And some farmers may soon be unable to irrigate their way through a drought. The Ogallala Aquifer lies beneath eight Great Plains states and feeds about 27 percent of the nation’s farmland. Some aquifers are regularly recharged with water from rain or snow, but not the Ogallala. If completely drained, the aquifer would take 6,000 years of rain to fill back up. Decades of irrigation, development and industry have taken their toll on this important water source. Farmers started noticing in the 1990s that the water in their wells was dropping. That drawdown has continued, and water levels have dropped by as much as several feet per year in some places. Just when the aquifer will become unusable is difficult to predict, but irrigated agriculture in the region may become near impossible within decades.
And now conservation—one of the great legacies of the Dust Bowl—is becoming a target in an era of government cuts. Critics find the policies difficult to justify, for example, paying farmers not to plant and to instead leave land covered with protective, native vegetation.
Scientists can’t predict whether another Dust Bowl will happen, but they see worrisome signs not only in the Great Plains but in other semi-arid regions across the world, such as northern China where frequent dust storms sweep air full of dirt and industrial chemicals from polluted cities into Japan and Korea. “On a regional level, human activities matter a lot,” Okin says.
That’s the big lesson from the Dust Bowl—that it’s possible for humans to take a natural disaster and make it worse for the environment and for themselves. “We’d better be very careful about how the land is treated,” Seager says, “to make sure that we don’t get remotely close to triggering that kind of feedback.”