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"Even in May, an extraordinary number of Westerners — especially those who live in the Rocky Mountain states — are still talking about March. In many places, it was an unusually warm month without precipitation. March put an end to the hope — a well-worn hope by now — that the weather would return to normal in a region that is now entering its fifth year of drought. Every indicator is grievous. Ranchers have radically destocked the range. In Arizona and New Mexico, more than a million acres of pinyon and ponderosa pine have died off. Critical reservoirs, like Lake Powell, are holding less than half their capacity. The Rio Grande is a trickle. The entire drainage of the Colorado River — the ultimate source of water for much of the metropolitan West — is at risk.
A drought of this severity naturally calls into question the definition of "normal." It appears, in fact, that what is normal is an oscillation in climate, from wet periods, like 1976 to 1998, to dry periods, which have recurred with some regularity. So far, this is a five-year drought. But no one knows how long it will last. The climatic history of Arizona, for instance, has been reconstructed by painstaking analysis of tree rings. That research shows that there have been two droughts that lasted 18 years and one, near the end of the 16th century, that lasted 28 years. Tree-ring evidence also shows that for parts of Arizona, 2002 was the driest year in the past 1,400 years.
This drought still isn't as dire as the one from 1900 to 1904. But everything in the West has changed since 1904. In fact, everything has changed since 1976, when two wet decades led to an almost unimaginable explosion of development and population across the region, an explosion that, in some places, is rapidly drawing down underground aquifers. In the short run, that pace of growth is unsustainable. In the long run, the question is whether the West can sustain even the growth it has managed so far."
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