-- The author is a Reuters Breakingviews columnist. The opinions expressed are his own --
By Martin Hutchinson
WASHINGTON (Reuters Breakingviews) - There may be 10 billion mouths to feed within a few generations. The United Nations sees the world's population hitting that landmark by 2100. Without efforts to change the pattern, the poorest countries will face the worst effects of the demographic drain.
Compared with its last effort two years ago, the new U.N. forecast both increases population projections and delays the date by which the global population will peak and begin to decline. Previously this was expected around 2070; the latest shows the population still increasing in 2100.
It's a dystopian prospect. Even allowing for humanity's undoubted ingenuity, that kind of population would surely strain the planet's resources and ecosystem severely, especially if growing numbers achieve developed-world living standards with the cars, flushing toilets and air conditioning that entails.
Also, the great majority of the projected population increase comes in the poorest countries, where clean water, food and other resources are already hard to come by -- to say nothing of transport and other infrastructure. The projected number of people in Africa by 2100 is 3.6 billion, over a third of the global total, while Nigeria's expected population is 730 million, up from some 155 million today and 39 million in 1960.
History has shown that rapid rates of population growth can thwart economic takeoff as the need for housing, education and infrastructure overwhelms the limited capital available. So Nigeria's population in 2100, for example, could be still poorer than today's. While the U.N. numbers are highly sensitive to small changes in assumptions, the latest forecast underlines the need to take demographic trends seriously. The economic implications aside, a growing population also implies more pollution and potentially accelerating global warming.
China's controversial one-child policy has helped put its population on track to fall by a third to 941 million in 2100, according to the U.N. forecast. But that has come at high social cost. More palatable ways to bring birth rates down include increased expenditure on education, particularly for girls. Richer countries might even consider funding old age pension schemes in very poor economies, reducing the incentive for large families. If that avoided the world's ever welcoming its 10 billionth resident, it would be money well spent.
-- The United Nations released its biennial revision of its "World Population Prospects" on May 3, extending its forecasts to 2100. The U.N. report estimates that the global population will be 10.1 billion in 2100 and will still be increasing. Its forecast of the population in 2050 was revised upwards by 156 million to 9.3 billion.
-- By 2100, Africa's population is forecast to increase by 350 percent to 3.6 billion, of which Nigeria will represent 730 million, and Zambia 140 million.
Editing by Richard Beales and Martin Langfield