Assessment of 2035 greenhouse gas mitigation pathways through an equity-sharing meta-analysis considering climate constitutional litigation judgments

This study builds on the 2024 Constitutional Court of Korea’s ruling to explore methodological pathways for verifying the constitutional legitimacy and equity of national greenhouse gas mitigation targets (NDCs). The research examines South Korea’s current 2030 NDC and the proposed 2035 mitigation targets. To address the divergent results of existing equity-sharing studies - which vary based on principles such as polluter pays, ability to pay, equality, and sovereignty - this study applies the meta-analysis of equity sharing (MAES). This method systematically collects, selects, and adjusts 127 mitigation pathways from prior research (incorporating an enhanced adjustment process for IPCC guideline transitions) to derive a ‘prevailing range’ that empirically reflects academic discourse trends. Specifically, the study introduces the 'Equity Compliance Ratio' as a quantitative metric to evaluate the adequacy of mitigation targets. The analysis reveals that Korea’s current 2030 NDC and proposed 2035 targets fail to meet more than half of the equity benchmarks consistent with the 1.5°C goal (Equity Compliance Ratio < 50%), with a 67% reduction from 2018 net-emissions by 2035 emerging as the meta-analytic median. Crucially, the results demonstrate the path dependency of climate action: postponing mitigation efforts inevitably shifts steeper reductions onto future generations, thereby undermining intergenerational equity. These findings highlight that Korea’s 2035 NDC serves as a critical gateway and must be established as an ambitious, early, and sustained mitigation pathway to fulfill constitutional duties. By applying MAES to the domestic context, this study contributes a methodological framework that bridges equity, science, and constitutional obligation, offering objective criteria for designing and verifying equitable mitigation targets.