A West Texas thunderstorm on July 24 kicked up a dust cloud as the winds passed over ground parched and barren from a drought that began back in 2010. As the dust passed over Interstate 20 just before 8 p.m., drivers lost sight of the road before them and quickly slowed down, setting off a chain of collisions as 17 cars and trucks ran into one another. Two 18-wheelers sandwiched one car, killing its driver and passenger.
Nearly 60 percent of the United States, mostly in the center and west of the country, is currently experiencing moderate to exceptional drought conditions, according to the National Drought Monitor, and the drought is expected to persist into 2013 for many of those already parched states. The effects of these dry times have come in many forms: The costs of agricultural products, including beef and corn, and the food products derived from them have risen. Barges are having difficulty traversing the Mississippi River. Dry soil is causing the foundations of some homes to crack and leak. And dust storms, like the one in Texas, are echoing the 1930s Dust Bowl, the subject of a new documentary by Ken Burns that premieres on PBS this weekend.
Drought is a natural phenomenon, especially in the semiarid Great Plains. But the way that humans interact with their environment prior to and during a drought can profoundly affect not only how well they weather such an event but also aspects of the drought itself. The Dust Bowl provides the best—or perhaps, most horrific—example of the phenomenon, but the current drought may be foreshadowing an even worse future.
The 1930s drought, though longer, was not too unlike the one now. Scientists have traced the drought of the Dust Bowl years to abnormal sea surface temperatures. and likewise have blamed La Nina for the current drought. “Those are naturally occurring events,” says Richard Seager, a climatologist at the Lamont-Doherty Earth Observatory of Columbia University.
Hot weather and little rain isn’t enough to create a Dust Bowl, though—humans helped. “Human-induced land degradation is likely to have not only contributed to the dust storms of the 1930s but also amplified the drought,” Seager and his colleagues wrote in a 2009 article in the Proceedings of the National Academy of Sciences. “These together turned a modest…drought into one of the worst environmental disasters the U.S. has experienced.”
That land degradation in the late 19th and early 20th centuries came from emigrants moving into the Great Plains as the American West opened up for settlement. Lured by promises of 160 acres of land and a seemingly good climate for growing things, people flocked to the semi-arid region. Using tractors and plows, they dug up 5.2 million acres of grassland between 1925 and the early 1930s.
Weather in the middle of the United States, then and now, is dominated by dry winds from the West but also marked by violent clashes caused by air moving in from the Arctic or the Gulf of Mexico. “It is an unreliable, intractable place, wildly oscillating around an almost meaningless mean,” University of Kansas historian Donald Worster wrote in Dust Bowl: The Southern Plains in the 1930s.
Wetter than average in the first decades of the 20th century, the weather of the Great Plains misled settlers, and they pushed into places not particularly suitable for agriculture. And when the pendulum had swung from wet to dry in the early 1930s, the native grasses and vegetation that had held the soil in place during previous droughts were gone, replaced by wheat and other crops that quickly withered and died under the hot sun.
“If you get rid of plant cover, or reduce it in various ways, then more of the energy of the wind is able to get to the soil surface and therefore, you [get] more dust emission,” says Greg Okin, a University of California, Los Angeles geographer.
The year 1932 saw 14 dust storms, followed by 38 in 1933 and another 22 in 1934. By the middle of the decade, the people of the Great Plains knew what to do when a dust storm was on the horizon. On April 14, 1935, when Pauline Winkler Grey of Meade County, Kansas, saw a smoky grey-blue haze in the distance, her family quickly sealed the cracks around the windows in their small house, despite the heat.