Monday, October 22, 2007

Adapting to Drought in the US Southwest

This week's New York Times Magazine has a long article on the drought in the Southwest by Jon Gertner. I've blogged about this situation here and here, but you've got to read all of this article to come to grips with how water shortage may be the climate change impact that takes a greater toll on humanity than a slow rise in the sea level.

Just considering the Colorado River - one of many rivers in the world that is depended on by people living in otherwise arid climates:

Some 30 million people depend on that water. A greatly reduced river would wreak chaos in seven states: Colorado, Utah, Wyoming, New Mexico, Arizona, Nevada and California. An almost unfathomable legal morass might well result, with farmers suing the federal government; cities suing cities; states suing states; Indian nations suing state officials; and foreign nations (by treaty, Mexico has a small claim on the river) bringing international law to bear on the United States government. In addition, a lesser Colorado River would almost certainly lead to a considerable amount of economic havoc, as the future water supplies for the West’s industries, agriculture and growing municipalities are threatened. As one prominent Western water official described the possible future to me, if some of the Southwest’s largest reservoirs empty out, the region would experience an apocalypse, “an Armageddon.
Bradley Udall, whose testimony before Congress was described in the article, took the author to visit some of the reservoirs in Colorado that are being impacted by the drought in the Southwest. He was, in essence, trying to illustrate the need for all of the dependents on the dwindling water supply to begin adapting to the current and future reality.
As he put it, he wants to connect the disparate members of the water economy in a way that has never really been done before, so that utility executives, scientists, environmentalists, business leaders, farmers and politicians can begin discussing how to cope with the inevitable shortages of fresh water.
The water manager for Aurora, Colorado described his town's efforts to find water sources where there are none. Drilling wells next to a nearby river, sucking the river water out through the "filter" of its shoreline, using the water and then releasing treated wastewater back into the river, upstream from their wells allows them to re-use the same water repeatedly...for a while. It's still going to be one of the most expensive municipal water systems in the US, but it may be the method used by other cities in the Southwest to replace the shrinking snowmelt water sources. It may even be adopted by towns in the drying Southeast, like Athens.

But if the current drought is, indeed, the leading edge of climate change and not just a periodic climatic variation, then such measures are just stop-gap. One scientist quoted in the article - Richard Seager - put it this way in a Q&A with the author:
“You know, it’s like, O.K., there’s trouble in the future, but how near in the future does it set in?” he told me. “In this case, it appears that it’s happening right now.” When I asked if the drought in his models would be permanent, he pondered the question for a moment, then replied: “You can’t call it a drought anymore, because it’s going over to a drier climate. No one says the Sahara is in drought.”
This is how they're approaching the megadrought in southern Australia, where it's become known as the Big Dry. Another climatologist, Roger Pulwarty - who has long studied adaptation to dry climates - is worried about this present stretch of drought.
Pulwarty is convinced that the economic impacts could be profound. The worst outcome, he suggested, would be mass migrations out of the region, along with bitter interstate court battles over the dwindling water supplies. But well before that, if too much water is siphoned from agriculture, farm towns and ranch towns will wither. Meanwhile, Colorado’s largest industry, tourism, might collapse if river flows became a trickle during summertime.
The article also includes extensive interviewing with the water manager of Las Vegas, who is endowed with enough money to offer to build large desalination plants on the Pacific coastline to supply California with water in exchange for getting some of Cali's share of the Colorado River water. (Desalination requires lots of energy and produces lots of brine.) Las Vegas continues to grow, and to use water lavishly as a desert city. Perhaps its collapse will come as a result of rising fuel (and airplane ticket) costs before it comes from lack of water.

Can humans adapt under these crisis situations? Can much less water still be enough water?
To Peter Gleick, head of the Pacific Institute, a nonprofit based in Oakland, Calif., that focuses on global water issues, whether we can adapt to a drier future depends on whether we can rethink the functions, and value, of fresh water. Can we can do the same things using less of it? How we use our water, Gleick believes, is considerably more complex than it appears.

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