Competitiveness of Terrestrial Greenhouse Gas Offsets: Are They a Bridge to the Future?
Bruce A. McCarl and Ronald D. Sands
Activities to reduce net greenhouse gas emissions by biological soil or forest carbon sequestration utilize currently known and readily implementable technologies. Many other greenhouse gas emission reduction options require future technological development or must wait for turnover of capital stock. Carbon sequestration options in soils and forests, while ready to go now, generally have a finite life, allowing use until other strategies are developed. This paper reports on an investigation of the competitiveness of biological carbon sequestration from dynamic and multiple strategy viewpoints. Key factors affecting the competitiveness of terrestrial mitigation options are land availability and cost effectiveness relative to other options including CO2 capture and storage, energy efficiency improvements, fuel switching, and non-CO2 greenhouse gas emission reductions. The analysis results show that, at lower carbon prices and in the near term, soil carbon and other agricultural/forestry options are important bridges to the future, initially providing a substantial portion of attainable reductions in net greenhouse gas emissions, but with a limited role in later years. At higher carbon prices, afforestation and biofuels are more dominant among terrestrial options to offset greenhouse gas emissions. But in the longer run, allowing for capital stock turnover, options to reduce greenhouse gas emissions from the energy system provide an increasing share of potential reductions in total U.S. greenhouse gas emissions.