Ocean Acidification

Global Warming and Ocean Acidification

• Global warming caused by increased carbon dioxide (CO2) levels.

• Ocean acidification is the "evil twin" of global warming, stemming from the same cause but differing mechanisms.

Demonstration of Ocean Acidification

• Regular distilled water has a pH around 7.

• Carbon dioxide added to water using a SodaStream makes carbonated water, lowering pH to 3.6.

Chemical Reaction

• When CO2 and water mix, carbonic acid (H2CO3) forms.

• Dissociation of carbonic acid leads to bicarbonate (HCO3-) and further dissociation yields carbonate (CO32-).

• pH is defined as the negative log of hydrogen ion (H+) concentration; more H+ results in lower pH and increased acidity.

Impacts of Ocean Acidification

• Decreasing pH negatively affects marine life metabolism and immune response due to its effect on proteins.

• Historical pH change of oceans: from 8.25 (pre-industrial) to 8.1 (post-industrial, a 30% change on a log scale).

• Predictions suggest pH could drop to 7.80 by 2100, significantly impacting ecosystems.

Importance of Carbonate

• Carbonate (CO32-) is crucial for shell formation in marine organisms.

• As pH decreases, carbonate availability declines, impairing shellfish and coral reef development.

Factors Influencing Ocean Chemistry

• Temperature, alkalinity, and pH levels affect the concentration of carbonic acid, bicarbonate, and carbonate.

• Jerome plots illustrate the logarithmic concentration changes of these compounds with pH variations.

Future of Marine Life

• At pH of 7.8, shells (like those of pteropods) dissolve.

• Coral reefs face challenges from both global warming and ocean acidification, hindering their ability to build and maintain structures.

Potential Solutions

• Reducing CO2 emissions can mitigate both global warming and ocean acidification.

• Emphasizes the interconnection between climate change and ocean health.