Everyone Who Ever Lived

How many human beings have ever lived?

What a question! I wasn’t there to count them all a few hundred thousand years ago when anatomically modern humans first burst onto the scene, but is there a way to reasonably estimate the number of people who have been born?

This idea first cropped up in my mind a long time ago, but within the last decade or so, it has become easier to come up with some kind of a reasonable estimate. After all, answers to virtually everything are on the internet.

If this problem seems insurmountable, you’re not alone in thinking that, but there’s a way to simplify it. Today, the global population is just over 8 billion, an almost unfathomable amount. Our brains are wired to understand numbers in the dozens, not in the billions.

One thing we are capable of grasping is ratios. Just a century ago, the human population was a hair under 2 billion, or a quarter of what it is today. A hundred years before that, it was about a billion.

A thousand years ago, there were mo…