SANTA FE, N.M., April 1 (UPI) -- Thousands of years before the Industrial Revolution and greenhouse gases, humans were having an impact on the climate, a Swiss researcher says.
A study says swathes of trees that otherwise would have soaked up naturally occurring carbon dioxide were cleared by people as they moved from hunting and gathering to farming, ScienceNews reported this week.
"Our data show very substantial amounts of human impact on the environment over thousands of years," study leader Jed Kaplan of the Federal Polytechnic School in Lausanne, Switzerland, said.
"That impact really needs to be taken into account when we think about the carbon cycle and greenhouse gases."
Before the start of the Industrial Revolution, human activity on the land resulted in nearly 380 billion tons of carbon being put into the atmosphere, ScienceNews.org reported Tuesday.
Climate researchers consider 1850 as the start of the Industrial Revolution, but that does not mean the world was free of human impact before then, Kaplan said.
"I call it the virgin continent myth," Kaplan said.
Much earlier than that, between 8,000 to 10,000 years ago, people were clearing land for agriculture in the Fertile Crescent.
Kaplan's carbon estimates support a theory that the human impact on the globe's climate must be considered to have begun far earlier in history than previously thought, scientists say.
