Too Many People?
The human population surpassed 7 billion in 2011—seven times the number at the turn of the 19th century, when Thomas Robert Malthus first explored the consequences of uncontrolled reproductive rates. But how many people are too many? As the global head count rises by more than two people per second, debate rages between neo-Malthusians, who contend that catastrophe is nigh, and those who argue, against received wisdom, that earth’s carrying capacity is potentially limitless.
Thomas Robert Malthus was not exactly a Malthusian. Although he’s often given credit for it, he did not predict a “Malthusian catastrophe”—a collapse of civilization resulting from the planet’s inability to support uncontrolled population growth. Rather, Malthus, whose 1798 Essay on the Principle of Population was the first systematic study of the effect humanity’s numbers have on economy (and vice versa), thought population growth and decline were cyclical. He believed the number of people was held in check, over time, by war, disease and—where these “active and able ministers of depopulation” were unsuccessful—by inevitable famine. Malthus (who was a pessimist) worried that periods of increasing birthrates, in his view, always ended up making the lives of the poor more miserable. But Malthus didn’t want to help the underprivileged climb out of poverty; instead, he favored intentionally worsening their living conditions to reduce their numbers. Following in his footsteps, some neo-Malthusians have suggested similar strategies. For example, Paul and Anne Ehrlich, in their 1968 best-seller The Population Bomb, lauded proposals to end international food aid to countries not taking serious population-control action—an idea that is truly Malthusian.
Thomas Robert Malthus may have been mistaken in perceiving human populations as subject to endless boom-and-bust cycles, but such successions do occur with wild animals, which, unlike us, can’t create new food sources when shortages threaten. Ordinarily, a species’s population, checked to some extent by predators, rises until food runs out, then falls; its predators’ numbers may then follow suit. That natural balancing act has, however, been thrown off kilter as human beings have claimed an ever-greater share of the earth. Overhunting, habitat degradation and disappearance, pollutants and other factors have led to the reduction or extinction of many wild species. But human interference with nature—eliminating predators, introducing nonnative species and releasing domesticated animals into the wild—has also fostered dramatic increases in certain species’ numbers. Some areas of the U.S. today are plagued by human-engendered overpopulations of white-tailed deer, feral hogs, Canada geese, mute swans, Asian carp, wild horses and feral cats that are the descendants of abandoned pets. Australia has been overrun by numerous invasive introduced species, including rabbits, foxes, venomous cane toads and even camels. Explosions in the numbers of certain animals can have many deleterious effects, including ecosystem degradation and biodiversity reduction.
The Population Bomb prophesied imminent disaster, predicting in its first edition that hundreds of millions worldwide would die of famine in the following decade. To lessen what they saw as overpopulation’s catastrophic potential, authors Paul and Anne Ehrlich recommended governments embrace coercive measures to get people to quit having kids—including imposing higher taxes on families with children than on those without. The Ehrlichs even flirted with the idea that governments should dose municipal water supplies with infertility-causing drugs. Compulsive or mandatory population-control efforts—including forced sterilization and abortion—face a sizable moral hurdle, however: Many people reject them as assaults on basic human rights. That’s one criticism leveled against the People’s Republic of China’s so-called one-child policy, introduced by the Chinese government in 1979 and limiting most city-dwelling couples to one son or daughter. The rule has spawned serious unintended consequences (parents desiring males have aborted or murdered female offspring) and human rights abuses, including state-imposed abortions even in late stages of pregnancy. The widely publicized 2012 case of Feng Jianmei, forced to undergo an abortion when she was seven months pregnant and unable to pay the fine for having a second child, provoked outrage across China and internationally.
