How Many People Can the Earth Support?
By Joel E. Cohen
532 pp, $30
Reviewed by Chase Madar
In 1798, a dour young cleric named Thomas Robert Malthus invented overpopulation. The growing numbers of poor, he wrote in Essay on the Principle of Population, were bound to starve because England simply couldn't produce enough food to feed them. England's population was, in his view, already higher then the country could ever hope to support. He urged his readers to let nature take its course, by which he meant making sure that all the poor people starved or went some place else.
Parson Malthus's book was a great success; in 1805 he went on to become the first tenured professor in a trendy new discipline, political economy.
Nearly 200 years later, educated people still worry about the poor interfering with the smooth functioning of the global economy. Worried that "the number of people on the Earth has reached, or will reach within half a century, the maximum number the Earth can support in modes of life that we and our children and their children will choose to want", Joel Cohen, head of Rockefeller University's Laboratory of Populations, has written How Many People Can the Earth Support? with an eye to the "population problem".
Cohen's book is a survey and critique of scholarly responses to three questions about the earth's human population. First, how and why did previous population growth occur? This is the book's best chapter, offering competing explanations for such conundrums as why Old World microbes decimated the New World's people and why population growth has accelerated so much in the past century.
The middle section discusses scenarios of future population growth, some of them more apocalyptic than others.
The last and longest part surveys previous investigations into the planet's "human carrying capacity" (the total number of people the Earth can support), given what Cohen calls natural constraints like food and water supplies. This inquiry into optimal population is the meat of the book, with an annotated catalogue of human carrying capacity estimates spanning four centuries and a perfunctory nod to the human agency necessary for breeding.
Cohen, who holds doctorates in both applied mathematics and population sciences, casts his erudite scepticism on the exorbitant extrapolations and inane inferences of the demographers and population biologists he surveys. At the same time, the author does not deviate at all from his colleagues' guiding assumption, which is that the crisis of the world is the population problem. It is this concept of overpopulation, informing and motivating Cohen's book, with which I quarrel.
Now, overpopulation is a subtle and inconsistent creature. Attentive readers will have already noted that Cohen does not see the planet's problem as hyper-exploitation of natural resources, to be solved by curbing consumption in the overdeveloped nations. Instead, the perpetrators of the population problem are the dark-skinned and the poor.
Inquisitive souls may wonder why overpopulation supposedly ravages Indonesia whereas the Netherlands, with a population density over three times as high, is only a little crowded. No doubt the answer to this ingenuous question lies in the fact that the Dutch are wealthy and the Indonesians are poor.
And there is no shortage of poor people in the world, especially in countries deemed overpopulated. But, contrary to the Malthusoid musings of Professor Cohen as well as the State Department, the Ford Foundation and many a God-fearing liberal, there is no such thing as overpopulation, nor a global population problem. We well know that hunger, exploitation and overcrowding exist in nearly every nation, and in some nations more then others. But to classify those living in these conditions as a "surplus population" is to deny these people, already with little money and less hope, the very right to exist. Not only have they no right to exist, but this is a scientific law, like gravity, with whole disciplines, i.e., population biology, demography and economics, to prove it.
The historical — that is, political, economic and social — reasons for poverty and misery become irrelevant. And this is Malthus' contribution to modern thought: a way to see fundamentally political problems as inexorable natural phenomena, like earthquakes and hurricanes.
Nothing shows better what an unnatural disaster mass starvation is than the famine that killed about a million in Ethiopia during the mid-1980s, a calamity commonly explained as an example of too many people and not enough food. Of course this is lunacy. Because the Horn of Africa was a highly strategic area to both the United States and the Soviet Union, these two superpowers together pumped the country full of guns, then managed to goad rival factions into civil war.
During the ensuing collapse of civil society, what little land the farmers were able to cultivate went to growing export crops in order to pay off the country's debts. The drought that coincided with the war and subsequent swindle would not have been an issue under less fraught conditions. Needless to say, this did not stop the neo-Malthusians from greeting the catastrophe with stern eructations about the limits of altruism, the self-regulating harmony of Nature and the environmental benefits of mass population die-off. They viewed the Ethiopians as they would view so many drosophila in a glass tank: breeding creatures with no history.
In this spirit of technocratic purity, Cohen prudishly forgoes all but the slightest mention of the economic policies and imperialist politics that continue to immiserate millions. True, he does concede that something called "human choices" can help stem his population problem, but he curtly dismisses the need for redder, greener economic policies to save the planet and ourselves.
It was probably this know-nothing stance toward politics and history that caused one reviewer, an economist, to praise this book as non-ideological. Or it might have been the appendices of mathematical models that give off a magical aura of objectivity. Or perhaps How Many People? seems non-ideological because, written in a calm and measured tone, it contains none of the hysterical shrieking that fills most over-populationist manifestoes, for example, Paul Ehrlich's 1968 trash thriller, The Population Bomb, which called for the US government to send in choppers and medics to aid the Indian authorities in sterilising every man with three or more children. (Amazingly, Ehrlich is still taken seriously.)
The deeply ideological "common sense" of Malthus still rules. So what rich Hong Kong has a higher population density than wretched Bangladesh? So what if five times more people live in Great Britain today than in Malthus' day, when he thought the limit had already been passed? So what if, according to the United Nations, per capita global food production has been increasing steadily the past 15 years? Population hysteria is as strong as ever.
And sometimes governments carry out the sadistic whimsies from the pages of Professor Ehrlich. In Indonesia, for example, the army, accompanied by medical personnel, has implanted thousands of women with Norplant, without any informed consent and with often gruesome results. At the same time, the Suharto regime discourages condoms and the pill, because these devices give the women too much choice and the population planners too little.
In the United States, where eugenics has always claimed many followers, a mandated use of Norplant to control the procreation of the poor would dovetail snugly with "ending welfare as we know it".
Cohen concludes with an ominous passage from John Stuart Mill, promising that we won't achieve a friction-free political economy until "in addition to just institutions, the increase of mankind shall be under the deliberate guidance of judicious foresight". But whose foresight? When mothers everywhere are able freely to control their child-bearing, we will have improved our lot. But when the state, desiring a more competitive and streamlined labour force, arrogates the right to plan our families, we will have progressed to a new age of barbarism.
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