overpopulation - Overpopulation is the condition of any organism's numbers exceeding the carrying capacity of its ecological niche. 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 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 food, shelter or water enough for 200, 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 use 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 management, and transportation. Negative impacts should also be considered including crowding stress and increased pollution. If addressing the environment as a whole, the survival and well-being of species other than humans must also be considered. In the context of human societies, overpopulation occurs when the population density is so great as to actually cause an impaired quality of life, serious environmental degradation, or long-term shortages of essential goods and services. This is the definition used by popular dictionaries such Merriam-Webster. Overpopulation is not merely an imbalance between the number of individuals compared to the resources needed for survival, or a ratio of population over resources, or a function of the number or density of individuals, compared to the resources (ie. food production) they need to survive. Some countries have managed to increase their carrying capacity by using technologies such as agriculture, desalination, and nuclear power. Some people 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, and that this leads to a higher standard of living.