Filmmaker Ken Burns’ latest documentary “The Dust Bowl” aired on PBS in November, serves as a reminder and wake-up call about the threats posed by climate change to agriculture.
The documentary, consisting of two 2-hour films “The Great Plow-Up” and “Reaping the Whirlwind”, brings to the audience a vivid picture of one of the darkest times of the 20th century through a combination of survivor’s accounts, historian’s input, and dramatic movie footage. According to PBS, “The Dust Bowl chronicles the worst man-made ecological disaster in American history, in which the frenzied wheat boom of the ‘Great Plow-Up,’ followed by a decade-long drought during the 1930s nearly swept away the breadbasket of the nation… It is also a morality tale about our relationship to the land that sustains us—a lesson we ignore at our peril.”
“We were just too selfish and were trying to make more money off of the wheat, and it didn’t work out,” says one survivor. Resulted from both severe drought and unsustainable farming practices, the 1930s Dust Bowl left millions of acres of farmland ruined and hundreds of thousands of people dislocated, causing incalculable damage to the environment and economy.
“The next dust bowl” published in Nature, Joe Romm wrote, “Warming causes greater evaporation and, once the ground is dry, the Sun’s energy goes into baking the soil, leading to a further increase in air temperature. That is why, for instance, so many temperature records were set for the United States in the 1930s Dust Bowl; and why, in 2011, drought-stricken Texas saw the hottest summer ever recorded for a US state.”
So, are there any lessons from the 1930s Dust Bowl applicable to California agriculture? Certainly water issues top the list of concerns — at times flooding from early and rapid spring melting of the Sierra snow pack will challenge growers, and later in the dry season water scarcity will be the problem. With some notable exceptions in parts of the Central Valley, severe dust issues are not likely (though Romm argues that the risks have been underestimated).
Nonetheless, there are practices that California growers can adopt to buffer against the myriad of potential climate challenges. Investing in soil building tops the list. Practices such as cover cropping, applying compost and manure and conservation tillage increase the soil organic matter and provide many benefits — for example, increased water penetration and retention, reduced runoff and erosion, elevated carbon sequestration, enhanced fertility and productivity and economic gain. Investing in soil organic matter may be the best insurance policy a farmer can get to buffer against climate change and whatever version of a dust bowl disaster may California face.