Water Shortages Go Global
The Economist, April 08, 2009
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.
Three weeks before that, on the other side of the world, Governor Arnold Schwarzenegger of California declared a state of emergency. Not for the first time, he threatened water rationing in the state. “It is clear,” says a recent report by the United Nations World Water Assessment Programme, “that urgent action is needed if we are to avoid a global water crisis.”
Local water shortages are multiplying. Australia has suffered a decade-long drought. Brazil and South Africa, which depend on hydroelectric power, have suffered repeated brownouts because there is not enough water to drive the turbines properly. So much has been pumped out of the rivers that feed the Aral Sea in Central Asia that it collapsed in the 1980s and has barely begun to recover.
Yet local shortages, caused by individual acts of mismanagement or regional problems, are one thing. A global water crisis, which impinges on supplies of food and other goods, or affects rivers and lakes everywhere, is quite another. Does the world really face a global problem?
Two global trends have added to the pressure on water. Both are likely to accelerate over coming decades.
The first is demography. Over the past 50 years, as the world’s population rose from 3 billion to 6.5 billion, water use roughly trebled. On current estimates, the population is likely to rise by a further 2 billion by 2025 and by 3 billion by 2050. Demand for water will rise accordingly.
Or rather, by more. Possibly a lot more. 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 agriculture is the modern Agasthya, the mythical Indian giant who drank the seas dry. 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.
The shift of diet will be impossible to reverse since it is a product of rising wealth and urbanisation. In general, “water intensity” in food increases fastest as people begin to climb out of poverty, because that is when they start eating more meat. So if living standards in the poorest countries start to rise again, water use is likely to soar. Moreover, almost all the 2 billion people who will be added to the world’s population between now and 2030 are going to be third-world city dwellers—and city people use more water than rural folk. The Food and Agriculture Organisation reckons that, without changes in efficiency, the world will need as much as 60% more water for agriculture to feed those 2 billion extra mouths. That is roughly 1,500km3 of the stuff—as much as is currently used for all purposes in the world outside Asia.
The other long-term trend affecting water is climate change. There is growing evidence that global warming is speeding up the hydrologic cycle—that is, the rate at which water evaporates and falls again as rain or snow. This higher rate seems to make wet regions more sodden, and arid ones drier. It brings longer droughts between more intense periods of rain.
Climate change has three big implications for water use. First, it changes the way plants grow. Trees, for example, react to downpours with a spurt of growth. During the longer droughts that follow, the extra biomass then dries up so that if lightning strikes, forests burn more spectacularly. Similarly crops grow too fast, then wilt.
Second, climate change increases problems of water management. Larger floods overwhelm existing controls. Reservoirs do not store enough to get people or plants through longer droughts. In addition, global warming melts glaciers and causes snow to fall as rain. Since snow and ice are natural regulators, storing water in winter and releasing it in summer, countries are swinging more violently between flood and drought. That is one big reason why dams, once a dirty word in development, have been making a comeback, especially in African countries with plenty of water but no storage capacity. The number of large dams (more than 15 metres high) has been increasing and the order books of dam builders are bulging.
Third, climate change has persuaded western governments to subsidise biofuels, which 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. Though small compared with the increase required to feed the additional 2 billion people, the biofuels’ premium is still substantial.
In short, more water will be needed to feed and heat a world that is already showing signs of using too much. How to square that circle? The answer is by improving the efficiency with which water is used. The good news is that this is possible: vast inefficiencies exist which can be wrung out. The bad news is it will be difficult both because it will require people to change their habits and because governments, which might cajole them to make the changes, are peculiarly bad at water policy.
Full story at: http://www.economist.com/world/international/displaystory.cfm?story_id=134
What Will Global Warming Look Like? Scientists Point to Australia
Drought, fires, killer heat waves, wildlife extinction and mosquito-borne illness — the things that climate change models are predicting have already arrived there, they say.
By Julie Cart, The Los Angeles Times, April 09, 2009
Reporting from The Murray-Darling Basin, Australia — Frank Eddy pulled off his dusty boots and slid into a chair, taking his place at the dining room table where most of the critical family issues are hashed out. Spreading hands as dry and cracked as the orchards he tends, the stout man his mates call Tank explained what damage a decade of drought has done .
“Suicide is high. Depression is huge. Families are breaking up. It’s devastation,” he said, shaking his head. “I’ve got a neighbor in terrible trouble. Found him in the paddock, sitting in his [truck], crying his eyes out. Grown men — big, strong grown men. We’re holding on by the skin of our teeth. It’s desperate times.”
A result of climate change?
“You’d have to have your head in the bloody sand to think otherwise,” Eddy said.
They call Australia the Lucky Country, with good reason. Generations of hardy castoffs tamed the world’s driest inhabited continent, created a robust economy and cultivated an image of irresistibly resilient people who can’t be held down. Australia exports itself as a place of captivating landscapes, brilliant sunshine, glittering beaches and an enviable lifestyle.
Look again. Climate scientists say Australia — beset by prolonged drought and deadly bush fires in the south, monsoon flooding and mosquito-borne fevers in the north, widespread wildlife decline, economic collapse in agriculture and killer heat waves — epitomizes the “accelerated climate crisis” that global warming models have forecast.
With few skeptics among them, Australians appear to be coming to an awakening: Adapt to a rapidly shifting climate, and soon. Scientists here warn that the experience of this island continent is an early cautionary tale for the rest of the world.
“Australia is the harbinger of change,” said paleontologist Tim Flannery, Australia’s most vocal climate change prophet. “The problems for us are going to be greater. The cost to Australia from climate change is going to be greater than for any developed country. We are already starting to see it. It’s tearing apart the life-support system that gives us this world.”
Full story at: http://www.latimes.com/news/nationworld/world/la-fg-climate-change-australia9-2009apr09,0,65585.story
