Earliest ever atmospheric CFC observation published

PhD student Jamal Makkor has just published the first ever observation of an atmospheric chlorofluorocarbon (CFC). He analysed historical 1951 solar absorption infrared spectra recorded at the high altitude site of Jungfraujoch,  Switzerland to retrieve the CFC-12 (CF2Cl2) surface mole fraction. The data had been recorded on paper rolls which Jamal digitised and processed.

This observation predates by over two decades the previous 'first detection of atmospheric CFCs' by James Lovelock in the 1970s.

The paper is published in Geophysical Research Letters.

Makkor, J., M. Palm, I. Pardo Cantos, M. Buschmann, E. Mahieu, Z. Wang, M.P. Chipperfield and J. Notholt, First measurements of CFC-12 in 1951 at Jungfraujoch and comparison to current measurements and atmospheric models,
Geophys. Res. Lett., 52, e2025GL117453, doi:10.1029/2025GL117453, 2026.