água e segurança nacional

SCARCITY CROSSING NATIONAL BORDERS – From Chapter 3. Emerging Water Shortages
Lester R. Brown, Plan B 2.0: Rescuing a Planet Under Stress and a Civilization in Trouble

Historically, water scarcity was a local issue. It was up to national governments to balance water supply and demand. Now this is changing as scarcity crosses national boundaries via the international grain trade. Since producing one ton of grain takes 1,000 tons of water (1,000 cubic meters), as noted earlier, importing grain is the most efficient way to import water. Countries are, in effect, using grain to balance their water books. Similarly, trading in grain futures is in a sense trading in water futures.


It is often said that future wars in the Middle East will more likely be fought over water than oil, but the competition for water is taking place in world grain markets. The countries that are financially the strongest, not necessarily those that are militarily the strongest, will fare best in this competition.


Since expanding irrigation helped triple the world grain harvest from 1950 to 2000, it comes as no surprise that water losses can shrink harvests. With water for irrigation, many countries are in a classic overshoot-and-decline mode. If countries that are overpumping do not move quickly to reduce water use and stabilize water tables, then an eventual drop in food production is almost inevitable

por Vitor Silva

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