Part two of a series:
The clouds were darkening when we entered the restaurant near our home in Sun City West, Arizona. A few minutes later, the summer monsoon storm hit us. Winds were so strong that they knocked a patron to the sidewalk as she and her husband tried to reach their car just outside the restaurant door. Then came the rain—so heavy that a stream of water curb high coursed down the street.
In an hour, everything was quiet, and the flooded streets were dry. We drove home as though nothing had happened.
Early the next morning, I took my regular bike ride on quiet desert roads. At one spot, near the village of Nadaburg, a stretch of the road thirty yards wide was covered with sand and debris a foot deep. I could see the relevance of signs that usually seemed so anomalous on these desert roads: “Watch for Water on the Road.”
For hundreds of years the people who lived in the southwestern deserts understood the climate: hot and dry, but with two seasons when rains would water the earth. They had learned how to use this limited precipitation to grow the food they needed and they had developed complex irrigation systems that sustained densely populated communities for generations.
Suddenly, these urban societies collapsed and, as we now know, with starvation and internecine conflict. Has the climate that wreaked havoc on these early desert societies changed so that we can plan our lives confidently? Or can we expect new periods of crisis? Are we wise enough and our regulatory systems sophisticated enough that we will be able to survive new periods of drought and flood?
These are the questions that meander through my mind as I and my bicycle wander over the quiet byways of the western world I love so much.
In their book The West Without Water: What Past Floods, Droughts, and Other Climatic Clues Tell us About Tomorrow, B. Lynn Ingram and Frances Malamud-Roam answer, in a disquieting way.
They base their climatic meditations on the painstaking work of a wide range of earth scientists, people who study trees, ice crystals extracted from glaciers, sediment in places like San Francisco Bay and ocean waters off of Santa Barbara, and archeological ruins across the West. They explain carefully, although in a largely nontechnical way, how their colleagues can develop detailed chronologies of climatic conditions and compare them with human history.
They also discuss how variations in the number of sunspots affect what happens on earth how changes in the orientation of the earth toward the sun affect periods and places that are wet and dry and hot and cold. Especially interesting to me are their descriptions of two oceanic and cosmic factors that largely control climate and weather.
The “seemingly random and unpredictable swings in climate [in the Pacific Southwest] are largely brought about by periodic changes in the Pacific Ocean and the atmosphere above it, producing phenomena known as the El Niño–Southern Oscillation (ENSO) and the Pacific Decadal Oscillation (PDO)…ENSO events are typically six to eighteen months in duration, whereas PDO phases last two to three decades or more” (51).
Ingram and Malamud-Roam reach three conclusions.
(1) Over the past 1,500 years, the climate of the American West has alternated between extended periods of intense drought and relatively well-watered interludes. Serious flooding and severe wild fires are part of the pattern, and changes can be sudden and catastrophic.
(2) The period since the Spanish occupation, even though it has seemed arid, is for the most part one of the well-watered interludes. Although there have been droughts in the recent history of the West (1927–1935 and 1987–1992, in particular) and floods (1861–1862, when the entire Central Valley of California was under water), these events have been short-lived manifestations of the western climatic pattern.
(3) The primary regulatory system in the American West since the early 1900s—the building of dams—has worked well but is nearing a crisis point. There is “a 50 percent chance that both Lake Mead and Lake Powell could reach ‘dead pool,’ rendering them useless for hydroelectric power generation or useful water storage as early as 2021” (196). When that moment comes, ordinary life in cities from Las Vegas to San Diego will be threatened in the most serious ways imaginable.
The authors of The West Without Water suggest a course of action for people throughout the West, actions that could help us avoid the catastrophic collapse of a way of life that most of us take for granted. Now in my octogenarian years, I may not live long enough to experience this climatic apocalypse. While time remains, I hope to continue as an open-road cyclist, especially in the West.
But even for me, living as I do in part of the West that is currently wet, life has to change. More about this next time.