WATER

Independent: News Analysis: Water scarcity could affect billions: is this the biggest crisis of all?

Glug-glug: Not normally a sound of foreboding. But mankind's most serious challenge in the 21st century might not be war or hunger or disease or even the collapse of civic order, a UN report says; it may be the lack of fresh water.

The report makes an alarming prediction. By the middle of the century, it says that, in the worst case, no fewer than seven billion people in 60 countries may be faced with water scarcity, although if the right policies are followed this may be brought down to two billion people in 48 nations.

Demand, of course, comes not just from the need to drink, the need to wash and the need to deal with human waste, enormous though these are; the really great calls on water supply come from industry in the developed world, and, in the developing world, from agri- culture. Irrigating crops in hot dry countries accounts for 70 per cent of all the water use in the world