Application of Scope 3 greenhouse gas emission estimation methods in response to international carbon regulations: Focusing on category 3 upstream electricity emission factors

As international ESG disclosure standards converge and global reporting frameworks such as IFRS, the EU, and the US continue to develop, the need for robust supply chain management of Scope 3 greenhouse gas emissions throughout the corporate value chain has become critical. Korean companies must proactively prepare to comply with these evolving disclosure requirements. In particular, when calculating upstream emissions of purchased electricity (category 3, activity B), domestic firms commonly apply domestic and international emission factors in combination or employ adjustment methods to address discrepancies. This study conducts a comprehensive analysis of both domestic and international electricity emission factors and proposes an application framework that reflects Korea’s unique national context for calculating scope 3 upstream electricity emissions. The findings have three key implications: First, establishing clear criteria and procedures for validating default emission factors is essential to ensure consistency between inventory-based and disclosed emissions. Second, improving the accuracy of disclosed emissions requires continued development and refinement of lifecycle-based emission factors that are differentiated by electricity generation source. Third, prior to mandatory disclosure requirements, Korean companies should proactively invest in building and stabilizing electricity disclosure systems to meet international transparency standards effectively. By offering practical methodologies and deriving emission factors tailored to Korea’s specific circumstances, this study makes a major contribution to advancing scope 3 greenhouse gas accounting and disclosure practices in Korea’s domestic corporate sector.