1Institut für Umweltphysik, Universität Heidelberg, INF 229, 69120 Heidelberg, Germany
2Centro de Investigación Atmosférica de Izaña, Instituto Nacional de Meteorología (INM), C/La Marina, 20, Planta 6, 38071 Santa Cruz de Tenerife, Spain
3Institut für Atmosphäre und Umwelt, J. W. Goethe Universität Frankfurt, Altenhöferallee 1, 60438 Frankfurt/Main, Germany
4Centre for Australian Weather and Climate Research / CSIRO Marine and Atmospheric Research (CMAR), Private Bag No. 1, Aspendale, Victoria 3195, Australia
5MetAir AG, Flugplatz, 8915 Hausen am Albis, Switzerland
6Alfred Wegener Institut für Polar- und Meeresforschung, Am Handelshafen 12, 27570 Bremerhaven, Germany
7Environment Canada, Climate Research Division/CCMR, 4905 Dufferin St., Toronto, ON M3H 5T4, Canada
8North East Section of the Russian Academy of Sciences, P.O. Box 18, Cherskii, Republic of Sakha (Yakutia), Russia
Received: 01 Dec 2009 – Discussion started: 11 Dec 2009
Abstract. Emissions of sulphur hexafluoride (SF6), one of the strongest greenhouse gases on a per molecule basis, are targeted to be collectively reduced under the Kyoto Protocol. Because of its long atmospheric lifetime (estimated as 800 to 3200 years), the accumulation of SF6 in the atmosphere is a direct measure of its global emissions. Examination of our extended data set of globally distributed high-precision SF6 observations shows an increase in SF6 abundance from near zero in the 1970s to a global mean of 6.7 ppt by the end of 2008. In-depth evaluation of our long-term data records shows that the global source of SF6 decreased after 1995, most likely due to SF6 emission reductions in industrialised countries, but increased again after 1998. By subtracting those emissions reported by Annex I countries to the United Nations Framework Convention of Climatic Change (UNFCCC) from our observation-inferred SF6 source leaves a surprisingly large gap of more than 70–80% of non-reported SF6 emissions in the last decade. This suggests a strong under-estimation of emissions in Annex I countries and underlines the urgent need for independent atmospheric verification of greenhouse gases emissions accounting.
Revised: 05 Mar 2010 – Accepted: 08 Mar 2010 – Published: 18 Mar 2010
Levin, I., Naegler, T., Heinz, R., Osusko, D., Cuevas, E., Engel, A., Ilmberger, J., Langenfelds, R. L., Neininger, B., Rohden, C. v., Steele, L. P., Weller, R., Worthy, D. E., and Zimov, S. A.: The global SF6 source inferred from long-term high precision atmospheric measurements and its comparison with emission inventories, Atmos. Chem. Phys., 10, 2655-2662, doi:10.5194/acp-10-2655-2010, 2010.