NEW YORK, MARCH 12, 2005 ( World population growth continues to slow down, with a projected figure of 9.1 billion in 2050, up from today's 6.5 billion. The latest forecasts were published Feb. 24 by the Population Division of the U.N. Department of Economic and Social Affairs.

In a study, "World Population Prospects: The 2004 Revision," the U.N. agency foresees that almost all growth will take place in the less developed regions, where the actual population of 5.3 billion is expected to reach 7.8 billion in 2050. By contrast, the population of the more developed regions will remain mostly unchanged, at 1.2 billion. In fact, the report calculates that currently 95% of population growth is taking place in the developing world.

The Population Division sets out a number of forecasts for the future. According to the medium variant, which is held to be the most probable, by 2050 the population of the more developed countries as a whole would be declining slowly by about 1 million persons a year and that of the developing world would be adding 35 million annually.

But, the report adds, estimates of future population growth depend on how fertility rates develop. The current fertility rate stands at 2.65 children per woman. This is about half the level of 50 years ago. And over the next half-century, in the medium variant, global fertility is projected to decline further to 2.05 children per woman. Adding half a child to this would result in a world population of 10.6 billion in 2050. And a rate of half a child less would lead to a population of 7.6 billion by midcentury.

Marked differences

The demographic situation in the near future will be characterized by notable differences between countries. Rapid population growth will occur in nations such as Afghanistan, Burkina Faso, Burundi, Chad, Congo, the Democratic Republic of Congo, Liberia, Mali, Niger and Uganda.

The uneven nature of population growth is evident from the fact that during the next 45 years just nine countries are expected to account for half of the world's projected population increase: India, Pakistan, Nigeria, the Democratic Republic of Congo, Bangladesh, Uganda, the United States, Ethiopia and China.

There are also notable differences among the developing countries. In 2000-2005, fertility remains above 5 children per woman in 35 of the 148 developing countries. However, in 23 developing countries, accounting for 25% of the world population, fertility has already reached below-replacement levels. This group includes China whose fertility during 2000-2005 is estimated at 1.7 children per woman.

In the 44 developed countries, which account for 19% of the world population, the fertility rate is now running at only 1.56 children per woman. The report also notes that in 15 countries, mostly located in Southern and Eastern Europe, fertility rates are now below 1.3 children per woman, a level so low as to be "unprecedented in human history."

The report observes that since 1990-1995, fertility decline has been the rule among most developed countries. Moreover, the few increases recorded, such as those in Belgium, France, Germany, the Netherlands and the United States, have been small. Yet, in spite of these current low levels, the United Nations expects that that trend of declining fertility will be reversed and it is projected to increase slowly to 1.84 children per woman in 2045-2050.

Even so, the low fertility in the developed world will lead to a situation where the population of 51 countries or areas, including Germany, Italy, Japan, the Baltic states and most of the members of the Commonwealth of Independent States, is expected to be lower in 2050 than in 2005.

Some living longer

One of the most marked changes in past decades has been the increase in life expectancy. The global average at birth is estimated to have risen from 46 years in 1950-1955 to 65 years in 2000-2005. It is expected to keep on rising to reach 75 years in 2045-2050.

In the more developed regions, the projected increase is from 75 years today to 82 years by midcentury. In the developing world as a whole, life expectancy if projected to rise from just under 66 years today to 76 years by midcentury. And, among the least developed countries, where life expectancy today is just under 50 years, it is expected to be 66 years in 2045-2050.

The unknown factor here is what may happen with the HIV/AIDS levels. The projected increases in the developing countries contained in the report are, in fact, "dependent on the implementation of effective programs to prevent and treat HIV infection."

In the most-affected region, southern Africa, life expectancy has fallen from 62 years in 1990-1995 to 48 years in 2000-2005, and is projected to decrease further to 43 years over the next decade before a slow recovery starts. Consequently, population growth in the region is expected to stall between 2005 and 2020.

Higher mortality, partly due to HIV/AIDS, is also a problem in the Russian Federation and Eastern Europe. In the latter, life expectancy during 2000-2005 stood at 66.6 years, down from 67.2 years in 1955-1960.

Global aging

Another important change in world population in coming decades is population aging. The combination of fertility decline and an increase in life expectancy means that the number of persons aged 60 years or over is expected almost to triple, from 672 million in 2005 to nearly 1.9 billion by 2050. And it is not just a phenomenon of the richer nations. Today, six out of every 10 seniors live in developing countries. By 2050 it will be eight out of every 10.

An even more marked increase is expected in the number of the oldest people, those 80 years or over. Their number will rise from today's 86 million to 394 million in 2050. In developing countries, the number will soar to 278 million from the current 42 million.

But if the absolute numbers of elderly are greater in developing countries, it is in the developed world that society will see the most dramatic aging in terms of the proportion of the population.

In these nations, 20% of today's population is aged 60 years or over. By 2050 that proportion is projected to be 32%.

The elderly population in developed countries has already surpassed the number of children in the age bracket of 0-14 and by 2050 there will be two elderly people for every child. In the developing world, the proportion of the population aged 60 or over is expected to rise from 8% in 2005 to close to 20% by 2050.

These forecasts and the experience of recent years show just how erroneous were the prophecies of past years about imminent disaster due to the "population bomb." This, however, has not stopped family planning advocates from continuing to push abortion and contraceptives.

Regarding this point, Archbishop Celestino Migliore, the Holy See's permanent observer to the United Nations, delivered a speech Feb. 24 in which he mentioned the theme of population and development.

"A wise and humane population policy," he told the United Nations, "will respect the people it is meant to serve, for the betterment of humanity." This means empowering people, especially women, and respecting their liberty.