Thanks to all this extra CO2, the pH of the oceans’ surface waters has already dropped, from an average of around 8.2 to an average of around 8.1. Like the Richter scale, the pH scale is logarithmic, so even such a small numerical difference represents a very large real-world change. A decline of .1 means that the oceans are now thirty percent more acidic than they were in 1800.
