Population growth describes the increase in the number of a particular species over a given period of time. The term is often used to refer to the expansion of the world’s population of human beings.

 

According to the United Nations Population Fund, the world will reach seven billion people as of Oct. 31, 2011, with some groups projecting that the seven billionth person will be born in India. However, it is difficult to claim that any one individual is that person.

 

A concern of population growth is overpopulation, which can put a significant strain on resources, including food production, water and energy sources. This has led some countries to adopt population control policies, such as China’s one-child policy that limits married urban couples to a single child.

 

(Text by Noel Kirkpatrick)

(Photo: James Cridland/Flickr)