Breathe Easy

William Fisk of the Lawrence Berkeley National Laboratory has studied the effect of CO2 levels on cognition. Outdoors, normal carbon dioxide levels are 350 to 400 parts-per-million (PPM). Indoors, 600 PPM is considered excellent, and 1,000 is normal. Fisk gave his subjects a bunch of cognitive tests in increasing CO2 concentrations. And the more carbon dioxide they breathed, the dumber they got. 1,000 PPM was bad enough, but up around 2,500 they got positively moronic, basically incapable of rational thought. Thank goodness you only get levels like that when folks are jammed together in a board room or legislative chamber.