The United Nations' population office, in an unprecedented move, is revising downward its world population predictions. The new figures reflect declining birth rates in many developing nations and the impact of the HIV/AIDS pandemic.
Two years ago, the U.N population division predicted that the global population would reach 9.3 billion by 2050. But current research indicates the figure will drop by 400 million to a mid-century population of 8.9 billion.
Joseph Chamie, director of the U.N. population division, attributes half of the decrease to a worsening of the AIDS epidemic.
"This AIDS epidemic, this pandemic, is increasing and although the probability of being infected by HIV is assumed to decline significantly in the future, the long-term impact of the epidemic remains dire," he said. "The response to date has been like putting a bandaid [bandage] on the epidemic. Over the current decade, the number of excess deaths because of AIDS among the 53 most-affected countries is estimated at 46 million and that figure is projected to ascend to 278 million by 2050."
The numbers are particularly sobering in Africa where Botswana, Lesotho, South Africa and Swaziland are expected to experience reductions in their populations.
Annually, the world's population is rising by about one percent, or 77 million people. India accounts for one-fifth of that growth. China and Pakistan follow. But by mid-century, Mr. Chamie predicts 33 nations will have smaller populations, including Japan, Italy, Bulgaria, and Russia. He says the new estimates also represent the first time his office has ever projected falling fertility rates in parts of the developing world.
"Fertility rates have come down faster than we were anticipating 10 years ago. As a consequence, our numbers are adjusted," he said. "For example, 10, 20, 30 years ago we never expected that Brazil would have such a drop in fertility. No one expected 25 years ago that Iran would be approaching a fertility rate of two children. Who would have expected in 1960 that Tunisia's fertility would be close to two when it was about six?"
Current projections indicate that the population of older people will triple by mid-century, raising the world's average age to 37.