John Bongaarts is a Population Council vice president and distinguished scholar. His research focuses on a variety of population issues, including the determinants of fertility, population–environment relationships, the demographic impact of the AIDS epidemic, population aging, and population policy options in the developing world.
Population growth has a negative impact on all environmental issues we care about. For example, rapid population growth is leading to fresh-water shortages and ground-water depletion, particularly in densely populated countries in the developing world. Steadily increasing population also contributes to pollution of both local and global environments. Local effects include air and water pollution and salination that makes land unsuitable for agriculture. Globally, rising human numbers obviously contribute to global warming.
Moreover, increasing population combined with improving diets is straining our food supply. The recent rise in food prices on the world market is a very worrisome trend. In the developed world, where we spend a relatively small portion of our income on necessities like food, this cost increase has little effect on our standard of living. In the developing world, however, poor people spend a large part of their incomes on food and will be forced to spend even more as prices rise further. We like to think that technological innovation will save the day and that population growth is, at most, a minor issue, but the reality is probably different.
The UN predicts that the world's population, now 7 billion, will be about 9.1 billion by 2050, and that population growth will likely peak around 9.4 billion later in the century. Can the planet handle 9 billion people? The answer probably is yes. However, is this a desirable trajectory? The answer is clearly no. Nearly all of this population growth will occur in the poorest regions of the world. Countries with limited natural resources and extremely rapid population growth, most of them in sub-Saharan Africa, will fare the worst. And despite the AIDS epidemic, sub-Saharan Africa is expected to add more than a billion to its current population in the next half century.
If we were to make much larger investments in family planning, this number could go down, possibly to 8 billion. In terms of human welfare and environmental benefits, the difference between 8 billion and 9.4 billion is huge. Family planning was high on the global agenda in the 1970s and 1980s with strong support from institutions like the World Bank and the UN. After the Cairo conference in 1994, however, interest in family planning fell off. Fortunately this neglect of family planning is now being reconsidered. The US administration has increased support for global reproductive health programs, and the World Bank has renewed its commitment to family planning. So, I am more optimistic now about a positive demographic outlook than I was a few years ago.
Sub-Saharan Africa is the most rapidly growing part of the developing world. Pakistan, Afghanistan, and Yemen are also countries that are growing extremely rapidly. This rapid population growth inhibits socioeconomic development through several mechanisms. A high birthrate means that a country needs to invest in additional schools, healthcare, and infrastructure just to keep even with rapid population growth. The flip side is that every averted birth means these funds can be spent instead on expanding school enrollment and improving healthcare. A second factor inhibiting socioeconomic development is a very young age structure, because it implies a high ratio of dependents to working people. Reducing fertility would result in a boost to the economic growth rate because it lowers this dependency ratio; this is called the demographic dividend. A third mechanism limiting socioeconomic development is found in the effect of high fertility on a woman's activities. If a woman has six or seven children, she often spends her entire life at home taking care of her children and performing household chores. Lower fertility can boost economic growth by encouraging women's participation in wage-earning work outside the home. Finally, poor women, women who live in rural areas, and those who are less educated tend to have higher fertility and much higher unwanted fertility than women who are richer, more urban, and better educated. By increasing access to family planning, we can help reduce inequality and poverty.
Adapted from a podcast by John Bongaarts on the Woodrow Wilson Center's New Security Beat. To listen the podcast, go to http://newsecuritybeat.blogspot.com/2010/11/pop-audio-john-bongaarts-on-impacts-of.html