World population is expected to increase by 2.6 billion over the next 45 years, from 6.5 billion today to 9.1 billion in 2050.
Almost all growth will take place in the less developed regions, where today’s 5.3 billion population is expected to swell to 7.8 billion in 2050. By contrast, the population of the more developed regions will remain mostly unchanged, at 1.2 billion.
These figures are from the 2004 Revision of the official United Nations population estimates and projections, released today by the Population Division of the Department of Economic and Social Affairs. The report provides crucial demographic information and population figures for the coming assessment of progress made towards achieving the Millennium Development Goals.
Other key findings of the 2004 Revision, which is based on the most recent national censuses, numerous specialized population surveys, and comprehensive review of past worldwide population trends and future prospects, include:
— By July 2005, the world will have 6.5 billion inhabitants, 380 million more than in 2000 or a gain of 76 million annually. Despite the lower fertility levels projected, by 2050 the world population is expected to reach 9.1 billion according to the medium variant and would still be adding 34 million persons annually by mid-century.
— Future population growth is highly dependent on the path that future fertility takes. In the medium variant, fertility declines from 2.6 children per woman today to slightly over 2 children per woman in 2050. If fertility were to remain about half a child above the levels projected in the medium variant, world population would reach 10.6 billion by 2050. A fertility path half a child below the medium would lead to a population of 7.7 billion by mid-century. That is, at the world level, continued population growth until 2050 is inevitable even if the decline of fertility accelerates.
— Because of its low and declining rate of population growth, the population of developed countries as a whole is expected to remain virtually unchanged between 2005 and 2050, at about 1.2 billion. In contrast, the population of the 50 least developed countries is projected to more than double, passing from 0.8 billion in 2005 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 4.5 billion to 6.1 billion between 2005 and 2050.
— Very rapid population growth is expected to prevail in a number of developing countries, the majority of which are least developed. Between 2005 and 2050, the population is projected to at least triple in Afghanistan, Burkina Faso, Burundi, Chad, Congo, Democratic Republic of the Congo, Timor-Leste, Guinea-Bissau, Liberia, Mali, Niger and Uganda.
— The population of 51 countries or areas, including
— During 2005-2050, eight countries are expected to account for half of the world’s projected population increase:
— In 2000-2005, fertility at the world level stood at 2.65 children per woman, about half the level it had in 1950-1955 (5 children per women). In the medium variant, global fertility is projected to decline further to 2.05 children per woman.
— Average world levels result from different trends by major development group. In developed countries as a whole, fertility is currently 1.56 children per woman and is projected to increase slowly to 1.84 children per woman in 2045-2050. In the least developed countries, fertility is 5 children per woman and is expected to drop by about half, to 2.57 children per woman by 2045-2050. In the rest of the developing world, fertility is already moderately low at 2.58 children per woman and is expected to decline further to 1.92 children per woman by mid-century, thus nearly converging to the fertility levels by then typical of the developed world.