By adding highly accurate radiocarbon dating of soil to standard Earth system models, environmental scientists from the University of California, Irvine and other institutions have learned a dirty little secret: The ground will absorb far less atmospheric carbon dioxide this century than previously thought.
Researchers used carbon-14 data from 157 sample sites around the world to determine that current soil carbon is about 3,100 years old -- rather than the 450 years stipulated by many Earth system models.
"This work indicates that soils have a weaker capacity to soak up carbon than we have been assuming over the past few decades," said UCI Chancellor's Professor of Earth system science James Randerson, senior author of a new study on the subject to be published in the journal Science. "It means we have to be even more proactive in finding ways to cut emissions of fossil fuels to limit the magnitude and impacts of climate warming."
By adding highly accurate radiocarbon dating of soil to standard Earth system models, environmental scientists from the University of California, Irvine and other institutions have learned a dirty little secret: The ground will absorb far less atmospheric carbon dioxide this century than previously thought.
Researchers used carbon-14 data from 157 sample sites around the world to determine that current soil carbon is about 3,100 years old -- rather than the 450 years stipulated by many Earth system models.
"This work indicates that soils have a weaker capacity to soak up carbon than we have been assuming over the past few decades," said UCI Chancellor's Professor of Earth system science James Randerson, senior author of a new study on the subject to be published in the journal Science. "It means we have to be even more proactive in finding ways to cut emissions of fossil fuels to limit the magnitude and impacts of climate warming."
Through photosynthesis, plants absorb CO2 from the air. When trees and vegetation die and decay, they become part of the soil, effectively locking carbon on or beneath Earth's surface -- keeping it out of the atmosphere, where it contributes to global warming. In their study, the researchers showed that since this process unfolds over millennia versus decades or centuries, we should expect less of this land carbon sequestration in the 21st century than suggested by current Earth system models.
Continue reading at ScienceDaily
Image credit: Missouri Department of Natural Resources
