Study On Estimation And Potential Impact Of Carbon In China’s Harvested Wood Products

Forests and harvested wood products (HWP) are part of the carbon cycle ofterrestrial ecosystem. Forests have an important role in mitigating global climatechange because these forests can remove a significant amount of CO2from theatmosphere. Carbon stock in forests can be transferred to wood products thatconstitute a carbon reservoir via timber harvest. The storage of carbon in HWP isan important forestry issue in the United Nations Framework on Climate ChangeConvention. However, no consensus has been made on how to attribute carbonsequestration in wood products involved in international trade to appropriateparties. Given that China is a large HWP-trading country, studies on carbonstorage and flow of HWP trade are important to help mitigate carbonconcentrations in this country.First, a comparative analysis on the IPCC default approach, Stock-changeapproach (SCA), Production approach (PA) and Atmospheric-flow approach(AFA) provided by IPCC guidance is made to build a theoretical framework forthe application of methods. Four approaches are used to estimate the carbonstorage and annual change of HWP of China during the period1961to2011. Theaverage annual growth of carbon sequestration of HWP in China’s consumptionof wood products from1961to2011was approximately10.78MtC per year, andthe total stock of carbon in HWP in2011reached676.69MtC. The IPCC defaultapproach assumes that the carbon storage is zero. From1961to2011, China’saverage annual carbon sequestration of HWP estimated based on the SCA, AFAand PA accpraches were10.6,7.6, and2.6MtC per year, respectively. Theaverage ratios of annual carbon sequestration in the HWP pool to the emissionsof energy consumption in China published in the U.S. Energy InformationAdministration were1.61%,1.22%, and0.47%, respectively. By contrast,China’s HWP carbon pool has a relatively lower contribution rate than the globalaverage level2%. China has a potential space to improve the contribution ofHWP to the removal of carbon from the atmosphere. As a result, carbonsequestration accounted by the SCA approach is the largest, by AFA approach isminimum; the accounting result by PA approach is in the intermediate level. Butusing Monte Carlo analysis, the uncertainty of results from the PA approach wasthe highest. The international trade of HWP and the choice of approaches affected thecarbon estimates results. From1961to2011, the carbon transfer in differentforms of wood product imports (including wood panels, roundwood, sawnwood,chips, wood residue, wood pulp, charcoal, paper, and paperboard) displayed arising trend. For the solid wood products, the carbon transfer of industrialroundwood imports in2011reached10.58MtC per year. For the paper products,the carbon transfer of wood pulp imports reached19.45MtC per year in2011.Large wood product imports increased the contribution to carbon sequestration ofthe wood products based on the SCA approach. Meanwhile, the carbon releasedinto the atmosphere from China’s net wood product imports reached14.7MtC peryear in2011. Wood pulp has the largest carbon sequestration. However, woodpulp belongs to the paper product category with a short half-life of two years,thereby contributing to large annual carbon emissions in the consuming country.Large wood pulp imports increase China’s annual domestic carbon sequestrationbased on the AFA approach but greatly increased the accounting of China’scarbon emissions. Based on carbon shared principle, an expanded stock-changeapproach is developed. And the estimated carbon sequestration of HWP is7.6MtC in2011, which is25MtC less than that by SCA approach and8.8MtC morethan that by AFA approach.Different approaches have different system boundaries to attribute carbonsequestration in wood products involved in international trade to appropriateparties. From the angle of market, the paper analyzes the possible effects ofaccounting of wood products on the international trade of products and the forestsustainable management. And from the angle of carbon flow of forest and woodproducts system, the paper analyzes the possible effects of accounting of woodproducts on the achivement of related policy goals. The results show that,application of the SCA approach would not only increase the contribution ofcarbon storage in wood products to reduce national greenhouse gas emissions, butalso have a positive impact on the sustainable management of China’s forests. Toenhance the function of carbon sequestration and carbon alternative reduction,the efficiency of carbon management of HWP, the wood products in China willplay a more active role in the mitigation of climate change.