The northern half of China, home to perhaps half a billion people, already is short of water. The water table under Beijing has fallen nearly 200 feet since 1965 and 8 feet in 1999 alone. Water usage is causing other problems as well. For example, irrigation water evaporates, leaving minerals in the soil. Salinization is already cutting crop yields in India, Pakistan, Egypt, Mexico, Australia, and parts of the United States.
Pollution further reduces the supply of safe drinking water.
Despite intensive clean-up programs, it will take between 25 and 50 years for nitrates to reach levels considered safe. In India alone, an estimated 300 million people lack access to safe drinking water, thanks to widespread pollution of rivers and groundwater. An estimated 40,000 people around the world die each day of diseases directly caused by contaminated water that s more than 14 million per year. By 2040, at least 3.5 billion people will run short of water, almost 10 times as many as in 1995. By 2050, fully two-thirds of the world s population could be living in regions with chronic, widespread shortages of water.