As far as green plants are concerned, CO2 is not a pollutant, but part of their daily breadlike water, sunlight, nitrogen, and other essential elements. Most green plants evolved at CO2 levels of several thousand ppm, many times higher than now. Plants grow better and have better flowers and fruit at higher levels. Commercial greenhouse operators recognize this when they artificially increase the concentrations inside their greenhouses to over 1000 ppm.
Fallacy: oversimplification