World population to hit 7 billion this year, 10 billion by 2100

In the 1960s, the world was populated by around 3.5 billion people. This year, the population is expected to double that mark.
According to a new report by the United Nations, the population of Earth is expected to hit seven billion by the end of 2011, with the tally expected to hit 10 billion by the year 2100. And while these numbers have caused no small amount of concern regarding the planet’s ability to sustain such a massive population, scientists are also expecting the population to level off near the end of the century.
The world’s population has increased dramatically since the industrial periods of the mid-18th century, with the planet hitting the one-billion mark around 1800, then doubling that number in the early 1900s. The growth from that number to seven billion took only 50 years.
However, the growth rate is expected to slow by the year 2100 as the countries with the highest birth rates develop better female education and family-planning systems. Currently, much of the population growth is occurring in developing nations like Africa, where a high birth rate has the population doubling every 20 years or so.
Discovery News notes that if every woman had two babies, the world’s population would remain stable. However, the global average currently sits at around 2.5 births per woman, which is down from five births per woman in 1950.
“Every billion people we add to the planet makes life more difficult for everyone and will do more damage to the environment,” John Bongaarts, a demographer at New York’s Population Council, told Discovery. “Can we support 10 billion people? Probably. But we would all be better off with a smaller population.”