Global warming is "unequivocal," according to the recently released report by the Intergovernmental Panel on Climate Change. The most likely culprits are people - all of us. Yet there never has been much public discussion about the role of human population growth in global warming.
According to professor Timothy Dyson of the London School of Economics, a 40 percent cut by 2050 in per capita carbon emissions in the developed world could be canceled by global population growth.
It's time to open a "second front" in the battle against global warming by stressing the need for population stabilization - sooner rather than later.
Scientists warn that temperatures will continue to rise unless we stabilize greenhouse gas levels. Global warming will be accompanied by increased sea levels resulting in massive flooding of homes and destruction of fragile wetland habitats. To slow this process, experts report that global CO2 emissions must be slashed.
Yet the United Nations projects that by 2050, world population will rise 40 percent to more than 9 billion. And even if we change our ways, the environmental footprint of each human being will never reach zero. As population increases, the challenge of slowing climate change becomes ever more difficult.
After all, it is people, not birds or bears, who drive Hummers and who heat and cool homes and offices. Although the vast majority of population growth occurs in the least-developed nations, the people there, too, are using more fossil fuels every day.
What can we do? We know that family planning works everywhere. When women and couples are free to make informed choices and have access to family planning resources, they choose to have smaller families. Thirty years ago, for example, Mexican women had almost seven children each. Today, thanks to education and the availability of family planning, they have an average of 2.4 children.
Globally, at least 350 million couples lack family planning services. In the U.S., one-third of all births are unplanned. If we could cut in half the number of unwanted births in America alone, we'd have about 5 million fewer births over 20 years.
It's vital to focus on thorny technical issues such as tax credits, energy alternatives and emissions trading programs. These efforts are especially important in the U.S., where less than 5 percent of the world's population produces about one-quarter of the world's carbon dioxide emissions. But cutting energy consumption must be coupled with stabilizing population. More people use more energy. If we had zero population growth, part of the global warming problem would, well, melt away.
Global warming is too big a problem to be solved by energy experts alone. It's about people. It's about how many of us there are and how we choose to live our modern lives. It's about the very personal decisions we make about whether and when to have children - and how many.
We can start by supporting the notion that every woman and every couple should have the resources and power to control their reproductive lives.
If every child is planned, we'll go a long way toward solving global warming and making a less-crowded and healthier world.
John Seager is national president of Population Connection (formerly Zero Population Growth). His e-mail is john@popconnect.org.