Skip to content

Re-Evaluation of the UK’s HFC-134a Emissions Inventory Based on Atmospheric Observations

Research output: Contribution to journalArticle

Original languageEnglish
Pages (from-to)11129–11136
Number of pages8
JournalEnvironmental Science and Technology
Issue number20
Early online date20 Sep 2016
DateAccepted/In press - 20 Sep 2016
DateE-pub ahead of print - 20 Sep 2016
DatePublished (current) - 18 Oct 2016


Independent verification of national greenhouse gas inventories is a vital measure for cross-checking the accuracy of emissions data submitted to the United Nations Framework Convention on Climate Change (UNFCCC). We infer annual UK emissions of HFC-134a from 1995 to 2012 using atmospheric observations and an inverse modeling technique, and compare with the UK’s annual UNFCCC submission. By 2010, the inventory is almost twice as large as our estimates, with an “emissions gap” equating to 3.90 (3.20−4.30) Tg CO2e. We evaluate the RAC (Refrigeration and Air-Conditioning) model, a bottom up model used to quantify UK emissions from refrigeration and air-conditioning sectors. Within mobile air-conditioning (MAC), the largest RAC sector and most significant UK source (59%), we find a number of assumptions that may be considered oversimplistic and conservative; most notably the unit refill rate. Finally, a Bayesian approach is used to estimate probable inventory inputs required for minimization of the emissions discrepancy. Our top-down estimates provide only a weak constraint on inventory model parameters and consequently, we are unable to suggest discrete values. However, a significant revision of the MAC servicing rate, coupled with a reassessment of non-RAC aerosol emissions, are required if the discrepancy between methods is to be reduced.

Download statistics

No data available



  • Full-text PDF (final published version)

    Rights statement: This is the final published version of the article (version of record). It first appeared online via ACS at Please refer to any applicable terms of use of the publisher.

    Final published version, 1 MB, PDF document

    Licence: CC BY


View research connections

Related faculties, schools or groups