A44D-02 Emissions of Perfluorinated Greenhouse Gases in China Determined from Atmospheric Observations Thursday, 12 December 2024

Perfluorinated greenhouse gases, including perfluorocarbons (PFCs), sulfur hexafluoride (SF₆) and nitrogen trifluoride (NF₃), are highly potent in warming the Earth’s surface. They have global warming potentials that are thousands to tens of thousands times that of CO₂ over 100-year horizons (GWP₁₀₀), and atmospheric lifetimes that range from several hundred to tens of thousands of years. Continuing emissions of these substances could impact progress towards meeting international global climate mitigation targets and China’s carbon neutrality goal.

In this study, we examined the emissions of the three most abundant PFCs tetrafluoromethane (CF₄, PFC-14), hexafluoroethane (C₂F₆, PFC-116), and perfluorocyclobutane (c­-C₄F₈, PFC-318), as well as emissions of SF₆ and NF₃ in China over the last decade. Our study is based on atmospheric observations from a Chinese network and an inverse modeling (top-down) framework. Through this top-down approach and observations from multiple monitoring sites, we not only determine the magnitudes of emissions, but also investigate possible industry sources of emissions based on the derived spatial distributions of these emissions. We identified substantial increases in emissions of these substances in China over the last decade. The cumulative CO₂-eq emissions of these substances in 2021 have reached around 236 Mt. The derived top-down emissions can serve as an important validation for the national bottom-up emission inventories (compiled by industry production and consumption data). The contribution of emissions of these substances in China to global total emissions was also investigated. We found that the absolute emission increases of these gases in China were able to explain most of their global emission increases as estimated from global (AGAGE network) observations over the same period. This indicates China’s significant contribution to global emission growth of these perfluorinated greenhouse gases.