Overpopulation refers to when an organism's numbers exceed the carrying capacity of its habitat. In common parlance, the term usually refers to the relationship between the human population and its environment, the Earth.Overpopulation is not simply a function of the size or density of the population. Overpopulation can be determined using the ratio of population to available sustainable resources. If a given environment has a population of ten, but there is food or drinking water enough for only nine, then that environment is overpopulated; if the population is 100 individuals but there is enough food, shelter, and water for 200 for the indefinite future, then it is not. Overpopulation can result from an increase in births, a decline in mortality rates due to medical advances, from an increase in immigration, a decrease in emigration, or from an unsustainable biome and depletion of resources. It is possible for very sparsely-populated areas to be overpopulated, as the area in question may have a very meager or non-existent capability to sustain human life (e.g. the middle of the Sahara desert or Antarctica).The resources to be considered when evaluating whether an ecological niche is overpopulated include clean water, clean air, food, shelter, warmth, and other resources necessary to sustain life. If the quality of human life is addressed as well, there are then additional resources to be considered, such as medical care, employment, money, education, fuel, electricity, proper sewage treatment, waste. Some countries have managed to temporarily increase their carrying capacity by using technologies such as agriculture, desalination, and nuclear power. However most technologies decrease the long-term carrying capacity unless they are designed to be sustainable. Some cornucopians have argued that poverty and famine are caused by bad government and bad economic policies, and that higher population density leads to more specialization and technological innovation, potentially leading to a higher standard of living. . Most standard analyses posit that overpopulation leads to a reduced standard of living.