[ipqk]

Sort of. While increasing global CO2 levels makes it worse, indoor CO2 levels is mostly a function of buildings being made more and more efficient/air-tight. I live in a new LEED-platinum condo building, and in the fall or spring if I don't may my A/C unit on, my bedroom CO2 levels will go from ~500ppm to 1,300 or higher. You can see the drastic drop in CO2 levels when I wake up and open the door to get air flow.

actual chart of my room: https://imgur.com/a/zZRNQGX