WHEN the word water appears in print these days, crisis is rarely far behind. Water, it is said, is the new oil: a resource long squandered, now growing expensive and soon to be overwhelmed by insatiable demand. Aquifers are falling, glaciers vanishing, reservoirs drying up and rivers no longer flowing to the sea. Climate change threatens to make the problems worse. Everyone must use less water if famine, pestilence and mass migration are not to sweep the globe. As it is, wars are about to break out between countries squabbling over dams and rivers. If the apocalypse is still a little way off, it is only because the four horsemen and their steeds have stopped to search for something to drink.
The language is often overblown, and the remedies sometimes ill conceived, but the basic message is not wrong. Water is indeed scarce in many places, and will grow scarcer. Bringing supply and demand into equilibrium will be painful, and political disputes may increase in number and intensify in their capacity to cause trouble. To carry on with present practices would indeed be to invite disaster.
Why? The difficulties start with the sheer number of people using the stuff. When, 60 years ago, the world’s population was about 2.5 billion, worries about water supply affected relatively few people. Both drought and hunger existed, as they have throughout history, but most people could be fed without irrigated farming. Then the green revolution, in an inspired combination of new crop breeds, fertilisers and water, made possible a huge rise in the population. The number of people on Earth rose to 6 billion in 2000, nearly 7 billion today, and is heading for 9 billion in 2050. The area under irrigation has doubled and the amount of water drawn for farming has tripled. The proportion of people living in countries chronically short of water, which stood at 8% (500m) at the turn of the 21st century, is set to rise to 45% (4 billion) by 2050. And already 1 billion people go to bed hungry each night, partly for lack of water to grow food.
People in temperate climates where the rain falls moderately all the year round may not realise how much water is needed for farming. In Britain, for example, farming takes only 3% of all water withdrawals. In the United States, by contrast, 41% goes for agriculture, almost all of it for irrigation. In China farming takes nearly 70%, and in India nearer 90%. For the world as a whole, agriculture accounts for almost 70%.
Farmers’ increasing demand for water is caused not only by the growing number of mouths to be fed but also by people’s desire for better-tasting, more interesting food. Unfortunately, it takes nearly twice as much water to grow a kilo of peanuts as a kilo of soyabeans, nearly four times as much to produce a kilo of beef as a kilo of chicken, and nearly five times as much to produce a glass of orange juice as a cup of tea. With 2 billion people around the world about to enter the middle class, the agricultural demands on water would increase even if the population stood still.
Industry, too, needs water. It takes about 22% of the world’s withdrawals. Domestic activities take the other 8%. Together, the demands of these two categories quadrupled in the second half of the 20th century, growing twice as fast as those of farming, and forecasters see nothing but further increases in demand on all fronts.
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