In a study released last week, NASA warned of a pending “megadrought” in the American Southwest and Central Plains, invoking comparisons to the Dust Bowl of the 1930s. The study, conducted by researchers from NASA and Cornell and Columbia universities, predicted that such a drought could start within the next 35 years, cause severe water shortages and destroy vegetation across the region.
The Dust Bowl lasted about a decade; this drought could extend three decades or longer, putting recent water shortages in California and Texas into tighter perspective. According to one of the study’s co-authors, Cornell’s Toby Ault, “We really need to start thinking in longer-term horizons about how we’re going to manage it.”
Much work must be done to minimize this predicted drought’s impact on ecosystems and people, such as tracking the status of the ecosystems that produce our fresh water. CI will contribute to this effort through work on our Freshwater Health Index, which will measure the overall condition of these ecosystems and their capacity to support healthy and economically sustainable human populations.
Lessons from the Past
My parents aren’t old enough to remember the Dust Bowl, yet this trying period of American history was recently brought to life for me as I read “The Worst Hard Time: The Untold Story of Those Who Survived the Great American Dust Bowl.” Timothy Egan’s highly readable narrative, which won the National Book Award in 2006, describes the horrible environmental catastrophe of the ‘30s and the lasting impact it had on the people, the communities and the landscape of our American heartland.
Egan explains how in the throes of the Great Depression, many families raced to plant subsidized wheat crops. Their plows destroyed the native prairie grass, a web of more than 470 species of tough, resilient, deep-rooted grasses that kept the soil intact for millennia. By the end of 1931, 33 million acres [13.3 million hectares] of robust grassland were gone.
The subsequent blanket of particulate matter ultimately grew to what Egan describes as a “great rectangle of dust from the Great Plains to the Atlantic,” weighing 350 million tons and stretching across 1,800 miles [almost 2,900 kilometers].
The destruction of the landscape threw the whole ecosystem out of whack: “In place of buffalo grass, prairie chickens, and mourning doves were black blizzards, black widows, cutworms, rabbits and … a frenzied sky of grasshoppers … locusts that laid eggs in the flatlands and multiplied during dry years without predators.” More than a million people left this land between 1930-1935.
Since then, the region has suffered more droughts — in the ‘50s, the ‘70s and again between 2000 and 2003. What kept the land from turning into another Dust Bowl? According to Egan, it was the concept of soil conservation districts: farmers entering contracts to manage their land as a single ecological unit. This is the only New Deal grassroots operation that survives to this day.
We will, of course, need more than careful soil management if we are to survive the coming megadrought. CI will contribute by developing our Freshwater Health Index. Following the lead of our Ocean Health Index, which is already influencing national governments to take action on protecting marine ecosystems that provide essential benefits for people, we hope that a similar tool for fresh water will contribute to the science and policy of long-term watershed management.
We may not be able to completely mitigate the effects of coming droughts. But with careful understanding, monitoring and protection of key ecosystems, we can minimize the impact of these kinds of weather events — and help nature continue to provide the multitude of benefits we all depend on every day.
Andy Wilson is CI’s vice president for development.
Cover image: Baked Earth in Botswana's Okavango Delta. (Sam D Cruz)