Abstract
The perfluorocarbons CF4 and C2F6 are among the most potent greenhouse gases with lifetimes of fifty and ten thousand years, respectively. They are both primarily emitted during aluminum smelting and electronics manufacturing. We perform the first regionally resolved global inversion of CF4 and C2F6, providing atmospheric measurement-based top-down emission estimates for 2006–2023 using the FLEXPART transport model and the FLEXINVERT+ framework. Introducing a global-total constraint to align the inversion results with the relatively accurate global total emissions from the AGAGE 12-box model stabilizes the emissions in poorly monitored regions. Compared to the global bottom-up inventory EDGAR, the inversion increases global CF4 and C2F6 emissions by factors of 2.6 ± 0.3 and 3.1 ± 0.7, respectively, for 2018–2023. China dominates global emissions, contributing 56 % (CF4) and 58 % (C2F6) in 2018–2023. The contribution of South and Southeast Asia to global emissions rose from about 6 % and 10 % in 2006–2011 to 22 % and 18 % by 2018–2023, respectively, though large uncertainties remain due to a lack of measurements in the region itself. European emissions declined until 2010, then stabilized and contribute 2 %–3 % to global emissions by 2018–2023. U.S. CF4 emissions remain constant and C2F6 emissions decreased steadily (reaching 3 %–4 % by 2018–2023), with a temporary drop in 2009 likely linked to the financial crisis. On the global scale, our results suggest a contribution of 81 % by the aluminum industry to total CF4 emissions and 48 % by the electronics industry to global C2F6 emissions.