Long term data from Mace Head (Ireland) and Jungfraujoch (Switzerland) show that annual European emissions of methyl chloroform did not exceed 3,400 tons between 2000 and 2003, as published in Nature on February 3, 2005. Methyl chloroform is one of the ozone depleting substances phased out under the Montreal Protocol. The data in this manuscript revise published European emission estimates of more than 20,000 tons per year from two short-term campaigns, which had raised questions about the implementation of the Montreal protocol and under-reporting of emissions by the EU member states. Although present emissions are still high for a compound forbidden beginning a decade ago, they can be explained by small-scale illegal usage from storage and potential emissions from waste dumping sites.
Accurate estimation of methyl chloroform emissions is not only important in relation to ozone decline, but also is used for the estimation of the hydroxyl-radical (OH) in the atmosphere, whose average global concentrations cannot be determined by direct measurements. The revised estimated European emissions of methyl chloroform are compatible with fluctuating OH radical concentrations in recent decades but no significant long-term trend.
For reprints and further information, please contact Stefan Reimann: Stefan.Reimann@empa.ch
Article: Low European methyl chloroform emissions inferred from long-term atmospheric measurements. Reimann, S., A.J. Manning, P.G. Simmonds, D.M. Cunnold, R.H.J. Wang, J. Li, A. McCulloch, R.G. Prinn, J. Huang, R.F. Weiss, P.F. Fraser, S. O'Doherty, B.R. Greally, K. Stemmler, M. Hill, and D. Folini, (2005), Nature 433: 506-508 (doi:10.1038/nature03220).