We are living in a world of unprecedented demographic change. After growing very slowly for most of human history, the world’s population more than doubled in the last half century to reach 6 billion in late 1999. By 2006 it had reached 6.7 billion. Lower mortality, longer life expectancy and a youthful population in countries where fertility remains high all contributed to the rapid population growh of recent decades.

According to the 2006 Revision, the world population is expected to rise in the next 43 years by 2.5 billion, to reach a total of 9.2 billion in 2050. The increase is equivalent to the total world population in 1950. Essentially all of the growth will take place in the less developed countries, and will be concentrated among the poorest populations in urban areas.

By contrast, the overall population of the more developed countries is likely to show little change over the next 43 years, remaining at about 1.2 billion. Fertility is below replacement level in all 45 developed countries or areas, as well as in 28 developing countries including China. The population of developed regions is ageing and would actually decline were it not for migration. The populations of Germany, Italy, Japan and most of the successor states of the former Soviet Union are expected to be lower in 2050 than they are today.

Projections Dependent on Continued Declines in Fertility

Fertility in the less developed countries as a whole is projected to decline from 2.75 children per woman in 2005-2010 to 2.05 in 2045-2050. The decline in the group of the 50 least developed countries is expected to be even sharper: from 4.63 children to 2.50 children per woman. However, realization of these projections is contingent on continued declines in fertility, even as funding for family planning has been declining.

Clearly, most people want and are having smaller families than in the past. This trend has been greatly helped by the wider availability of high quality, safe and affordable family planning services. Still, many people are having more children than they want to. Some 200 million women who would like to use contraceptives lack access to them.

Achieving the predicted projections will require expanded access to family planning, especially in the poorest countries. The urgency of this is clear: If fertility were to remain at current levels, the population of less developed regions would increase to 10.6 billion, instead of the 7.9 billion that is projected. Even if fertility rates are lower than projected, the large proportion of young people still makes population growth until 2050 virtually inevitable.

Accounting for the Toll of AIDS in Population Projections

The response to the AIDS epidemic, in terms of treatment and prevention, contributed to the fact that the most recent population projections are higher than the 2004 estimates. The 2006 projections assume that by 2015, 31 of the most affected countries will manage to provide treatment to 70 per cent or more of persons suffering from AIDS.  In the rest of the affected countries, treatment levels are expected to be lower.  Anticipated progress in treatment and prevention means that from 2005-2020, some 32 million fewer deaths are expected to occur in the most affected countries compared to projections from two years earlier.

Learn More:
	State of World Population 2007: Unleashing the Potential of Urbanization
	Family Planning: So that Every Child is Wanted
	The Impact of HIV/AIDS: A Population and Development Perspective
	A Passage to Hope:Women and International Migration
	Meeting the Challenge of Migration: Progress Since the ICPD
	Population Ageing and Development: Operational Challenges in Developing Countries
	Population Ageing and Development: Social, Health and Gender Issues