The Oregonian reports on a study by OSU statisticians that suggests that the biggest carbon footprint we have is our children. This begs certain moral and metaphysical questions like is it appropriate to control individuals' fertility decisions, and when is my carbon footprint my own and not my parent's? But to me, the focus on the individual aspect of population growth it totally misses the bigger points: one, what are the incentives for families to have children and what can we do to alter these incentives; and two, do the incentives that more people provide actually represent the solution to the climate change problem?
In high income countries, birth rates are very low - in fact in some Western European countries, they are below the replacement rate. This is true for may reasons but some of the biggest are the expense of children (more space, more food, more clothes, etc.), and the fact that children are less important for ensuring the welfare of the parents in their old age. In the United States space is generally less expensive and old age benefits smaller, but education is much more expensive for individual families and there are less generous benefits for families who have children. In general, however, as societies become more wealthy, birth rates decline. Families in low income countries face a tremendously higher risk of a child dying in infancy, often need many children for labor and security and may have lower access to birth control information and supplies.
As energy becomes more expensive it will further increase the expense of children in high income countries and we might expect birth rates to fall farther. So, once again, it is the middle income countries with relatively high birth rates and rapidly increasing energy needs that are the most pressing challenge to the global climate. Countries like India are going to be the key. So continuing to focus on what we are doing at home is great, but misses the real elephant in the room (to quote the LA Times): high-income countries must become serious about assisting low and middle income countries develop and do so with moderate energy usage if we are going to address in any meaningful way global climate change. As these countries become more prosperous, it is highly likely that population growth rates will fall significantly.
The other problem with this assertion about children having to do with incentives is the fact that population pressures create the very incentives that can transform the energy economy. [And what is shocking is that the authors of this study are statisticians and yet they seem comfortable assuming that correlation and causation are the same thing] Demand pressures on oil are raising the price of gas and spikes in gas prices (like last summer's) are just about the only thing that can cause people to drive less and drive more efficient cars.
To understand how this study assumes correlation and causation are troublingly conflated, consider this thought experiment: if the globe had a significantly smaller population, would the climate be much better off as is assumed? I am not so sure, it has been the pressures of population that have made us concerned about acid rain, the health concerns from pollution, the dirtying of rivers, the collapsing of fisheries, the effects of rising sea levels and on and on and on. With fewer people we can more easily ignore the impact of our actions. And going forward will more people actually create the very incentives to make rapid changes to our energy consumption - I think it pretty likely that it will. And as I have said before, in each new person comes the potential for creating the new technology or coming up with the next great idea that will transform the way we live. It is people who have discovered the global climate - human activity link. It is people who are figuring our how to effectively harness the energy of the wind, sun and waves. And it is future generations that provide us the incentives to be good caretakers of the planet.
So I am not afraid of population per se. I see it largely as a development problem and another aspect of the challenge high income countries face when they ignore the reality of poverty in the rest of the world. It is becoming harder and harder for the high income countries of the world to consider themselves as insulated from the problems in other countries. The externality aspect of global climate change make that less and less true. This calls for a new engagement with the developing world.