Human overpopulation (or population overshoot) occurs when the ecological footprint of a human population in a specific geographical location exceeds the carrying capacity of the place occupied by that group. A more controversial definition of Overpopulation as advocated by Paul Ehrlich is a situation where a population in the process of depleting non-renewable resources. Under this definition changes in lifestyle could cause an overpopulated area to no longer be overpopulated without any reduction in population, or vice versa.
The term human overpopulation refers to the relationship between the entire human population and its environment: the Earth, or to smaller geographical areas such as countries. Overpopulation can result from an increase in births, a decline in mortality rates, an increase in immigration, or an unsustainable biome and depletion of resources. It is possible for very sparsely populated areas to be overpopulated if the area has a meagre or non-existent capability to sustain life (e.g. a desert). Advocates of population moderation cite issues like quality of life, carrying capacity, and risk of starvation as a basis to argue for population decline. Scientists suggest that the human impact on the environment as a result of overpopulation, profligate consumption and proliferation of technology has pushed the planet into a new geological epoch known as the Anthropocene.