Probably the most interesting revelation regarding the causes and effects of droughts was the determination of their linkage to human activity. Droughts have occurred throughout history, so clearly are not solely the result of human interaction with the environment. To the extent that droughts are occurring more frequently and lasting longer, however, the connection between activities like deforestation, the burning of fossil fuels and destruction of the ozone layer of Earth’s atmosphere, and the process of desertification, a direct outgrowth of prolonged droughts, was an eye-opening experience for many people.
Deforestation is a contributor to desertification and a cause of drought because the process of eliminating moisture-storing plants on a mass scale, and the consequent drying of the surrounding soil, cause long-term damage to both the surface and to the air. Construction of dams also contributes to droughts by diverting water from regions where it historically flowed and, when combined with poor soil management, creates deserts, the latter a contributing factor in the creation of the Dust Bowl during the 1930s – a development that destroyed an agrarian economy and forced mass migration to other regions, including to water-starved California.
If, as scientific studies have determined, global climate changes are a product of human activities, and that average temperatures are rising, then already dry, arid regions may become hotter and drier – again, a cause of desertification, which is occurring in northern Africa. The U.S. National Oceanic and Atmospheric Administration (NOAA) reported in 2011 that increasing incidences of wintertime droughts in the Mediterranean region are caused at least in part from human activity. While the data and findings on the issues of climate change and its causes are disputed, there is considerable irrefutable evidence that regional climates are changing, and that substances released into the air from human manufacturing processes and by automobile emissions have cumulatively contributed to these changes.
Flying into Los Angeles in the late summer of 1979, this educator was struck by the massive, dark cloud that sat over the city, and, while transiting through the city, by my inability to actually see skyscrapers when only a block away. That was a particularly bad time for that region’s air quality, but it was not uncommon on a global basis. It was inconceivable to me that such pollution could not have long-term environmental consequences. Decades later, the air in Los Angeles is better, but massive industrialization in countries like China and India, combined with the enduring legacy of America’s consumption of fossil fuels, have created major problems that are almost certainly contributing to climate change and to increased incidences of droughts.