It would be equivalent to lowering the surface of the Earth by 6 centimetres. That’s how much soil humankind has so far eroded. At the height of the Roman empire, people started moving more earth than all natural forces combined, while today, erosion from agriculture alone moves more sediment – about 21 gigatons per year -than continental glaciers managed at their peak during the Pleistocene Ice Age.
Geologists at Syracuse University in New York and the University of Texas at Austin calculated the natural rate of sediment erosion and deposition over the past 500 million years from previously published studies. They…
