Global warming potentials and radiative efficiencies of halocarbons and related compounds: A comprehensive review

Abstract

[1] In the mid-1970s, it was recognized that chlorofluorocarbons (CFCs) were strong greenhouse gases that could have substantial impacts on radiative forcing of climate change, as well as being substances that deplete stratospheric ozone. Around a decade later, this group of radiatively active compounds was expanded to include a large number of replacements for ozone-depleting substances such as chlorocarbons, hydrochlorocarbons, hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), bromofluorocarbons, and bromochlorofluorocarbons. This paper systematically reviews the published literature concerning the radiative efficiencies (REs) of CFCs, bromofluorocarbons and bromochlorofluorocarbons (halons), HCFCs, HFCs, PFCs, sulfur hexafluoride, nitrogen trifluoride, and related halogen containing compounds. In addition, we provide a comprehensive and self-consistent set of new calculations of REs and global warming potentials (GWPs) for these compounds, mostly employing atmospheric lifetimes taken from the available literature. We also present global temperature change potentials for selected gases. Infrared absorption spectra used in the RE calculations were taken from databases and individual studies and from experimental and ab initio computational studies. Evaluations of REs and GWPs are presented for more than 200 compounds. Our calculations yield REs significantly (> 5%) different from those in the Intergovernmental Panel on Climate Change Fourth Assessment Report (AR4) for 49 compounds. We present new RE values for more than 100 gases which were not included in AR4. A widely used simple method to calculate REs and GWPs from absorption spectra and atmospheric lifetimes is assessed and updated. This is the most comprehensive review of the radiative efficiencies and global warming potentials of halogenated compounds performed to date.

Inhomogeneous Radiative Forcing of NF3

“…In this work, RE was 0.188 W·m −2 ·ppb −1 . The difference between our results and those of Hodnebrog et al [8], which are used in the IPCC AR5, was 6%. Using the global mean NF 3 concentration as 1.24 ppt, the NF 3 radiative forcing was 2.33 × 10 −4 W·m −2 which is only about 0.015% that of CO 2 .…”

“…RE is 0.188 W·m −2 ·ppb −1 , as recorded in this work. RE was recorded as 0.211 W·m −2 ·ppb −1 [2] when using a narrow-band-model, and RE was recalculated as 0.20 W·m −2 ·ppb −1 [8] based on methods outlined by Pinnock et al [9]. The difference between our results and those of Hodnebrog et al [8], which are used in the IPCC AR5, is 6%.…”

“…RE was recorded as 0.211 W·m −2 ·ppb −1 [2] when using a narrow-band-model, and RE was recalculated as 0.20 W·m −2 ·ppb −1 [8] based on methods outlined by Pinnock et al [9]. The difference between our results and those of Hodnebrog et al [8], which are used in the IPCC AR5, is 6%. However, the difference between the results in this work and Totterdill et al [10] is large, for in that paper, new NF 3 absorption cross-sections was used.…”

Global warming potential estimates for the C<sub>1</sub>–C<sub>3</sub> hydrochlorofluorocarbons (HCFCs) included in the Kigali Amendment to the Montreal Protocol

“…Radiative efficiencies (REs) were calculated using the 298 K infrared absorption spectra calculated theoretically in this work and the Earth's irradiance parameterization given in Hodnebrog et al (2013). The calculated spectra were broadened using a Gaussian broadening function with a FWHM (full width at half maximum) of 20 cm −1 , which reproduces the training dataset spectra reasonably well and provides a more realistic representation of the spectrum and overlap with Earth's irradiance profile.…”

Atmospheric histories and emissions of chlorofluorocarbons CFC-13 (CClF<sub>3</sub>), ΣCFC-114 (C<sub>2</sub>Cl<sub>2</sub>F<sub>4</sub>), and CFC-115 (C<sub>2</sub>ClF<sub>5</sub>)

“…Uncertainties are ± for "possible"/"most likely" (on a 95 % confidence interval). f IPCC (Intergovernmental Panel on Climate Change) 2013 ) based on Hodnebrog et al (2013). g WMO Scientific Assessment of Ozone Depletion 2014 (Harris and Wuebbles, 2014).…”