The Population Debate Is Screwed Up

Chris Hedges ("Are We Breeding Ourselves to Extinction?") and Betsy Hartmann ("Stop the Tired Overpopulation Hysteria") reprise an argument that has raged for decades. Hedges identifies "overpopulation" as the root cause of climate change and other environmental problems and calls for "vigorous population control." Hartmann dismisses population growth as a cause of environmental harm and reminds us of the shameful history of top-down population-control programs.

This polarized debate has generated lots of heat and little light over the last half-century. According to the combatants, population growth is either the biggest problem facing humanity, or it is a complete non-issue.

The debate usually begins with a dire, Malthusian warning -- often by an environmentalist: "The sky is falling! Rapid population growth is the cause!"

In 1968, for example, Paul Ehrlich famously declared that - -- because of population growth - -- "The battle to feed all humanity is over." He warned that hundreds of millions of people would starve to death in the 1970s and recommended "triage" in foreign aid programs. (India, considered a lost cause, didn't make the cut.) Hedges fits squarely within this tradition.

The dire warnings cue the chorus of "population deniers," who assert that growing human numbers pose no problem at all. Over the years, that chorus has included a surprisingly diverse array of groups, including feminists, neoclassical economists, Marxists and the religious right.

For some -- like Hartmann -- population denial springs from legitimate fears that the Malthusians will trample human rights in their pursuit of lower birthrates, or that a focus on population growth will distract us from bigger issues, like inequality and unsustainable consumption.

Nonetheless, viewing population growth in such all-or-nothing terms does little to advance understanding -- or action -- on this important issue. The fact is, we now have a much more sophisticated understanding of population dynamics and their environmental impact than we did in 1968.

First, while the rate of population growth has slowed in most parts of the world, rapid growth is hardly a thing of the past. Our numbers still increase by 75 million to 80 million every year, the equivalent of adding another U.S. to the world every four years or so. We know that a certain amount of future growth is virtually inevitable -- an echo of the great boom of the late 20th century. But choices made and services available today will determine whether human numbers -- now at 6.8 billion -- climb to anywhere between 8 billion and 11 billion by midcentury.

We have also learned that population growth has a significant impact on the natural environment, but that impact is neither linear nor uniform, and it is shaped by a wide range of mediating factors, including technology, consumption patterns, economic policies and political choices.

Of course, some people have much greater environmental impact than others; we in the industrialized countries use about 32 times the resources -- and emit 32 times as much waste -- as our counterparts in the developing world.

Still, while there are great disparities in environmental impact among the world's citizens, everyone has some impact. We all share an inalienable right to food, water, shelter and the makings of a good life.

If we take seriously the twin imperatives of sustainability and equity, it becomes clear that it would be easier to provide a good life -- at less environmental cost -- for 8 billion rather than 11 billion people.

Slowing population growth, then, is one of the things we must do to address the current environmental crisis. Take climate change, for example. An analysis of climate studies by Brian O'Neill at the National Center for Atmospheric Research shows that slower population growth could make a significant contribution to solving the climate problem.