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Updates to the calculation of radiative efficiencies and global warming potentials for halocarbons using the Pinnock method

Several metrics quantify the effect of greenhouse gases on global surface temperatures. The most common of these metrics are the radiative efficiency (RE) and the global warming potential (GWP) of a given compound. The radiative efficiency measures the change in net downward flux at the tropopause due to the addition of greenhouse gas. The global warming potential quantifies the contribution of a given substance to global warming relative to an equivalent mass of carbon dioxide over a given period, usually 100 years. The calculations of these metrics follow the Pinnock method, which saw significant updates in 2020. This work uses previously collected infrared spectra for Perfluorotributylamine (PFTBA), Perfluorodecalin (PFDC), 2,2,3,3,3-pentafluoropropanol (PFPO), 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP), HFC-245ca (HFCP), HFC-236ea (HFCH), and HFC-43-10mee (HFC43) measured using Fourier transform spectroscopy to calculate the aforementioned metrics via the original and updated Pinnock methods. Results show that the update from the old to the new method yields similar stratospheric temperature-adjusted radiative efficiency values for all seven compounds to within 3%. Yet, the updated method results in, on average, 14% larger global warming potential values. Therefore the potential climate impact of these seven greenhouse gases on global surface temperatures is greater than previously thought.

Event series  Brewer-Wilson Seminar Series