"Review of A Great Aridness: Climate Change and the Future of the American Southwest"
Debuys: “If one were to write a survey of all the instances in the history of civilization when societies accepted difficult medicine in order to spare their descendants worse pain in the future, it would make a very short book.”
by Gerald R. Rising
Williams DeBuys has written what I consider the most frightening book of this century. In A Great Aridness: Climate Change and the Future of the American Southwest (Oxford, 2011), he describes a situation already out of control with an ever-worsening future projected. Writing beautifully (which only makes what he says still more scary), DeBuys places the current status of the Southwest in historical context, brings to bear not only the research of academics but also the experiences of affected individuals, and reorganizes masses of data to present them in terms we can (too) easily understand.
This is a book about ever increasing levels of CO2 and higher temperatures; of forest fires, insect scourges and dust storms; of population pressure and power brown-outs in seven western states: Arizona, California, Colorado, New Mexico, Nevada and Utah. But the deeper focus is on water, or more appropriately the absence thereof.
There is much to say about this book, but I will deal here with just one aspect: water in the Colorado River basin, water that is stored and managed for downstream human use in Lakes Mead and Powell.
DeBuys is not talking about some distant future. For example, he quotes one Scripts Institute research paper: “Lake Mead has a 50-50 chance of going dry by 2021.” That’s just ten years from now and it threatens the water supplies of Las Vegas, Tucson, Phoenix, San Diego and Los Angeles.
Consider the evidence that suggests this future. When full, Lake Mead is 360 feet deep. In 2010 it was 224 feet deep, down 37%. At 215 feet a 4% downstream legal reduction will kick in and at 190 feet a further 7% reduction will be necessary. The water level is already so low it threatens Hoover Dam’s electricity generation. Those projected reductions will worsen shortages already being felt at a time when the regional population continues to increase.
Today federal laws governing the use of water in the Colorado Basin below Lake Mead together with natural losses are not being satisfied by new water from rain and snow-melt upstream. The current annual shortfall of water in that area is over 890 billion gallons per year. Translated into human terms, that is an annual water deficit of enough to serve 11 million homes. Water quality is declining as well: DuBuys tells us, “The joke about Las Vegas is that eventually no one in that high-strung city will need anti-depressants. People will get all they need from their drinking water.”
The stage is set according to Brad Udall of Colorado University, for a collision “between 19th century water law, 20th century infrastructure, and 21st century population and climate.”
And solutions are not ready at hand. Sneaking water across the divide from the nearby Mississippi River system would provide very little; running a pipeline down from Canada has been considered and rejected; desalination is prohibitively expensive.
Indeed we have a very serious problem, a national as well as regional problem. We cannot simply write off a section of our country. We could, for example, have an out-migration comparable to that from the Dust Bowl in the 1930s. As DeBuys has it, “Notwithstanding a large cast of senatorial idealogues, right-wing bloviators, and modern-day Iagos lobbying for Big Coal and Big Oil, the protagonists in this drama are the rest of us, our collectivity, the commonweal.
How are we responding? You guessed it: aside from a few individual and too narrowly focused activities, we are doing essentially nothing. Reducing lawn watering doesn’t respond to these kinds of problems.
Why aren’t we stepping up to the plate? DeBuys refers to a 2010 American Psychological Association report: “The list of mental obstacles to action identified by the APA report reads like a catalog of biblical afflictions: Ignorance, Uncertainty, Mistrust and Reactance (i.e., mulishness), Denial, Habit, Impotence (‘What can I do?’), Tokenism, Conflicting Goals, and Belief in Devine Intervention.”
“An insightful body of analysis holds that sudden catastrophes, like earthquakes, fires and great storms, bring people together. They pitch in, cooperate, and ignore the economic and social divisions that previously held them apart. But drought is different. It is gradual and drawn out. An earthquake shudders and is over; a fire blazes and dies; a storm finally passes. But a drought creeps on. Drought doesn’t dissolve differences in the shock of thunderbolt change; it gives people plenty of time to erect defenses, pick sides, and meditate on the defects of their neighbors. Drought divides people, a fact that should remind us that solving the conundrum of water, growth, and hardened demand is work best done in the present, before the curve of rising need and the downshifting line of limits slam together.”
And the temperature is ever rising.
– Gerald R. Rising, SUNY Distinguished Teaching Professor at the University at Buffalo, writes a weekly “Nature Watch” column for the Buffalo News.
Book Excerpt (via the NYT):
The model simulations analyzed by Seager and his team showed the Southwest to be drying out “for a different reason, and that different reason is just a simple consequence of warming up.” Seager explains that when Earth’s surface and its atmosphere warm up, two things happen. One is the intensification of the hydrologic cycle: warmer air holds more water vapor; more vapor converges in wet regions, and it rains more there. “The pattern of water vapor transport intensifies. That makes dry regions drier and wet regions wetter. So that’s part of why the Southwest dries, because it’s already in one of these places where important parts of the atmosphere circulation take moisture away.” The other reason Seager cites is the expansion of the subtropical subsidence zone, where the dry, downwelling air of the Hadley cell returns to the surface of the land.
“And that’s not the same as what causes the natural droughts,” he concludes. “The cycle of natural dry periods and wet periods will continue, but they continue around a mean that gets drier. So the depths—the dry parts of the naturally occurring droughts—will be drier than we’re used to, and the wet parts won’t be as wet as we’re used to, because they’re both happen- ing around a mean state that gets drier and drier.” That new “mean state” is what he calls the new climatology of the Southwest, something similar to the Dust Bowl or the 1950s—a far cry from the anomalously wet period that ran from the late ’70s into the ’90s, which forms many people’s notion of what is “normal” for the region.
JR: For more on Seager’s work, see Seager et al. in Science (subs. req’d), which “predicted a permanent drought by 2050 throughout the Southwest” — levels of aridity comparable to the 1930s Dust Bowl would stretch from Kansas to California. And they were only looking at a 720 ppm of atmospheric CO2 concentrations by 2100. We’re on track for 1000 ppm.