Human population estimates over time

Estimated global human population, in millions:

70,000 BC	< 1
10,000 BC	1
9000 BC	3
8000 BC	5
7000 BC	7
6000 BC	10
5000 BC	15
4000 BC	20
3000 BC	25
2000 BC	35
1000 BC	50
1	200
1000	310
2000	6,070

According to the Toba catastrophe theory, a huge volcanic eruption in Sumatra around 70,000 BC caused an ice age which all but wiped out humans outwith Africa. The human population dropped to between 5,000 and 10,000, and the process of recolonising Eurasia had to begin again.