Monday, June 8, 2009

U.N.: Young and Old Boom on the Road to 9 Billion

By Andrew C. Revkin, New York Times, March 11, 2009

The United Nations Population Division has updated its population forecasts through 2050, and concludes that, despite a longstanding global decline in fertility rates, the world is still on a path to exceed 9 billion people by mid-century, with the vast majority of the increase coming in the world’s poorest countries.

In those countries, large proportions of the population are children or teenagers, who could contribute either to a large workforce and economic gains or — in the absence of education and jobs — to instability and conflict.

The other fast-growing group around the globe is the oldest segment of the populations, according to the United Nations — and that trend also can pose challenges, particularly in the absence of a large working-age population.

Three factors have nudged population projections upward over the past decade, Hania Zlotnik, the director of the population division, said in an interview: lengthening lifespans; the success of HIV/AIDS treatment and prevention efforts, particularly in Africa; and “a slower than expected decline in fertility” (meaning the number of children a woman bears).

Staff members at the population division warned in interviews that the updated projection for 2050 is premised on continuing declines in the fertility rate, but those declines are no longer a safe bet. The demand for reproductive information and contraceptives still exceeds the supply in dozens of developing countries, according to the report and separate assessments by other population groups — meaning that tens of millions of women are probably having larger families than they want.

Conditions that keep girls out of school, ranging from a lack of toilets to the demand for their labor gathering firewood and water, also contribute to elevated birth rates.

Some milestones have been passed in the report, U.N. officials said. India now has a higher population density than Japan. Africa’s total population has topped 1 billion for the first time.

The report contained hints that 9 billion is the new floor for population by 2050, instead of a best guess.

The importance of sustaining a decline in fertility by increasing access to family planning was stressed in the report summary:

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.

Officials at the U.N. Population Fund, which supports family planning programs around the world, said the new projections illustrated the importance of rich countries continuing to help poorer ones to ensure that couples have no more children than they want.

The population division’s country-by-country data on population trends can be sifted and explored online. The United States, whose population is growing faster than most other wealthy countries, has just over 300 million people now and will probably top 400 million by 2050. The report projects that the United States will, on average, gain 1.1 million people a year from 2010 to 2050 through immigration, nearly five times as many immigrants as Canada, which has the second highest inward immigration flow.

Given that Americans, per person, produce many times more carbon dioxide emissions than people in developing countries (at least for a few more decades), the growth in the United States has added significance for climate projections, said Leiwen Jiang, senior demographer at Population Action International, a nonprofit research group.