"Eliminating water shortages depends on a global attempt to raise water productivity similar to the effort launched a half-century ago to raise land productivity, an initiative that has nearly tripled the world grain yield per hectare." –Lester R. Brown, World Facing Huge New Challenge on Food Front in Plan B 3.0: Mobilizing to Save Civilization
Chapter 2. Stopping at Seven Billion: A New Demographic Era
Nearly 3 billion people are expected to be added to our world during the first half of this century—slightly fewer than the 3.5 billion added during the last half of the twentieth century. There are some important differences in these numbers, however. Whereas the growth in 1950–2000 occurred in both industrial and developing countries, the growth in the next 50 years will be almost entirely in the developing ones. Big additions are projected for the Indian subcontinent and sub-Saharan Africa, which together will account for nearly 2 billion of the 3 billion total increase. 5
As noted, populations are projected to shrink in some developing countries, but for the wrong reasons. Whereas the populations of Russia, Japan, and Germany are projected to decline by 2050 by 30, 13, and 3 percent, respectively, due to falling fertility, those of Botswana, South Africa, and Swaziland are expected to decline by 43, 11, and 2 percent because of rising mortality. Are these three African countries an aberration or are they merely among the first of many countries where HIV/AIDS, spreading hunger, the loss of water supplies, and possibly civil conflict lead to rising death rates and population decline? 6
Another major shift will come as record variations of national population growth and decline redraw the world demographic map. A comparison of the 20 most populous countries in 2000 and those projected for 2050 illustrates these changes. (See Table 2–1.) To begin with, the two largest countries—China and India—will trade places as India’s population, projected to grow by over 500 million by 2050, overtakes that of China sometime around 2040. 7
In the four most populous industrial countries after the United States—Russia, Japan, Germany, and the United Kingdom—populations are projected to be smaller in 2050 than they are today. Indeed, only Japan and Russia will remain among the top 20 by mid-century. Germany and the United Kingdom will drop off the list, as will Thailand, a developing country that is approaching population stability. 8
The three countries on the list with the greatest growth, with each expected to more than double by 2050, are Pakistan, Nigeria, and Ethiopia. The three newcomers on the top 20 list in 2050—the Democratic Republic of the Congo, Uganda, and Yemen—are each projected to triple their populations by mid-century. 9
What these demographic projections do not take into account are the constraints imposed by the capacity of life-support systems in individual countries. In many cases, the projection clearly exceeds the country’s apparent ability to support its population. For example, the notion that Yemen—a country of 21 million people, where water tables are falling everywhere—will one day be able to support 84 million people requires a stretch of the imagination. Is Pakistan, with 158 million people today, likely to add nearly 200 million by 2050, making it larger than the United States today? And is it really possible that Nigeria will have 258 million people by 2050—almost as many as the United States has now? 10
|Table 2-1. The World's 20 Most Populous Countries, 2000 and 2050|
|Source: See endnote 7.|
5. United Nations, op. cit. note 1.
6. Population projections for Germany, Japan, and Russia from United Nations, op. cit. note 1; Botswana, South Africa, and Swaziland from PRB, op. cit. note 2.
7. Table 2–1 from United Nations, op. cit. note 1.
Copyright © 2004 Earth Policy Institute