Why is it that higher concentrations of CO2 in our environment is harmful to the brain?

Question

Why is it that higher concentrations of CO2 in our environment is harmful to the brain?

In: Chemistry

Answer 1

Currently, atmospheric CO2 is *not* at a level that is harmful to our brains (~400 parts per million).

Indoors, it is very easy for CO2 to exceed 1,500 parts per million; at that level, people can feel sleepy or have trouble concentrating.