From the Wikipedia article: "Another study of humans exposed in 2.5 hour sessions demonstrated significant effects on cognitive abilities at concentrations as

From the Wikipedia article: "Another study of humans exposed in 2.5 hour sessions demonstrated significant effects on cognitive abilities at concentrations as low as 0.1% (1000ppm) CO2 likely due to CO2 induced increases in cerebral blood flow." You can easily reach .1% in a normal office. Therefore, office-environmentally conscious people install CO2 sensors ;-) Here's an example: https://metrics.librato.com/share/dashboards/l7pd2aia?duration=608400 https://metrics.librato.com/share/dashboards/l7pd2aia?durati...