To economists, 32 is special, because it measures the difference in lifestyles between the first world and the developing world. The average rates at which people consume resources like oil and metals, and produce wastes like plastics and greenhouse gases, are about 32 times higher in North America, Western Europe, Japan and Australia than they are in the developing world. That factor of 32 has big consequences.

The population especially of the developing world is growing, and some people remain fixated on this. They note that populations of countries like Kenya are growing rapidly, and they say that’s a big problem. Yes, it is a problem for Kenya’s more than 30 million people, but it’s not a burden on the whole world, because Kenyans consume so little. (Their relative per capita rate is 1.)