I live with 3 dogs and was alone the entire day.
For the interested, here is the graph for a year: https://i.imgur.com/mrXI3y1.png
> However, since the advent of widespread industrialisation, atmospheric CO2 levels have exponentially increased (Fig. 1). In just the last ~ 50 years it has risen from < 340 ppm (in 1980), to > 420 ppm in 2025 (Lan et al., 2025). Atmospheric CO2 is currently increasing at more than 2 ppm each year, largely due to humanity’s activities, such as the burning of fossil fuels (Eggleton, 2012).
There's good reason to believe we're on the cusp of a solar energy revolution and, more generally, ready to turn things around. But even in the worst scenarios I can imagine, outdoor air 50 years from now (as posited in the title) would not be as bad as indoor air now.
Rising carbon dioxide levels now detected in human blood
https://phys.org/news/2026-02-carbon-dioxide-human-blood.htm...
This story could give a hint of what to expect in the far future. Replace Nitrogen with CO2 and you may see what people could be in for :(