Water is one of the most important natural resources on earth. We treat it as plentiful, inexhaustible with no intrinsic value. The amount of available freshwater is declining due to rising populations expressed through increased energy needs, increased irrigation and farming of marginal lands and increasing pollution. Africa, Middle East are the most water-poor regions. Irrigation tends to be very inefficient and excess water can be contaminated with fertilizer, pesticides or cause erosion.
Developed nations use water in energy production.