Population growth rate and population size—these are ideas that people sometimes confuse when they discuss population's role in climate change. The two are related, of course. But they differ significantly when it comes to policy options for mitigating population's effect on climate change.
Wang Haibin's first essay in this roundtable includes an example of such confusion. It's true, as Wang notes, that China's population growth rate—1.25 percent between 1987 and 2000—declined to 0.56 percent between 2000 and 2014. But Wang goes wrong when, while minimizing population's role in greenhouse gas emissions, he contrasts quickening growth in China's emissions to its slowing population growth. What he overlooks is that China's actual population—1.09 billion in 1987—increased to 1.27 billion in 2000 and to 1.37 billion in 2014. That's a very significant increase in population, even if the rate of population growth has been slower in recent years than in past ones. The truth is that increased population has had much to do with growth in China's carbon dioxide emissions.
To be sure, China's carbon footprint would be much heavier today if its population growth rate hadn't slowed since the 1980s. The Chinese Communist Party claims that the one-child policy averted 400 million births—a number larger than the total population of any country in the world except India and China itself. The one-child policy cannot be condoned. But still one must acknowledge that it accomplished more for the global environment than any other state policy in the world.
The good news, though, is that population growth rates can be influenced by policies that—unlike the one-child policy—respect people's right to make individual reproductive choices. The same can't be said of a population's current size, which can only be drastically altered through unthinkable steps such as genocide and forced expulsion.
This brings me around to agreeing with Wang's Round One statement that "the best way to limit carbon dioxide emissions is through altering behavior—not through limiting population." I agree because limiting population, under any circumstances, is unethical and criminal. Limiting a population's growth rate, however, can be achieved by providing universal access to voluntary family planning services; encouraging females to marry later; and improving female education. These are effective policy tools that provide huge benefits for individuals, societies, and the environment. Indeed, where altering behavior for the climate's sake is concerned, the easiest approach of all is to help women avoid unplanned pregnancies.
Wang expresses enormous faith in the potential of good governance to address climate change—and in the capacity of individuals, once good governance has freed them from want, to act in ways that benefit the environment. But he overstates his point. He writes, for example, that "[w]here governance is poor, a larger population will likely entail more pollution" whereas, in well-governed societies, "greater population only increases the chances that humans will discover brilliant solutions to the challenges that face them." The problem with his reasoning is that richer countries pollute more than poorer countries, and larger populations (all else being equal) pollute more than smaller populations.
There's no denying that addressing climate change requires good governance of Earth's systems. Likewise, eradicating poverty depends in part on establishing good political governance. But addressing climate change while also ending poverty will be much, much easier if sex can be decoupled from childbearing everywhere in the world. Ending the tyranny of unplanned pregnancy is a key component in establishing the sort of green economy that can both lift people from poverty and help avert the worst consequences of climate change.
So our colleague Alisha Graves, who champions "green sex," has got the right idea. Go green!