“The world’s human population is so large that the number of people alive today exceeds the number of people who died in the past!” Surely, you must have heard such claims. But how many of you have verified the truth behind such statements? Well, the Population Reference Bureau (PRB) do have estimates on it.
The number of people who ever lived is related to three factors:
- The duration of human existence
- The average number of people at different periods in history
- The birth rate during each period.
The duration of human existence
The assumption was made based on the current evidence that modern Homo sapiens appeared around 190,000 B.C.E., originated in Africa.
The average number of people
Available information/estimations about the world populations in different eras of human history are collected.
| YEAR | POPULATION |
| 190,000 B.C.E | 2 |
| 50,000 B.C.E. | 2,000,000 |
| 8000 B.C.E. | 5,000,000 |
| 1 C.E. | 300,000,000 |
| 1200 | 450,000,000 |
| 1650 | 500,000,000 |
| 1900 | 1,656,000,000 |
| 2000 | 6,149,000,000 |
| 2022 | 7,963,500,000 |
Birth rate (BR)
Humans’ average life expectancy (LE) has stayed at about 12 years for most of history. Twelve years translates to 1000/12 ~ 80 births per year per 1,000 population. The number has since improved to the present value of 17. This equation (BR = 1000/LE) works in a stable population.
Once the birthrates are available at the different periods, one can assume a stable population between intervals and estimate the births each year (in between those intervals) as
the number of years (between two periods) x BR x average population /1000
The estimated cumulative number of humans as of 2022 was 117,020,448,575. In other words, today’s world population of 7,963,500,000 (2022) is 6.8% of all homo sapiens ever lived.
Reference
How Many People Have Ever Lived on Earth?: prb.org
