An increase in atmospheric CO2 results in an increase
in the CO2 of the oceans, in turn the CO2 in the upper surface waters of the ocean will alter
the oceanic carbon system.
enters the oceans the following reactions take place:
CO2 + H2O ß à H2CO3
H2CO3 ß à HCO3- + H+
HCO3- + H+ ß à CO32- + 2H+
These reactions help
show how pH decreases with addition of CO2 to ocean waters. From these we can deduce that calcification will decrease
as well, since there is a decrease in surface CO32- concentration which will lead to a decrease in CaCO3
Exchange of CO2 between the ocean and
atmosphere is so rapid, that the increase in concentration of CO2 in the atmosphere has already been seen to affect
marine chemistry substantially.
Future predictions for the state of pH in the oceans
have indicated an expected decrease of 0.3 to 0.4 units by 2100, such a decrease would have severe effects on organisms that
make their shells out of calcite and aragonite because of destabilization of the these minerals, which in turn can have a
drastic effect on marine ecosystems.
The Honolulu Declaration On Ocean Acidification and Reef Management
- Shows projected increase in CO2
(Orr, et.al. 2005)