Environmental Engineering Reference
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eastern Pacific), the Southwest typically has more rain and floods, while during La Niña
events (the cooling of the eastern tropical Pacific), there is typically below-average pre-
cipitation. The recent drying of the region is likely due to a series of La Niñas since the
1997-98 El Niño, but it is also probably due to emerging climate change. According to
Seagar's report, “human-induced aridifications” will become noticeable in the first half
of this century.
I asked Seagar if he really believed that “a perpetual drought” was possible in the
Southwest, as he had written. He shrugged and replied, “You can't really call it a drought
because that implies a temporary change. The models show a progressive aridification.
You don't say, 'The Sahara is in drought.' It's a desert.” If the models are right, then the
American Southwest could face a permanent drying out. The effects of El Niños and La
Niñas will continue to be felt, but the wet years will become less wet while the dry years
will become more dry.
“We are very confident about the realism of these model projections,” Seagar said.
“Federal and state governments need to start planning for this right now.”
Australia, the driest inhabited continent in the world (Antarctica is drier), has felt the
effects of climate change earlier than most other nations, and its experience holds les-
sons for places such as the American Southwest and equatorial Asia and Africa. At first,
Australians reacted to shifting conditions with stubborn refusal to change, but as weath-
er patterns became increasingly extreme in the early 2000s, they had no choice but to
resort to innovative solutions.
THE BIG DRY
Goulburn, New South Wales , Australia's oldest inland city, is usually a lush green from
an annual wash of twenty-six inches of rain. With a population of twenty thousand,
Goulburn sits 120 miles southwest of Sydney, in a pastoral region that celebrates its her-
itage with the world's largest cement sculpture of a sheep, “the Big Merino.” But, in the
first decade of the twenty-first century, Australia suffered the worst drought in its recor-
ded history.
By 2002, 99 percent of New South Wales—the country's most populous state, located
on its southeastern flank—was suffering from a lack of water. By late 2006, average rain-
fall in South Australia was the lowest since 1900. That year, Goulburn saw only four-
teen inches of rain , and its rolling hills turned a depressing brown. By late 2008 and
early 2009, temperatures hit 109 degrees in Melbourne and 114 degrees in Adelaide, the
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