Countdown to Six Billion

Why is it that we have so much trouble making the connection between runaway population growth and environmental degradation? It seems plain that the issues that matter most to us—biodiversity, urban sprawl, loss of rainforests and old-growth trees, air and water pollution—have their roots in the incredibly successful propagation of the human species.

Illustration: Jerry Russell

And yet we often talk about these problems as if they exist in a void, instead of in an intricate web of interconnected threads. I thought about this recently while writing about the plight of the Asian tiger. This stately and critically endangered beast can travel 37 miles in a single day, and has a home range of 1,500 square miles. How will it be able to peacefully coexist with humanity in modern India, whose population is expected to nearly double—to 1.5 billion, surpassing China—by 2050?

Ken Strom, executive director of the National Audubon Society's Population and Habitat Campaign, talks about the “disconnect” he sees in press coverage of environmental issues. “They'll write about, say, the destruction of forests, and never attribute it to population pressures,” he says. But what else is responsible? We can fight the good fight to protect individual wilderness areas, and even win some important victories, but population growth is an inexorable force swallowing up undeveloped land.

According to the United Nations, every year, an estimated 39 to 49 million acres of tropical forests and woodlands are lost, cleared for development or agriculture. An additional 12 to 17 million acres of agricultural land falls victim to erosion and developers' bulldozers. Freshwater scarcity, a result of both water pollution and increased human demand, now affects 20 countries with a combined population of 130 million.

Unsustainable population growth forces the rural poor into such destructive practices as burning forests to make way for agricultural production, land depletion through intensive use, and overpumping of ground water, all of which deplete our increasingly vulnerable supply of arable land.

To meet increasing human demand, we add 50 million cars to the planet's roads every year. By 2030, there could be an incredible one billion of them—including 100 million in China—wreaking various forms of havoc. Even if cars were to become more fuel efficient and reduce their per capita production of carbon dioxide, the sheer numbers of them on the road would have a devastating impact on global warming. Atmospheric concentrations of carbon dioxide are already 28 percent higher than they were in pre-industrial times, and few countries—and that definitely includes the U.S.—are even close to reaching the ambitious pollution-reducing goals they reaffirmed at the Kyoto summit in 1997.

In October of this year, scientists predict that world population will reach the six billion milestone. Our cover story in this issue concerns not only how we added a billion people in just 12 years, but also how we did it with so few of our pundits taking note of it as an issue. Declining fertility, a very real phenomenon around the world, has created the false impression that we face a “birth dearth.” Added to that is the political controversy unjustifiably linking birth control with abortion. It's time for a reality check: Because of the very young populations in developing countries, human numbers will creep inexorably up for at least the next 50 years, with drastic implications for our environment.