Detectability of Chlorofluorocarbons in the Atmospheres of Habitable M-dwarf Planets

The presence of chlorofluorocarbons (CFCs) in Earth's atmosphere is a direct result technology. Ozone-depleting CFCs have been banned by most countries, but some persistent elevated concentrations due to their long stratospheric lifetimes. are effective greenhouse gases and could serve as remotely detectable spectral signature Here we use three-dimensional climate model synthetic spectrum generator assess the detectability CFC-11 CFC-12 technosignature on exoplanets. We consider case TRAPPIST-1e well habitable Earth-like planet around 3300 K M-dwarf star, with CFC abundances ranging from one five times present-day levels. Assuming an optimistic James Webb Space Telescope (JWST) Mid Infrared Instrument (MIRI) low resolution spectrometer (LRS) noise floor level 10 ppm multiple co-added observations, find that features potentially attributable present or historic Earth-level be detected SNR $\ge 3-5$ TRAPPIST-1e, if present, $\sim 100$ hours in-transit time. However, applying very conservative 50 even 5x would not no matter observation Such observations carried out simultaneously at additional cost searches for biosignature gases. Non-detection place upper limits concentration. launch JWST, humanity may approaching cusp being able detect passive atmospheric technosignatures equal strength its own nearest stars.