The number of people in the world is expected to reach 7 billion by the end of October 2011. Our rate of increase continues to slow from the high point of over 2 percent in 1968. Still, this year’s 1.1 percent increase means some 78 million people will be added to the global population in 2011.
The human population did not reach 1 billion until the early nineteenth century, and it took more than 100 years to reach 2 billion. After that, the intervals between billions grew even shorter: we added the third billion in 33 years, the fourth in 14 years, the fifth in 13 years, and the sixth and seventh in 12 years each.
Anyone alive today who was born by 1940 has seen our numbers triple. The most widely cited United Nations projection shows world population hitting 8 billion in 2025 and 10 billion before the end of this century.
With populations stabilizing in much of the industrial world, almost all population growth in the near future is expected to occur in developing countries. Of the 2.3 billion people to be added by 2050, more than a billion will live in sub-Saharan Africa. The Indian subcontinent will add some 630 million people.
