CO₂ is not "pollution", without it at at least 150ppm none of us would be alive for a lack of plant life. NOx and SO₂ are pollutants responsible for smog (etc.)

CO₂ is not "pollution", without it at at least 150ppm none of us would be alive for a lack of plant life. NOx and SO₂ are pollutants responsible for smog (etc.), better focus on those if you want to give an example of something which can be seen in the light you try to place CO₂.