How often CO2 is blamed on burning of fossil fuels, I often get gobsmacked by how many people forget plants breathe CO2 and release O2 yet no one ever correlates the increase to deforestation of rain forests. Possibly 1 is not enough to merit the change on it's own, but the two combined could account for the increase of CO2, not enough plants and trees in the rain forests to scrub the atmos of CO2 fast enough.
I recall in the 70's and 80's it was ozone, at some point we shifted and now it's CO2.