Resolution of the uncertainties in the radiative forcing of HFC-134a

✍ Scribed by Piers M. de F. Forster; J.B. Burkholder; C. Clerbaux; P.F. Coheur; M. Dutta; L.K. Gohar; M.D. Hurley; G. Myhre; R.W. Portmann; K.P. Shine; T.J. Wallington; D. Wuebbles

• Publisher: Elsevier Science
• Year: 2005
• Tongue: English
• Weight: 498 KB
• Volume: 93
• Category: Article
• ISSN: 0022-4073
• DOI: 10.1016/j.jqsrt.2004.08.038

✦ Synopsis

HFC-134a (CF 3 CH 2 F) is the most rapidly growing hydrofluorocarbon in terms of atmospheric abundance. It is currently used in a large number of household refrigerators and air-conditioning systems and its concentration in the atmosphere is forecast to increase substantially over the next 50-100 years. Previous estimates of its radiative forcing per unit concentration have differed significantly $25%. This paper uses a two-step approach to resolve this discrepancy. In the first step six independent absorption cross section datasets are analysed. We find that, for the integrated cross section in the spectral bands that contribute most to the radiative forcing, the differences between the various datasets are typically smaller than 5% and that the dependence on pressure and temperature is not significant. A ''recommended'' HFC-134a infrared absorption spectrum was obtained based on the average band intensities of the strongest bands. In the second step, the ''recommended'' HFC-134a spectrum was used in six different radiative transfer models to calculate the HFC-134a radiative forcing efficiency. The clear-sky instantaneous