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Increase in global emissions of HFC-23 despite near-total expected reductions

TitleIncrease in global emissions of HFC-23 despite near-total expected reductions
Publication TypeJournal Article
Year of Publication2020
AuthorsStanley K.M, Say D., Mühle J, Harth CM, Krummel PB, Young D, O'Doherty S.J, Salameh PK, Simmonds PG, Weiss RF, Prinn RG, Fraser PJ, Rigby M
Date Published2020/01
Type of ArticleArticle
ISBN Number2041-1723
Accession NumberWOS:000511940400001
Keywordschf3; gases; growth; halocarbons; history; Science & Technology - Other Topics

Under the Kigali Amendment to the Montreal Protocol, new controls are being implemented to reduce emissions of HFC-23 (CHF3), a by-product during the manufacture of HCFC-22 (CHClF2). Starting in 2015, China and India, who dominate global HCFC-22 production (75% in 2017), set out ambitious programs to reduce HFC-23 emissions. Here, we estimate that these measures should have seen global emissions drop by 87% between 2014 and 2017. Instead, atmospheric observations show that emissions have increased and in 2018 were higher than at any point in history (15.9 +/- 0.9 Gg yr(-1)). Given the magnitude of the discrepancy between expected and observation-inferred emissions, it is likely that the reported reductions have not fully materialized or there may be substantial unreported production of HCFC-22, resulting in unaccounted-for HFC-23 by-product emissions. The difference between reported and observation-inferred estimates suggests that an additional similar to 309 Tg CO2-equivalent emissions were added to the atmosphere between 2015 and 2017.

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