IT took hundreds of thousands of years, from the origin of the species until 1800, for the world's population to reach 1 billion people. It took only 130 years, to 1930, to double that number and reach 2 billion. Now the total has grown to 5.7 billion, and another billion are being added every 12 years.
This rate of growth cannot be sustained. The pressure of people on resources is already reducing living standards in much of the world and is causing environmental degradation that will lead to further declines.
So what do we do about it?
To look for some answers, the United Nations is holding another of its periodic world population conferences in Cairo next week. The prospects for constructive action are bleak. Perhaps no other problem with such a great potential for disaster impinges on so many strongly held beliefs that inhibit rational analysis.
Underlying a good many of these beliefs is the mistaken notion that more is better. A nation or a city with many people is thought to be stronger and worthy of more respect than one with few people. If each individual is to be cherished as uniquely valuable, then individuals en masse are held to be even more valuable.
People are indeed a community's most valuable assets, but only if the community has invested enough in the people to make them productive. No other species has such a long period of maturation during which its young must be cared for - housed, clothed, fed, educated. It is a process that takes a minimum of 18 years from birth through secondary education and as much as 30 years for those who complete college and advanced technical and scientific training. This costs tens of thousands, in some cases hundreds of thousands of dollars for each one.
The more people you have, the less you can afford to make investments that would turn them into productive citizens. And so a vicious downward spiral begins. With each person less productive, you need more people to produce the same amount. Since they are not producing much more than subsistence anyway, everyone gets locked into deepening poverty. There is never a surplus for more schools or better housing and health care.
This is the root cause of the widening gap between the industrialized countries and the third world. It is what foreign-aid programs have spent hundreds of billions of dollars trying to rectify, mostly to no avail. In some respects, foreign aid has made the problem worse: While it has succeeded in keeping babies from dying, it has failed to support adequate family planning.
There are several collateral effects of this unfortunate phenomenon. One is that racism has been added to the complex of emotions. In the view of much of the third world (and even parts of the black community in the United States) the industrialized world (largely white) feels threatened by the prospect of too many colored people.
Yet the threat has more to do with survival than with race. It is what lies behind the Clinton administration's efforts to keep Haitians and Cubans from inundating Florida. It is why the French are concerned about stability in Algeria and why uglier manifestations of xenophobia have occurred in Germany.
As population pressure mounts, so will the pressure for draconian, coercive measures to relieve it - abortion and sterilization, for example.
These procedures need not have anything to do with controlling population growth. No responsible Western leader has suggested that they should. But India and China are generating a good deal of government pressure for sterilization; compulsion may not be far down the road. At least in China's case, pressure or compulsion may apply to abortion as well. Those whose opposition to abortion drives them to oppose all population programs may be bringing on the evil they are trying to avoid.
Perhaps the gloomiest outlook for the UN's Cairo conference comes from the fact that even if the improbable occurred and world population growth was reduced to, say, 1 percent a year, the numbers are so huge that 57 million people would still be added every year. The period required to add a billion to the total would be stretched only to 17.5 years.
If we do not have the wit and the will to restore the balance between people and resources ourselves, nature has more-drastic means of doing so, in time. We will all suffer if it comes to that. The Opinion/Essay Page welcomes manuscripts. Authors of articles we accept will be notified by telephone. Authors of articles not accepted will be notified by postcard. Send manuscripts to Opinions/Essays, One Norway Street, Boston, MA 02115, by fax to 617 -450-2317, or by Internet E-mail to OPED@RACHEL.CSPS.COM.