Since you mentioned, you are the only one explaining. And there I say that there is also no concern that CO2 would harm us humain or animals or plants. The only concern with higher CO2 concentration is that the general temperature heats up with the greenhouse effect. This is such a basic experiment, I am sure you are able to replicate it yourself.

And this is a full counterargument against your arguments about CO2 not being harmful. Because you debunk nothing, since there is no one in the first place to make the claim that CO2 is harmful to anything else but the climate.