Sometime yesterday, a mother gave birth to the 7 billionth person on the planet. At least, that’s the news story. There’s a bit of uncertainty involved. Turns out predicting population growth isn’t an exact science. The math nerds at the UN and the US Census Bureau differ a bit on the precise numbers. This doesn’t have to be exact. This is a lot of people.

The pure number itself (7 billion) is hard to get my head around. Sure sounds like a lot of people, but then the infographic nerds at Per Square Mile show us that the entire population of the world could pretty easily crowd into Texas with a population density of New York City or we could stretch out a bit with a population density equal to Houston and still not fill up the entire United States. Okay, that makes me fill a little better. So, 7 billion people won’t physically fill up the earth. Obviously not, since most of these 7 billion people are living in Asia and Africa.

What’s more fascinating is the rate at which the population increases. We hit our first billion in 1804. The second billion took another 123 years. The third billion just another 33 years with shorter intervals each billion since. I remember hitting 6 billion in 1999. 7 billion came quick.

How did this happen? This very clever video explains it pretty well.

I remember learning in high school about Malthus’ idea that the industrialized society’s geometric population growth could not be sustained by the arithmetic growth in the food supply. So far, this hasn’t proven out. We may not be far away from testing the theory.

The smart people at Per Square Mile are right in saying that the major issue isn’t really how many people are currently on the planet but how many of those people want to live like Americans. If everybody wants to live like Americans, then we’ve got a major head scratcher on our hands.

The symoblic power of numbers is really to give language to things outside the scope of everyday experience. For the UN, this was an opportunity to call for action.

Fascinating times.