420ppm seems to ignore how bad it actually is for a lot of humans.

A lot of buildings have over 1000ppm of CO2 due to being poorly ventilated, levels where humans start to have noticeable cognitive decline.

Spending so much time at home post COVID I got an indoor air monitor to tell me when to open the windows. 2-3 days of not ventilating will get it over 1000ppm

Full Title: Carbon dioxide levels are higher than humans have ever experienced. It could be changing our blood chemistry

Discussed 15 days agohttps://news.ycombinator.com/item?id=47261968

"The study did not take into account other potential influencing factors"