Global population to pass 10 billion by 2100: UN

Posted: 9 May 2011

The world’s population is projected to surge past 9 billion before 2050 and then reach 10.1 billion by the end of the century if current fertility rates continue at expected levels, according to United Nations figures unveiled on 3 May.

Most of the increase will come from so-called “high fertility countries,” mainly in sub-Saharan Africa but also in some nations in Asia, Oceania and Latin America, the figures reveal.

The 2010 Revision of World Population Prospects , prepared by the Population Division at the UN’s Department of Economic and Social Affairs, shows that a small variation in fertility could lead to major long-term differences in the size of the global population.

Based on the medium projection, the number of people in the world – currently close to 7 billion – should pass 8 billion in 2023, 9 billion by 2041 and then 10 billion at some point after 2081.

Estimated and projected population by major area, medium variant , 1950-2100 (billions)
Asia will remain the most populous major area in the world during the 21st century but Africa will gain ground as its population more than triples, passing from 1 billion in 2011 to 3.6 billion in 2100. Source: 2010 Revision of World Population Prospects


But a small increase in fertility could mean a global population of as much as 15.8 billion by 2100, while a small decrease could result in an eventual overall decline in population to 6.2 billion by the end of the century.

Hania Zlotnik, Director of the Population Division, said that the populations of many countries are ageing and will continue to do so as their fertility rates decline.

The population of countries classed as low-fertility or intermediate-fertility – including China, Russia and many countries in Europe – would thus peak well before the end of the century.

Life expectancy is expected to rise across all categories of countries, particularly as better treatment for HIV/AIDS cuts early deaths in many sub-Saharan African countries. Global life expectancy is projected to increase from 68 years to 81 by the years 2095 to 2100.

Ms. Zlotnik noted also that the world population will probably reach 7 billion by October this year.

A group of women hold their newborns at a family planning clinic in Kampala, Uganda. Photo: 2001 Hugh Rigby/CCP, Courtesy of Photoshare
Family planning must have higher priority. Clinic in Kampala, Uganda.
© Hugh Rigby/CCP, Courtesy of Photoshare

Commenting on the reasons for the increase in UN projection figures in an interview with ScienceInsider, John Bongaart, a vice president of the Population Council, explained:

"It's both fertility being a little bit higher and mortality being a little lower. In the '90s some epidemiologists predicted that the population of Africa would decline because of AIDS. That has not happened. There have been a lot of deaths due to AIDS, but population momentum is so strong that we're going to have a billion more people in Africa by 2050 and 3.5 billion people in Africa by 2100.

"One reason that fertility is higher than expected is that African governments have neglected to invest in family planning programmes... There are exceptions. Kenya had a programme starting in the 1970s that did some good, but was underfunded in the last decade. A success story that is now being followed very closely is Rwanda. The Rwandan government in the last few years has made a major investment in health and in family planning, so that is bringing down the fertility rate. But most governments in Africa do almost nothing in family planning or very little."