Logs burning in a fireplace, an image of green energy - or so we thought. Apparently it depends upon how the logs are harvested. If your fireplace is fed by commercial clearcutting, you may be pumping CO2 into the air from deep soil.
Global atmospheric studies often don't consider carbon in deep (or mineral) soil because it is thought to be stable and unaffected by timber harvesting. But the Dartmouth findings show deep soil can play an important role in carbon emissions in clear-cutting and other intensive forest management practices. The findings suggest that calls for an increased reliance on forest biomass be re-evaluated and that forest carbon analyses are incomplete unless they include deep soil, which stores more than 50 percent of the carbon in forest soils.
"Our paper suggests the carbon in the mineral soil may change more rapidly, and result in increases in atmospheric carbon dioxide, as a result of disturbances such as logging," said Dartmouth Professor Andrew Friedland, a co-author. "Our paper suggests that increased reliance on wood may have the unintended effect of increasing the transfer of carbon from the mineral soil to the atmosphere. So the intended goal of reducing carbon in the atmosphere may not be met." [emphasis mine]