Sunday, August 17, 2008

Global warming aside, fresh water dwindling

Arizona Republic: …"Water stress" has profoundly different meanings in developed and developing countries. In Africa and many parts of Asia, it means inadequate water for drinking, sanitation and crops. In emerging economies such as India and China, it translates as an inability to meet the dietary and lifestyle aspirations of a growing middle class. Water stress in richer nations, and in places such as Phoenix and Las Vegas, means an inability to sustain a growth economy and support lavish oasis-style lifestyles featuring irrigated lawns, outdoor swimming pools, artificial waterfalls and urban lakes.

…Future water demand, with or without climate change, will grow substantially. According to the Population Reference Bureau, the world will grow by 6.6 million to 8 million by 2025, and by up to 9.3 million in 2050, with nearly all growth occurring in developing countries lacking capacity to increase water supplies or improve delivery.

The world is also rapidly urbanizing, creating additional stress by concentrating demand in small areas. Currently, the developed world is more than 70 percent urbanized, whereas less than 40 percent of the population of Africa and Asia is urban. However, 50 percent of Africans and Asians and 60 percent of the world will live in urban areas by 2030.

As needs grow, cities will intensify aquifer drawdown and divert more distant surface-water flows, leading to potential conflicts between sectors, people, regions and countries. One need only consider the approximately 2 million people displaced by China's Three Gorges Dam or the depleting aquifer that Israel currently shares with its neighbors to see the potential outcomes of such shifts.

…Water resources are in crisis, with or without climate change, because, barring unforeseen technological advances in desalination, Earth's freshwater supply is limited and geographically variable….

The upper side of the Ladybower Dam, at the south end of Ladybower Reservoir, in Derbyshire, England. Photo by Dave Pape, who has generously released it into the public domain via Wikimedia Commons

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