NEW YORK (UN Population Division/DESA) ­ World population is projected to reach 7 billion early in 2012, up from the current 6.8 billion, and surpass 9 billion people by 2050, reveals the 2008 Revision of the official United Nations population estimates and projections, released today.

Ethiopia population count
1950: 18,434,000
2009: 82,825,000
2015: 96,237,000
2025: 119,822,000
2050: 173,811,000
(Source: DESA)

Click here for detailed figures.

Most of the additional 2.3 billion people will enlarge the population of developing countries, which is projected to rise from 5.6 billion in 2009 to 7.9 billion in 2050, and will be distributed among the population aged 15-59 (1.2 billion) and 60 or over (1.1 billion) because the number of children under age 15 in developing countries will decrease.

In contrast, the population of the more developed regions is expected to change minimally, passing from 1.23 billion to 1.28 billion, and would have declined to 1.15 billion were it not for the projected net migration from developing to developed countries, which is projected to average 2.4 million persons annually from 2009 to 2050.

The results of the 2008 Revision incorporate the findings of the most recent national population censuses and of numerous specialized population surveys carried out around the world. The 2008 Revision provides the demographic data and indicators to assess trends at the global, regional and national levels and to calculate many other key indicators commonly used by the United Nations system.

Population in developing countries still young

Currently the population of the less developed regions is still young, with children under age 15 accounting with 29 per cent of the population and young persons aged 15 to 24 accounting for a further 19 per cent. In fact, the numbers of children and young people in the less developed regions are at an all time high (1.7 billion children and 1.1 billion young people), posing a major challenge for their countries, which are faced with the necessity of providing education or employment to large cohorts of children and youth even as the current economic and financial crisis unfolds. The situation in the least developed countries is even more pressing because children under 15 constitute 40 per cent of their population and young people account for a further 20 per cent.

In the more developed regions, children and youth account for just 17 per cent and 13 per cent of the population, respectively, and whereas the number of children is expected to change little in background image the future, remaining close to 200 million, the number of young people is projected to decrease from 160 million currently to 134 million in 2050.

In both the more and the less developed regions, the number of people in the main working ages, 25 to 59, is at an all time high: 605 million and 2.5 billion, respectively. Yet, whereas in the more developed regions that number is expected to peak over the next decade and stagnate thereafter, in the less developed regions it will continue rising, reaching 3.6 billion in 2050 and increasing by nearly half a billion over the next decade. These population trends justify the urgency of supporting employment creation in developing countries as part of any strategy to address the global economic crisis that the world is experiencing.

Globally, population aged 60 or over is the fastest growing

Furthermore, the implications of population ageing cannot be dismissed. In the more developed regions, the population aged 60 or over is increasing at the fastest pace ever (growing at 1.9 per cent annually) and is expected to increase by more than 50 per cent over the next four decades, rising from 264 million in 2009 to 416 million in 2050. Compared with the more developed world, the population of the less developed regions is ageing rapidly. Over the next two decades, the population aged 60 or over in the developing world is projected to increase at rates far surpassing 3 per cent per year and its numbers are expected to rise from 475 million in 2009 to 1.6 billion in 2050.

Projected trends are contingent on fertility declines in developing countries

Population ageing results mainly from declining fertility. According to the 2008 Revision, fertility in the less developed regions as a whole is expected to drop from 2.73 children per woman in 2005-2010 to 2.05 in 2045-2050. The reduction projected for the group of 49 least developed countries is even steeper: from 4.39 children per woman to 2.41 children per woman. To achieve such reductions, it is essential that access to family planning expands, particularly in the least developed countries. Around 2005, the use of modern contraceptive methods in the least developed countries was a low 24 per cent among women of reproductive age who were married or in union and a further 23 per cent of those women had an unmet need for family planning. The urgency of realizing the projected reductions of fertility is brought into focus by considering that, if fertility were to remain constant at the levels estimated for 2005-2010, the population of the less developed regions would increase to 9.8 billion in 2050 instead of the 7.9 billion projected by assuming that fertility declines. That is, without further reductions of fertility, the world population could increase by nearly twice as much as currently expected.

Projected growth linked to sustained progress in HIV/AIDS prevention and treatment

The projected population trends also depend on achieving a major increase in the proportion of AIDS patients who get anti-retroviral therapy to treat the disease and on the success of efforts to control the further spread of HIV.

