THE SHAPE OF THINGS TO COME

There is a most striking paradox in global population trends: on one hand we have had a rapid decline in fertility for over two decades in many developing countries - not to mention the already very low fertility in most of the highly developed nations; on the other hand we will almost certainly experience a further massive increase of the world population. Between now and the middle of the next century world population will most likely increase by some 3.68 billion people - all of these increase will be contributed by the developing countries.

From the 3.68 billion people that will be added to the world population between 1995 and 2050, Asia will contribute some 2 billion. Most of this growth will occur in the next three decades. Between 1995 and 2025 Asia's population will grow by 1.35 billion - between 2025 and 2050 the increase is projected to be just 658 million. Despite a projected increase in mortality due to AIDS, we cannot expect a significant slowing down of population growth in Africa. This continent will contribute 1.3 billion people to the world population between 1995 and the middle of the next century - almost twice as much as its current total population. Europe's population will almost certainly decline - by 27 million over the next 30 years and by another 64 million between 2025 and 2050.

Which countries, worldwide, will have the highest increase in population during the 100-year period between 1950 and 2050? If the 1996 UN medium variant population assessments and projections are accurate (and there is no reason to believe otherwise) India will lead the group with an increase of 1.18 billion people - significantly larger than that of China, which will have a population increase of "only" 962 million (see Table C1_3). The third largest contributor to world population growth between 1950 and 2050 will be Pakistan with an increase of 318 million people. The ranking of the other 7 countries is as follows: Nigeria (+306 million); Indonesia (+ 239 million); Ethiopia (+ 194 million); United States of America (+ 190 million); Brazil (+ 189 million); Bangladesh (+ 176 million) and Iran (+ 153 million).

There are several overwhelmingly Muslim populations with very high population growth rates, such as those of Saudi Arabia, Kuwait or the United Arab Emirates. But none of them is projected to have such a massive absolute increase of the population as Pakistan. In 1950 Pakistan had a population of about 40 million people. Since then it has more than tripled and stood at 136 million in 1995. But the real population explosion in Pakistan will only come over the next few decades, because the country not only has a very young population, but also still an extremely high fertility - much higher, for instance, than in Bangladesh or Thailand. These large numbers of children and young adults will soon come into reproductive age and will produce a large number of offspring even if we assume, as in the UN medium variant, a rapid decline in average fertility to reproductive level (of 2.1 children per woman) by 2020. Pakistan's population will be about 357 million by 2050 (according to the UN medium variant projection) (see Figure C1_6).

Over the next decades the world population will inevitably age. This is an unavoidable consequence of large birth cohorts during the 1950s and 1960s and the rapid fertility decline since the 1970s. In 2025 the "baby boomers" of the 1950s and 60s will be between 65 and 75 years of age. These large aging cohorts are followed by the relatively small "baby bust" generations of the worldwide fertility decline.

While currently population aging is most serious in Europe and Japan, China will experience a dramatic increase in the proportion of elder people by the middle of the next century. This is largely due to the country's success in family planning, which rapidly reduced the relative size of birth cohorts since the 1970s.