Demographic Transition
Death rates fall first and birth rates later: world population grows from about 1 billion (c. 1805) to 8 billion (15 November 2022) while births per woman drop from nearly 5 to 2.25.
Open in the interactive tree →In the late 18th century northwestern Europe saw death rates fall through better food, sanitation and public health while birth rates stayed high, so populations grew fast; birth rates fell later as cities grew, girls went to school and contraception spread. Warren Thompson described the pattern around 1930 and Frank Notestein formalised it in the 1940s and 1950s. Asia, Latin America and parts of Africa went through the same shift much faster in the 20th century: world growth peaked above 2% a year in the 1960s and was about 0.9% in 2023. The UN projects a peak of about 10.3 billion people in the mid-2080s.
Prerequisites
- Compulsory Schooling & Literacy1763Schooling, especially of girls, lowers the number of births.
- Vaccination1796Vaccination began the fall in child deaths.
- Sewers and Clean Water1858Clean water and sewers cut deaths from infectious disease.
Unlocks
- Aging SocietiesopenPopulation ageing is the late stage of the same shift to low birth and death rates.
- Feeding 10 Billion PeopleopenThe transition sets how many people must be fed: a UN peak near 10.3 billion.