Publication Type:Journal Article
Source:Geophysical Research Letters, Volume 38, Issue 15, p.L15808 (2011)
Keywords:Climate change and variability, Decision making under uncertainty, emission verification, greenhouse gas emissions, HFC-23, industrial production, Kyoto Protocol, Legislation and regulations, Troposphere: composition and chemistry
Western European emission inventories of the potent greenhouse gas trifluoromethane (HFC-23) are validated at a country level by combining 2-hourly atmospheric in-situ measurements at Jungfraujoch (Switzerland) and Mace Head (Ireland) with Lagrangian transport simulations. HFC-23 has an atmospheric lifetime of ∼270 yr and a 100-yr global warming potential (GWP) of 14,800 and is unintentionally produced during the manufacture of chlorodifluoromethane (HCFC-22). For the study region we derive emissions of 144–216 Mg/yr for July 2008–July 2010, which are 60–140% higher than the official emissions gathered from the national reports for the year 2009. The largest discrepancy is found for Italy, where our estimate of 26–56 Mg/yr exceeds the national inventory (2.6 Mg/yr) by more than an order of magnitude. These findings suggest that non-reported emissions from Annex 1 countries partly explain the recently derived gap between global bottom-up and top-down HFC-23 emission estimates. The results presented here provide independent information to relevant authorities on effective reporting of HFC-23 emissions, and demonstrate the potential of atmospheric measurements for real-world verification of greenhouse gas emissions.