@JunkScience
@Apple
CO2 is harmless trace gas in the air, as compared to nitrogen (78%) and oxygen (21%), CO2 makes up only 0.03-0.04% (300-400ppm), even far behind the other trace element, noble gas argon (0.9%, or 9000ppm). Though it only has such a small part, CO2 is the key food for plants. In