In this study, long-term AGAGE measurements with global coverage are presented for four potent greenhouse gases: two newly commercially used foam blowing substances, HFC-245fa and HFC-365mfc; and for the fire-suppressant HFC-227ea and the refrigerant HFC-236fa. Combining in-situ measurements and measurements on archived air samples, the atmospheric histories of these four compounds could be reconstructed and global emissions were calculated using the AGAGE 12-box model. The study shows that all four compounds are growing in the atmosphere and so do their emissions. While their abundances are currently still low, there is concern on long-term accumulation, particularly for HFC-236fa, which has the second-longest atmospheric lifetime of all hydrofluorocarbons (242 yr).
Atmospheric histories and global emissions of the anthropogenic hydrofluorocarbons HFC-365mfc, HFC-245fa, HFC-227ea, and HFC-236fa. M.K. Vollmer et al. (2011), Journal of Geophysical Research: Atmospheres 116(D8): 2156-2202.