Persistent fluorinated greenhouse gases

Long-lived fluorinated greenhouse gases are characterized by a long atmospheric residence time and a very high global warming potential. They are not degraded in manageable periods of time, but accumulate in the atmosphere. Besides sulfur hexafluoride (SF₆), nitrogen trifluoride (NF₃) and fully fluorinated hydrocarbons (PFC), such as CF₄ and C₂F₆, belong to this group of substances.

A report by the Joint Research Centre (JRC) revealed as early as 2018 a growing discrepancy between officially reported emissions of sulfur hexafluoride (SF₆) and the actual measured atmospheric concentrations. Since SF₆ is an extremely long-lived greenhouse gas with significant climate impact (GWP100 = 24,300 CO₂ equivalents (IPCC Sixth Assessment Report)), even small amounts of emissions have a substantial impact on the climate. Time and again, regional and global studies have highlighted discrepancies between reported and measured values (Simmonds et al. (2020), Cui et al. (2024), Vojta et al. (2025)).

In this context, atmospheric measurement data in Germany were analyzed in detail and compared with national emissions inventories. In a research project conducted with Goethe University Frankfurt, a previously undefined point source in Germany was identified and quantified. This source was narrowed down to a specific region using measurement data and inverse modeling. The final report, which confirms this emission source, is now available. At the same time, the report concludes that the total reported national emission inventory is plausible and consistent in its overall sum. The discrepancies primarily concern the spatial and source-specific attribution of individual emissions, but not the total amount of reported emissions. The key findings of this study were previously published in a scientific journal article (Meixner et al. (2025)) .

The final report also analyzes the role of individual monitoring stations in the accuracy of atmospheric measurements and analyses. It clearly demonstrates that such analyses can contribute to quality assurance and transparency in international climate reporting.

The levels of German SF₆ emissions can be found in the UBA’s Data Cube. It should be noted that the discrepancies mentioned above have not yet been taken into account in the Data Cube. This will be addressed in the current submission, which is scheduled for release in early 2026.
In Germany, SF₆ emissions are declining, due in no small part to voluntary commitments by industry, reduced emissions from soundproof windows, and a shift to alternatives.

Since SF₆ is primarily used in industrial applications that are currently experiencing strong growth, attention is also turning to future trends in emissions. Particularly relevant is the use of SF₆ in electrical switchgear, where the gas has been used exclusively to date due to its excellent insulating properties. Against this backdrop, a separate research project developed emission projections for Germany, Europe, and the world through the year 2100. Various scenarios were considered, including market development, technological progress, and the introduction of alternatives to SF₆.

The scenarios indicate that a significant increase in emissions is to be expected globally unless alternatives to SF₆ are consistently adopted in switchgear worldwide, and existing equipment is properly maintained and disposed of in accordance with regulations at the end of its service life.

The significance and dynamics of global grid expansion are analyzed in detail in a separate academic publication. The full research report, including all findings and scenarios, will be published shortly.

The global concentration of NF₃ in the atmosphere increased at the fastest rate among fluorinated greenhouse gases, rising by 12% per year between 2013 and 2016 (JRC Bericht 2018). In Germany, consumption volumes are rising sharply. NF₃ emissions can be found in the UBA’s Data Cube. 

As part of the research project with Goethe University Frankfurt, an NF₃ atmospheric measurement system was set up for the first time at the Taunus Observatory. Initial analyses are promising. However, a longer observation period is needed to validate the results.

This group of substances includes compounds ranging from CF₄ to C₆F₁₄.

In Germany, emissions of these compounds have declined in recent years. However, measured global atmospheric concentrations continue to rise due to their persistence.

PFCs are a type of PFAS. An update to the restriction proposal was published by ECHA. Further information on PFCs and PFAS can also be found on our PFAS-Portal.