Regional Emissions of Anthropogenic Halocarbons Derived from Continuous Measurements of Ambient Air in Switzerland

Abstract

Man-made halocarbons have a considerable impact on the environment. Chlorine- and bromine-containing organic compounds such as chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) are responsible for the decline of stratospheric ozone and their use has therefore been regulated in the Montreal Protocol. Fluoro-containing halocarbons are not regulated within this treaty, but as all halocarbons act as greenhouse gases, this group of compounds was included in the Kyoto Protocol. Halogenated ozone destroying CFCs and chlorinated solvents were continuously measured in Switzerland at a suburban site near Zürich (Dübendorf) from 1994 until 2000 and since 2000 at the high alpine site of Jungfraujoch together with all greenhouse-active halocarbons. Furthermore, all anthropogenic halocarbons were measured in a campaign in Dübendorf in 2002. The analysis of the measurements confirms that a substantial decline of their emissions took place as a consequence of the Montreal Protocol. On the other hand, the concentration of substitutes such as hydrofluorocarbons (HFCs) increased dramatically. Linking continuously measured time series with meteorological information allows an estimation of regional emissions of the regulated compounds for Switzerland. In contrast to trade survey statistics or inventories, this method is an efficient tool to track the development of diffusive emissions of substances in long term usage such as foams and refrigerant systems.