Boomers and Doomers : Population Growth Inspires Lively Debate Among Researchers
If the population of the Earth doubles as predicted by the middle of the next century, what kind of world will our children see?
The popular image is often nightmarish, a teeming planet covered by megalopolises, the Third World a neo-Malthusian hell where bodies are stacked like cordwood and all but the very richest are reduced to nibbling cakes of bioengineered fish meal.
This is the version of the future in the crystal ball of biologist Paul Ehrlich, the pen behind “The Population Bomb” and “The Population Explosion,” who predicts that growing human numbers spell mass starvation and environmental ruin.
Such a future, however, is anything but certain. The popular images obscure a lively debate among researchers, who are fighting over whether population growth is good or bad or irrelevant to the quality of human life.
“I venture to say no one knows,” said Carl Haub, a demographer with the Population Reference Bureau here. “But it is a hell of a good fight.”
Squared off in the ring are the optimists and the pessimists, the boomers and the doomers, go-go economists and neo-Malthusian ecologists. The optimistic economists focus on labor and capital. Above all, they value human ingenuity and technological development.
The ecologists look at natural resources, at the finite supplies of land, water and air. As biologists, they speak of carrying capacity and the limits of a closed system. They point to the habitat loss, species extinction and environmental degradation.
“Ecologists are concerned with the natural world. Economists are concerned with what is valued in the marketplace. It is a very different set of approaches,” said Sam Preston, a University of Pennsylvania economist with an interest in population.
“Is the world going to be more or less prosperous? That’s the real question. And population growth doesn’t tell you very much about that,” said Duke University economist Allen Kelly, a guarded optimist. “Prosperity depends on market economics and government policies.”
The optimists like to point out that, on average, standards of living have improved throughout the world. Between 1960 and 1990, as world population went from 3 billion to 5.3 billion, infant mortality dropped and life expectancy, literacy, per capita income, food production and nutrition all increased on average. Even in Bangladesh, considered a textbook case on the horrors of population pressure, literacy, infant mortality and life expectancy have all improved.
The ecologists reply that the economists fail to take into account the fact that the world is consuming its natural resources at a furious clip.
“They don’t ask, ‘Is there enough water? Is there enough land? Is there enough wood? What are people going to cook with? What are they going to eat?’ ” said Lester Brown of the Worldwatch Institute and author of the popular annual “State of the World” reports.
How many people can the world support? The upper limit of Earth’s population has been debated for centuries. Abraham and Lot were concerned about carrying capacity. Chinese scholars in the time of Confucius played the game. So did the ancient Greeks, who worried about overpopulation, overgrazing and the loss of forests. (The barren, rocky landscape of today’s Greece was thick with trees in ancient times.)
The United Nations is currently revising its population projections for the next century. U.N. forecasters say that instead of reaching a stable world population of 10.2 billion in the year 2085, today’s population figure could double by the middle of next century. Almost all of the growth will occur in the cities of the developing world.
Of course, demographers have been wrong before. They missed, for example, the Baby Boom in the United States. In the 1950s, they were predicting that Japan, then a crowded, less-developed country that made rubber sandals, would be worse off than India in the future.
The United Nations now predicts world population will stabilize at 11.6 billion. The reason for stabilization is that as countries grow rich, their birthrates fall. It happened in the United States, Japan and European nations. The Greek government now frets its population growth is “too low.” Germany and Hungary are shrinking.
A similar fate may await South Korea, Taiwan, Thailand and other so-called NICs, or Newly Industrialized Countries. NICs are marked by increased use of birth control, falling birthrates, growing affluence and an increased life expectancy. Some optimists see no reason why every country on Earth won’t eventually be like South Korea.
But before Bangladesh can become like South Korea, some scholars fear, the planet will run out of natural resources. The traditional candidates for causing limits in population growth have been energy, metals, minerals, arable land and food.
Yet even if all renewable and nuclear energies were ignored, researchers have calculated that there are enough known fossil fuel reserves to sustain population growth for 280 years.
“On the global level, existing energy resources do not appear to constitute a limiting factor for many generations to come,” according to Paul Demeny, a scholar at the Population Council in New York. Moreover, minerals and metals will also probably hold out, or as the optimists contend, will be replaced by materials derived from recycling.
Food is the subject of hottest debate. Brown and colleagues contend that the ever-increasing productivity of agriculture, supported by fertilizers and new high-yield plant varieties, is showing signs of exhaustion.
“Developing countries as a whole have suffered a serious decline in food self-sufficiency,” according to the U.N. Population Fund, which estimates that about 560 million people are now living in absolute poverty.
Robert Repetto of the World Resources Institute points out that a world population twice the present size, coupled with improved dietary standards in the developing world, would mean that all the world’s current cropland would have to produce 2.8 tons of grain per acre per year. This is like saying that all the world’s farmers will have to be as productive as an Iowa corn farmer--the most productive in the world.
But the U.N. Food and Agriculture Organization found that in 90 developing countries, less than half the potential cropland is under cultivation. The optimists add that in addition to expanding the area under cultivation, genetic engineering and improved technologies will continue to increase yields.
“In the future, every single measurement of human life will be better than it is now,” said Julian Simon of the University of Maryland and perhaps the most optimistic of the optimists. “Why? Because that is the trend.”
“You can’t assume the future will be an extrapolation of the past,” said Brown. “We’re entering uncharted territory.”
