Characterization of German SF ₆ Emissions

Sulfur hexafluoride (SF₆) is a highly potent greenhouse gas with a Global Warming Potential (GWP) of 24,700 over 100 years and is globally mainly used as an electrical insulator in switchgear. Several measurement networks have tracked SF₆ for many years and their European data reveal significant emissions in southern Germany. This study focuses on German SF₆ emissions (2020-2023), using atmospheric measurements from 22 European sites, offering high spatial and temporal resolution for robust emission assessments. While German UNFCCC inventory bottom-up emission estimates report a major source of SF₆ through the disposal of soundproof windows, the spatial distribution of German SF₆ emissions derived on top-down inversion techniques (InTEM and Flexinvert+) reveals a different picture: The continuous pattern of high emissions from a particular region is responsible for one-third of total SF₆ emissions in Germany. Despite this, total German SF₆ emissions have decreased from 112 ± 26 t in 2020 to 89 ± 15 t in 2023 (InTEM), with estimates from all methods (both bottom-up and top-down) showing similar trends. Our findings suggest that the emissions from soundproof windows are overestimated, while industrial sources - particularly from SF₆ production and recycling in the focus region - are likely underestimated.