Sivu 34

"W hiskey is for drinking; water is for fighting over," America's greatest writer Mark Twain reportedly said during the 1800s. Without water, we would not have whiskey either, but can we imagine a future without water? About one billion people live in areas with water shortages, and by the middle of this century that number is expected to rise to as high as four billion. Population growth, climate change and pollution are the main reasons for the worsening situation. A lack of water has always been a regional problem. For instance, North America has 15 times as much renewable water resources per person than the Middle East and North Africa. In the areas where water is scarce, water management is a matter of war and peace. For nearly 35 years, scientists at the Jacob Blaustein Institute in the middle of Israel's Negev Desert have been studying how desertification can be prevented and life sustained with minimal water levels. About one third of the researchers at the Blaustein Institute for Desert Research are focused on water chemistry and technology. Cost-efficient means of recycling water and desalinating sea water could solve the problem of water supply, but it will take time before they are fully developed. In the meantime, we must learn to get by with scarcity. Hendrik J. Bruins, who has studied the lives of herders in the Negev Desert, says that it is increasingly important that people around the world improve their readiness for intermittent droughts brought on by climate change. "As the world's population continues to grow, a drought in India or China could lead to a really serious food shortage everywhere. The seminomadic and sedentary pastoralists in Negev engage in water harvesting in order to collect and store rainwater in order to survive the dry spells. The rest of us must prepare for rainless periods by building up our grain reserves. This is particularly important in big countries such as China, India and United States," says Bruins. VIRTUAL WATER Growing a kilo of wheat takes an average of 900 litres of water, and a single slice of bread some 40 litres. A kilo of beef takes at least 10,000 litres, in some areas as much as 200,000 litres of water. When we take into consideration the kind of unseen so-called virtual water that lies behind our food and other consumption, we begin to see the Earth's water economy in a new way. "Agriculture accounts for 80 to 90 per cent of the world's water consumption. So the choices we make regarding food are extremely important in terms of the global water economy," says professor John Anthony Allan of King's College London, who developed the concept of virtual water. The Worldwide Fund for Nature (WWF) estimates that the average Briton uses about 150 litres of water per day, but 30 times that in virtual water used to manufacture food, clothing and other consumer goods. That would be enough water to take 58 baths a day. "Considering people's continually growing affluence and the projection that the world's population will increase from the current six billion to nine billion by the year 2050, our renewable water resources simply are not going to suffice. We have to develop better water processing technology and change our consumption habits," says Allan. iStockphoto "Growing a kilo of wheat takes an average of 900 litres of water, and a single slice of bread some 40 litres." 34 BLUE WINGS NOVEMBER 2008

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