For want of a drink

Economist: For want of a drink

Finite, vital, much wanted, little understood, water looks unmanageable. But it needn’t be, argues John Grimond (interviewed here)

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.

That’s your lot

Meeting that demand is a different task from meeting the demand for almost any other commodity. One reason is that the supply of water is finite. The world will have no more of it in 2025, or 2050, or when the cows come home, than it has today, or when it lapped at the sides of Noah’s ark. …

… Many of these conceptual difficulties arise from other unusual aspects of water. It is a commodity whose value varies according to locality, purpose and circumstance. Take locality first. Water is not evenly distributed—just nine countries account for 60% of all available fresh supplies—and among them only Brazil, Canada, Colombia, Congo, Indonesia and Russia have an abundance. America is relatively well off, but China and India, with over a third of the world’s population between them, have less than 10% of its water. …

… Scarce or plentiful, water is above all local. It is heavy—one cubic metre weighs a tonne—so expensive to move. If you are trying to manage it, you must first divide your area of concern into drainage basins. …

… The 20m inhabitants of Mexico City and its surrounding area, for example, draw over 70% of their water from an aquifer that will run dry, at current extraction rates, within 200 years, maybe much sooner. Already the city is sinking as a result. In Bangkok, Buenos Aires and Jakarta, the aquifers are similarly overdrawn, polluted or contaminated by salt. Just as serious is the depletion of the aquifers on which farmers depend. In the Hai river basin in China, for example, deep-groundwater tables have dropped by up to 90 metres. …

… Industrial use takes about 60% of water in rich countries and 10% in the rest. The difference in domestic use is much smaller, 11% and 8% respectively. Some of the variation is explained by capacious baths, power showers and flush lavatories in the rich world. All humans, however, need a basic minimum of two litres of water in food or drink each day, and for this there is no substitute. …

John Grimond Interview