January 26, 2007 -- By Lester R. Brown, The Huffington Post
Last night I was privileged to attend a dinner at the World Economic Forum that was sponsored by the Japan Water Forum. The dinner had an important focus: Sustainable Growth in Asia.
While sustainable growth in our world's most populous continent carries many environmental implications there is one area that emerges as the most critical, namely water shortages.
In recent decades, water has become a dominant issue in many countries around the world. In Plan B 2.0, which can be downloaded free of charge from the Earth Policy Institute's web site, I spend a great deal of time focused on this issue, especially as it relates to Asia.
In the last half century water demand has tripled, exceeding the sustainable yield of aquifers in scores of countries, and ultimately leading to falling water tables. In fact, water tables are now falling in countries that contain more than half the world's people
In Asia, this problem is particularly acute. The Amu Darya river, formerly a major source of water for the Aral Sea, is now drained dry by Uzbek and Turkmen cotton farmers upstream. In China, the Yellow River, which flows some 4,000 kilometers through five provinces before it reaches the Yellow Sea, has been under mounting pressure for several decades. It first ran dry in 1972, and since 1985 it has often failed to reach the sea.
A similar situation is taking place in Southeast Asia where the flow of the Mekong - which provides water to Cambodia, Laos, Thailand, and Viet Nam - is being reduced by the dams being built on its upper reaches by the Chinese.
What does this mean for Asia? It means not only water scarcity, but eventually a dramatic drop in crop yields.
Countries that are pressing against the limits of their water supply typically satisfy the growing need of cities and industry by diverting irrigation water from agriculture, and then importing grain to offset the loss of productive capacity. Since it takes 1,000 tons of water to produce 1 ton of grain, importing grain is the most efficient way to import water.
The link between water and food is strong. We each drink on average nearly 4 liters of water per day in one form or another, while the water required to produce our daily food totals at least 2,000 liters--500 times as much. This helps explain why 70 percent of all water use is for one purpose--irrigation. Another 20 percent is used by industry, and 10 percent goes for residential purposes. With the demand for water growing in all three categories, competition among sectors is intensifying, with farmers almost always losing.
In China, a combination of aquifer depletion, and the diversion of irrigation water to cities are making it difficult to expand the grain harvest. After peaking at 392 million tons in 1998, the harvest dropped to 346 million tons in 2002 before gradually recovering during the four harvests since then. China's food bubble may be about to burst, as more and more irrigation wells go dry. In recent years, China has covered its grain shortfall by drawing down its stocks, but it will soon have to turn to the world market to fill this deficit. When it does, it could destabilize world grain markets.
Asia can lead the charge to solve the world's ballooning water problems. I see two important steps to this end. First, Asia - as well as developing countries around the world where water scarcity is already a real problem - can reduce demand by stabilizing population and raising water productivity. This is an extraordinary challenge considering that nearly all of the 3 billion people to be added by 2050 will be born in developing countries
The second step in stabilizing the water situation is to raise water productivity, not unlike the way we have raised land productivity. After World War II, with population projected to double by 2000 and with little new land to bring under the plow, the world launched a major effort to raise cropland productivity. As a result, land productivity has nearly tripled since1950. We now need to make a similar effort when it comes to water.
For more Davos coverage -- including news, videos, and blog posts -- visit the Davos Conversation site.
No comments:
Post a Comment