If you want to increase your CO2 simply wear a mask. Del Bigtree in the latest Highwire YouTube video measured the CO2 concentrations for various Covid-19 masks. All masks measured concentrations of 9000+ ppm after a few minutes. Normal concentrations without a mask are around 800 ppm. Wear a mask long enough, like for hours while walking and shouting or exercising and you can do some real damage to yourself.
Last edited: