Now that China has laid to rest its infamous "one-child" rule, it's time to retire the "population bomb" fears that inspired it.
The one-child rule grew from a population panic in the 20th century, when human numbers were growing at a faster rate than ever before (or since). The increase conjured a dystopian hell of environmental destruction, resource shortages and massive human suffering.
In 1968, for example, biologist Paul Ehrlich famously declared, "The battle to feed all humanity is over" — and humans had lost. He warned that hundreds of millions would starve to death in the next decade, and counseled "triage" in foreign aid programs. (India, considered a lost cause, didn't make his cut.)
Ehrlich's worst predictions never came to pass, thanks in part to the Green Revolution and improved access to family planning. But population alarmism continued to inspire abuses.
In addition to China's one-child rule, there were abhorrent campaigns of forced sterilization in Indira Gandhi's India and Alberto Fujimori's Peru.
Though the population bomb was defused, the issue never really went away. Human numbers still increase by more than 80 million every year, the equivalent of adding another United States to the world every four years. And, while a certain amount of future growth is inevitable, choices made today will determine how high world population — now at 7.3 billion — climbs. According to the U.N. Population Division, there will be somewhere between 9 billion and 13 billion of us by the end of the 21st century.
What does that mean, for people and the planet? Today we have a much better understanding of the dynamics of population growth, which are shaped by a wide range of factors, including consumption patterns, technology and the distribution of wealth.
It's hard to generalize about the environmental impact of population growth because some people have a much bigger footprint than others. The average American, for example, emits 17 tons of climate-changing carbon dioxide every year, while most sub-Saharan Africans produce less than a ton. So, relatively slow growth in the United States contributes more to climate change than rapid growth in Africa.
Still, while there are great disparities in environmental impact among the world's people, everyone has some impact. We all share an inalienable right to food, water, shelter and the makings of a decent 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 9 billion rather than 13 billion people.
Consider water, a resource Californians no longer take for granted. While there is no global shortage of water, a growing number of regions are chronically parched. That is where human numbers are growing most rapidly. In the world's "water poor" countries, population could double by 2050. In those countries, slower growth could reduce demand and buy time to craft long-term solutions.
Or poverty. Thanks to family planning, fertility rates are dropping nearly everywhere, but they remain high in the least-developed countries. As a result, the population of those countries, now at nearly 1 billion, will double by mid-century and triple by 2100, raising the hurdles development must leap.
Let's be clear: Slowing population growth is not a panacea for the challenges of the 21st century. It will not cool the planet, solve the water crisis or eradicate poverty. But it could give families and nations a chance to make essential investments in education, healthcare and sustainable economic development. And it could reduce pressure on natural systems that are reeling from stress.
The good news is that we know how to do this without coercion and abuse. A half-century of experience has shown that the best way to slow population growth is not by limiting family size but by ensuring that all people are able to make real choices about childbearing.
That means access to voluntary family planning and other reproductive health information and services. It means education and job opportunities, especially for women. And it means tackling the deep inequities — gender and economic — that prevent people from determining the course of their lives.
Elements of this approach have been successful in countries around the globe. But there is still much to be done. Today, the United Nations estimates that some 225 million women in developing countries want to delay or prevent childbearing but lack access to contraception. More than 60 million girls are not in school. And there are very few countries where women have achieved economic or political parity with men.
Addressing these challenges is vitally important as a matter of human rights and social justice. It is also fundamental to managing population growth.
In the 20th century, population alarmism spawned policies that trampled human rights. Today, better understanding can drive better policy. By expanding individual choice — and protecting rights — we can shape a more sustainable, equitable future.
Laurie Mazur is the editor of "A Pivotal Moment: Population, Justice and the Environmental Challenge."