The Age of Perpetual Drought - The Ripple Effect: The Fate of Freshwater in the Twenty-First Century - page 111

Once he returned to civilization, McGee wrote an analysis of Valencia's extreme de-
hydration entitled “Desert Thirst as Disease.” It is a closely observed record of what hap-
pens to the human body when it runs out of water:
Pablo's … formerly full-muscled legs and arms were shrunken and scrawny; his ribs
ridged out like those of a starveling horse … his lips had disappeared as if ampu-
tated, leaving low edges of blackened tissue; his teeth and gums projected like those
of a skinned animal, but the flesh was black and dry as a hank of jerky; his nose was
withered and shrunken to half its length; his eyes were set in a winkless stare … his
skin generally turned a ghastly purplish yet ashen gray … the heartbeat was slow, ir-
regular, fluttering, and almost ceasing in the longer intervals between the stertorous
breathings.
When we imagine the worst-case scenario for climate change, this is one possible
image: all of us reduced to Pablo Valencias, lost in a desert without a drop to drink.
In Phoenix, Arizona, which rises from the Sonoran in “the Valley of the Sun,” not far
from where Valencia wandered, such a fate is more than idle speculation. For three
months a year, average high temperatures in Phoenix surpass one hundred degrees .
There is less than 10 percent humidity, and rainfall averages only seven inches a year.
According to the National Weather Service, the average temperature of Phoenix has
risen five degrees since 1960. Every summer, about eight hundred Phoenicians are hos-
pitalized with heat-related problems; some of them, usually the very young or old, die. A
report published by the ArizonaRepublicpredicts that average temperatures in Phoenix
could rise by fifteen to twenty degrees over a generation, due to the “urban heat-island
effect”—i.e., the more blacktop highways, parking lots, air-conditioned office towers,
and sports stadia that are built in the desert, the more heat will be trapped in the valley,
raising temperatures to blast-furnace heights. Most credible scientists believe this shift
is due to climate change.
Life in Phoenix can be viewed as a kind of experiment in extreme living, like a dress
rehearsal for life on Mars, or perhaps for a future America beset by regions of extreme
heat and dryness. “Having already seen an increase … in our average temperatures,” the
Tucson Citizenreported in 2009, “ we are at ground zero for climate change . ”
When there is a lot of moisture, trees grow thick rings; when it is dry, the rings become
thin. Looking at wood samples from around the West, paleoclimatologists from the