In 1988 the world's population reached five billion. The figure suggests a veritable population boom, but the explosion is not being heard everywhere. Throughout the 80's, the population growth rate will be negative or near-zero in most European countries, the USA and Japan. In both the USA and France, the birth rate plunged from 3.6 to 1.8 births per woman (the replacement rate is 2.1). In Germany the birth rate has fallen from 2.6 to less than 1.3. Italy is even lower than Germany; Spain, Greece and Portugal are following suit.
Constant medical advances are prolonging life. There will be more women among the elderly population and the number of very old people (80 and up) will create medical and social problems. The results will be an aging population in general, although some sectors will have distinctive differences - for example, migrant populations are settling in industrialized countries and their populations are becoming younger relative to that of the nation as a whole.
According to a 1997 report, the United States population was increasing by 0.9 percent (2.5 million) per year, more than three times the average for the rest of the industrialized world.
If UN calculations are correct and Asians and Africans will make up just under 80 percent of humanity by 2050, they will simply have returned to being proportionately almost exactly as numerous as they were before the European industrial revolution.