Population Pessimists are More than Merely Wrong

Recently I frightened a newspaper reporter.

She was doing a story on the latest gloomy predictions of Cornell University entomologist David Pimentel. He warns of global food shortages, rapidly disappearing topsoil, and overpopulation destroying the world's wildlife. Pimentel recommends pushing the world human population down from the current six billion to two billion. I told the reporter that the world has two choices for saving both its wildlands and its quality of life. Either we eradicate billions of people or use farm chemicals and biotechnology to triple the yields on the world existing farmland. "Wait!" she cried. "Who's talking about killing people? Pimentel is talking about family planning!"

The reality, however, is that family planning cannot hope to cut the world's population quickly and deeply enough to save the planet's wildlife. Affluence, urbanization, and contraceptives have helped to cut birth rates radically, from six births for every Third World woman in 1960 to approximately 2.9 today. (The "replacement" level is 2.1 births per woman.) Demographers say that current birth trends project a peak human population of 8 to 8.5 billion in 2030. That would be approximately 40 percent more people than today's six billion, but far less than the twelve billion Pimentel claims to expect.

We can actually expect the earth's human population to decline slightly during the second half of the twenty-first century, as more countries reach the First World average of 1.7 children per woman. However, the population decline produced by lower birth rates will come very slowly. It won't be nearly quick enough to save the topsoil or wildlife from the pressures of feeding a large human population. Trends from the last several decades suggest that the affluent people of the 21st century will demand lots of meat, milk, fruit, and cotton. Thus we will have to produce 2.5 to 3 times the farm output we harvest today. Without higher yields, getting 2.5 to 3 times as much farm output by 2050 would force us to plow the half of the global land area not currently under cultivation or permanent ice.

Jacques Cousteau, the smiling French marine biologist whose Undersea World television program took us to the far reaches of the world's oceans, wrote in 1991 of the necessity of eliminating 350,000 people a day to stabilize the world’s population. He said that it was horrifying to speak of such things, but just as bad not to. Cousteau was at least being candid. Scaremongers like Pimentel pretend that condoms and contraceptive pills can radically cut the world's population. They cannot do so quickly enough to avert mass starvation if we fail to increase yields.

Cousteau also had something of an excuse for his population pessimism: he wasn't an agriculturist. Pimentel, an entomologist, has no excuse. He has told me in private that he admires using herbicides instead of plowshares to control weeds, which conserves topsoil almost completely. Yet, he claims publicly that the world is losing ten times as much topsoil as it is actually losing.

The media and politicians have had great fun riding the world's recent wave of environmental pessimism. This pessimism can even be a good thing if it pushes us to invest in energy efficiency and better sewage treatment. Unfortunately, it has also led people like Costeau and Pimentel to start "preparing" the world for massive depopulation. Essentially, Pimentel is saying that mass death is preferable to using nitrogen fertilizer, conservation tillage, and genetically modified seeds. For a trained agriculturist, such an attitude is unconscionable. Unfortunately, it is becoming increasingly common.