Robert Enns from Guymon, Oklahoma, remembers Sunday, 14 April 1935 as a fine spring day with a cloudless blue sky. But around 4 pm, he watched a black cloud approach from the horizon. Seeing this cloud and its rapid progress, Enns’ father instructed the boy Robert and his brother to hurry and bring the cows from the pasture to the barn.
As they returned to the barn with the cows, Enns, who shared his story in a 2012 documentary, Memories of Black Sunday, remembers being engulfed in a black cloud of dirt, carried on 60-mile-per-hour winds, that obscured all light so that the boys couldn’t see their hands in front of their faces. Panicked and lost, Enns called out to his brother, who told him to grab hold of a cow’s tail. “The cows know where they’re goin’ and we don’t.” So, they grabbed hold of a cow’s tail and made it safely back to the barn.
This storm, which came to be known as “Black Sunday,” whipped up millions of tons of dirt and dust. In his book The Worst Hard Time, Timothy Egan notes that the Black Sunday “duster” moved twice the amount of soil that was excavated while building the Panama Canal, a project that took seven years. Black Sunday lasted an afternoon.
In the Great Plains of the United States, the 1930s came to be known as the Dust Bowl era, in reference to storms like this one. These dust storms were the result of a prolonged drought combined with the consequences of an agricultural boom following World War I that resulted in thousands of miles of native prairie being plowed under for wheat and corn crops. Unfortunately, the soil that had been stabilized by the roots of the prairie grasses for hundreds of years was now unmoored, creating the perfect recipe for columns of blowing dust.
The Dust Bowl era was the first human-made large-scale ecological disaster in US history. Fortunately, the government recognized the need to improve land management strategies and responded by ordering the Civilian Conservation Corps to plant millions of trees from Canada to Mexico, which served as a windbreak and held water and soil in place. The government also offered subsidies to farmers who were willing to embrace different farming methods, such as cover crops and no-till farming, that would preserve topsoil.
As we consider the myriad impacts of climate change on our global resources and environment, the events of the Dust Bowl era serve as a stark reminder of the consequences when humans neglect to consider the impact of our actions on our environment.
This issue of Photonics Focus looks at the ways that photonics technologies are working to sustain our planet’s resources, including light-based technologies to purify polluted water, and heliostats, which direct solar radiation to receivers that can capture solar-thermal energy for conversion to electricity, or for storage in materials like molten salt that allow delayed use of solar thermal energy. Another feature article takes a critical look at the enormous resources consumed by data centers—a problem that is compounded by the prevalence of AI—and looks towards low-energy photonic computing solutions.
Today, the perils of deeply plowed soil are fully understood, and soil conservation techniques are widely practiced by farmers around the world. We learned the lessons from the Dust Bowl era and changed course. We can do it again.
Gwen Weerts, Editor-in-chief
