Thanks for all of the responses over the past two days to my queries about proposed solutions to the population problem and the “optimum” global population. So here are some observations followed by my response to the questions Robert Walker posed in his piece claiming that population is still a major issue:

  1. “Doomsayers” is an appropriate term for many of those who think population is a huge problem; nowhere do I see more apocalyptic and defeastist rhetoric in the environmental movement. For many, it seems like the battle is lost and all we have to do now is watch humanity’s ultimate decline. And there is a pretty big dose of heartlessness too. I cringe everytime I hear people writing off entire countries and using words like “triage” for entire populations of people.
  2. Where there is the greatest agreement is in the need for increased female empowerment and access to contraception since this is the greatest driver of decreasing fertility rates. Ironically, it is the great strides that have been made in these areas that have led to the decreasing fertility rates that allow Fred Pearce and others like myself to procalim population growth as not a serious problem anymore. We absolutely should continue efforts in this vein and also combat religious extremism that denies women’s freedom. On this there is close to unanimity.
  3. There really aren’t that many other policies proposed by the “population is the problem” side because there are very few other options that aren’t extremely coercive. The fact is that many of the demographic trends today have a lot of inertia. There was some mention about decreasing urbanization, but this doesn’t directly address population, and the trends are precisely the opposite. Billions of people from the countryside are flocking to cities and will continue to do so.
  4. With respect to the “optimum” number of people on the planet, the reason I posed this question was to show how tricky it is. Those who tried to answer it said the sustainable population is in the range of 2 billion to 3 billion. Since the population is expected to peak at around 9 billion in 2050, these people basically think it would be best if 2/3 to 3/4 of the planet’s people were wiped out. While there’s no doubt that fewer people (all else equal) means fewer impacts, there is no compelling scientific evidence that I have seen that says that 9 billion people can’t enjoy a high standard of living and maintain earth’s life support. There’s a big difference between eating a vegan diet and using wind to power your car versus eating meat three times a day with your gasoline-powered SUV, and these are the questions that seem much more relevant, rather than the absolute number of people. And since I don’t want to advocate the demise of the majority of the world’s people, I will stick with this side of the equation.

I’d like to take a few moments to respond to Robert Walker’s questions to Fred Pearce at the end of his piece:

Looking ahead, Fred, will these countries be able to feed themselves? Will they have enough safe drinking water? Will their lands be deforested or their rivers polluted? Will their maternal mortality rates and infant mortality rates remain unacceptably high? Will they be caught in a demographic poverty trap? Will they become failed states?

No one has the answers to these questions, but what I can say is that in almost all cases the absolute number of people will not be the deciding factor. For example, there is plenty of food to feed everyone in the world already, but many go hungry. There is probably five times the amount of food to feed everyone in the U.S., but we have hungry people here. Why? Because of how the food is distributed, not because we don’t grow enough. Same with drinking water; the quality of water, while affected by population, is not determined by it. And the list goes on.

In summary, while no doubt efforts to reduce fertility, especially through increasing women’s rights and decreasing child mortality, are exceptionally important (and the right thing to do), they do not impact the main drivers of environmental degradation. We could have substantially fewer people and still irreparably pollute our world. And just the same, we can (and will) have a lot more people and live sustainably. It’s how we live, not how many of us there are, that will determine our and the planet’s fate.