Global population growth

Population pyramids show the structure of a population by comparing relative numbers of people in different age groups. Population structures differ markedly between LEDCs and MEDCs.

Demographic transition models show population change over time - and also show marked differences between LEDCs and MEDCs.

At present the world's population is growing quickly, though this has not always been the case.

  • Until the 1800s the world's population grew slowly for thousands of years.
  • In 1820 the world's population reached one billion.
  • In the early 1970s, the world's population reached three billion.
  • In 1999, less than 30 years later, the population doubled to six billion.
  • The global rate of population growth is now one billion every 15 years.

The graph shows this pattern of accelerating growth (including the predicted population for 2025).

Graph showing the growth of the global population