Observations of HFC‐134a in the remote troposphere

Hydrofluorocarbon‐134a (CF 3 CH 2 F) has been detected and quantified in air samples collected at remote, globally dispersed locations. Using gas chromatography and mass spectrometry detection techniques, we have observed increases for HFC‐134a throughout the global troposphere from <50 fmol mol −1 (ppq) in the late 1980s to 1.6 pmol mol −1 (ppt) in mid‐1995. Results obtained from samples collected during two cruises in 1994 indicate that mixing ratios more than doubled during that year. Increases observed globally from early 1994 through mid‐1995 are consistent with exponential growth at ∼100% yr −1 .