Effective realization of abatement measures can reduce HFC-23 emissions.

HFC-23 is a potent greenhouse gas, predominantly emitted as an undesired by-product during the synthesis and processing of HCFC-22 (ref. ). Previously, the Clean Development Mechanism and national efforts called for the implementation of abatement technology for reducing HFC-23 emissions. Nevertheless, between 2015 and 2019, a divergence was found between the global emissions derived from atmospheric observations and those expected from reported abatement. Primarily, this points to insufficient implementation of abatement strategies, calling for independent verification of the emissions at the individual chemical facility level. Here we use regional atmospheric observations and a new, deliberately released tracer to quantify the HFC-23 emissions from an HCFC-22 and fluoropolymer production facility, which is equipped with waste gas destruction technology. We find that our inferred HFC-23/HCFC-22 emission factor of 0.19% (0.13-0.24%) broadly fits within the emission factor considered practicable for abatement projects. Extrapolation to global HCFC-22 production underscores that the operation of appropriate destruction technology has the potential to reduce global HFC-23 emissions by at least 84% (69-100%) (14 (12-16) Gg yr). This reduction is equivalent to 17% CO emissions from aviation in 2019 (ref. ). We also demonstrate co-destruction of PFC-318, another by-product and greenhouse gas. Our findings show the importance of the 2016 Kigali Amendment to the Montreal Protocol, which obligates parties to destroy HFC-23 emissions from facilities manufacturing hydrochlorofluorocarbons and hydrofluorocarbons "to the extent practicable" from 2020 onwards.