IPS - While the world's population of 7.4 billion is growing at 1.1 percent per year - about half the peak level of the late 1960s - enormous differences in demographic growth among countries are increasingly evident and of mounting concern to countries and the international community.
At one extreme are the doublers: 29 countries whose populations are expected to at least double by the middle of the 21st century. At the other extreme in striking contrast are the decliners: 38 countries whose populations are expected to be smaller by the middle of the 21st century.
The doublers are all located in sub-Saharan Africa except for Iraq and the State of Palestine. The largest countries among the doublers are Nigeria (187 million), followed by the Democratic Republic of the Congo (80 million) and Tanzania (55 million).
Today the doublers together account for 10 percent of the world's population. By 2050, however, due to the doublers' rapid rates of demographic growth that proportion is expected to increase to 18 percent of the world's projected population of nearly 10 billion people.
The top ten countries with the projected population declines of no less than 15 percent are all located in Eastern Europe (Figure 2). The country with the most rapid decline among the decliners is Bulgaria (27 percent), followed by Romania (22 percent), Ukraine (21 percent) and Moldova (20 percent).
The largest decliner population, China, is expected to decrease by more than 2 percent by 2050, with the Chinese population peaking in less than a decade. Other large populations projected to experience demographic declines by midcentury are Japan (15 percent), Russia (10 percent), Germany (8 percent) and Italy (5 percent). Moreover, some of the decliners have already experienced population decline for a number of years in the recent past, including Bulgaria, Hungary, Japan, Latvia, Lithuania, Romania, Russia, Serbia and Ukraine.