So Many People . . . How Will We Feed Them? : HOW MANY AMERICANS? Population, Immigration and the Environment, <i> By Leon F. Bouvier and Lindsey Grant (Sierra Club Books: $18; 174 pp.)</i>

Those who liked Proposition 187 are going to love some of the measures proposed in “How Many Americans” for making the United States “less attractive” for illegal immigration:

Proof of citizenship or legal status would be mandatory for entering real estate contracts, for obtaining drivers’ licenses or motor vehicle registration, qualifying for professional or occupational licenses, obtaining business and alcoholic beverage licenses or enrolling in state or federally funded colleges. They also ask us to consider “more expeditious procedures for deportation and summary exclusion of aliens entering illegally.” They would erect higher obstacles for those seeking political asylum. Finally, they call for a “tamper-proof” identification system in the form of a national ID card.

With such actions, authors Leon F. Bouvier and Lindsey Grant say, illegal immigration can be curbed “without resorting to Draconian measures.” One wonders what they have in mind as “Draconian.”

Harshness against aliens, however, is not really what this book is about. The authors are not xenophobic. They have nothing in particular against Mexicans or Chinese or East Europeans. What they are against is people or, more precisely, too many people. Their central thesis--and I believe they are correct--is that excessive numbers of human beings are the single greatest threat to the environment, to a healthy economy and to the quality of life of American citizens.

The current U.S. population, around 255 million, is already too high, the authors contend. We are producing too much waste and too much pollution, consuming unsustainable amounts of energy, eroding our soil, degrading our air and water supplies, using up our forests, making housing ever more expensive, creating more joblessness and poverty. Our cities are becoming more crowded, dirty and violent, our traffic choking, our open space is disappearing.

If population trends continue on their current path, the book argues, we will be in much worse, perhaps desperate straits in the not-very-distant future. According to their projections, there would be just under 400 million Americans by 2050, when children born in the 1990s will still be in the prime of their life. By the end of the 21st Century, unchecked population growth would mean as many as a half-billion people living in this country. Except for the rich few, Americans will be living mean, hungry lives in an unstable, violent society by the middle of the next century. And that might not be the worst. The stress placed on life-support systems by the pressure of human numbers could cause “the collapse or extinction of our own species.”

The answer to this threat, Bouvier and Grant argue with cool, cogent urgency, is not just to slow population growth but to roll it back to an optimal level. Their number is 150 million, the size of the U.S. population at the time of World War II. Continued reductions in already declining fertility rates would not be sufficient to achieve this goal. Legal immigration must therefore be limited to 200,000 a year, down from the current level around 700,000, and illegal immigration must be stopped entirely.

“How Many Americans?” is a thoughtful, even admirable book about what is arguably the most important dilemma facing humanity. Population projections are just that--projections. But Bouvier, a professor at Tulane University and Senior Fellow at the Center for Immigration Studies, has a reputation as a careful demographer. While the population threat has been the subject of many previous books, it is an issue that cannot be called often enough to public attention, and this one is well-researched, readable and, for the most part, well argued.

It does, however, have one significant flaw. Unfortunately, that flaw is a central premise of the book.

The population problem--the harm that the rapid growth of human numbers is inflicting on the natural world, on human society and on individual members of the human species--is not an American problem. It is a global problem. The question that must be answered is not how many Americans, but how many people can live on the planet with a modicum of comfort and dignity?

Studies such as Worldwatch’s State of the World series and Beyond the Limits suggest that the global population may already be approaching the carrying capacity of the planet in a number of ways, particularly the capacity of the atmosphere and oceans to absorb our wastes. One-fifth of the world’s people already suffer from utter poverty and hunger.

The United States is part of a global environment, a global economy. It is folly to think that if we erect a fence around the country to keep people out, it will also keep out the greenhouse effect, toxic substances, resource scarcity, economic competition and joblessness.

The authors argue, for example, that with a lower population, the American farmers would need to put fewer acres under cultivation, use less chemical pesticides and fertilizers and create less erosion. But of course, U.S. agriculture serves a global market and, as world population grows, it will have to put increased pressure on the land to meet the rising needs of the hungry around the world. U.S. jobs are not protected by restricting the number of immigrants; millions of manufacturing jobs have been exported by American corporations to low-wage workers in poor countries in recent decades.

Lowering the fertility rate in the United States would be a contribution to slowing the rocketing ascent of global population. Further restrictions on immigration, however, would not reduce such growth by a single soul. In fact, the contrary argument could be made. As the authors themselves point out, for example, fertility among Hispanic immigrants drops sharply as they learn English and become acculturated.

Sharply limiting immigration might keep some environmental and economic problems at bay for a time. It might serve some immediate political or social interests. But inevitably the misery and destruction created by the rising tide of people around the rest of the world would overwhelm us as well. There is no place to hide.

The best policy answer, therefore, would not be to restrict immigrants but to do more to help the poorer nations attain the economic and educational levels and improved status for women that would lower domestic birth rates and encourage their populations to stay at home. That, after all, is what the nations of the world agreed on two years ago at the Earth Summit in Rio and at this year’s population conference in Cairo. The conventional and probably accurate wisdom is that spurs to development in the poorer countries, including external debt relief, improved terms of trade with the industrialized nations, greater access to markets and advanced technology, along with increased assistance for family planning and education for women, are the best tools for lowering fertility. (Given the recent pronouncements by Jesse Helms, the next chairman of the Senate Foreign Relations Committee, about slashing foreign aid, that probably is not a very realistic option for the immediate future.)

National policy kept immigration at low levels during the 1930s. Many European Jews were denied asylum and were exterminated in the German concentration camps. But, it might be useful to recall, such restrictive immigration policies did not keep America out of the World War.

BOOKMARK: For an excerpt from “How Many Americans?” see the Opinion section.