This week, the world’s population ticks over a historic milestone. But in the next century, society will be reshaped dramatically — and soon we’ll hit a decline we’ll never reverse.

Casey Briggs

“We have now reached peak child,” Dr Charles-Edwards says. “There will never be more children alive on the Earth than there is today.”

Fertility peaked in the 1950s when women were, on average, having five children each.

That number varied dramatically between regions of the world.

But since then, fertility rates have reliably fallen. In fact, in some parts of the world, including Australia, Europe, North America, and some parts of Asia, fertility rates are already below that replacement number.