It was 200 years ago that English cleric Thomas Malthus warned that unchecked population growth could lead to famine, disease and conflict. His reasoning was simple: populations tend to increase faster than food supplies. So far, the world's farmers have managed to overcome short water supplies and depleted croplands to feed a population that has more than doubled in the last half century. United Nations demographers predict that the global population could climb from its current 5.9 billion to as high as 11.2 billion in 2050. But at least one expert on global population sees signs that the scenario predicted by Malthus is already coming true - with a twist.
In a report on demographic trends conducted by the think tank Worldwatch Institute, Lester Brown, president of Worldwatch, identifies signs of faltering growth in some of the countries that were expected to have the greatest population increases. Populations in 32 countries - all in the industrialized world - have stabilized because of declining birthrates. Some, including Russia, Italy and Germany, are even losing populations. But in a handful of developing countries where population growth is slowing, the cause isn't something to celebrate: it isn't increased education or family planning. The population is growing more slowly now because more people are dying.
The trend is called, chillingly, "demographic fatigue," and it's beginning in many of the developing countries that have experienced soaring birthrates and sharp population growth for several decades: India, Ethiopia, Pakistan and Nigeria. Governments are having trouble dealing with feeding, housing and educating an increasing number of children, while at the same time confronting the falling water tables, deforestation and soil erosion that rapid population growth brings. In these conditions, any new threat - infectious disease, drought or famine - can become a full-blown crisis.
AIDS is a case in point. The most recent World Health Organization estimates calculate that one quarter of the adult populations of Zimbabwe and Botswana are infected with the virus that causes AIDS, with Zambia, Swaziland and Namibia not far behind. In other words, these countries stand to lose at least one quarter of their adult populations in the next decade from AIDS alone, a situation unparalleled since the bubonic plague swept through Europe in the 14th century.
Disease is far from the only threat to overburdened societies. U.N. projections show India may add 600 million more people by 2050, overtaking China as the world's most populous country. But India already faces serious water shortages. A recent report from the International Water Management Institute shows that recent growth in food production and population has been based on unsustainable use of water. So far, the government has taken no steps to manage resources. Social unrest is also increasing. One example is the longstanding conflict between the Tutsis and the Hutus in Rwanda, where population pressures reduced cropland to a point where it could no longer feed those who lived on it. Demands on the world's fisheries and shared water resources are likely to spark similar conflicts. Already the waters of the Nile are so heavily used that little reaches the Mediterranean, so any increase in demand or shift in allocation will also increase tensions.
The bottom line, says Brown, is that human population growth is
destined to slow, one way or the other. Developing societies will
either recognize problems on the horizon and act to encourage smaller
families - or unchecked births will have their price in rising death
rates.