Characterization of German SF₆ Emissions

Area of Science:

• Environmental Science
• Atmospheric Chemistry
• Climate Change Research

Background:

• Sulfur hexafluoride (SF₆) is a potent greenhouse gas primarily used as an electrical insulator.
• European data indicate significant SF₆ emissions in southern Germany.
• Accurate assessment of SF₆ emissions is crucial for climate change mitigation.

Purpose of the Study:

• To assess German SF₆ emissions from 2020-2023 using high-resolution atmospheric measurements.
• To compare top-down emission estimates with bottom-up inventory data.
• To identify the primary sources of SF₆ emissions in Germany.

Main Methods:

• Utilized atmospheric measurements from 22 European sites for spatial and temporal analysis.
• Applied top-down inversion techniques (InTEM and Flexinvert+) for emission modeling.
• Compared results with German UNFCCC inventory bottom-up estimates.

Main Results:

• Identified a specific region responsible for one-third of total German SF₆ emissions.
• Observed a decrease in total German SF₆ emissions from 112 ± 26 t (2020) to 89 ± 15 t (2023).
• Top-down and bottom-up methods showed similar emission trends, but disagreed on source attribution.

Conclusions:

• Emissions from soundproof windows appear overestimated in current inventories.
• Industrial sources, particularly SF₆ production and recycling, are likely underestimated.
• Refined emission inventories are needed for effective SF₆ management and climate policy.