There are a ton of reasons not to want to increase atmospheric CO2, but I don’t think direct human health impact is something to worry about. Since humans have

There are a ton of reasons not to want to increase atmospheric CO2, but I don’t think direct human health impact is something to worry about. Since humans have been building shelter and living in caves, we have regularly been exposed to long term CO2 levels of 1000-2000ppm. The natural variations in ventilation dwarf a few hundred extra ppm in the atmosphere. We’ve also been exposing submariners to thousands of ppm for extended periods with no observed effect, and we have many studies shows no observed effects up to 40k ppm. We even have studies showing that small babies sleeping next to the mothers are exposed to CO2 levels of 5-10kppm.