A Few Notes about Trees and Carbon
One half of a tree’s dry weight is carbon. (Nowak, D.J., 1994b, Atmospheric carbon dioxide reduction by Chicago’s urban forest, in: Chicago’s Urban Forest Ecosystem: Results of the Chicago Urban Forest Climate Project, (E.G. McPherson, D.J. Nowak, and R.A. Rowntree, eds.) Gen. Tech. Rep. NE-186, USDA Forest Service, Northeastern Forest Experiment Station, Radnor, PA, pp. 83-94.)
Approximately 800 million tons of carbon are stored in U.S. urban forests with a $22 billion equivalent in control costs. (Coder, Dr. Kim D., “Identified Benefits of Community Trees and Forests”, University of Georgia, October, 1996.)
A single mature tree can absorb carbon dioxide at a rate of 48 lbs./year and release enough oxygen back into the atmosphere to support 2 human beings. (McAliney, Mike. Arguments for Land Conservation: Documentation and Information Sources for Land Resources Protection, Trust for Public Land, Sacramento, CA, December, 1993.)
What happens to all that carbon when a tree is cut down?
If a tree is taken to the landfill, the tree decomposes and releases its sequestered carbon back into the atmosphere as gases. The sequestered carbon is wasted and the volume of greenhouse gases increases.
Alternative uses for the removed tree include mulch, firewood, and lumber. While mulch and firewood certainly have their function, lumber production maintains the most sequestered carbon.
Urban lumber also plays another roll to reduce carbon in the air. Because it is a local product, it spends fewer miles in transport than imported materials. And less time in transport, mean less carbon emissions from the transportation.