In the 2008 Revision, the impact of the epidemic was modeled in 58 countries where adult HIV prevalence reached 1 per cent or higher at some point during 1980-2007 or where the number of people living with HIV/AIDS was at least half a million in 2007. Among those 58 countries, 38 are in Africa and 15 had an adult HIV prevalence of at least 5 per cent in 2007.

The 2006 Revision modeled the impact of HIV/AIDS in 62 affected countries, five of which have been dropped from the list of affected countries in the 2008 Revision because their HIV prevalence was revised downward (Gambia, Madagascar, Moldova, Myanmar and Niger) and one background image has been added (Mauritius). In projecting the effect of the disease, it has been assumed that 26 of the affected countries will manage to provide by 2015 anti-retroviral treatment to 70 per cent or more of the persons suffering from AIDS and that another nine will reach treatment levels ranging from 50 per cent to 60 per cent by 2015. In the rest of the affected countries, treatment levels are expected to be lower, reaching between 40 per cent and 50 per cent by 2015. It is further assumed that persons receiving treatment survive, on average, 27.8 years instead of the 11.7 years expected in the absence of treatment.

These assumptions together with the generally lower prevalence levels estimated for recent years lead to an estimated 30 million fewer deaths during 2005-2020 than were projected in the 2006 Revision for the 58 countries concerned. However, the realization of these new projections depends on sustained funding for HIV/AIDS prevention and treatment programmes in the affected countries, funding that is highly dependent on the commitment of donor countries and needs to be maintained despite the global economic downturn.

The full results of the 2008 Revision will be issued in a series of three volumes and a wall chart that are currently under preparation. Data on particular countries can also be accessed online at the website of the Population Division (www.unpopulation.org).

For further information on the 2008 Revision, please contact Ms. Hania Zlotnik, Director, Population Division, New York, NY 10017, USA, (Tel: (212) 963-3179, Fax: (212) 963-2147).

2008 Revision of World Population Prospects
Key Findings

1. In July 2009, the world population will reach 6.8 billion, 313 million more than in 2005 or a gain of 78 million persons annually. Assuming that fertility levels continue to decline, the world population is expected to reach 9.1 billion in 2050 and to be increasing by about 33 million persons annually at that time, according to the medium variant.

2. Future population growth is highly dependent on the path that future fertility takes. In the medium variant, fertility declines from 2.56 children per woman in 2005-2010 to 2.02 children per woman in 2045-2050. If fertility were to remain about half a child above the levels projected in the medium variant, world population would reach 10.5 billion by 2050. A fertility path half a child below the medium would lead to a population of 8 billion by mid-century. Consequently, population growth until 2050 is inevitable even if
the decline of fertility accelerates.

3. In the more developed regions, fertility has increased slightly in recent years so that its estimated level in 2005-2010, 1.64 children per woman, according to the 2008 Revision is higher than the one reported in the 2006 Revision (1.60 children per woman). As a result of the slightly higher projected fertility and a sustained net in-migration averaging 2.4 million annually, the population of the more developed regions is expected to increase slightly from 1.23 billion in 2009 to 1.28 billion in 2050.

4. The population of the 49 least developed countries is still the fastest growing in the world, at 2.3 per cent per year. Although its rate of increase is expected to moderate significantly over the next decades, the population of the least developed countries is projected to double, passing from 0.84 billion in 2009 to 1.7 billion in 2050. Growth in the rest of the developing world is also projected to be robust, though less rapid, with its population rising from 4.8 billion to 6.2 billion between 2009 and 2050 according to the medium variant.

5. Slow population growth brought about by reductions in fertility leads to population ageing, that is, it produces populations where the proportion of older persons increases while that of younger persons decreases. In the more developed regions, 22 per cent of population is already aged 60 years or over and that proportion is projected to reach 33 per cent in 2050. In developed countries as a whole, the number of older persons has already surpassed the number of children (persons under age 15), and by 2050 the number of older persons in developed countries will be more than twice the number of children.

6. Population ageing is less advanced in developing countries. Nevertheless, the populations of a majority of them are poised to enter a period of rapid population ageing. In developing countries as a whole, just 9 per cent of the population is today aged 60 years or over but that proportion will more than double by 2050, reaching 20 per cent that year.

7. Globally, the number of persons aged 60 or over is expected almost to triple, increasing from 739 million in 2009 to 2 billion by 2050. Furthermore, already 65 per cent of the background image world’s older persons live in the less developed regions and by 2050, 79 per cent will do so.

