The rising numbers of humankind.
Population and Societies
n° 394, October 2003
For a very long time, humankind comprised just a few hundred thousand individuals at most, and it was not until thirty to forty thousand years ago— almost yesterday in human history—that the population passed the one million mark. It has continued to grow since, reaching a billion in about 1800, and six billion in 1999 (figure 1). But how exactly did it get there?