a young person's guide to population growth

Mortality started to decline in Europe and North America about two hundred years ago. In the developing countries, enormous reductions in child mortality occurred between 1960 and 1990, mainly through the prevention of infectious diseases but also through improved nutrition. The factors that have been important in the decline of mortality are income growth, improvements in medical technology, and public health programs combined with the spread of knowledge about health. However, death control without birth control has sparked a population explosion. Two hundred years ago, there were about one billion people on earth. The second billion was added over the next 130 years; the third in 35 years; the fourth in 15 years; and the fifth in just 10 years. The population of the world is now close to 6.3 billion. Each year, it increases by almost 100 million. It was once forecast that the world population would settle at about 10.2 billion by 2100; this estimate has now been revised to 12 billion. More than 90 percent of this growth is occurring in developing countries, where death rates have been falling without commensurate declines in birth rates, and much of the population increase will be in cities, as it has been in the past. The age structure of population in developing countries also gives ground for deep concern. This population contains more children who have yet to reproduce than it does adults (the mean proportion of the population under 16 years of age in developing countries ranges from 40-50 percent). With age structures so heavily skewed toward the young, the obvious conclusion would be that, when these children move up to reproductive age, the population will grow rapidly. Without birth control and with low death rates for children, this will be true. Moreover, the age structure of the population provides a measure of the economic impact of the population. The dependency ratio, the ratio of people over 65 and under 15 years of age to the rest of the population, indicates the proportion of the population that contributes little to the economy and must be supported. A high dependency ratio is a fearful burden on the economy; it is now increasing in most countries. The worldwide economic slowdown experienced since the late 1970s and population growth mean that incomes have declined in many countries. More than one billion people, or one fifth of the world’s population, live in poverty. Between 700 and 800 million are in Asia and about 500 million of these live in absolute poverty. It is now accepted (if not acted upon) that economic growth is by itself not enough to reduce poverty. Governments must also promote employment and offer poor people the opportunity to acquire skills, health, and the information they require to improve their lives. The proportion of people living in poverty can be reduced if there is, at least, broad-based economic growth; a firm Government commitment to reduce poverty; an institutional capacity to design and follow through on appropriate policies and programs; good public sector management that minimizes unproductive expenditures; and a strengthening of essential services, e.g., primary education and vocational training, preventive health care, family planning, nutrition, clean water, sanitation, and rural infrastructure. None of these are easy to achieve. Population growth adds to the need for employment and livelihoods, which exerts additional direct pressure on the environment. It also increases the demand for food, drinking water, and sewage and solid waste disposal, as well as for energy-intensive products and services such as transportation. To the extent that per capita incomes rise and practices remain unchanged, such demand will be exacerbated. Excessive demand for natural resources from a rapidly increasing population leads directly to environmental degradation as economic, social, and political systems fail to keep pace with demands. In rural areas, inequitable land distribution obliges the poor to survive on marginal lands, causing erosion and other environmental problems. To survive, the poor tend to use the resource base to derive the quickest benefit: this is an action forced on them by poverty. One way or the other, population growth will slow down because many developing countries simply cannot sustain their escalating numbers. It will happen through family planning and development, or by famine, disease, and war brought about by collapsing economies. The risk to future generations would be less and the options would be greater if population growth were to cease sooner rather than later. The longer population growth continues, the more committed all countries become to a particular set of problems: more rapid depletion of resources; greater pressures on the environment; more dependence on continued rapid technological development to solve these problems; fewer options; and perhaps continued postponement of the resolution of other problems, including those resulting from past growth. The sooner population increase slows, the more time humanity has to redress the mistakes of past growth, the more resources it has to implement solutions, and the more options it has to decide how it wants to live in the future. (December 1996) Copyright ©2002 Olivier Serrat