This report presents the highlights of the results of the 2010 Revision of the official United Nations population estimates and projections prepared by the Population Division of the Department of Economic and Social Affairs of the United Nations Secretariat. The 2010 Revision constitutes the twenty second round of the global population estimates and projections produced by the Population Division since 1951.

The 2010 Revision is the twenty second round of official United Nations population estimates and projections prepared by the Population Division of the Department of Economic and Social Affairs of the United Nations Secretariat. These are used throughout the United Nations system as the basis for activities requiring population information. The 2010 Revision builds on the 2008 Revision and incorporates the results of the 2000 and 2010 round of national population censuses as well as of recent specialized surveys carried around the world. These sources provide both demographic and other information to assess the progress made in achieving the internationally agreed development goals, including the Millennium Development Goals (MDGs). The comprehensive review of past worldwide demographic trends and future prospects presented in the 2010 Revision provides the population basis for the assessment of those goals.

On 1 July 2011, the world population reached more than 6.9 billion with 5.7 billion (or 82 per cent of the world’s total) living in the less developed regions (table I.1). Out of these, 851 million reside in the 48 least developed countries and account for 12.2 per cent of the world population. More developed countries, whose total population amounts to 1.2 billion inhabitants, account for 17.8 per cent of the world population (table I.2).

According to the 2010 Revision, total fertility—that is, the average number of children a woman would bear if fertility rates remained unchanged during her lifetime—is 2.52 children per woman in 2005-2010 at the world level (table II.1). This average masks the heterogeneity of fertility levels among countries and regions (figure 2). In 2005-2010, 75 countries or areas (44 of them located in the more developed regions) have fertility levels below 2.1 children per woman, that is, below replacement level1, whereas 121 countries or areas (all of which are located in the less developed regions) have total fertility levels at or above 2.1 children per woman. Among these 121 countries, 26 have total fertility levels at or above 5 children per woman, 25 of which are least developed countries (table II.2).

The twentieth century witnessed the most rapid decline in mortality in human history. In 1950-1955, life expectancy at the world level was 48 years and it had reached 68 years by 2005-2010. Over the next 45 years, life expectancy at birth at the global level is expected to reach 76 years in 2045-2050 and 81 years in 2095-2100 (table III.1). The more developed regions already had a high expectation of life in 1950-1955 (66 years) and have since experienced further gains in longevity. By 2005-2010 their life expectancy stood at 76.9 years, 11 years higher than in the less developed regions where the expectation of life at birth was 65.9 years. Although the gap between the two groups is expected to narrow between 2005 and mid-century, in 2045-2050 the more developed regions are still expected to have considerably higher life expectancy at birth than the less developed regions (82.7 years versus 74.4 years). Throughout 2010-2100, systematic progress against mortality is further expected to increase life expectancy at birth up to 88.2 years in the more developed regions and 80.1 years in the less developed regions thereby further reducing the gap in mortality between the two groups.

Estimates of net migration between the major development groups show that since 1960 the more developed regions have been net gainers of emigrants from the less developed regions (table IV.1). Furthermore, net migration to the more developed regions has been increasing steadily from 1960 to 2010. During 2000-2010, the more developed regions were gaining annually 3.4 million migrants. About 39% of that net flow was directed to Northern America (1.33 million annually). During 2000-2010, the level of net migration to the more developed regions as a whole changes moderately, reaching a peak of 3.4 million migrants annually. Over the rest of the projection period, net migration to the more developed regions is projected to decline smoothly to about 1.9 million per year during 2040-2050, of which 1.1 million are directed to Northern America.

The preparation of each new revision of the official population estimates and projections of the United Nations involves two distinct processes: (a) the incorporation of all new and relevant information regarding the past demographic dynamics of the population of each country or area of the world; and (b) the formulation of detailed assumptions about the future paths of fertility, mortality and international migration. The data sources used and the methods applied in revising past estimates of demographic indicators (i.e., those referring to 1950-2010) are presented online1 and in an Excel file (WPP2010_F02_METAINFO.XLS).