Ocean Acidity

Gases emitted into the atmosphere are inevitably absorbed by our oceans. Much of the CO2 already emitted has gone into the oceans and the ocean acidity has been measured to be increasing (historically around 8.17 pH). The implications are that by the end of the century there may be no corals left as they will be unable to form the Calcium Carbonate from the ocean waters that they need to form coral. The collapse of the coral reef system will seriously impact on biodiversity with the consequent disruption to food sources from the ocean on which human society depends. Also to be impacted are species using Calcium to form shells or protection such as plankton, prawns, crabs, etc.

Impact type                       2050                             2100                          2300

                                   Low        High                Low        High             Low        High

Decreased pH                 8.0        7.9                  7.8         7.7

% Loss of carbonate
forming species              10          30                  70          90

% Loss of foraminifera
and plankton                  10           30                 60          85

 [Assessed Dec 2010]