How many people will inhabit Earth in the future? Future population depends primarily on fertility. How many babies will women in the future bear in their lifetimes? Despite the importance of this question, the answer is unknowable.

The United Nations estimates that world population in 2100 will be 11.2 billion. If the U.N.’s highest estimate is followed, world population in 2100 would more than double to 16.2 billion. If the low variant is followed, world population would actually decline to 7.2 billion

Future Population Estimates

Possible Demographic Transition Stage 5

• Very low CBR

• Increasing CDR

• Declining NIR

Demographers predict a possible stage 5 of the demographic transition for some developed countries. Stage 5 would be characterized by a very low CBR, an increasing CDR, and therefore a negative NIR. After several decades of very low birth rates, a stage 5 country would have relatively few young women aging into childbearing years. If those in the smaller pool of women have fewer children, the CBR would fall lower than in stage 4.

Demographic Transition With Five Stages

If the demographic transition is to include a stage 5, Japan will be one of the world’s first countries to reach it. Japan’s population hit a historic high of 128 million in 2010 and is now starting to decline. The U.N. forecasts Japan’s population to fall to 84 million in 2100. With the population decline will come an increasing percentage of elderly people.

Japan’s Population Pyramids

Japan faces a shortage of workers. Instead of increasing immigration, Japan is addressing its shortage primarily by encouraging more Japanese people to work. Rather than combine work with child rearing, Japanese women are expected to make a stark choice: either marry and raise children or remain single and work. According to Japan’s most recent census, the majority of women have chosen to work.

In addition to Japan, several European countries, notably Russia and other former Communist countries, already have negative NIRs. Russia’s high CDR and low CBR are a legacy of a half-century of Communist rule. The low CBR may stem from a long tradition of strong family-planning programs and a deep-seated pessimism about having children in an uncertain world. The high CDR may be a legacy of inadequate pollution controls and inaccurate reporting by the Communist government.

China & India

The world’s two most populous countries, China and India, will heavily influence future prospects for global overpopulation. A pronatalist policy is a government policy that supports higher birth rates, whereas an antinatalist policy is one that supports lower birth rates. In recent decades, China and India have both instituted antinatalist policies with varying success. These two countries—together encompassing more than one-third of the world’s population—have adopted different family-planning programs. As a result of less effective policies, India adds 10 million more people each year than does China. Current projections show that India could surpass China as the world’s most populous country during the 2020s.

China’s Population Policies

China has made substantial progress in reducing its NIR. The core of the Chinese government’s family planning program was the One Child Policy, adopted in 1980. Under the One Child Policy, a couple needed a permit to have a child. Couples received financial subsidies, a long maternity leave, better housing, and (in rural areas) more land if they agreed to have just one child. To discourage births, people received free contraceptives, abortions, and sterilizations. Rules were enforced with penalties by a government agency.

China: Wall Art Promotes Family Planning

Largely as a result of the One Child Policy, China’s CBR declined from 18 in 1980 to 12 in 2018, and consequently the NIR declined from 1.2 to 0.5. Since 2000, China and the United States have had about the same CBR. The number of people added to China’s population each year dropped from 14 million to 7 million during the four decades.

With the United Nations now forecasting China to lose population by 2100, the government relaxed the One Child Policy. But China’s CBR is unlikely to increase much because, after three decades of intensive educational programs as well as coercion, most Chinese have accepted the benefits of family planning. As a result of preference for male children, there are fewer young women of childbearing years.

India’s Population Policies

India was the first country to embark on a national family planning program, in 1952. The government established clinics, provided information about alternative methods of birth control, distributed free or low-cost birth control devices, and legalized abortions.

Most controversially, during the 1970s India set up camps to perform sterilizations—surgical procedures in which people were made incapable of reproduction. Widespread opposition to the sterilization program grew in the country because people feared that they would be forcibly sterilized, and it increased distrust of other family-planning measures as well.

Government-sponsored family-planning programs in India now emphasize education, including advertisements on national radio and TV networks and information distributed through local health centers (Figure 2-50). Still, the dominant form of birth control in India continues to be sterilization of women, though in many cases after the women have already borne several children. Family planning measures lowered the CBR from 34 in 1980 to 20 in 2018, but India’s population increased by 19 million in 2018, compared to only 15 million in 1980.

India: Poster Promotes Family Planning

Pause & Reflect 2.4.1

Based on Japan’s population pyramids, how might the potential support ratio change?