The increasing atmospheric burden of the greenhouse gas sulfur hexafluoride (SF<sub>6</sub>)

Abstract

Abstract. We report a 40-year history of SF6 atmospheric mole fractions measured at the Advanced Global Atmospheric Gases Experiment (AGAGE) monitoring sites, combined with archived air samples, to determine emission estimates from 1978 to 2018. Previously we reported a global emission rate of 7.3±0.6 Gg yr−1 in 2008 and over the past decade emissions have continued to increase by about 24 % to 9.04±0.35 Gg yr−1 in 2018. We show that changing patterns in SF6 consumption from developed (Kyoto Protocol Annex-1) to developing countries (non-Annex-1) and the rapid global expansion of the electric power industry, mainly in Asia, have increased the demand for SF6-insulated switchgear, circuit breakers, and transformers. The large bank of SF6 sequestered in this electrical equipment provides a substantial source of emissions from maintenance, replacement, and continuous leakage. Other emissive sources of SF6 occur from the magnesium, aluminium, and electronics industries as well as more minor industrial applications. More recently, reported emissions, including those from electrical equipment and metal industries, primarily in the Annex-1 countries, have declined steadily through substitution of alternative blanketing gases and technological improvements in less emissive equipment and more efficient industrial practices. Nevertheless, there are still demands for SF6 in Annex-1 countries due to economic growth, as well as continuing emissions from older equipment and additional emissions from newly installed SF6-insulated electrical equipment, although at low emission rates. In addition, in the non-Annex-1 countries, SF6 emissions have increased due to an expansion in the growth of the electrical power, metal, and electronics industries to support their continuing development. There is an annual difference of 2.5–5 Gg yr−1 (1990–2018) between our modelled top-down emissions and the UNFCCC-reported bottom-up emissions (United Nations Framework Convention on Climate Change), which we attempt to reconcile through analysis of the potential contribution of emissions from the various industrial applications which use SF6. We also investigate regional emissions in East Asia (China, S. Korea) and western Europe and their respective contributions to the global atmospheric SF6 inventory. On an average annual basis, our estimated emissions from the whole of China are approximately 10 times greater than emissions from western Europe. In 2018, our modelled Chinese and western European emissions accounted for ∼36 % and 3.1 %, respectively, of our global SF6 emissions estimate.

Evidence of a recent decline in UK emissions of hydrofluorocarbons determined by the InTEM inverse model and atmospheric measurements

“…In this work the Numerical Atmospheric dispersion Modelling Environment (NAME) (Jones et al, 2007), a Lagrangian atmospheric transport model developed by the UK Met Office, was used to describe the dilution of emissions from source to measurement location. NAME has been used for this type of work in many studies (Manning et al, 2011;Say et al, 2016;Lunt et al, 2018;Montzka et al, 2018a;White et al, 2019;Ganesan et al, 2020;Say et al, 2021;Fraser et al, 2020) and comprehensive details can be found in Arnold et al (2018). NAME uses a three-dimensional description of the atmosphere as calculated by meteorological models.…”

“…InTEM (Manning et al, 2011;Arnold et al, 2018) has been developed over many years and has been applied to many gases and regions, e.g. Bergamaschi et al (2018) and Fraser et al (2020). InTEM is used here to estimate UK emissions using the observations described in Table 2.…”

Global Biogeochemical Cycle of Fluorine

“…In recent years, SF 6 has gained importance in the electronics industry as an inert, insulating gas, with 2012 emissions of approximately 9 × 10 9 g/yr, contributing 0.0062 Tg F/yr to the atmosphere (Simmonds et al, 2020). NF 3 is also of increasing use in the electronics industry, where it serves as an etching and cleansing agent for silicon components (Weiss et al, 2008).…”

Das perfekte Treibhausgas ersetzen

“…3) Eine im Juni erschienene Studie schätzte den weltweiten Ausstoß im Jahr 2018 auf über 9000 Tonnen. 4 "Die Industrie befindet sich in einer Aufbruchstimmung", sagt Physiker Christian Franck, Professor für Hochspannungstechnik an der ETH Zürich. "Es gibt gute Alternativen, die sich etablieren werden.…”