Human beings must consume natural resources to survive. Therefore they produce carbon pollutants. The larger the human population, the greater the carbon emissions and the greater the consequences for the environment.
This is a fundamentally pessimistic outlook on the relationship between population and carbon emissions—and both my roundtable colleagues appear to be proponents of it.
A more optimistic alternative is the idea that human beings themselves, in the words of the late economist Julian Simon, are the "ultimate resource." Optimists would argue that although people consume natural resources and cause pollution, in the end they do more good through what they create than harm through what they consume. People will ultimately find ways to overcome pollution problems—and even turn pollutants into valuable resources.
These opposing viewpoints have one thing in common: Both are absolutist. Absolutist approaches to population generally entail problematic consequences.
In China, for example, political leaders over the past several decades implemented two sets of population policies that, though very different from one another, were both absolutist and problematic. Under Mao Zedong, the Chinese government took the position that a larger population would make the people mightier and the nation stronger. The government enacted policies that allowed and even encouraged more births. Then, in the late 1970s and early 1980s, the government changed its approach, deciding that a large population was a burden on the nation's economy and social structure. So Beijing initiated its coercive one-child policy—very controversial and broadly unpopular. In 2010 the government, finally recognizing that China's population was aging fast and its demographic dividend was fading, relaxed the one-child policy by allowing couples—if both individuals were only children—to have a second child. The policy has since been loosened further, and now there is essentially a two-child policy in China.
The truth is that population growth can be either an asset or a liability where mitigation of climate change is concerned. The real key in climate mitigation is whether societies exhibit good or bad governance.
Where governance is poor, a larger population will likely entail more pollution. Wherever it's a struggle simply to survive, people have no choice but to consume the natural resources within their reach, no matter how unsustainable and polluting their consumption may be. If coal, especially low-quality coal, is the cheapest energy resource, people will consume it. Moreover, people in poorly governed countries anticipate that future resources will be meager. They have no faith that society will provide for their care in old age. Concerned about this risk, they invest in their futures by producing many offspring when they are young. This leads to faster population growth.
Where good governance exists, societies are stable. Material necessities are abundant. To be sure, this leads to higher carbon dioxide emissions today. But it also gives people scope to solve problems and to make contributions to future well-being. Humans may not always be the "ultimate resource," as Simon would have it. But if human talent and knowledge are fully utilized, people can steadily expand the scope of usable resources, deepen resource utilization, and at the same time reduce pollution—including carbon pollution. In such societies, greater population only increases the chances that humans will discover brilliant solutions to the challenges that face them. Good governance frees people from worry and fear, giving them the time and resources to, for example, replace fossil fuels with low-carbon energy sources.
Since global warming is at least partially man-made, individuals must of course modify their behavior in certain ways. But ordinary people are not to blame for climate change. Bad governance is at fault. What needs to be contained is not population growth but rather bad governance.
So where my roundtable colleague Alisha Graves promotes "green sex" as a key element in climate mitigation, I would argue instead for green public administration, including good education and social welfare systems. Achieving green administration worldwide would do more for the climate than any approach to population ever could.