The different trends of population growth in the world from an early period to the present day are as follows:
- In the early periods of history i.e., 8000 to 12000 years ago the populations grow at a slow rate. The population of the era was8 million.
- The count of the population in the first century was below 300 million.
- By 1600 AD world population increased to 0.5 billion as expansion in trade and industrial revolution increased settlements.
- World population touched 1 billion in 1830 due to advancement in the field of science and technology.
- In the next 100 years i.e. 1930, the population doubled to 2 billion due to improved medical, health and sanitation facilities.
- In 1960, the population was 3 billion, in 1975, it was 4 billion after that one billion is added in every 12 years.
- There is a great variation among regions in doubling their population.