From The "Who Would Have Thunk it?" Dept.
"Wood burning does not release any more carbon dioxide than the eventual biodegradation of the wood would if it was not burned.
Wood burning can therefore be considered "carbon neutral" - the CO2 released to the atmosphere by combustion is recycled continuously into new plant growth as part of the carbon cycle, while the energy released during combustion is simply a form of stored solar energy."
"Rather than cutting fewer trees and using less wood, we should be growing more trees and using more wood." -Patrick Moore Co-Founder of Greenpeace