PROGRAM TITLE: Analysis of Terrestrial Carbon Sinks ACTIVITY STREAM: Process Studies SCIENCE ELEMENT:Biogeochemical Dynamics TENNESSEE VALLEY AUTHORITY (TVA) SCIENTIFIC MERIT: The degree to which terrestrial systems are able to capture and sequester carbon is an important uncertainty In both modeling carbon flux and in the development of mitigation and CO2 offset strategies. Most efforts in this area to date have been either national or global in scale. However, it is important to address this question regionally since this is the most likely level at which reductions and options will be evaluated and instituted. GIS date bases provide an excellent opportunity to inventory and delineate both existing carbon stores and assess the potential for future storage at the regional level. This project would first determine existing conditions to determine if further storage potential exists in the currently forested areas and more importantly the extent of areas that might lend themselves to either afforestation or to the production of woody biomass fuels as dedicated plantations. Urban areas would also be evaluated to determine how much of an impact an aggressive urban tree planting program could have within the region. Based on these analyses and ongoing research activities, the carbon storage potential within the region could be assessed and options for carbon dioxide offsets evaluated within the next two years. More specifically, this project will use the TVA region as a case study to: (1) inventory standing pools of carbon in soils and forests in the region; (2) determine the areas best suited to serve as long-term sites for carbon sequestration in soils and plants, including urban areas; and (3) assess the magnitude of opportunities to create carbon dioxide offsets using soil and plant sequestration options. This effort will be based exclusively on extant data bases which have been subjected to quality assurance procedures during their development. Data manipulations will be conducted within standard GIS software frameworks and final analyses and products will be summarized in a peer-reviewed technical journal. STAKEHOLDERS: EPA and state regulators along with public and private policy and environmental interests. Linkages exist with the U.S. Forest Service Southern Global Change Program. Linkages are likely with the Soil Conservation Service, and Department of Energy (Oak Ridge National Laboratory). POLICY RELEVANCE: Increasing levels of atmospheric carbon dioxide raise significant concerns with respect to changes in both the physical and chemical climate. In anticipation of a doubling of atmospheric carbon dioxide levels within the next few decades, policy and regulatory groups are assessing available options to both slow the rate and reverse the trend of increasing atmospheric carbon dioxide levels. One option being considered would be the granting of carbon dioxide offsets based on either long-term afforestation to sequester carbon in conventional forests or the use of biomass plantations as a means of reducing the consumption of fossil fuels while achieving some carbon sequestration in the soil as well. Obviously, these options are important from a power production perspective. However, it should be realized that from a natural resource management perspective, the potential value of woody fuels in existing forests will put greater pressure on the utilization of these materials and so it is important to be in a position to determine both the positive and negative impacts of this option on the carbon dioxide balance. PROGRAM CONTACT:James F. Meagher, TVA, P.O. Box 1010, Muscle Shoals, AL 35660, (205) 386-2342 (Programmatic); J. M. Kelly, TVA Cooperative Forest Studies Program, P.O. Box 2008, Oak Ridge, TN 37831-6038, (615) 574- 7815 (Scientific).