摘要：Forestry has been considered to have potential in reducing the atmospheric concentration of carbondioxide by sequestrating carbon in above-ground timber and below-ground roots and soil. This potentialhas been noted in the Kyoto Protocol, which identified specific forestry activities for which carbonsequestration credits could be obtained. To date, a few forestry efforts have been undertaken for carbonpurposes, but most of these efforts have been on a small scale. Proposals have been under discussion,however, that would result in the creation of very large areas of new forest for the purpose of offsettingsome of the additional carbon that is being released into the atmosphere. Concerns are expressed,however, that large-scale sequestration operations might have impacts on the world timber market,affecting timber prices and thereby reducing the incentives of traditional suppliers to invest in forestmanagement and new timber production. Such a "crowding out" or "leakage" effect, as it is called in theliterature, could negate much or all of the sequestered carbon by the newly created sequestration forests.Accordingly, the purpose of this study is to examine and assess the interactions between carbonsequestration forestry, particularly, newly created carbon forests, and the markets for timber.The approach of this study involves utilizing an existing Dynamic Timber Supply Model (DTSM) toexamine the interactions between newly created sequestration forests and the markets for timber. Thismodel has been used to examine global timber supply and, more recently, has been modified to includecarbon considerations. This study suggests that even without any specific sequestration efforts,commercial forestry offers the potential to sequester substantial volumes of carbon, approaching tengigatons (Gt) (or petagrams (Pg)), in vegetation, soils and market products over the next century. Atcurrent rates of atmospheric carbon build up this is equal to about three years of net carbon releases intothe atmosphere. This volume of carbon sequestration could be increased 50–100% by 50 million hectares(ha) of rapidly growing carbon-sequestering plantation forests, even given the anticipated leakages due tomarket price effects. Finally, the projections suggest that the amount of crowding out and carbon leakagesare likely to be very modest. The 50 million ha of carbon plantations are projected to reduce land areas inindustrial plantations, that is, crowd out, only from 0.2 to 7.8 million ha over the 100-year period. Theaddition of carbon sequestration forests offers the potential to increase the carbon sequestration of theforest system more than 50%, up to 5.7 Gts, above that already captured from market activity. Thisestimate assumes that crowding out and associated projected leakages will occur. At current rates ofatmospheric carbon buildup, about 2.8% of the expected total buildup in atmospheric carbon over the nextcentury could be offset by 50 million ha of carbon plantations.
