind until 1800 for the world’s population to reach one billion. It reached two billion in 1930, three billion in 1960, four billion in 1975, five billion in 1987, and six billion in 1999.
Secretary-General Kofi Annan of the United Nations, speaking in Sarajevo, Bosnia and Herzegovina, declared October 12, 1999, “Day Six Billion.” Adnan Mevic, a boy born in Sarajevo at two minutes past midnight on that day, was designated “Baby Six Billion.” The quality of global data made it possible for experts to pinpoint the year of this event, although there were some discrepancies among estimates regarding the day because of differences in estimates of the numbers of daily births and deaths worldwide (for example, the U.S. Census Bureau placed the day on July 19). The exact location was, of course, impossible to determine. Some demographers speculated that the milestone birth would probably occur in Asia, given that, of the approximately eighty million births in 1999, about fifty million were in Asia. On October 12, 1999, Day Six Billion
The accelerating rate of global population growth was dramatized by the fact that, whereas it had taken several million years for the planet to accumulate a population of one billion, it was entirely possible that the two, three, four, and five billionth persons on Earth were still alive on Day Six Billion (and “Baby Five Billion” was not yet a teenager). The basic reason that human populations can grow exponentially is that each woman can have multiple children, and each of her daughters can have multiple children, and so forth, creating the potential for geometric population growth in the absence of high mortality rates.
For most of humankind’s existence, high death rates limited population growth. Beginning in the mid-1700’s, however, the Industrial Revolution brought technological advances to northern and western Europe and North America that resulted in declining mortality rates. This created periods of explosive population growth in these regions until fertility rates declined and stabilized along with low and stable death rates. Societies with low and relatively stable birth and death rates are said to be in the third stage of the “demographic transition,” that is, the transition from high birth and death rates to low birth and death rates that occurs as societies industrialize and urbanize.
In the 1970’s, the more developed countries (MDCs) experienced even further declines in mortality and fertility rates, and the mortality rates of most less developed countries (LDCs) had decreased, some significantly, while their fertility rates remained relatively high. In all LDCs combined, from 1971 to 2000, the acceptance of “death control” measures and assistance resulted in a reduction in the number of deaths per 1,000 population from 16.3 to 8.5, while cultural and political resistance to family planning produced total fertility rates—that is, the average number of children per woman—that were two to three times those in the MDCs during this period. Therefore, population growth in LDCs far surpassed that in MDCs, where the total fertility rate was only 1.5 by 2000. In 2000, the annual growth rate in LDCs was five times that in MDCs. In 1971, of the approximately 3.8 billion people in the world, 2.8 billion were in LDCs, and by 2000, of the world’s 6.1 billion people, 4.9 billion (80 percent) were in LDCs. During this period, the population of Western Europe increased from 354 million to 391 million, and North America’s population grew from 230 million to 314 million, while Africa’s population grew from 371 million to 801 million, Asia’s increased from 2.2 billion to 3.7 billion, and the population of Latin America and the Carribean grew from 293 million to 521 million.
Because mortality declines initially benefit the youngest age groups in developing societies, the age structure in LDCs became quite “young.” Their infant mortality rate—that is, the annual number of infant deaths per 1,000 live births—dropped from 126.2 in 1971 to 58.4 in 2000, when one-third of the population was younger than fifteen years old and only 5 percent was sixty-five years old and older. In Africa, 40 percent of the population was younger than fifteen in 2000, and 3.2 percent was sixty-five and older. In the “aging” MDCs, the under-fifteen population declined from 27.8 percent in 1971 to 18.2 percent in 2000, and the proportion of people sixty-five and older had grown from 9.9 to 14.4 percent of the total.
Differences of opinion were expressed by various population analysts regarding the impacts of and action warranted by the world’s population growth from 1971 to 2000. Paul R. Ehrlich and other “neo-Malthusian” theorists asserted that exponential population growth had created a world in which overcrowding, impoverishment, malnutrition, resource depletion, and environmental degradation had increased geometrically. They further posited that the LDCs’ large number of children dependent on a relatively small workforce-age population had slowed the pace of these nations’ economic development. In contrast, “nationalist” theorists such as Julian Simon argued that humankind’s quality of life had improved historically as growing populations created the motivation for technological advances that produced more food and more efficient methods of production, which in turn stimulated economic development, and that these trends should continue as the global population increased even more. They also claimed that neo-Malthusians were exaggerating environmental concerns related to overpopulation.
These differing perspectives on the need to control population growth were brought to bear at the 1994 International Conference on Population and Development
The “program of action” that was produced by the conference included strong recommendations for increased technological and financial aid from MDCs to LDCs to accelerate economic development as well as recommendations for policies that would increase women’s educational and career opportunities and expand access to reproductive health and family-planning services. The document made it clear, however, that no sovereign nation was bound by its recommendations. By the late 1990’s, 44 percent of the world’s nations had initiated policies that included some or all of these recommendations.
Projections of population growth in the twenty-first century vary, but the widely accepted middle-level projections put global population at around nine billion by 2050, with population stabilization in the late twenty-second century. Neo-Malthusians contend that further action to reduce fertility rates is necessary, because by 2050 some 87 percent of the world’s population will be in LDCs, where 89 percent of reproducing women will reside. They claim that LDCs’ large dependent populations will continue to slow these nations’ economic development and modernization transitions as growing elderly populations offset reductions in child dependents. They also assert that resource depletion and pollution will destroy the planet as people in LDCs aspire to the high-consumption lifestyle of the MDCs. Furthermore, they believe that the proportion of people in LDCs who live in abject poverty will continue to grow and that billions of people without jobs, housing, health care, clean water, electricity, adequate nutrition, educational opportunities, and other basic amenities will increase the problems of civil instability and the attendant erosion of civil rights and constitutional protections that characterized the late twentieth century.
Nationalists, in contrast, insist that population-reduction “alarmists” are wrong. Instead, they say, concerns should focus on the coming “population implosion”—that is, the decline in population after stabilization that will wreak economic havoc because of worldwide labor shortages. Neo-Malthusians contend that, without their “alarmism,” world population would have been nine billion in 1999. They continue to assert that more aggressive population control programs are essential.
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Frejka, Tomaš. The Future of Population Growth: Alternative Paths to Equilibrium. New York: John Wiley & Sons, 1973. Provides population projections from 1970 to 2150, focusing on when zero population growth might occur in industrialized and developing nations as well as globally. -
Leisinger, Klaus M., Karin Schmitt, and Rajul Pandya-Lorch. Six Billion and Counting: Population Growth and Food Security in the Twenty-First Century. Washington, D.C.: International Food Policy Research Institute, 2002. Discusses the “optimistic” view based on reductions in fertility and increases in longevity and food production, and the “pessimistic” perception that severe resource shortages and environmental degradation will occur without aggressive population growth controls. -
Rostow, Walt W. The Great Population Spike and After: Reflections on the Twenty-First Century. New York: Oxford University Press, 1998. Examines the debates surrounding exponential population growth through the twentieth century and proposes that further technological development may improve living standards in spite of continued population growth.
World Fertility Survey Is Conducted
Heilbroner Predicts Growth Limits
India Adopts Compulsory Birth Control
China Announces Birthrate Reduction Plans
The Global 2000 Report Is Issued
The Ultimate Resource Argues in Favor of Population Growth
United Nations Holds a Population Conference