Estimation of forest carbon stocks for national greenhouse gas inventory reporting in South Korea

The development of country-specific emission factors in relation to the Agriculture, Forestry, and Other Land Use (AFOLU) sector has the potential to improve national greenhouse gas inventory systems. Forests are carbon sinks in the AFOLU that can play an important role in mitigating global climate change. According to the United Nations Framework Convention on Climate Change (UNFCCC), signatory countries must report forest carbon stocks, and the changes within them, using emission factors from the Intergovernmental Panel on Climate Change (IPCC) or from country-specific values. This study was conducted to estimate forests carbon stocks and to complement and improve the accuracy of national greenhouse gas inventory reporting in South Korea. We developed country-specific emissions factors and estimated carbon stocks and their changes using the different approaches and methods described by the IPCC (IPCC_EF: IPCC default emission factors, CS_FT: country-specific emission factors by forest type, and CS_SP: country-specific emission factors by species). CS_FT returned a result for carbon stocks that was 1.2 times higher than the value using IPCC_EF. Using CS_SP, CO₂ removal was estimated to be 60,648 Gg CO₂ per year with an uncertainty of 22%. Despite a reduction in total forest area, forests continued to store carbon and absorb CO₂, owing to differences in the carbon storage capacities of different forest types and tree species. The results of this study will aid estimations of carbon stock changes and CO₂ removal by forest type or species, and help to improve the completeness and accuracy of the national greenhouse gas inventory. Furthermore, our results provide important information for developing countries implementing Tier 2, the level national greenhouse gas inventory systems recommended by the IPCC.