Should we store carbon in trees?
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In order to explore for the most effective strategy for using forests to mitigate global climate change, we have constructed a simple model of C uptake during forest growth and the fate of this C when forests are harvested and used as fuel to replace fossil fuels. We suggest that trees are equally effective in preventing the accumulation of CO2 in the atmosphere if they remove a unit of C from the atmosphere or if they supply a sustainable source of energy that substitutes for a unit of C discharged by burning fossil fuels. The model shows that the most effective strategy for using forest land to minimize increases in atmospheric CO2 will depend on the current status of the land, the productivity that can be expected, the efficiency with which the forest harvest is used to substitute for fossil fuels, and the time perspective of the analysis. For forests with large standing biomass and low productivity the most effective strategy is to protect the existing forest. For land with little standing biomass and low productivity, the most effective strategy is to reforest or otherwise manage the land for forest growth and C storage. Where high productivity can be expected, the most effective strategy is to manage the forest for a harvestable crop and to use the harvest with maximum efficiency either for long-lived products or to substitute for fossil fuels. The longer the time perspective, the more likely that harvesting and replanting will result in net C benefits.
KeywordsBiomass Atmosphere Climate Change Simple Model Fossil Fuel
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- Dyson, F.J., and G. Marland (1979) “Technical Fixes for the Climatic Effects of CO2”, p. 111–118 in W.P. Elliott and L. Machta (eds.), Workshop on the Global Effects of Carbon Dioxide from Fossil Fuels, Miami Beach, Florida, March 7–11, 1977, U.S. Department of Energy CONF-770385.Google Scholar
- Harmon, M.E., W.K. Ferrell, and J.F. Franklin (1990) “Effects on Carbon Storage of Conversion of Old-Growth Forests to Young Forests”, Science, 247, 699–701.Google Scholar
- Lynd, L.R., J.H. Cushman, R.J. Nichols, and C.E. Wyman (1991) “Fuel Ethanol from Cellulosic Biomass”, Science, 251, 1318–1323.Google Scholar
- Marland, G. (1983) “Carbon Dioxide Emission Rates for Conventional and Synthetic Fuels” Energy 8, 981–992.Google Scholar
- Marland, G. (1988) The Prospect of Solving the CO2 Problem Through Global Reforestation, DOE/NBB-0082, U.S. Department of Energy, February, 66p.Google Scholar
- Moulton, R.J., and K.R. Richards (1990) Costs of Sequestering Carbon Through Tree Planting and Forest Management in the United States, GTR WO-58, U.S. Department of Agriculture, Forest Service.Google Scholar
- Sherman, W.R. (1990) Personal Communication.Google Scholar
- Turhollow, A.F. and R.D. Perlack (1991) “Emissions of CO2 from Energy Crop Production”, Biomass and Bioenergy, 1, 129–135.Google Scholar
- U.S. Congress Office of Technology Assessment (1991) Changing by Degrees: Steps to Reduce Greenhouse Gases, OTA-O-482, U.S. Government Printing Office.Google Scholar
- Wright, L.L, R.L. Graham. A.F. Turhollow, and B.C. English (1992) “Opportunities to Mitigate Carbon Dioxide Build-up Using Short Rotation Woody Crops”, in R.N. Sampson and D. Hair (eds.) Forests and Global Warming, Vol. 1, American Forestry Association, Washington, D.C., in press.Google Scholar