Superheated American City Dealing with 110 Degrees for 33 Days -- Phoenix Confronts Apocalyptic Climate Change
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In Flight From the Sun
It goes without saying that Phoenix’s desert setting is hot by nature, but we’ve made it hotter. The city is a masonry world, with asphalt and concrete everywhere. The hard, heavy materials of its buildings and roads absorb heat efficiently and give it back more slowly than the naked land. In a sense, the whole city is really a thermal battery, soaking up energy by day and releasing it at night. The result is an “urban heat island,” which, in turn, prevents the cool of the desert night from providing much relief.
Sixty years ago, when Phoenix was just embarking on its career of manic growth, nighttime lows never crept above 90°F. Today such temperatures are a commonplace, and the vigil has begun for the first night that doesn’t dip below 100°F. Studies indicate that Phoenix’s urban-heat-island effect may boost nighttime temperatures by as much as 10°F. It’s as though the city has doubled down on climate change, finding a way to magnify its most unwanted effects even before it hits the rest of us full blast.
Predictably, the poor suffer most from the heat. They live in the hottest neighborhoods with the least greenery to mitigate the heat-island effect, and they possess the least resources for combatting high temperatures. For most Phoenicians, however, none of this is more than an inconvenience as long as the AC keeps humming and the utility bill gets paid. When the heat intensifies, they learn to scurry from building to car and into the next building, essentially holding their breaths. In those cars, the second thing they touch after the ignition is the fan control for the AC. The steering wheel comes later.
In the blazing brilliance of July and August, you venture out undefended to walk or run only in the half-light of dawn or dusk. The idea for residents of the Valley of the Sun is to learn to dodge the heat, not challenge it.
Heat, however, is a tricky adversary. It stresses everything, including electrical equipment. Transformers, when they get too hot, can fail. Likewise, thermoelectric generating stations, whether fired by coal, gas, or neutrons, become less efficient as the mercury soars. And the great hydroelectric dams of the Colorado River, including Glen Canyon, which serves greater Phoenix, won’t be able to supply the “peaking power” they do now if the reservoirs behind them are fatally shrunken by drought, as multiple studies forecast they will be. Much of this can be mitigated with upgraded equipment, smart grid technologies, and redundant systems. But then along comes the haboob.
A haboob is a dust/sand/windstorm, usually caused by the collapse of a thunderstorm cell. The plunging air hits the ground and roils outward, picking up debris across the open desert. As the Arabic name suggests, such storms are native to arid regions, but -- although Phoenix is no stranger to storm-driven dust -- the term haboob has only lately entered the local lexicon. It seems to have been imported to describe a new class of storms, spectacular in their vehemence, which bring visibility to zero and life to a standstill. They sandblast cars, close the airport, and occasionally cause the lights -- and AC -- to go out. Not to worry, say the two major utilities serving the Phoenix metroplex, Arizona Public Service and the Salt River Project. And the outages have indeed been brief. So far.
Before Katrina hit, the Army Corps of Engineers was similarly reassuring to the people of New Orleans. And until Superstorm Sandy landed, almost no one worried about storm surges filling the subway tunnels of New York.