Low European methyl chloroform emissions inferred from long-term atmospheric measurements

摘要: Use of the solvent methyl chloroform is being phased out under Montreal Protocol because its ozone-depleting properties. Its atmospheric concentrations are declining, but recent studies have come to conflicting conclusions about trends in European emissions. Estimates range from less than 100,000 kg per year over 20 million year, latter more doubling previous global estimates. A new study evaluates these estimates based on data Mace Head Ireland and Jungfraujoch, Switzerland. The results do not support unexpectedly high estimates, with emission 60 mid-1990s up 3.4 2000 2003, they higher latest consumption-based figures. authors speculate that if figures correct, unrecorded sources must exist, suggesting under-reporting emissions by industry or consumption reporting process. Methyl (CH3CCl3, 1,1,1,-trichloroethane) was used widely as a before it recognized be an substance phase-out introduced Protocol1. Subsequently, concentration has declined steadily2,3,4 were estimated 0.1 gigagrams year1,5. However, short-term tropospheric measurement campaign (EXPORT) indicated could been (ref. 6), almost previously emissions1,4. Such enhanced would significantly affect CH3CC13 method deriving abundances hydroxyl radicals (OH) (refs 7–12)—the dominant reactive chemical for removing trace gases related air pollution, ozone depletion greenhouse effect. Here we use long-term, high-frequency Head, Switzerland, infer We find 0.3–1.4 1.9–3.4 2000–03, Jungfraujoch data, respectively. Our therefore calculated data1,5, considerably lower those derived EXPORT 6).