This refers to rapid increase in the population of a given area relative to the available resources.

Population Explosion is the rapid and dramatic rise in world population that has occurred over the last few hundred years. The world's population increased from 1.65 billion in 1900 to 3.02 billion in 1960. The United Nations estimated that the population reached 6 billion in late 1999. Thus, the size of the population nearly quadrupled in the span of 100 years, a historically unprecedented rate of increase.

Most of this growth is now taking place in the world's developing countries, where rates of natural increase are much higher than they are in industrialized countries. Concern that this might lead to overpopulation has led some countries to adopt population control policies.