Picture from the National Archives, taken during the “Dust Bowl” in the 1930′s
The world’s croplands are in decline due to the pressure of human activities. The figure shows the regional and global trends in the total available area of the world’s croplands. The loss of arable land has been caused by a number of factors, many or most of which are tied to human development. The primary causes are deforestation, overexploitation for fuelwood, overgrazing, agricultural activities and industrialization. On the global basis, the soil degradation is caused primarily by overgrazing (35%), agricultural activities (28%), deforestation (30%), overexplotation of land to produce fuelwood (7%), and industrialization (4%).
The University of Washington published that throughout history civilizations expanded as they sought new soil to feed their populations, and then ultimately fell as they wore out or lost the dirt they depended upon. When that happened, people moved on to fertile new ground and formed new civilizations. That process is being repeating today but the results could be far more disastrous for humans because there are very few places left with fertile soil to feed large populations, and farming practices still trigger large losses of rich dirt.
“We’re doing the same things today that past societies have done, and at the same rate,” said David Montgomery, a UW professor of Earth and space sciences who studies the evolution and structure of the various aspects of the Earth’s surface. In essence, he said, we are slowly removing our planet’s life-giving skin. “It only takes one good rainstorm when the soil is bare to lose a century’s worth of dirt.”
Montgomery is the author of “Dirt: The Erosion of Civilizations,” in which he examines how soil is slowly created over time, the vital role it has played in the rise and fall of civilizations from Mesopotamia to Rome, and how it shaped where and how we live today