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From Drought to Deluge
“normal” climate in the west
And it never failed that during the dry years the people
forgot about the rich years, and during the wet years they lost all
memory of the dry years. It was always that way.
John Steinbeck, East of Eden
Humans tend to perceive climate as a force of nature, one
to be measured, classii ed, and ultimately conquered. John Steinbeck's quote
speaks to another human characteristic: the tendency to forget. h is seems
especially true when it comes to the periods of wet and dry over the past
century or so in the American West.
Perhaps, however, we can be sympathetic to this tendency when we
realize that to “measure the climate” at any given point is really a mea-
surement of the current weather. To understand complex climatic pat-
terns requires a much longer timescale. h us, in our lifetimes, we expe-
rience only a small sampling of climate ef ects—not the full range—in
the West. Imagine a performance of a Beethoven symphony with
only the i rst chords, played over and over again. If that were all we heard
of the symphony, we would believe it was beautiful—but simple. We could
hum along and predict what would come at er the initial chord sequence.
However, as we know, Beethoven wrote complex and intricate sympho-
nies, ot en full of surprises. h ese may be pleasurable in musical composi-
tions, but surprises in climate can have catastrophic results for societies.
We can remove the element of surprise by understanding as much about
our climate as possible.
In this topic, we focus primarily on those aspects of climate that have
an impact on water resources in the West. To further our understanding of
those resources, imagine “l ying over” North America using Google Earth.
Traveling from east to west, we see obvious contrasts: shades of green that
dominate the eastern portion of the country abruptly give way to vast areas
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