Methodologies for improving forest land greenhouse gas inventory in South Korea using National Forest Inventory and model

Following the Paris Agreement, countries are required to report their efforts to mitigate greenhouse gas emissions. Particularly, reliable estimation of greenhouse gas sequestration by forest lands has gained significant attention. Nevertheless, comprehensive guidelines for the Tier 3 method, which is regarded as the most reliable method, remain ambiguous. This study analyzed the requirements for the Tier 3 method by reviewing IPCC guidelines and national inventory reports from developed countries such as the United States, Canada, and Sweden. Additionally, the study proposed methodologies for the Tier 3 inventory report tailored to the situation in South Korea by reviewing domestic modeling research studies and available data. The requirements for the Tier 3 method included seven criteria, including the combined use of measurement- and model-based inventories, temporal and spatial interpolation of measurement data, and model verification and validation. However, the degree to which these requirements were met varied among the United States, Canada, and Sweden. This study proposed that South Korea could report a Tier 3 forest land greenhouse gas inventory using national forest inventory data and domestic models. For the Tier 3 inventory, it is necessary to assess the uncertainty of national forest inventory data, perform spatial interpolation, adjust model parameters, and conduct model verification and validation. This study will facilitate discussions among relevant departments and experts involved in the forest land greenhouse gas inventory report. Moreover, the proposed methodologies in this study will adhere to the Tier 3 inventory requirements, using time and resources effectively and progressively advancing the reliability of greenhouse gas inventory reports.