Emissions of Perfluorinated Greenhouse Gases in Southeastern China Derived From High-Frequency In Situ Observations

Abstract

Sulfur hexafluoride (${\text{SF}}_6$), nitrogen trifluoride (${\text{NF}}_3$), and three perfluorocarbons (PFCs; ${\text{CF}}_4$, ${\mathrm{C}}_2{\mathrm{F}}_6$, and $c$-${\mathrm{C}}_4{\mathrm{F}}_8$) are perfluorinated greenhouse gases (PF-GHGs) with long atmospheric lifetimes and high global warming potentials. Using high-frequency observations and a Bayesian inversion framework, we assess 2021–2023 PF-GHG emissions in southeastern China, a rapidly industrializing region. Total PF-GHG emissions rise from 69.50 (55.16–84.97) in 2021 to 96.19 (69.53–127.14) Mt ${\text{CO}}_2$-eq ${\text{yr}}^{-1}$ in 2023, accounting for 21.74% of global total PF-GHG emissions in 2023. ${\text{NF}}_3$ emissions nearly double, reaching 0.94 (0.69–1.25) Gg ${\text{yr}}^{-1}$, with an annual growth rate of 40.38%, likely driven by semiconductor industry expansion. ${\text{SF}}_6$ (51.75%) and ${\text{NF}}_3$ (30.86%) dominate 3-year PF-GHG growth. $c$-${\mathrm{C}}_4{\mathrm{F}}_8$ shows strong seasonality, with a potential winter increase linked to HCFC-22 feedstock use. Seasonal ${\text{SF}}_6$ peaks align with winter electricity demand, while ${\mathrm{C}}_2{\mathrm{F}}_6$ variations suggest potential links with semiconductor industry.