
Ask HN: How has a near doubling of atmospheric CO2 not affected our respiration? - ralusek
CO2 is basically poison within the context of our respiration. How has there been no serious biological&#x2F;performance implications from such a drastic change in atmospheric composition? Obviously as a percentage of atmospheric makeup, CO2 is extremely low, but I would assume that the relative figures are what matters here.
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heavyset_go
Atmospheric CO2 concentration is ~0.04%. When you exhale, your breath contains
a CO2 concentration of ~3.8%.

Acidosis occurs in humans at atmospheric CO2 concentrations of ~5%.

Looking at statistics of indoor CO2 concentrations, it seems that offices,
classrooms and under ventilated spaces often have CO2 concentrations reaching
2%.

I'd posit that there is probably an order of magnitude of leeway in regard to
increasing atmospheric CO2 concentration affecting human respiration.

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thedevindevops
Also of note - we don't have an extensive history of human resting pulse &
respiration over generational time (primarily because modern medicine isn't
old enough)

