Of the several threats that are looming large on our planet, human overpopulation is a major one. In terms of sociology, population refers to a collection of humans. In simpler terms, population is the number of people in a city, town, region, country or world. Human overpopulation is a state in which there are too many people, consuming too much, for the environment to sustain. If we delve a little deeper, we see that there are several other grave problems which are triggered by this population explosion. Actually, human overpopulation is among the most pressing environmental issues, silently aggravating the forces behind global warming, environmental pollution, habitat loss, intensive farming practices and the rapid depletion of finite natural resources, such as fresh water, arable land and fossil fuels. Over population can result from an increase in birth rate, a decline in mortality rate, an increase in immigration, social and religious factors, depletion of natural resources, etc.