The ~420ppm statistic is considered a global average. The concentration is already quite a bit higher in cities. Poke around here [1] for yourself. In indoor u

The ~420ppm statistic is considered a global average. The concentration is already quite a bit higher in cities. Poke around here [1] for yourself. In indoor urban spaces, concentrations are probably already typically 800ppm. It might explain some of our social dysfunction... [1] https://earth.nullschool.net/#current/chem/surface/level/overlay=co2sc/orthographic=-67.82,33.15,727/loc=-73.308,41.582 https://earth.nullschool.net/#current/chem/surface/level/ove...