Warmer forests expel carbon from soils creating "vicious cycle"

13 June 2012

As the world warms, temperate forests could become a source of carbon dioxide emission rather than a sink according to a new study in the Proceedings of the National Academy of Sciences (PNAS). Scientists found that two forest sites in the U.S. (Wisconsin and North Carolina) emitted long-stored carbon from their soils when confronted with temperatures 10-20 degrees Fahrenheit (5.5-11.1 degrees Celsius) higher than average.
 

"We found that decades-old carbon in surface soils is released to the atmosphere faster when temperatures become warmer," explained lead author Francesca Hopkins with the UNiversity of California Irvine in a press release. "This suggests that soils could accelerate global warming through a vicious cycle in which man-made warming releases carbon from soils to the atmosphere, which, in turn, would warm the planet more."