claim: We simply could never release enough CO2 into the atmosphere to cause the pH to go below 7 [ the point in the pH scale at which a solution becomes acidic ].”
evidence: CO2 + H2O ⇌ H2CO3 ⇌ H+ + HCO− 3 It is the decrease in pH that signals the brain to breathe faster and deeper, expelling the excess CO2 and resupplying the cells with O2.