U.N. Raises “Low” Population Projection for 2050  

WorldChanging reports that UN population modellers have increased their "low" estimate for global population in 2050 - thought the "most likely" estimate remains fixed at 9.2 billion people - U.N. Raises “Low” Population Projection for 2050.

The United Nations has raised its optimistic "low" estimate of world population growth due to an increase in childbirths in some industrialized nations.

In a biennial report released last week, the U.N. Population Division increased slightly a projection it uses to forecast the size of the human population. The "low-variant" scenario of population growth now foresees 117 million more people on the planet in 2050 than it did two years ago.

While the "median-variant" scenario, often seen as "most likely," remains almost the same as before - predicting a world with 9.2 billion people by mid-century, up from nearly 6.8 billion today - the earlier low projection did not anticipate jumps in fertility in Europe and the United States [PDF].

U.N. demographers selected a high, medium, and low fertility rate in 2006 to estimate how many children would be born between the years 2005 and 2010. Three years later, the analysis concluded that the low fertility rate was too optimistic, according to Hania Zlotnik, director of the Population Division.

"[The difference] is tiny, but it affects how we think of the path over time. The more-developed regions are not losing population by 2050; they're maintaining their population size," Zlotnik said. "The high won't be as high and the low won't be as low just because of that change."

The revised projection has implications for the timing of the possible stabilization and reduction of world population, a target that is now pushed back a few years under the most hopeful of scenarios.

The United Nations expects nearly 8 billion people on Earth by 2050 in its low population estimate, according to the study [PDF].

The high projection, however, foresees some 10.5 billion people - a 295 million person decrease from the previous high projection. The medium projection is 9.2 billion people, about 41 million less than previously reported [PDF].

The revision in the low variant's total fertility rate - the average number of children per woman - was due to a rise in births in Europe and the United States following years of an "artificially depressed" fertility rate, according to demographics expert John Bongaarts. This lower rate was a consequence of large proportions of women delaying pregnancy until later in their lives.

"During the ‘90s, while the average age at childbearing was rising, women became more educated, wanted a job," said Bongaarts, vice president of the Population Council. "That artificial depression is now being removed as the average age of childbearing stops rising."

The 2008 U.N. revision projects that the industrialized world will average 1.64 children per woman between 2005 and 2010, up from an average as low as 1.35 projected in 2006.

"In the developed world, Europe and so on, fertility dropped well below two births per woman," Bongaarts said. "Very few people predicted fertility rates would increase. That has now happened."