"... just put-downs with no substantiation ..."   Not at all!  Words have meanings, SkeptiCat, and when we use words in our argument, well outside the bounds of their accepted definitions, we are indeed being either ignorant or willfully misleading.  My post wasn't "attacking" anybody; it was setting the record straight in reference to the genuine "toxic" limits of CO2.  :-/

Clear communication in technical subjects depends on the accurate use of terms, wouldn't you agree?  Hype, wild exaggeration, or distortion of words does nothing to support our arguments, SC - in fact, those tactics *undermine* our arguments.

Thank you for sharing.