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: The beginning of human agriculture during the current Holocene epoch may have been strongly connected to the atmospheric CO 2 increase after the last ice age ended, a fertilization effect raising plant biomass growth and reducing stomatal conductance requirements for CO 2 intake, consequently reducing transpiration water losses and increasing water usage efficiency.