Notes on ?carrying capacity?

Abstract

Why is carrying capacity, not land area, the key to estimates of the population size that is sustainable over the long term? In the United States, why not just disperse poopulation over the "wide open spaces" which (de creasingly) still exist in such places as Alaska, Utah, Nevada, Texas, some of the central states, and elsewhere? Why is large land area not a solution for population growth? The answer lies in the essential fact of environmental limits. Limits exist in both the resource and sink functions of the environment. These functions can be considered together and related to population size through the concept of carrying capacity. "Carrying capacity" refers to the longterm capacity of the natural envi ronment to detoxify pollution and provide needed resources such as food, clothing and shelter as well as the capacity of the social environment to provide a reasonable quality of life. While many factors (e.g., energy, forests, traffic congestion, pollu tants) could be chosen to illustrate limitations on population size, consid eration of one striking example, water, brings home very quickly the im portance of the carrying capacity concept. The West, Southwest and certain central states, indeed many areas of the United States (generally those experiencing the most rapid population growth), are afflicted either with water shortages or with the toxic pollution of water. Many areas have limited rainfall or few other naturally occurring sources of potable water,