A recent report on global population trends indicates that the world population continues to increase, and less developed countries account for nearly 99 percent of that growth in the near term. Despite declining birth rates in most developed countries and in China, the world continues to grow by an estimated 80 million people each year.
The report by the Population Research Bureau in Washington says much of the growth comes from high fertility rates in the world's poorest countries. Women in Niger lead the world, bearing an average of eight children during their lifetime. In South Central Asian countries, the fertility rate is three point two. These large populations in Africa and parts of Asia help raise the global average to 2.7 kids per woman.
Countries below the average include Thailand and China, where decades of government policies aimed at curbing population growth have lowered the fertility rate to about 1.6 children per woman, on par with many developed nations.
In Europe, the fertility rate decline has been so severe that it is the only region projected to have fewer people by the year 2050.
Carl Haub of the Population Reference Bureau says in Poland, the fertility rate has fallen to 1.2 children per woman.
"Nobody ever thought that countries would have a fertility rate that low, outside of war or some other calamity," said Mr. Haub. "But this has become absolutely chronic throughout Europe and there really is no sign of change, no sign of increase in fertility."
Mr. Haub says low birth rates can affect a nation's economic growth, by shrinking the number of workers. The United States leads all major industrialized nations with a fertility rate of two children per woman, high enough to replace its aging workforce.
The World Population study says fertility rates have a significant impact on long-term population trends, and gauging them over time is the focus of much debate. Because the highest fertility rates occur in poor and rural regions of the world, accurate data can be difficult to obtain.
Mr. Haub says this year's report on population growth in Africa relied on recent studies that are more reliable and caused researchers to modify some projections.
"These are two key things in Africa; fertility is not coming down as fast as we thought and the HIV/AIDS may not be as devastating to some of the countries," he added.
New survey data indicate the HIV infection rate in some countries may not be as high as previous studies indicated. Mr. Haub says the AIDS pandemic is still a tremendous problem for the continent, but nationwide surveys in several key African nations appear to indicate slightly lower infection rates. The recent data also indicates fertility rates remain high in sub-Saharan African nations, averaging more than five children per woman.
The report projects that by the year 2050, the world population will increase by 43 percent, to 9.2 billion people.