Will there be space for everyone in 2050?
The world population is projected to exceed nine billion in 2050, up from 6.8 billion this year and seven billion early in 2012, according to United Nations estimates released on Wednesday.
Most of the additional 2.3 billion people will swell the population of the developing world, estimated to soar from 5.6 billion this year to 7.9 billion in 2050, and to spread among the 15-59 age group (1.2 billion) and those 60 or over (1.1 billion), the data showed.
The 2008 Revision of the official UN populations projections forecast minimal change in the population of the more developed nations, which should rise from 1.23 billion to 1.28 billion during the same period.
That population would have in fact dipped to 1.15 billion without the projected net migration from developing to developed countries, expected to average 2.4 million persons annually from 2009 to 2050, it noted.
In 2005-2010, net migration in eight countries or areas more than doubled the contribution of natural increase (births minus deaths) to population growth: Belgium, Macau, Czech Republic, Luxembourg, Qatar, Singapore, Slovenia and Spain.
During the 2010-2050 period, major net receivers of foreign migrants are projected to be the United States (1.1 million annually), Canada (214 000), Britain (174 000), Spain (170 000), Italy (159 000), Germany (110 000) Australia (100 000) and France (100 000).
Major countries of net emigration are expected to be Mexico (334 000 annually), China (309 000), India (253 000), the Philippines (175 000) and Pakistan (161 000).
The population of the 49 least developed nations is meanwhile slated to double from 0.84 billion this year to 1.7 billion in 2050. Growth in the rest of the Third World is estimated to be robust, but less rapid, with its population increasing from 4.8 billion to 6.2 billion between now and 2050.
Future growth would depend on the future direction of fertility rates, with fertility declines from 2.56 children per woman in 2005-2010 to 2.02 children per woman in 2045-2050, according to the most probable scenario.
The data, prepared by the Population Division of the UN Department of Economic and Social Affairs, however show that slowing population growth resulting from reductions in fertility leads to population ageing.
In the more developed countries, 22 percent of people are already 60 and over and that proportion is expected to reach 33 percent in 2050. By then, the number of older persons in the developed world is expected to be more than twice that of children.
By contrast, just nine percent of the population of developing countries today is aged 60 or over but the proportion will more than double by 2050 to reach 20 percent.
The study incorporates findings of the most up-to-date national population censuses and of several specialised population surveys conducted around the world.
Most of the additional 2.3 billion people will swell the population of the developing world, estimated to soar from 5.6 billion this year to 7.9 billion in 2050, and to spread among the 15-59 age group (1.2 billion) and those 60 or over (1.1 billion), the data showed.
The 2008 Revision of the official UN populations projections forecast minimal change in the population of the more developed nations, which should rise from 1.23 billion to 1.28 billion during the same period.
That population would have in fact dipped to 1.15 billion without the projected net migration from developing to developed countries, expected to average 2.4 million persons annually from 2009 to 2050, it noted.
In 2005-2010, net migration in eight countries or areas more than doubled the contribution of natural increase (births minus deaths) to population growth: Belgium, Macau, Czech Republic, Luxembourg, Qatar, Singapore, Slovenia and Spain.
During the 2010-2050 period, major net receivers of foreign migrants are projected to be the United States (1.1 million annually), Canada (214 000), Britain (174 000), Spain (170 000), Italy (159 000), Germany (110 000) Australia (100 000) and France (100 000).
Major countries of net emigration are expected to be Mexico (334 000 annually), China (309 000), India (253 000), the Philippines (175 000) and Pakistan (161 000).
The population of the 49 least developed nations is meanwhile slated to double from 0.84 billion this year to 1.7 billion in 2050. Growth in the rest of the Third World is estimated to be robust, but less rapid, with its population increasing from 4.8 billion to 6.2 billion between now and 2050.
Future growth would depend on the future direction of fertility rates, with fertility declines from 2.56 children per woman in 2005-2010 to 2.02 children per woman in 2045-2050, according to the most probable scenario.
The data, prepared by the Population Division of the UN Department of Economic and Social Affairs, however show that slowing population growth resulting from reductions in fertility leads to population ageing.
In the more developed countries, 22 percent of people are already 60 and over and that proportion is expected to reach 33 percent in 2050. By then, the number of older persons in the developed world is expected to be more than twice that of children.
By contrast, just nine percent of the population of developing countries today is aged 60 or over but the proportion will more than double by 2050 to reach 20 percent.
The study incorporates findings of the most up-to-date national population censuses and of several specialised population surveys conducted around the world.