Trends and emissions of six perfluorocarbons in the Northern Hemisphere and Southern Hemisphere
Author
dc.contributor.author
Droste, Elise S.
Author
dc.contributor.author
Adcock, Karina E.
Author
dc.contributor.author
Ashfold, Matthew J.
Author
dc.contributor.author
Chou, Charles
Author
dc.contributor.author
Fleming, Zoë
Author
dc.contributor.author
Fraser, Paul J.
Author
dc.contributor.author
Gooch, Lauren J.
Author
dc.contributor.author
Hind, Andrew J.
Author
dc.contributor.author
Langenfelds, Ray L.
Author
dc.contributor.author
Leedham Elvidge, Emma
Author
dc.contributor.author
Mohd Hanif, Norfazrin
Author
dc.contributor.author
O’Doherty, Simon
Author
dc.contributor.author
Oram, David E.
Author
dc.contributor.author
Ou Yang, Chang Feng
Author
dc.contributor.author
Panagi, Marios
Author
dc.contributor.author
Reeves, Claire E.
Author
dc.contributor.author
Sturges, William T.
Author
dc.contributor.author
Laube, Johannes C.
Admission date
dc.date.accessioned
2020-06-15T22:30:06Z
Available date
dc.date.available
2020-06-15T22:30:06Z
Publication date
dc.date.issued
2020
Cita de ítem
dc.identifier.citation
Atmos. Chem. Phys., 20, 4787–4807, 2020
es_ES
Identifier
dc.identifier.other
10.5194/acp-20-4787-2020
Identifier
dc.identifier.uri
https://repositorio.uchile.cl/handle/2250/175481
Abstract
dc.description.abstract
Perfluorocarbons (PFCs) are potent greenhouse gases with global warming potentials up to several thousand times greater than CO2 on a 100-year time horizon. The lack of any significant sinks for PFCs means that they have long atmospheric lifetimes of the order of thousands of years. Anthropogenic production is thought to be the only source for most PFCs. Here we report an update on the global atmospheric abundances of the following PFCs, most of which have for the first time been analytically separated according to their isomers: coctafluorobutane (c-C4F8), n-decafluorobutane (n-C4F10), ndodecafluoropentane (n-C5F12), n-tetradecafluorohexane (nC(6)F(14)), and n-hexadecafluoroheptane (n-C7F16). Additionally, we report the first data set on the atmospheric mixing ratios of perfluoro-2-methylpentane (i-C6F14). The existence and significance of PFC isomers have not been reported before, due to the analytical challenges of separating them. The time series spans a period from 1978 to the present. Several data sets are used to investigate temporal and spatial trends of these PFCs: time series of air samples collected at Cape Grim, Australia, from 1978 to the start of 2018; a time series of air samples collected between July 2015 and April 2017 at Tacolneston, UK; and intensive campaign-based sampling collections from Taiwan. Although the remote "background" Southern Hemispheric Cape Grim time series indicates that recent growth rates of most of these PFCs are lower than in the 1990s, we continue to see significantly increasing mixing ratios that are between 6% and 27% higher by the end of 2017 compared to abundances measured in 2010. Air samples from Tacolneston show a positive offset in PFC mixing ratios compared to the Southern Hemisphere baseline. The highest mixing ratios and variability are seen in air samples from Taiwan, which is therefore likely situated much closer to PFC sources, confirming predominantly Northern Hemispheric emissions for most PFCs. Even though these PFCs occur in the atmosphere at levels of parts per trillion molar or less, their total cumulative global emissions translate into 833 million metric tonnes of CO2 equivalent by the end of 2017, 23% of which has been emitted since 2010. Almost two-thirds of the CO2 equivalent emissions within the last decade are attributable to c-C4F8, which currently also has the highest emission rates that continue to grow. Sources of all PFCs covered in this work remain poorly constrained and reported emissions in global databases do not account for the abundances found in the atmosphere.
es_ES
Patrocinador
dc.description.sponsorship
European Research Council (ERC): EXC3ITE-678904-ERC-2015-STG.
NERC Natural Environment Research Council: NE/J016012/1, NE/I021918/1, NE/1210143, NE/L002582//1.
Taiwanese Academia Sinica: AS-KPQ-106-DDPP.