Humans reportedly erode soil 100 times faster than nature, an astonishing new study revealed.
Through activities such as logging and the cutting down of native forests to make way for agricultural land, we are doing damage that would normally occur over thousands of years in just a matter of decades.
"Soils fall apart when we remove vegetation," study co-author Paul Bierman said in a statement, "and then the land erodes quickly."
"Earth doesn't create that precious soil for crops fast enough to replenish what the humans took off," researcher and geologist Dylan Rood added. "It's a pattern that is unsustainable if continued."
It is well known that deforestation and agriculture increases erosion above normal levels. But accurately measuring these rates is easier said than done, and also makes it difficult to determine humanity's impact on Earth's soil. In this new study, published in the journal Geology, researchers for the first time have determined our influence on erosion rates ever since Europeans settlers began clearing trees and farming in the 1700s.
A team from the University of Vermont collected 24 sediment samples from the Roanoke, Savannah, or Chattahoochee Rivers, where hundreds of years ago there was a lot more clay soil than you see today. They relied on measurements of the isotope beryllium-10, where the more beryllium they find means the slower the rate of erosion (because the isotope builds up in the top few feet of the soil).
Astonishingly, they discovered that rates of hillslope erosion before European settlement were about an inch every 2500 years. However, after the peak in land disturbance in the late 1800s and early 1900s, human activity caused rates to surge to an inch every 25 years.
"Our study shows exactly how huge an effect European colonization and agriculture had on the landscape of North America," Rood said, "humans scraped off the soil more than 100 times faster than other natural processes!"
Soil is more important than you think, with its underground organisms boasting incredible diversity that is still little understood but impacts various ecosystems around the world.
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