August 10, 2012

Not A Drop To Drink


In Fifty Years of Global Warming, I focus on the modern-day Three Horsemen of the Apocalypse: climate change, population growth, and peak oil. While climate change is getting a lot of press, we still don't hear much talk about peak oil and population growth, even though they portend an equally bleak future of increased demand pushing up against decreasing supply. We ain't making any more oil, at least any time soon, but we sure as hell are making lots more people. Sooner or later, that has to cause problems.

Oil isn't the only vital resource running dry. The demand for water is outstripping supply in many parts of the world ... water ... the only other thing besides the air we breath that is essential to life. Amanda Mascarelli, writing in Nature magazine, reports on a recent  study led by Tom Gleeson, a hydrogeologist at McGill University in Montreal, Quebec. They found that 20 percent of the world's aquifers are over-exploited. India, Pakistan, Saudi Arabia, Iran, Mexico, and the United States are among the thirstiest places in the world. The study also noted that demand exceeds the capacity for renewal in many of  the world’s major agricultural regions, including the Central Valley in California, the Nile delta region of Egypt, and the Upper Ganges in India and Pakistan.

It is true that, unlike oil, we do store new supplies of water all the time. The land and the sea are constantly exchanging water through the mediums of evaporation and condensation. But like oil, we are extracting water faster than the water cycle can replenish supplies through the normal processes of rainfall and snow melt. These systems run on geological time. We don't. And it's not just humans who consume water. Every other life form needs water, from the ants and beetles that equal mankind in biomass to all vegetative matter, including the food we grow to eat.

Just as the logic of peak oil is hard to argue with--at some point the rate of consumption of known sources outruns the rate of discovery of new sources--so, too, the logic of sucking on a straw seems pretty simple to grasp. Sooner or later you reach the bottom of the glass. How fast depends on how quickly the aquifer can refresh itself from groundwater seeping down through the soil. Right now, we are sucking pretty damn hard on that straw in certain parts of the world.

The recent drought compounds the problem. Crops survive on rainfall and irrigation. In places like the High Plains, which runs from southern Montana to northwest Texas, both are in a long-term shortfall. Never a region with much rainfall, the main source of irrigation water has been the Ogallala Aquifer, one of those over-exploited aquifers listed by the McGill University scientists. Daily, we see images of farmers scratching their heads as they stand in sun-baked stretches of caked and parched soil that once held their corn crop. The situation is made worse by laws that govern the use of water, laws that were created in times of abundance, laws that gave landowners unlimited rights to extract water on their own property.

We hear the phrase "the new normal" more and more, of late. What exactly does that mean? Well, for one thing, it means hotter and, for some places, much drier weather. If those places happen to be where we grow the food needed to feed the world's rising population, then we are also in for for higher food prices and more starving people. Corn is especially critical, given that it is used in just about everything these days, and what we don't use to make other products we feed to our cattle, so you can look for the price of a Big Mac to start inching up, along with everything else.

We think of climate change and its impact on people and we tend to think of some tiny island in the Pacific slowly being displaced by rising seas. But no place is an island when it comes to climate change. We are all facing massive shifts in ways of living that have persisted for centuries. You don't believe me, just ask the old boy standing in his corn field, wondering how he will hold on for another season.

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