Population trends



It took hundreds of thousands of years for the world population to grow to 1 billion, and in just another 200 years or so it grew sevenfold. In 2011, the global population reached the 7 billion mark, and it is projected to climb to over 9 billion by 2050.



Source: Estimates and UN Population Division: World Population Prospects: The 2012 Revision, online

Population prospects

The UN has developed three population projections, called variants – one high, one low, and one in between. Of these, the medium variant suggests that the world population will grow to about 10 billion by the middle of this century, and will level off at about 11 billion by the end of it. However, if fertility declines by less than assumed, the world population could grow to about 17 billion by the end of the century. If fertility falls by more than assumed, the world population could slightly fall over current levels to about 7 billion.

The UN publishes its population projections every two years, and over the past decades, the medium variant of the projections has often been corrected upward, meaning the population has grown more quickly than expected. The most recent upward correction was due to a slower fertility decline than anticipated in countries in sub-Saharan Africa and South Asia, as well as higher-than-expected levels of fertility in large and populous countries of Asia.


The recent past has seen enormous changes in fertility rates and life expectancy. In the early 1970s, women had on average 4.5 children each; by 2014, total fertility for the world had fallen to around 2.5 children per woman. Meanwhile, average global lifespans have risen, from 64.8 years in the early 1990s to 70.0 years today.



Why is the population growing so quickly?



A varied landscape

General population trends mask considerable differences between countries. On the one side stand the world’s least developed countries, which continue to have high fertility levels. According to conservative projections, the population of the world’s least developed countries will double by 2050, and in some countries it will even triple. On the other side are high-income and rising-income countries, which are experiencing slow population growth or no population growth at all. Whereas the former continue to have large, growing, populations of young people, the latter have large, growing populations of older persons. (There are some countries experiencing a decline in population size. However, in most cases this is not only the result of low fertility, but also the result of high mortality and emigration due to weak and deteriorating economic, social and political conditions.)



Human rights



What UNFPA is doing?
