The world’s population is more than three times larger than it was in the mid-twentieth century. On November 15, 2022, the world’s population reached 8 billion people up from an estimated 2.5 billion people in 1950, adding 1 billion people since 2010, and 2 billion since 1998.
This dramatic growth has been driven largely by increasing numbers of people surviving to reproductive age, the gradual increase in human lifespan, increasing urbanization, and accelerating migration. Major changes in fertility rate have accompanied this growth. These trends will have far-reaching implications for generations to come.
While it took the global population 12 years to grow from 7 to 8 billion, it will take approximately 15 years—until 2037—for it to reach 9 billion, a sign that the overall growth rate of the global population is slowing. Yet levels of fertility remain high in some countries. Countries with the highest fertility levels tend to be those with the lowest income per capita. Global population growth has therefore over time become increasingly concentrated among the world’s poorest countries, most of which are in sub-Saharan Africa.
China (1.4 billion) and India (1.4 billion) remain the two most populous countries of the world, each representing nearly 18% of the world’s population. However, in April 2023, India’s population surpassed the population of mainland China. India’s population is expected to keep growing for several decades. Meanwhile, China’s population recently reached its maximum size and has shown a decline since 2022. According to projections, the number of people in China will continue to decrease and may fall below 1 billion before the end of the century.
The world population is projected to reach 9.7 billion in 2050, and 10.4 billion by 2100. As with any type of projection, there is a degree of uncertainty surrounding these latest population projections. Survival prospects are also projected to improve in all countries.
More than half of global population growth between now and 2050 is expected to occur in Africa. The population of sub-Saharan Africa is projected to double by 2050. A rapid population increase in Africa is anticipated even if there is a substantial reduction of fertility levels in the near future. Regardless of the uncertainty surrounding future trends in fertility in Africa, the large number of young people currently on the continent, who will reach adulthood in the coming years and have children of their own, ensures that the region will play a central role in shaping the size and distribution of the world’s population over the coming decades.
In sharp contrast, the populations of 61 countries, largely in Europe, are expected to decrease by 2050, of which 26 may see a reduction of at least 10%. Several countries are expected to see their populations decline by more than 15% by 2050, including Bosnia and Herzegovina, Bulgaria, Croatia, Hungary, Japan, Latvia, Lithuania, Republic of Moldova, Romania, Serbia, and Ukraine. Fertility in all European countries is now below the level required for full replacement of the population in the long run (around 2.1 children per woman). 74% of the earth’s population reside in countries where fertility is around or below this replacement level.
International migration is a much smaller component of population change than births or deaths. However, in some countries the impact of migration on population size is significant, namely in countries that send or receive large numbers of economic migrants and those affected by refugee flows. Between 2010 and 2021, seventeen countries saw a net inflow of more than one million migrants, while ten countries will see a net outflow of similar magnitude.
