Abstract Chlorofluorocarbons (CFCs) have played a major role in the depletion of stratospheric ozone. Understanding historical trends in emissions and atmospheric concentrations is crucial for quantifying their impact. The first measurements of atmospheric CFCs were performed in‐situ by Lovelock in 1970. We have analyzed historical 1951 solar absorption infrared spectra, recorded at Jungfraujoch, to retrieve the CFC–12 $\text{CFC}\text{\mbox{–}}\,12$ surface mole fraction. We compare to routine solar absorption measurements starting at Jungfraujoch in 1986 and emission‐based forward models. The surface mole fraction derived from the historical spectra is (26.1±18.5) $(\mathrm{26.1}\pm \mathrm{18.5})$ pptv $\mathrm{p}\mathrm{p}\mathrm{t}\mathrm{v}$ compared to (9.2±0.2) $(\mathrm{9.2}\pm \mathrm{0.2})$ pptv $\mathrm{p}\mathrm{p}\mathrm{t}\mathrm{v}$ from a reconstructed history model, and (7.00±0.28) $(\mathrm{7.00}\pm \mathrm{0.28})$ pptv $\mathrm{p}\mathrm{p}\mathrm{t}\mathrm{v}$ from the Advanced Global Atmospheric Gases Experiment 12‐Box model. The 1951 measurement and model values agree within error bars although the models may be biased low due to unreported emissions. Our result represents the earliest atmospheric CFC measurement, predating Lovelock’s detection by over two decades.
Observations from the Little Bunker
Last updated: February 24, 2026 10:22 PM
Atmospheric CO₂
429.9 ppm
+17.3
ppm/year
Atmospheric CH₄
1946.47 ppb
+6.49
ppb/year
Global Temperature
+1.48 °C
Peak: +1.73°C
World Population
8.1 billion
+67
million/year