Probably not! That was a mistake on my part. The better term would be photoacoustic sensing I believe, so I have edited the post to use that term instead.

Although the response is proportional to the absorbance value at a narrow wavelength range, and CO2 is detected selectively because its molar absorption coefficient is high at that specific wavelength. I think the argument can be made that this is an action spectroscopy method limited to a single point. But I am not quite sure, so ‘photoacoustic sensing’ wins. Thanks!