Andrei Maruntelu

To summarize, most of us are living with high CO2 concentrations in our offices, bedrooms, classrooms, and cars without even thinking about it. Double-blind experimental studies suggest that CO2 exposure can reduce cognitive and decision-making performance dramatically — by 50% or more at common indoor levels.

If you want to solve the problem, you can usually keep CO2 levels low just by keeping your bedroom door or a few windows open [Strøm-Tejsen 2016]—especially if you live in a place with moderate temperatures year round (say, northern California).

Remember, CO2 levels in our classrooms, bedrooms, and cars are often above 1000 ppm, 2000 ppm, and 4000 ppm, respectively—600–3600 ppm above outdoor levels. That means we could be handicapping our brains—as we learn, sleep, and drive—by 50% or more!