The world is heading towards a water crisis. The doubling of the world's population between 1940 and 1990 has led to a doubling in per capita use of water, from 400 to 800 cubic metres per person per annum. The result: global use of water quadrapled. Africa and West Asia are likely to be badly hit by water scarcity, but over time the ratio of people to renewable water supply is likely to become a concern in parts of Asia and Latin America, and possibly in Europe.

A shortage of clean water can adversely affect the birth rate. In countries where access to safe water was high, the mortality rate of children was low and vice versa.