South Korea

Historical emissions data from 1990 to 2022 was taken from South Korea’s National Greenhouse Gas Inventory (NGHGI) presented in its combined First Biennial Transparency Report (BTR1) and Fifth National Communication (NC5) (Republic of Korea, 2025b). It was extended to 2023 using the PRIMAP National Historical Greenhouse Gas Emissions Database (Gütschow et al., 2024). A historical time series of LULUCF emissions until 2022 is also derived from the BTR.

There was a notable upward revision in South Korea’s historical emissions compared with earlier government estimates. Total emissions (excl. LULUCF) in 2018, for example, increased from 728 to 782 MtCO₂e. The government primarily attributes this adjustment to previously unaccounted-for coal consumption from private power plants, identified through updates to energy balance statistics, while reported emissions from industrial F-gases also appear to have considerably increased (Republic of Korea, 2025b).

For our current policy projections (CPP), we establish a range using multiple sources. The lower bound of the CPP is based on estimated emissions reductions relative to the BAU scenario from the 8th Edition of APEC Energy Demand and Supply Outlook (APEC, 2022) and the US EPA non-CO₂ emission projections through 2080 (EPA, 2025). Emission projections considered the impact of South Korea's 11th Basic Plan on Electricity Supply and Demand, which forecasts electricity generation until 2038. The average electricity CO₂ emission factors for each fossil fuel type in South Korea are assumed to be similar to the values forecast for Japan in the IEA’s 2020 World Energy Outlook (Republic of Korea, 2021a). Non-energy-related CO₂ emissions are assumed to have a similar growth rate to energy-CO₂ emissions.

The upper end of our CPP is based on projections reported in South Korea’s BTR1, which reflects policies up to the 10th Basic Plan (Republic of Korea, 2025b). To estimate the impact from the slightly lower coal generation in the 11th Plan, we calculated the difference in electricity generation by fuel type between the plans.

For the both bounds of our current policy projections, we quantified the amended Renewable Portfolio Standard target in addition to the 11th Plan. While South Korea originally set an RPS quota of 23% and 25% by 2023 and 2026, respectively, it was amended to 13% and 15% by 2023 and 2026, respectively, pushing back the 25% RE quota to 2030. The revised target is still higher than the share of renewables outlined in the 11th Plan, so we assume that any additional renewable energy generation displaces that of coal.

The updated 2021 NDC set a new emissions reduction target of 40% below 2018 levels. The government report on the NDC update, published in October 2021, provides a breakdown of emissions per sector, in addition to details on expected reductions and removals from LULUCF, CCUS, and overseas (Republic of Korea, 2021a). We use this information to calculate South Korea’s domestic component of the 2030 target (i.e. emissions excluding LULUCF and international credits). Although the update report is presented using SAR GWPs, we assume that the LULUCF fluxes and international credits consist almost entirely of CO₂ emissions, so differences due to GWP are likely to be negligible for these components.

The CAT presents all targets excluding LULUCF. For South Korea’s 2035 NDC, we excluded the projected land sector emissions from the target using the most recent government data available from the 2025 Biennial Transparency Report (BTR1).

Global Warming Potentials values

South Korea uses GWP values from the IPCC’s Second Assessment Report (SAR) for its 2030 NDC. We convert to AR5 GWP values to ease comparison of countries’ targets and emission trajectories. We use detailed emissions data per gas from the national inventory (SAR) to derive a full emissions dataset in AR5. We use the ratio of total emissions in SAR and AR5 in 2017 to convert the target to AR5 (the annual difference between SAR and AR5 is around 7 MtCO₂e, with low variance).

South Korea’s 2050 carbon neutrality scenarios presents sector-specific emissions targets, along with details on targeted removals from LULUCF and CCUS (Republic of Korea, 2020). The data is reported using SAR GWPs, so we applied a conversion factor based on historical inventory data to align it with AR5 values. Based on this information and assuming that the target covers all GHGs, we estimate the LULUCF sink will be 26 MtCO₂e and thus South Korea’s total emissions excl. LULUCF will be 26 MtCO₂e in 2050.

The CAT uses Global Warming Potential (GWP) values from the IPCC's Fifth Assessment Report (AR5) for all its figures and time series. Assessments completed prior to June 2025 (COP29) used GWP values from the Fourth Assessment Report (AR4), and those completed prior to December 2018 (COP24) used GWP values from the Second Assessment Report (SAR).