Reports from a government monitoring system in the central and western U.S. indicate that rangeland soils there could be storing a share of unaccounted for carbon.
Climatologists say they cannot account for 20 billion tons of carbon emitted every year as carbon dioxide from fossil fuel burning, deforestation and other human activities. The monitoring network, formed in 1995, began looking for the missing carbon in the nation's 824 million acres of rangeland.
Government scientists estimate that U.S. rangeland soils have the potential to store up to 110 million metric tons of carbon each year. That's about 5 percent of the annual U.S. emissions of carbon.