Long-Term Trends in Greenhouse Gases in the Atmosphere over South Korea

Abstract. Global warming is driven by rising atmospheric greenhouse gases (GHGs), yet long-term regional observational records remain limited. We analyze multi-decadal records of CO₂, CH₄, N₂O, and SF₆ measured since 1999 at four climate monitoring stations in South Korea (Anmyeondo, Gosan, Ulleungdo, and Dokdo) and compare them with datasets from East Asia, Europe, and North America. Quality-controlled daily and annual means were used to quantify trends, growth rates, and spatial and seasonal variability. In 2024, national annual mean concentrations reached 429 ± 4 ppm (CO₂), 2020 ± 26 ppb (CH₄), 339 ± 0.60 ppb (N₂O), and 12.98 ± 0.33 ppt (SF₆), generally exceeding levels in China and Japan and showing comparable or faster growth. Over the past decade, mean growth rates were 2.41 ppm yr^-1 (CO₂), 9.30 ppb yr^-1 (CH₄), 1.25 ppb yr^-1 (N₂O), and 0.37 ppt yr^-1 (SF₆). CO₂ and CH₄ exhibit pronounced winter maxima and summer minima, whereas N₂O and SF₆ show weak seasonality. South Korea's national emissions and terrestrial sink capacity alone cannot explain the elevated atmospheric burdens, implying substantial transboundary transport superimposed on rising regional backgrounds. These increases align with observed atmospheric and ocean warming around the Korean Peninsula and underscore the need for strengthened domestic mitigation, sustained monitoring, and coordinated East Asian emissions reduction and transport–climate modeling.