8. In ageing populations, the numbers of persons with older ages grow faster the higher the age range considered. Thus, whereas the number of persons aged 60 or over is expected to triple, that of persons aged 80 or over (the oldest-old) is projected to increase four-fold, to reach 395 million in 2050. Today, just about half of the oldest-old live in developing countries but that share is expected to reach 69 per cent in 2050.

9. Although the population of all countries is expected to age over the foreseeable future, the population will remain relatively young in countries where fertility is still high, many of which are experiencing very rapid population growth. High population growth rates prevail in many developing countries, most of which are least developed. Between 2010 and 2050, the populations of 31 countries, the majority of which are least developed, will double or more. Among them, the populations of Afghanistan, Burkina Faso, Niger, Somalia, Timor-Leste and Uganda are projected to increase by 150 per cent or more.

10. In sharp contrast, the populations of 45 countries or areas are expected to decrease between 2010 and 2050. These countries include Belarus, Bosnia-Herzegovina, Bulgaria, Croatia, Cuba, Georgia, Germany, Hungary, Japan, Latvia, Lithuania, Moldova, Poland, the Republic of Korea, Romania, the Russian Federation and Ukraine, all of which are expected to see their populations decline by at least 10 per cent by 2050.

11. Population growth remains concentrated in the populous countries. During 2010-2050, nine countries are expected to account for half of the world’s projected population increase: India, Pakistan, Nigeria, Ethiopia, the United States of America, the Democratic Republic of Congo, the United Republic of Tanzania, China and Bangladesh, listed according to the size of their contribution to global population growth.

12. Fertility has continued to fall in the vast majority of countries in the less developed regions. The number of developing countries with high fertility (5 children or more per woman) declined from 59 in 1990-1995 to 27 in 2005-2010, and their share of the world population dropped from 13 per cent to 9 per cent. Over the same period, the number of developing countries with fertility levels that do not ensure the replacement of the population increased from 15 to 38.

13. Most developed countries have had below-replacement fertility (below 2.1 children per woman) for two or three decades. Among the 45 developed countries with at least 100,000 inhabitants in 2009, 42 had below-replacement fertility in 1990-1995 and 44 did in 2005-2010. However, between the 2000-2005 and 2005-2010, 34 developed countries experienced slight increases in fertility. For the more developed regions as a whole, total fertility increased from 1.58 to 1.64 children per woman between those two periods. Yet, in 2005-2010, 25 developed countries, including Japan and most of the countries in Southern and Eastern Europe, still had fertility levels below 1.5 children per woman.

14. In 2005-2010, the 76 countries with below-replacement fertility accounted for 47 per cent of the world population. The most populous developing countries with below-replacement fertility are China, Brazil, Viet Nam, the Islamic Republic of Iran, Thailand and the Republic of Korea, in order of population size.

15. Globally, total fertility is expected to fall from 2.56 children per woman in 2005-2010 to 2.02 in 2045-2050 according to the medium variant. However, in the more developed regions, total fertility is projected to increase from 1.64 children per woman currently to 1.80 in 2045-2050. A major reduction of fertility is projected for the group of least developed countries (from 4.39 to 2.41 children per woman) and the fertility of the rest of the developing world is expected to drop from 2.46 children per woman currently to 1.93 in 2045-2050, thus nearly converging to the fertility levels by then typical of the developed world.

16. The median age, that is, the age that divides the population in two halves of equal size, is an indicator of population ageing. Globally, the median age is projected to increase from 29 to 38 years between 2009 and 2050. Europe has today the oldest population, with a median age of nearly 40 years, which is expected to reach 47 years in 2050.

17. The median age is higher in countries that have been experiencing low fertility for a long time. In 2010, 19 developed countries or areas are expected to have a median age of 40 years or higher, up from 11 in 2005. In addition, two developing countries, Hong Kong SAR China and Singapore, have also reached median ages above 40 years. The pervasiveness of population ageing will increase by 2050 when all 45 developed countries are projected to have median ages higher than 40 years and 43 developing countries will also have similarly high median ages. Whereas today about 7 per cent of the world population lives in countries where median ages are 40 years or higher, the equivalent proportion in 2050 is projected to be 43 per cent.

