Desalination: the quest to quench the world's thirst for water
Technological advances have made removing salt from seawater and waste water less energy-intensive, but will they simply encourage us to use more?
The average Briton uses 150 litres of water a day; the average American gets through 570 litres of the stuff. The world is getting thirstier and the global demand for fresh water is rising by 640bn litres a year.