World population hits eight billion — here’s how researchers predict it will grow

According to the models of the United Nations (UN), the world’s population will reach 8 billion today — a mere 12 years since it passed 7 billion, and less than a century after the planet supported just 2 billion people.

The latest UN population update, released in July this year, also revises its long-term projection down from 11 billion people to 10.4 billion by 2100.

Demographers will never be sure whether 15 November really was the Day of Eight Billion, as the UN has named it, but they do agree on one thing. Although the human population has grown rapidly, that growth is slowing — and, within a few decades, Earth’s population will begin to shrink.

“It is a crude approximation that is more of a symbolic finding,” says Patrick Gerland, who leads demographic work at the UN Population Division in New York City. “We may have passed it, or it may be a little later, but it’s around this time that humanity is reaching 8 billion.”