EPIBuilding a Sustainable Future
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Wednesday, August 29, 2012

Every August, scientists gather in Stockholm to participate in World Water Week and discuss the various issues related to water.

Water is as necessary to life as breath. This year in the United States, the lack of rain has resulted in drought conditions throughout the Corn Belt that, combined with excessive heat, will drastically reduce the U.S. corn harvest. According to Lester Brown, the drop could be roughly 100 million tons or 30 percent of the expected harvest.

In some parts of the Midwest, homeowners are turning on their taps and getting nothing but air as the water tables have so precipitously dropped. More intense droughts and heat waves are likely as the Earth’s temperature rises.

With regard to agricultural water use, Lester Brown has long been talking about the need for a major push to raise the level of water productivity. Two decades ago, he said that a shortage of water was the most underreported threat to civilization.

Here is some of what he writes on the subject (from Chapter 2 of World on the Edge)

The global water deficit is a product of the tripling of water demand over the last half-century coupled with the worldwide spread of powerful diesel and electrically driven pumps. Only since the advent of these pumps have farmers had the pumping capacity to pull water out of aquifers faster than it is replaced by precipitation.

As the world demand for food has soared, millions of farmers have drilled irrigation wells to expand their harvests. In the absence of government controls, far too many wells have been drilled. As a result, water tables are falling and wells are going dry in some 20 countries, including China, India, and the United States—the three countries that together produce half the world’s grain.

The overpumping of aquifers for irrigation temporarily inflates food production, creating a food production bubble, one that bursts when the aquifer is depleted. Since 40 percent of the world grain harvest comes from irrigated land, the potential shrinkage of the supply of irrigation water is of great concern. Among the big three grain producers, roughly a fifth of the U.S. grain harvest comes from irrigated land. For India, the figure is three fifths and for China, roughly four fifths. …

There are two rather scary dimensions of the emerging worldwide shortage of irrigation water. One is that water tables are falling in many countries at the same time. The other is that once rising water demand climbs above the recharge rate of an aquifer, the excess of demand over sustainable yield widens with each passing year. This means that the drop in the water table as a result of overpumping is also greater each year. Since growth in the demand for water is typically exponential, largely a function of population growth, the decline of the aquifer is also exponential. What starts as a barely noticeable annual drop in the water table can become a rapid fall.

Lester believes we may have already reached “peak water,” a concept similar to peak oil. To punctuate his words, earlier this month, a report was released showing that the world’s groundwater is being depleted faster than it can be replenished. See also.

You can find more information about what the Institute has to say on this subject in Lester’s forthcoming book, Full Planet, Empty Plates: The New Geopolitics of Food Scarcity, which you can pre-order today.

Other articles of interest.


Reah Janise Kauffman

Posted by Reah Janise on 08/29 at 09:00 AM


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