Ocean AcidificationOcean Acidification

Victoria J. Fabry and Andrew G. DicksonScripps Institution of Oceanography

and California State University San Marcos

fabry@csusm.edu

Atmospheric CO2 concentration at Mauna Loa Observatory, Hawaii

Atmospheric CO2 concentration at Mauna Loa Observatory, Hawaii

Ocean pH at the Hawaii Ocean

Time-Series Site

Effect of adding CO2 to seawater

increase in dissolved CO2

increases bicarbonate

decreases carbonate

hydrogen ion concentration increases

CO2 CO32 H2O Ä 2HCO3

pH = –log [H+] decreases

and the saturation state of calcium carbonate decreases

↔

CO2 concentration in the atmosphere

Measured

CO2 concentration in the atmosphere

Measured

IPCC scenarioA1FI

1765 280 ppm

Aragonite saturation state(from corals’ point of view)

Extremely low Optimal

2010 390 ppm

Extremely low Optimal

Aragonite saturation state(from corals’ point of view)

2040 495 ppm

Extremely low Optimal

Aragonite saturation state(from corals’ point of view)

2080 788 ppm

Extremely low Optimal

Aragonite saturation state(from corals’ point of view)

1997 2008

Science, 2009

Sabine et al. (2004) & Doney (2006)

Distribution of excess CO2 in the oceans