The CO2 readings that have been increasing annually are basic indication that there are more and more aircraft in the sky annually.
Nothing to do with cow farts, baby burps and beer drinking.
Just draw a chart comparing the co2 measurements and number of aircraft in air that same year.
you all must understand, the air composition is always balanced back to what is able to sustain human beings. if not , all of us will be dead by now. its not magic but the amount of oxygen we survive on is a delicate % bandwidth. Any deviation we either get hypoxia or toxic poisoning.
