It took 200,000 years for human population to reach one billion. The next billion took 130 years. The latest took just 12 years. We are living through the steepest demographic curve in our species' history.
A person born in 1970 has watched the world add more humans than existed at the start of the Industrial Revolution. The acceleration is slowing — but the absolute numbers are unprecedented.
Global fertility has fallen from 5.0 to 2.2 children per woman since 1960. By the 2080s, the human population is projected to peak — possibly for the first time since the Black Death.
Nearly all population growth from now to 2100 will come from sub-Saharan Africa. Nigeria alone will pass the United States in population before 2050.
Japan, Italy, South Korea, and a growing number of countries have already crossed peak working-age population. By 2050, a quarter of all Europeans will be over 65.