UNITED NATIONS, Feb. 26 (UPI) -- For the first time, fertility levels in developing countries are likely to fall below replacement levels, the U.N. Population Division said Wednesday, reporting the anticipated world's population in 2050 to be 8.9 billion people, or 400-million below the 2000 projection.
More than half the projected decrease in the median variant was blamed on HIV-AIDS deaths and the other on a reduction in the projected number of births, reflecting a lower expected fertility rate.
The 2002 Revision of the official U.N. population estimates and projections breaks new ground in terms of the assumptions made on future human fertility and the impact of the HIV/AIDS epidemic, said Joseph Chamie, director of the division. It's the 18th population projection revision since 1950.
"The results of these exercises, namely the various population estimates and projections are extremely important, having profound social, economic and political implications," he told reporters at a briefing. "They provide the basic foundations for understanding where we are we've been and where we are headed."
He pointed out they are "vital for policies and plans and programs relating to virtually every area of human activity, including health, education, social services, housing employment, consumption and production, economic markets as well as voting and political representation."
In a statement accompanying 46-pages of highlights from "The 20002 Revision," he said, "For the first time, the U.N. Population Division projects that future fertility levels in most developing countries will likely fall below 2.1 children per woman, the level needed to ensure the long-term replacement of the population, at some point in the 21st century. By 2050, the medium variant of the 2002 Revision projects that 3 out of every 4 countries in the less developed regions will be experiencing below-replacement fertility."
The latest revision anticipates a more serious and prolonged impact of the HIV-AIDS epidemic in the most affected countries than in previous revisions.
"The impact of the disease is explicitly modeled for 53 countries, up from the 45 considered in the 2000 Revision," Chamie said. "The dynamics of the epidemic, as estimated by UNAIDS, are assumed to remain unchanged until 2010."
After that prevalence levels were assumed to decline "in a manner consistent with modifications of behavior, such as protected sex, that reduce the rates of recruitment into the high risk groups as well as the chances of infection among those engaging in high risk behavior," he said.
"The resulting HIV prevalence levels remain relatively high until 2010 and then decline, but are still substantial by mid-century," he said.
"The 2002 Revision projects a lower population in 2050 than the 2000 Revision did: 8.9 billion instead of 9.3 billion according to the medium variant," the highlights said. "About half of the 0.4 billion difference in these projected populations results from an increase in the number of projected deaths, the majority stemming from higher projected levels of HIV prevalence," the highlights said. "The other half of the difference reflects a reduction in the projected number of births, primarily as a result of lower expected future fertility levels.
"The 2002 Revision confirms key conclusions from previous revisions," the highlights said. "Despite the lower fertility levels projected and the increased mortality risks to which some populations will be subject, the population of the world is expected to increase by 2.6 billion during the next 47 years, from 6.3 billion today to 8.9 billion in 2050.
"However, the realization of these projections is contingent on ensuring that couples have access to family planning and that efforts to arrest the current spread of the HIV/AIDS epidemic are successful in reducing its growth momentum," the report highlights said. "The potential for considerable population increase remains high.
"According to the results of the 2002 Revision, if fertility were to remain constant in all countries at current levels, the total population of the globe could more than double by 2050, reaching 12.8 billion," it said. "Even a somewhat slower reduction of fertility than that projected in the medium variant would result in additional billions of people. Thus, if women were to have, on average, about half a child more than according to the medium variant, world population might rise to 10.6 billion in 2050 as projected in the high variant."
Chamie, who likes to use props to bring alive his dry demographic reports, extended a steel wound tape measure to nearly the 9-foot mark to demonstrate the projected increase from the estimated current 6.3 billion people.
However, he had to ask chief U.N. spokesman Fred Eckhard to hold up the end so reporters could appreciate the growth.
