Standard deviation among the spectra shown in Figure 1 with varying CO₂ (black) compared with the 1σ observational uncertainties for 10 (magenta) and 100 (orange) stacked transits of TRAPPIST-1e with JWST’s NIRSpec Prism. The spectroscopic differences caused by the silicate weathering CO₂ trend are less than 10 ppm for Earth-sized exoplanets transiting TRAPPIST-1, indicating that approximately 100 stacked transits may be necessary to clearly resolve the deviations in CO₂ mixing ratios across HZ instellations.