CO2 is Not a Pollutant
This is one of the most easily misunderstood concepts regarding CO2. Mainly because it is somewhat counter-intuitive if one does not understand the science behind the statement.
Once one understands the context, the relevance appears and it is actually quite simple. First one needs to understand the actual definition of the word pollutant. Second, one needs to know the difference between naturally respirated CO2 in the seasonal carbon cycle and how to identify CO2 from human, or industrial sources.
The simple answer is that any carbon dioxide that has been breathing in and out of the natural carbon cycle is exposed to Galactic Cosmic Rays (GCR's) that cause a change in the isotopic signature of the CO2 molecule. The key isotope is C-14.
Carbon dioxide that has the C-14 signature has been exposed to GCR's. If the C-14 signature is missing, the that CO2 has not been exposed to GCR's and therefore originated from an area protected from solar rays (underground). The amount of increase of atmospheric CO2 and the amount of CO2 expected from burning the amount of fossil fuel we have burned are approximately the same (check this link for more detail).
The conclusion is that the quantitative analysis and the C-14 signature provides solid evidence for the human fingerprint on the increase atmospheric carbon dioxide, therefore:
According to Webster
Greenhouse Gas Emissions
CO2 originating from the human industrial system, according to the dictionary, is a pollutant. CO2 from the natural cycle system is not a pollutant.
Likewise, as regards climate, atmospheric aerosols can be natural, or a pollutant.