Though China’s population—about 1.3 billion in 2011—has continued to grow, the one-child policy has succeeded in slowing the rate (by just how much is a matter of debate). But the policy has also altered the age ratio of a significant share of the population, creating an unforeseen difficulty: An only child born to parents who are themselves only children may, on reaching adulthood, be solely responsible for the care and support not just of two parents but also four grandparents. This situation, known in China as the four-two-one problem, is akin to issues afflicting countries experiencing real declines in their numbers. There’s a birth dearth throughout much of the developed world. Fertility rates have fallen below replacement levels as life spans continue to lengthen, resulting in graying populations with too few younger people to do the work needed to sustain society. In some countries with low fertility rates, the problem is at least temporarily offset by immigration from higher-growth regions; but in Japan, where birthrates have dipped below death rates and immigration is almost nonexistent, demographic disaster caused by depopulation is almost certainly in the offing.
Science fiction filmmakers and writers have often imagined dystopian futures in which humanity is discomfited or endangered by overcrowding. Examples include Ridley Scott’s film Blade Runner (1982), Terry Gilliam’s movie Brazil (1985), Kurt Vonnegut’s short story “Welcome to the Monkey House” (1968) and Harry Harrison’s 1966 novel Make Room! Make Room! Harrison’s book inspired the plot of the 1973 film Soylent Green (directed by Richard Fleischer), in which the populace, other food sources having been exhausted, is unknowingly sustained by state-sanctioned cannibalism. Few sci-fi prophets, however, have envisioned a world brought to ruin by the opposite menace: depopulation. British mystery writer P.D. James is one who has. Her only foray into speculative fiction, The Children of Men (1992), conjures a near-future society teetering on the brink of collapse, because, when the story opens, no children have been born on earth for more than a quarter century. Perhaps this tale’s grimmest aspect is the death of hope that accompanies the absence of offspring. “As the sound of the playgrounds faded, the despair set in,” a character intones in the book’s loosely rendered 2006 film adaptation, directed by Alfonso Cuarón.
Some believe overpopulation is a myth, preferring to ignore the notion that earth’s resources—water, food, energy—are finite and will reach a breaking point as we add billions more humans to the planet. Overpopulation deniers are also appalled, understandably so, by the inhumaneness of certain neo-Malthusian solutions to the perceived problem. From the neo-Malthusian point of view, however, refusing to impose any limit on human reproductive freedom invites global catastrophe.
Neo-Malthusian policies, ranging from compelling people to stop reproducing to actively killing off some portion of the citizenry, appear regularly in dystopian science fiction: In Anthony Burgess’s The Wanting Seed (1962), a tyrannical state controls the birthrate by encouraging homosexuality. In William F. Nolan and Clayton Johnson’s Logan’s Run (1967), the execution of people on their 21st birthday keeps the population in check (the 1976 film adaptation generously raised the age cutoff to 30). In Aldous Huxley’s Brave New World (1932), women capable of childbearing are obliged, by indoctrination and social pressure, to use contraceptives; they wear their birth-control meds in fashionable bandoliers, which Huxley named “Malthusian belts” in witty homage to the founder of population science. These books all endorse rebellion against such constraints.
Thomas Robert Malthus seriously underestimated the capacity of agriculture to keep up with population growth. Writing at the beginning of the Industrial Revolution, he didn’t foresee how mechanization would transform farming and bring about a massive increase in food production during the 19th century and beyond. Some of Malthus’s intellectual heirs have made similar miscalculations. Paul and Anne Ehrlich’s The Population Bomb may stand as a landmark work of the modern environmental movement, but the authors were dead wrong in their forecast of imminent, widespread famine: Across the globe, average caloric intake has risen in the years since the book’s debut. This is an ongoing legacy of the green revolution, the postwar transformation of food production that raised farm outputs by as much as 500 percent. The green revolution was largely the brainchild of American scientist Norman Borlaug, who devoted his life to breeding high-yield, disease- and pest-resistant crops and disseminating modern agricultural methods in developing countries worldwide. But it’s an open question whether the green revolution’s successes can be maintained, as freshwater reserves and arable land expanses diminish. The “population bomb,” though it hasn’t yet detonated, may still be ticking.