The success of HIV/AIDS prevention and treatment programs, along with slower than expected declines in fertility and increased longevity, has prompted the United Nations to increase its forecast for the future global population from 9.1 billion by 2050 to 9.2 billion people.
The vast majority of this growth (2.5 billion) will occur in the developing world. The populations of the United States, Europe, and other developed countries will remain roughly the same in number, but will-along with the rest of the global population-age considerably.
“As a result of declining fertility and increasing longevity, the populations of more and more countries are aging rapidly,” says the UN. “Between 2005 and 2050, half of the increase in the world population will be accounted for by a rise in the population aged 60 years or over, whereas the number of children (persons under age 15) will decline slightly. Furthermore, in the more developed regions, the population aged 60 or over is expected to nearly double (from 245 million in 2005 to 406 million in 2050), whereas that of persons under age 60 will likely decline (from 971 million in 2005 to 839 million in 2050).”
Nations are treating HIV/AIDS more effectively, according to the report, but the virus remains a severe threat to the global population. “Although HIV prevalence in some countries has been revised downward on the basis of newly available nationally representative data, the toll of the disease continues to be high and is expected to remain so, despite projected reductions in the prevalence of HIV/AIDS,” the report states. The UN considers 62 countries to be “highly affected” by the HIV/AIDS epidemic, 40 of which are in Africa.
Also of significance is the finding that fertility (i.e., reproduction rates), while still decreasing, is not going down as quickly as many population watchers had hoped. Carl Haub, senior demographer at the Population Reference Bureau, suggests that the upward revision may partly be due to people taking declining fertility rates for granted. The result is waning enthusiasm for family-planning programs and policies. “Once something turns around, people feel like the battle is over,” he says.
Fertility rates vary considerably by country and region. For instance, the reproduction rates in Thailand have been trending steadily lower for some time, averaging two children per woman-a statistic that Haub says is very good for a semi-industrialized country. Iran’s fertility rates are among the lowest of the developing world; as a result, Iran’s population is aging much like that of the United States.
“In the late 1980s and 1990s, Iran allowed the introduction of family planning and health clinics,” says Haub. “I think that most people would say that Iran was already a highly educated country. People reacted [to the programs] very positively, so the fertility rate in Iran came down to virtually what it is in the United States. Obviously, that means dramatically less population growth and even-in the long run-an aging population just like we have here [in the United States].”
The population forecast for a country like India, however, is considerably more mixed. “When you compare Iran to rural India, it’s a very different world,” says Haub. “The vast majority of the Indian population is scattered in very small villages and quite difficult to reach. Much of the success in lowering the fertility in India has been in the south, in states that-not coincidently-have high educational levels. Now the battle is in the north, in the big states. Uttar Pradesh, for example, is approaching 190 million people. Bihar is approaching about 100 million, and so on. In those areas the birthrate is not coming down the way it did in the south.”
The UN figures portend continued movement to urban areas and more disputes and tension over immigration, not only between developing nations like Mexico and rich countries like the United States, but also between developing nations themselves.
“There’s going to be a push-pull, of course, from the rural to the urban areas, particularly as the urban areas become wealthier,” Haub predicts. “Among developing countries, there’s always been a certain amount of migration back and forth. Today, India is upset about illegal immigration from Bangladesh and Nepal. India has talked for years about building a border fence. That’s been going on a lot in Western Africa, too. Certainly there will be a lot of economic migration, but I think a lot of political migration as well, particularly in Africa.”
Africa’s population forecast is particularly worrisome for Haub, and he thinks it may herald even slower declines in fertility in the years ahead: “It does appear that fertility is not declining as quickly as one might have hoped. There’s been a slower decline in the birthrate throughout many countries in Africa, so we may see further upward revisions.”
Originally published in THE FUTURIST, July-August 2007.