A paper funded under this project published in Nature Geoscience detailed how the atmospheric abundance of five CFCs, and their emissions, have risen in the atmosphere since 2010 (the year of their phase out).
It has been quite well publicised, with explainers elsewhere and an article published in the Conversation has been reposted on this site. One of the interesting things about this work, that hasn’t been drawn on elsewhere, is that measurements of three of these gases – CFC-112a, CFC-113a and CFC-114a – are hard to make. The conclusions for these CFCs are drawn from measurements made from air collected at one location it the world, Cape Grim in Tasmania, Australia, which have been analysed by Johannes Laube and colleagues. This makes any further determination of the geographical location difficult, without something like short-term measurement campaigns (which have happened before for CFC-113a, and exists from aircraft data for CFC-112a).
The big thing will be to see the response this article provokes, and whether any long-term changes will be made with respect to emissions from feedstocks, byproducts and intermediates.
The published article is:
Western, L.M., Vollmer, M.K., Krummel, P.B. et al. Global increase of ozone-depleting chlorofluorocarbons from 2010 to 2020. Nat. Geosci. 16, 309–313 (2023). https://doi.org/10.1038/s41561-023-01147-w