18. Countries where fertility remains high and has declined only moderately will experience the slowest population ageing. By 2050, slightly fewer than one in five countries is projected to have a median age under 30 years (37 countries). The youngest populations will be found among the least developed countries, eight of which are projected to have median ages below 25 years in 2050, including Afghanistan, Chad, Guinea-Bissau, Niger, Somalia, Uganda, United Republic of Tanzania and Zambia.

19. Increasing longevity also contributes to population ageing. Globally, life expectancy at birth is projected to rise from 68 years in 2005-2010 to 76 years in 2045-2050. In the more developed regions, the projected increase is from 77 years in 2005-2010 to 83 years inn 2045-2050, while in the less developed regions the increase is expected to be from 66 years currently to 74 years by mid-century.

20. Life expectancy remains low in the least developed countries, at just 56 years in 2005-2010, and although it is projected to reach 69 years in 2045-2050, realizing such increase is contingent on reducing the spread of HIV and combating successfully other infectious diseases. Similar challenges must be confronted if the projected increase of life expectancy in the rest of the developing countries, from under 68 years today to 76 years by mid-century, is to be achieved.

21. A major concern is that most developing countries are unlikely to meet the goal of reducing under-five mortality by two-thirds between 1990 and 2015, as called for in the Millennium Development Goals. According to the 2008 Revision, 134 of the 151 developing countries with more than 100,000 inhabitants in 2009 will not reach that goal. Furthermore, 59 developing countries, located mainly in sub-Saharan Africa or belonging to the group of least developed countries, are projected to have in 2015 an under-five mortality higher than 45 deaths per 1000, the less demanding target set by the Programme of Action of the International Conference on Population and Development.

22. Among the more developed regions, Eastern Europe has the lowest life expectancy and it has experienced reductions in life expectancy at birth since the late 1980s. In 2005-2010 life expectancy in the region increased somewhat but at 69.2 years was lower than it had been in 1965-1970 (69.6 years). Despite having recorded some recovery since the late 1990s, Moldova, the Russian Federation and Ukraine have currently the lowest life expectancies among developed countries (below 70 years).

23. Although the HIV/AIDS epidemic continues to be a major issue of concern in the global health agenda, adult HIV prevalence reached a peak over the past decade or so in at least two thirds of the 58 countries considered to be most affected by the epidemic and a growing number of them are reaching and maintaining lower prevalence levels. Nevertheless, in countries where prevalence has been high, the impact of the epidemic in terms of morbidity, mortality and slower population growth continues to be evident. Thus, in Southern Africa, the region with the highest prevalence of the disease, life expectancy has fallen from 61 years in 1990-1995 to 52 years in 2005-2010 and is only recently beginning to increase. Nevertheless, life expectancy in the region is not expected to recover the level it had in the early 1990s before 2045. As a consequence, the growth rate of the population in the region has plummeted, passing from 2.4 per cent annually in 1990-1995 to 0.6 per cent annually in 2005-2010 and is expected to continue declining for the foreseeable future.

24. Given the low fertility prevailing in developed countries, deaths are expected to exceed births over the foreseeable future. Consequently, the population of the more developed regions would be decreasing if the excess of deaths over births were not counterbalanced by a net migration gain. During 2010-2050, the net number of international migrants to more developed regions is projected to be 96 million, whereas the excess of deaths over births is 58 million, implying an overall growth of 38 million.

25. In 2005-2010, net migration in nine countries or areas more than doubled the contribution of natural increase (births minus deaths) to population growth: Belgium, Macao SAR China, Luxembourg, Malta, Qatar, Singapore, Slovakia, Slovenia and Spain. In addition, in a further 11 countries or areas, net migration counterbalanced totally or in part the excess of deaths over births. These countries are: Austria, the Channel Islands, Croatia, the Czech Republic, Germany, Greece, Hungary, Italy, Japan, Portugal and the Russian Federation.

26. In terms of annual averages, the major net receivers of international migrants during 2010-2050 are projected to be the United States (1.1 million annually), Canada (214,000), the United Kingdom (174,000), Spain (170,000), Italy (159,000), Germany (110,000), Australia (100,000) and France (100,000). The major countries of net emigration are projected to be Mexico (-334,000), China (-309,000 annually), India (-253,000), the Philippines (-175,000), Pakistan (-161,000), Indonesia (-156,000) and Bangladesh (-148,000). Although the current economic crisis may reduce migration flows in comparison to those registered over the recent past, the major economic and demographic asymmetries that will persist are likely to remain powerful generators of international migration over the medium-term future.