The current world population of 7.2 billion is projected to increase by almost one billion people within the next twelve years, reaching 8.1 billion in 2025 and 9.6 billion in 2050, according to a new United Nations report, World Population Prospects: The 2012 Revision.
Nigeria is expected to have about 400 million people in 2050 and 914 million people in 2100 in the medium scenario.
Most results presented are based on the UN’s “medium-variant” projection, which assumes a substantial reduction in the fertility levels of intermediate- and high-fertility countries in the coming years. For these countries, it is assumed that the pace of future fertility decline will be similar to that observed for other countries, mostly in Asia and Latin America, when they underwent similar declines during the second half of the 20 th century.
“The actual pace of fertility decline in many African countries could be faster or slower than suggested by this historical experience ,” Mr. Wilmoth said. “Small differences in the trajectory of fertility over the next few decades could have major consequences for population size, structure and distribution in the long run.”
The “high-variant” projection, for example, which assumes an extra half of a child per woman (on average) than the medium variant, implies a world population of 10.9 billion in 2050. The “low-variant” projection, where women, on average, have half a child less than under the medium variant, would produce a population of 8.3 billion in 2050.
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