I think you've used a wrong link. There's nothing about cognitive side effects on there. Also, the OP is talking about indoor ventilation and much higher concen

I think you've used a wrong link. There's nothing about cognitive side effects on there. Also, the OP is talking about indoor ventilation and much higher concentrations than our atmosphere has even today. From the OP: > There does not seem to be a clear dose-response relationship between CO2 levels and cognitive performance It also cites studies where concentrations in the thousands ppm were used where no effect was measured. As a probably ignorant aside, I don't get how it should affect cognition. Don't we have massive amounts of CO2 in our lungs at all times?