On Nov. 15, a Tuesday, somewhere in the world, a baby was born who brought global population to a staggering 8 billion. This figure is more than double the 1972 headcount, reflecting a historically unprecedented half-century of rapid population growth.
But reaching 8 billion signals much more than the achievement of a catchy milestone. It also marks an important shift in demographic trends. That shift is going to require substantial adjustments for both societies and individuals. Population growth is expected to slow in the years ahead and, in a growing number of countries, populations will decline. The main demographic challenge of the past century has been to support a rapidly growing population.