I'd agree being in a room pumped with CO₂ would significantly deteriorate cognitive functions, but I have a feeling the studies are overblown WRT climate change.
Humans have high adaptability to increased CO₂ loads (see e.g. freedivers), but adaptation takes time. The studies usually deal with temporary CO₂ increases / O₂ decreases, often in way higher concentrations like 1-10%, whereas a couple percent atmospheric CO₂ would already burn us to a crisp (figuratively).
Thanks, seems I've missed a decimal. My questionable sources[1][2] mention concentrations up to 14000 ppm = 1.4% and seem to disagree whether going higher cognitive decline plateaus or it becomes harmful.
Seems there is merit for concern, though I stand by my claims of cognitive effects probably being more temporary than permanent.
