No reasonable solution to climate change can be excluded from the world's arsenal of climate mitigation options. Family planning deserves a prominent place in that arsenal because of population's profound implications for future global emissions. Because population will be a much bigger factor in emissions in the century's second half than in its first, decision makers may be inclined to push family planning down the list of climate priorities. But population growth must slow in the current decade if desirable population changes are to occur later on. That is the nature of demographic momentum.
Too often, family planning is treated as taboo in policy debates. It simply slides off the policy table. This isn't because population's importance to carbon emissions is poorly understood. Far from it—the Intergovernmental Panel on Climate Change, the world’s foremost authority on climate change, has identified reproductive health services, including modern family planning, as an opportunity "to reduce emissions of warming [climate-altering pollutants] and at the same time improve health." But many climate discussions, even when otherwise excellent, simply overlook family planning. A new World Bank report on climate change and poverty, for example, mentions population growth more than 10 times, either as a contributor to climate change or as an impediment to climate adaptation in poor countries. But the report's authors, in 70 pages of proposed solutions, make no mention of contraception. As I wrote earlier in this roundtable, people who appreciate population's impact on the environment can be afraid of the criticism they'll attract if they openly advocate family planning. But the real controversy is that voluntary family planning is systematically excluded from recommendations about how to achieve climate mitigation and adaptation, despite the evidence that it plays such an important role.
Revolutionary shift. My roundtable colleague Wang Haibin wrote in Round Two that people in poorly governed countries "invest in their futures by producing many offspring when they are young." I am always skeptical about such claims—they are grounded in economists' over-reliance on the rationality of human behavior. Sex is not usually a rational act. It is an animal instinct inherited from our ape ancestors.
For heterosexual couples, a large family is the default outcome of normal sexual activity. Most people can avoid this outcome only by taking consistent preventive measures over the course of decades. Even so, contraceptives sometimes fail, so women need access to safe abortion services or else they will risk their lives trying to end an unintended pregnancy. The idea that children represent rational decisions is, to adapt language used by my colleagues Martha Campbell and Malcolm Potts, a mirage—you only see it if you think that the world is full of people who, like yourself, can make easy, actionable decisions about whether and when to have children.
Another key factor in the climate equation—consumption—may be as irrational as sex is. From an early age, people in wealthy societies are confronted with marketing that aims to manipulate their behavior. This engenders very powerful desires to consume more than necessary. For the environment, the effects are disastrous. And with most nations on Earth now on a path toward development, how long will the carbon footprints of developing countries remain lighter than those of developed countries?
One of the most effective responses to climate change may also be the most difficult: reining in excessive consumption. What's needed is a revolutionary, planet-saving shift in economics—one that might begin with defining success in terms other than material wealth. If the global economic paradigm does not respect the limits that the biosphere imposes, it is time to change the economic paradigm.
Earth is just a tiny island adrift in infinite space. We must acknowledge that reality for the sake of our children.