Crowding

On the heels of another prominent UN report about the coming "planet of slums," Chris Rapley asks that we turn our attention towards an increasing threat to life on earth: human overpopulation.

Unfortunately, he says, this is a topic that gets far too little attention, particularly when juxtaposed with the growing popularity of fretting over global warming:

What do the following have in common: the carbon dioxide content of the atmosphere, Earth's average temperature and the size of the human population? Answer: each was, for a long period of Earth's history, held in a state of equilibrium. Whether it's the burning of fossil fuels versus the rate at which plants absorb carbon, or the heat absorbed from sunshine versus the heat reflected back into space, or global birth rates versus death rates - each is governed by the difference between an inflow and an outflow, and even small imbalances can have large effects. At present, all of these three are out of balance as a result of human actions. And each of these imbalances is creating a major problem.

Second question: how do these three differ? Answer: human carbon emissions and climate change are big issues at the top of the news agenda. And rightly so, since they pose a substantial threat. But population growth is almost entirely ignored. Which is odd, since it is at the root of the environmental crisis, and it represents a danger to health and socioeconomic development.