Man's Hope

"How large," asks Dr. Harrison Brown, "can the human population become? To what extent, if any, does man still possess the power to determine his destiny?"

Many books by neo-Malthusian prophets of doom have attempted to answer these questions. Most of them have been superficial, emphasizing minor and easily corrected threats to man's food supply, such as erosion of farmlands. Others have ignored the enormous possibilities of man's scientific techniques. Brown's The Challenge of Man's Future (Viking Press; $3-75) is in a different class. Geochemist Brown of CalTech is thoroughly at home in the tangle of sciences that bear on man's future on earth. He is also at home in history and sociology, and unlike most scientists, he is a good writer. The result is a readable and frightening book.

In 1798, the gloomy Rev. Thomas Robert Malthus made his famed pronouncement that human populations, unless checked by enemies or disasters, tend to increase until finally checked by hunger. Malthus foresaw only catastrophe ahead. In fact he predicted that within 50 years Britain would be in disaster because of overpopulation. Malthus was wrong in his prediction. Around him in England, as he was writing, his countrymen were developing the machine culture that permitted a new cycle of human expansion. But many scientists are convinced that in his broader sense Malthus may still be proved right. Today's neo-Malthusians maintain that catastrophe has only been postponed, that overpopulation, starvation and misery will yet catch up with industrial man.

Ancient Pattern. Can man, who dominates other life, do nothing to keep his species in equilibrium with the earth? With great clarity, Dr. Brown describes the interrelated factors that have affected populations in the past. It is not a happy picture. Except for brief "Golden Age" respites, man has suffered biologically, like any other animal. His women have borne so many children that not all could be fed. They have died in infancy, or lived brief, sickly, hungry lives. Each period of abundance has brought a jump in population, followed by famine and pestilence.

This is still the pattern, says Brown, for that part of the human race which is still in the agricultural stage. Only the industrial one-third of the world's population escapes the Malthusian trap. Dr. Brown is not sure that it will escape for long.

He does not believe, however, that the final reckoning will come because of material factors. He concedes that there is some limit, far in the future, to the number of humans that the earth can support, but many bugbears dear to the neo-Mathusians he dismisses as of little moment. Industrial man will need, and can get, ever-increasing supplies of energy. Coal and oil may burn out in a relatively short time, but sunlight and atomic energy can take their place. He points out that one ton of ordinary granite, from which the continents are largely made, contains as much energy in the form of uranium and thorium as 50 tons of coal. He thinks this energy can be drawn on when needed.

He feels the same way about structural metals, such as iron, aluminum and magnesium. Rich and handy ore deposits will be exhausted soon, but there will always be plenty of low-grade stuff. Sea water can be mined for many useful materials, and the same granite that provides uranium can supply nearly every mineral.

Brown is also optimistic about food supply. Theoretically, he shows, a highly industrialized earth could produce enough food for 25 or even 50 billion humans. They might have to eat algae and plankton, but he thinks they could get used to it.

Human Obstacle. These cheerful chapters are not entirely representative of Dr. Brown's book. Reason: he has no great confidence that man will be able to tap the resources that he has listed. The chief trouble is that the nonindustrial two-thirds of the human race is increasing so rapidly that it cannot become industrial. Geochemist Brown's worst example is India, where 90% of the people are concerned with growing or distributing food, but where nearly everyone is in danger of starvation. The situation gets worse every year, by 5,000,000 more Indians.

Many other countries, says Brown, are far along the road to teeming, struggling starvation. Unless something changes soon, says Brown, a large part of the world will reach the ultimate population limit that can be supported non-industrially. When each country gets there, it will be too harassed to better its situation.

Fatal Gifts. Overpopulation of the agricultural countries, says Brown, is actually aggravated by the well-off industrial countries. Their medical science, shared with the best of motives, has cut death rates all over the world. Birth rates in the backward areas have not fallen much. Unless they fall much faster, he says, most of the world will become a permanent and hopeless slum.

Even the industrial countries are not secure, says Brown, because the populations of many of them are apt to increase faster than their industrial equipment. When this happens to a country, it will fall to something like the Indian level. If the surplus humans of the backward countries are permitted to migrate to the industrial ones, the end will come quicker.

What can be done? Scientist Brown is not confident that anything can be done, but he insists that population control is the first and essential measure; only by cutting their birth rates drastically can the crowded agricultural countries hope to enjoy the benefits of industrialization. Dr. Brown has little hope that this will be done in time or in many places.

The chief barrier to population control, in Scientist Brown's view, is the Roman Catholic Church and its doctrines against contraception. This attitude, he says, "is all the more interesting in view of the fact that it is the children who suffer most . . . When I walk through such regions, where birth rates are at a biological maximum, and I see dirt-encrusted, malnourished, disease-ridden children, I know that this is not the sort of world advocated by the One who said: 'Suffer little children to come unto Me, and forbid them not, for of such is the Kingdom of Heaven.' "

Courage & Effort. There are other dangers ahead. Brown is aware of the catastrophe that would be caused by atomic war. The world might recover, he admits, but he doubts that it could ever climb again above the agricultural level. Another danger is that health and welfare measures may be favoring the reproduction of weak human strains.

Brown ends with only a faint note of hope. "We see that, although our high-grade resources are disappearing, we can live comfortably on low-grade resources. We see that, although a large fraction of the world's population is starving, all of humanity can, in principle, be nourished adequately. We see that, although world populations are increasing rapidly, those populations can, in principle, be stabilized . . . But it is equally clear that the achievement of this condition will require the application of intelligence, imagination, courage, unselfish help, planning and prodigious effort . . . Man is rapidly creating a situation from which he will have increasing difficulty extricating himself."

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