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: Also, the Intergovernmental Panel on Climate Change ( IPCC ) writes in their Climate Change 2007 : Synthesis Report : The uptake of anthropogenic carbon since 1750 has led to the ocean becoming more acidic with an average decrease in pH of 0.1 units.