Investigating the abundances of CO₂ on WASP-107 b’s evening and morning limbs. We performed a χ² comparison between our observed limb spectra and model spectra with varying CO₂ abundance, focusing on the ∼4.5 μm feature in NIRCam/F444W. Panel (A) shows the evening-limb spectrum with all models consistent within the 68% confidence level, and panel (B) shows the same for the morning-limb spectrum. Panel (C) shows the full results of these tests, plotting the χ² value, relative to the minimum, as a function of the input CO₂ abundance for both the evening- (orange) and morning-limb (blue) cases. The corresponding confidence intervals based on J. V. Wall & C. R. Jenkins (2012), are plotted as horizontal lines. For reference, we also show CO₂ abundances previously inferred for WASP-107 b from the limb-combined spectrum in the literature.