The average person, when talking about climate change, will speak of the severely increased CO2 levels in the atmosphere and its global warming effects. The rise in C02 levels are often attributed to anthropogenic (man-made) causes such as combustion of fossil fuel, deforestation and cement production. However, there is an understated fact that the ocean plays a major role in this issue.
The ocean absorbs one-fourth of anthropogenic C02 from the atmosphere. This may seem like a great thing at surface level since it gets rid of atmospheric CO2; however there are consequences to that absorption.
The CO2 absorbed reacts with water to form carbonic acid, and hydrogen ions [H+] released. This increase in hydrogen ion reacts with carbonate ions that usually act as buffers. This whole process results in a decrease in pH due to increase hydrogen ion concentration, and a decrease in carbonate ions. Carbonate ions now don’t bind with calcium ions to form calcium carbonate. Calcium carbonate is what shells are made out of for the shelled organisms such as molluscs. This is ocean acidification. This is irreversible for at least hundreds of years.
Ocean Acidification – Video describing ocean acidification process.
This is where some controversy comes in. Critics, such as Andrew Bolt, state that ocean acidification is not a problem because organisms are adaptive and will show positive and negative responses. Also, there is huge variation in the pH change in the ocean. Finally, we don’t understand how ocean acidification works anyways, so can’t predict the outcome.
While these issues might be valid in some situations, I argue that overall, ocean acidification is a major concern. Firstly, the issue that certain organisms are not affected by acidity of the ocean is preposterous. An organism can be directly affected by changes in physiology. Other organisms are connected by such an intricate food web that organisms are indirectly affected by it or may have a disruption to their habitat. Secondly, there is huge variation in the ocean acidity at any time point or locations, however on average; there is a 0.1 pH unit decrease. That is 25% decrease over the past two centuries. Lastly, it is true that ocean acidification is a relatively new discovery with knowledge gaps, however there are models of physical environment that show predictions of the projected future accurately. There is more research to be done and greater awareness to be made.
It seems odd that people might want to turn a blind eye on matters such as there that affects the people. A recent study looked at the effect of ocean acidification in the Mediterranean Sea. This semi-enclosed sea is economically important for the 21 countries surrounding it from three continents. Both lab and Field results indicate a negative impact on commercially important species from ocean acidification.
In conclusion, ocean acidification should not be controversy, but a fact. A fact that increasing atmospheric CO2 decreases the pH levels of the oceans and will lead to major disasters to marine organisms and to humans.