According to a new study by a group of scientists of the University of California (UCI), a rise of global temperatures will release more carbon dioxide from forest soils. And that increased release of the greenhouse gas in the atmosphere could make the climate heat yet even faster.
It is the first study that shows that most carbon in the topsoil is vulnerable to a warm weather effect, said Francesca Hopkins, a doctoral researcher at the UOC and an author of the report. Carbon dioxide is an odorless gas that helps trap heat in the atmosphere. It is produced both naturally and through human activities, such as burning gasoline, coal, oil and wood.
“We found that decade-old carbon in surface soil is released to the atmosphere faster when temperatures become warmer,” Hopkins said. That suggests that warming soil could accelerate global warming.
Forest soil contains a large amount of carbon from decaying leaves and roots.
It was recently published a map of carbon storage in the forests.
Hopkins and a team of scientists from across the country collected samples of it and tested them in the laboratory. Climate scientists are concerned that trees and soils could contribute more carbon to the atmosphere than they capture and store.
“Our results suggest that large stores of carbon that build up over the last century as forests recovered, will erode with rising temperatures,” said Susan Trumbore, professor of Earth system science at the UOC.
Microbes near the tree roots consume carbon and then release it into the air as carbon dioxide, the study says.
The finding is a challenging issue for those looking to limit the release of carbon dioxide to lessen global climate change.
“There are carbon dioxide sources that we can’t control,” Hopkins said. “We can control how much gasoline we burn, how much coal we burn, but we don’t have control over how much carbon the soil will release once this gets going.”