World population and the modern demographic situation

World population grew slowly for a long time because both births and deaths were high. It reached about 1 billion in the early 19th century, and after the middle of the 20th century growth accelerated sharply: 3 billion in the 1960s, 7 billion in 2011 and 8 billion in 2022; it is now roughly 8.2 billion. Such a sharp rise is called the demographic explosion; its cause is falling death rates thanks to better medicine and living standards. Natural increase = birth rate − death rate (per 1000 people, ‰). By demographic transition theory a society passes through four stages: 1) births and deaths high, growth low; 2) deaths fall sharply, explosion; 3) births begin to fall; 4) births and deaths low, growth minimal. In developed countries growth is very low and in some places population is shrinking; in Africa birth rates and growth remain high. States carry out demographic policy: measures to slow or raise growth.