World population

World population is the total number of people living on Earth at a given time. The figure is estimated by compiling national census data, birth and death records, and household surveys. In 2022, the United Nations announced that the total had reached 8 billion.

Changes in population depend on three factors: birth rate, death rate, and migration (which affects different regions but does not change the global total). When births exceed deaths, the population grows.

History of growth

For much of human history, population growth was slow, constrained by high mortality rates, particularly among children and from widespread disease. Industrialization, advances in healthcare, access to clean water, and vaccination reduced death rates, leading to rapid growth in the nineteenth and twentieth centuries. The first billion was reached around the mid-nineteenth century, while the seventh billion was reached in 2011.

Regional distribution

Asia holds the largest share of the world's population, with China and India alone accounting for roughly one-third. Africa has the fastest growth rate, and its share of the global population is expected to increase this century. Europe and parts of eastern Asia have low birth rates and aging populations.

Future projections

Projections from major international agencies suggest that growth rates will continue to decline, as birth rates fall in most countries. Standard estimates indicate the population could reach around 10 billion in the middle of this century, after which it may stabilize or decline. These projections depend on assumptions about fertility, which can change.