Ocean Acidification Calculator
Estimate the change in ocean pH from rising atmospheric CO2 using the Revelle factor approximation.
ppm
ppm
Estimated Current pH
8.030
pH Decrease0.150
H+ Ion Increase41.1 %
Estimated Current pH vs Pre-industrial CO2
Ocean Acidification and CO2
When CO2 dissolves in seawater it forms carbonic acid, lowering the pH. The ocean has absorbed about 30% of human-produced CO2.
Simplified Formula
Delta pH = 0.85 x log10(C / C0)
Where C and C0 are current and pre-industrial CO2 levels. The coefficient 0.85 approximates the buffering chemistry of seawater (the Revelle factor). Since pH is logarithmic, even a small drop represents a large increase in acidity.
Example Calculation
CO2 has risen from 280 ppm to 420 ppm with pre-industrial pH of 8.18.
- 01CO2 ratio = 420 / 280 = 1.5
- 02log10(1.5) = 0.1761
- 03pH drop = 0.85 x 0.1761 = 0.1497
- 04Estimated pH = 8.18 - 0.150 = 8.030
- 05H+ increase = (10^0.150 - 1) x 100 = 41.3%