Is the world running out of water?
Excellent overview of water scarcity in last week’s Economist. Here are a few highlights
‘The overthrow of Madagascar’s president in mid-March was partly caused by water problems—in South Korea. Worried by the difficulties of increasing food supplies in its water-stressed homeland, Daewoo, a South Korean conglomerate, signed a deal to lease no less than half Madagascar’s arable land to grow grain for South Koreans. Widespread anger at the terms of the deal (the island’s people would have received practically nothing) contributed to the president’s unpopularity. One of the new leader’s first acts was to scrap the agreement.
In 2007, most nations outside the Gulf were using a fifth or less of the water they receive—at least in 2000, the only year for which figures are available. The global average withdrawal of fresh water was 9% of the amount that flowed through the world’s hydrologic cycle. Both Latin America and Africa used less than 6%.
On this evidence, it would seem that all water problems are local. The trouble with this conclusion is that no one knows how much water people can safely use. It is certainly not 100% (the amount taken in Gulf states) because the rest of creation also has to live off the water. In many places the maximum may well be less than one fifth, the average for Asia as a whole. But there is some admittedly patchy evidence that, given current patterns of use and abuse, the amount now being withdrawn is moving dangerously close to the limit of safety—and in some places beyond it.
It is not the absolute number of people that makes the biggest difference to water use but changing habits and diet. Diet matters more than any single factor because farmers use about three-quarters of the world’s water; industry uses less than a fifth and domestic or municipal use accounts for a mere tenth.
Different foods require radically different amounts of water. To grow a kilogram of wheat requires around 1,000 litres. But it takes as much as 15,000 litres of water to produce a kilo of beef. The meaty diet of Americans and Europeans requires around 5,000 litres of water a day to produce. The vegetarian diets of Africa and Asia use about 2,000 litres a day (for comparison, Westerners use just 100-250 litres a day in drinking and washing).
So the shift from vegetarian diets to meaty ones—which contributed to the food-price rise of 2007-08—has big implications for water, too. In 1985 Chinese people ate, on average, 20kg of meat; this year, they will eat around 50kg. This difference translates into 390km3 (1km3 is 1 trillion litres) of water—almost as much as total water use in Europe.
Without changes in efficiency, the world will need as much as 60% more water for agriculture to feed those 2 billion extra mouths [the predicted global population increase by 2050]. That is roughly 1,500km3 of the stuff—as much as is currently used for all purposes in the world outside Asia.
Biofuels could prove as big a disaster for water as they already have been for food. At the moment, about 2% of irrigated water is used to grow crops for energy, or 44km3. But if all the national plans and policies to increase biofuels were to be implemented, reckons the UN, they would require an extra 180km3 of water.’
The Economist comes up with a predictable answer, given the magazine’s neoclassical default position – countries should increase the role of markets in the provision and consumption of water. effectively rationing it through price. This may increase efficiency (you waste less if you have to pay for it), but has real problems in terms of equity – poor people risk being excluded in new ways from access to water. In any case, privatizing water collides with deeply ingrained cultural attitudes to water in many countries, where people see it as a gift from nature and so free for all. But some kind of rationing will probably have to take place – tiered taxes on water consumption anyone? For anyone interested in learning more, check out the website of WaterAid– an excellent specialist NGO, or read the brilliant 2006 Human Development Report, ‘Beyond Scarcity: Power, poverty and the global water crisis’.