Civilization Collapse, The Dust Bowl

"The Dust Bowl was actually a series of dust storms that ran through the Great Plains of the United States and Canada beginning in 1933. Farmers in the American Midwest were encouraged to develop marginal lands to meet the demand for food and fiber that the Great War and its aftermath had created. At the same time many Midwest farms became 'overcapitalized' relative to the actual carrying capacity of their lands. To cover the expenses of tractors, listers, and a new generation of plows, farmers tried to press as much land as possible into production. When the United States fell into the Great Depression at the end of the 1920s, prices for food dropped and farmers had to cultivate even more marginal lands to pay their debts. Once these lands were striped of the natural vegetation, they either fell out of production or the continuous plowing exposed the soil, making it vulnerable to the ferocious winds of the American Midwest. Damage might not have been as acute had these events not coincided with a period of prolonged drought."