Nitrogen trifluoride global emissions estimated from updated atmospheric measurements

Abstract

Nitrogen trifluoride (NF 3 ) has potential to make a growing contribution to the Earth’s radiative budget; however, our understanding of its atmospheric burden and emission rates has been limited. Based on a revision of our previous calibration and using an expanded set of atmospheric measurements together with an atmospheric model and inverse method, we estimate that the global emissions of NF 3 in 2011 were 1.18 ± 0.21 Gg⋅y −1 , or ∼20 Tg CO 2 -eq⋅y −1 (carbon dioxide equivalent emissions based on a 100-y global warming potential of 16,600 for NF 3 ). The 2011 global mean tropospheric dry air mole fraction was 0.86 ± 0.04 parts per trillion, resulting from an average emissions growth rate of 0.09 Gg⋅y −2 over the prior decade. In terms of CO 2 equivalents, current NF 3 emissions represent between 17% and 36% of the emissions of other long-lived fluorinated compounds from electronics manufacture. We also estimate that the emissions benefit of using NF 3 over hexafluoroethane (C 2 F 6 ) in electronics manufacture is significant—emissions of between 53 and 220 Tg CO 2 -eq⋅y −1 were avoided during 2011. Despite these savings, total NF 3 emissions, currently ∼10% of production, are still significantly larger than expected assuming global implementation of ideal industrial practices. As such, there is a continuing need for improvements in NF 3 emissions reduction strategies to keep pace with its increasing use and to slow its rising contribution to anthropogenic climate forcing.

History of chemically and radiatively important atmospheric gases from the Advanced Global Atmospheric Gases Experiment (AGAGE)

“…Compounds added only recently to routine Medusa measurements (and therefore not yet in Table 1) are HCFC-133a and CF 3 CFOCF 2 , while the light hydrocarbons C 2 H 2 and C 2 H 4 , although still measured, are also not included in Table 1 because co-elution compromises their measurement as the GC column ages. The AGAGE Medusas were the first instruments monitoring in situ the global distributions and trends of the high-GWP industrial gases CF 4 , NF 3 , and SO 2 F 2 Weiss et al, 2008;Arnold et al, 2013). In addition to the compounds listed in Table 1, additional species (e.g., CFC-112) are in various stages of being added to the station measurements.…”

Atmospheric lifetimes, infrared absorption spectra, radiative forcings and global warming potentials of NF<sub>3</sub> and CF<sub>3</sub>CF<sub>2</sub>Cl (CFC-115)

“…The present-day mixing ratio will therefore be close to 1 ppt, assuming no change in emission rate. Arnold et al (2013) found undetectable levels of NF 3 prior to 1975 in archived air samples and ice cores, indicating that the major source of the gas is anthropogenic.…”

“…NF 3 is being used increasingly as a replacement for banned perfluorocarbons (PFCs) which were utilised in processes such as chemical cleaning and circuit etching. It is an extremely potent greenhouse gas with an estimated 100-year global warming potential (GWP) between 10 800 and 17 000 (Arnold et al, 2013;Robson et al, 2006;Weiss et al, 2008). Weiss et al (2008) reported a 2008 mean global tropospheric mixing ratio of 0.45 ppt increasing at a rate of 0.053 ppt yr −1 .…”

Inhomogeneous Radiative Forcing of NF3

“…According to an expanded set of atmospheric measurements [5], the global atmospheric abundance of NF 3 continues to rise; the mean concentration in the global background troposphere was 0.86 ± 0.04 ppt during mid-2011 [1]. On the AGAGE (Advanced Global Atmospheric Gases Experiment) website (http://agage.mit.edu/), the global mean concentration of NF 3 was 1.236 ± 0.058 ppt in February 2015.…”

“…Nitrogen trifluoride (NF 3 ) has the potential to make a growing contribution to the Earth's radiative budget [1]. The use of NF 3 has increased rapidly as a replacement for perfluorocarbons (PFCs) and SF 6 in industrial processes [2].…”