Human Numbers Through Time

Publish Date: Topic: Physics + MathPhysics & MathNova

For most of humans' existence, our ancestors led precarious lives as scavengers, hunters, and gatherers, and there were fewer than 10 million people on Earth at any one time. Today, many cities have more than 10 million inhabitants each, and populations continue to skyrocket. Trace the dramatic growth of human populations over recent centuries on our global map, and see where on Earth as many as three billion more people may live by 2050.

Editor's Note:
The global map was adapted from World Population: A Graphic Simulation of the History of Human Population Growth, a 2003 video produced by Population Connection ( In the map, each dot represents one million people. In areas where populations are widely dispersed, dots are placed in the middle of an approximate range.

When areas become super-populated, as they begin to do in certain parts of the world in the 20th century, the dots merge and spread outward like a stain. As a result, some dots may appear in places that are not in reality densely inhabited; even countries or regions that appear "filled up" in later maps may still have sparsely populated regions.

Sources for the graph entitled "World Population Growth, 1800-2050," which appears at the end of the series, are the United Nations, World Population Prospects, The 2003 Revision, and estimates by the Population Reference Bureau (

Major funding for NOVA is provided by the David H. Koch Fund for Science, the NOVA Science Trust, the Corporation for Public Broadcasting, and PBS viewers.