The 7th Billion – Malthus Resurrected?

The United Nations predicts that on Halloween (October 31st, 2011) we will reach an unprecedented milestone in human history: the world’s population will reach 7 billion. Somehow the coincidence with this most macabre of holidays seems ironic; it’s still unclear whether the 7 billion mark is a testament to human vitality or the harbinger of future collapse.

Every previous billion in population increase has taken less time to occur than the last. Going from 1 to 2 billion took 125 years (1804-1927). Going from 5 to 6 billion took only 12 years; 6 to 7 billion a mere 11. And while modeling future population growth is by no means an exact science (think about all of the endogenous factors involved), even the most conservative of UN estimates have world populations peaking at around 8 billion, more likely 9 billion.

What does this mean for us today?

At the very least, we might want to take a moment to reflect on the sheer physical footprint of 7 billion human beings on the planet. I’m not one for numerical hyperbole, but that’s 7,000,000,000 people!

In a recent video message at Columbia University’s roundtable discussion on “The 7 Billion Challenge”, Jeffrey Sachs speaks about some of the implications of this milestone on economic and environmental sustainability.

As Sachs notes, while Malthusian soothsaying fell out of fashion long ago, we are increasingly in a position where Malthus’ claims of overpopulation and collapse may come back to haunt us if we do not think hard about how to lower the collective footprint of human activity.

Of course, what we should do about “the population problem” is not entirely clear. Some advocate a wholesale “population policy”: at the extreme,  Chinese-style one-child policy. Others call for a more indirect approach: say, through female empowerment, or subsidizing contraceptives in developing countries. I, frankly, am still not sure where I stand.

One thing seems clear, however. While the overall size of the world population definitely matters, the resource intensity of economic activity matters just as much. A path to a more sustainable economic future will inevitably need to go through non-trivial reductions in both over time.


Image credits: The Costume Discount Razor:; Triple