Water politics, sometimes called hydropolitics, is politics affected by the availability of water and water resources, a necessity for all life forms and human development. The first use of the term, hydropolitics, came in the book Hydropolitics of the Nile Valley. Arun P. Elhance's definition of hydropolitics is "the systematic study of conflict and cooperation between states over water resources that transcend international borders".The availability of drinking water per capita is inadequate and shrinking worldwide. The causes, related to both quantity and quality, are many and varied; they include local scarcity, limited availability and population pressures, but also human activities of mass consumption, misuse, environmental degradation and water pollution, as well as climate change.