What is it?
The highly acclaimed industrial revolution has changed the fate of human beings. Yes, in both good and bad ways. The privileges of the industrial revolution are well celebrated and need no discourse. However, some sacrifices must be brought to our attention. The cherished offsprings of the industrial revolution, fossil fuel-powered machines have unfortunate consequences, most alarming being the emission of tons of carbon dioxide and other greenhouse gases into the atmosphere.
Oceans are home to myriads of life forms, and their beauty is beyond description. But, unfortunately, their assistance to the human race can never be compensated. For example, oceans are the biggest sinks for CO2 (not plants and trees), and they absorb about a third of carbon dioxide emissions, roughly 20million tons a day!! This clearly implies that global warming could be far worse if it were not for the oceans. However, recent studies now show that the CO2 absorbed by the ocean is changing the chemistry of water leading to ocean acidification(poor oceans had to pay for their generosity!).
More scientifically, when CO2 dissolves in seawater, it forms carbonic acid, which results in an increase in the hydrogen ion (H+) concentration and thus a decrease in pH.
CO2 (aq) + H2O ↔ H2CO3 ↔ HCO3− + H+ ↔ CO32− + 2 H+.
The amount of hydrogen ions produced is larger than that of the bicarbonate (CO32− + 2H+). Therefore, to maintain chemical equilibrium, the carbonate ions already present in the ocean react with some of the hydrogen ions resulting in the dissolution of CaCO3 sources.
There has already been an increase of almost 30% in H+ ion concentration in the world’s oceans between 1751 and 1994 (pH has decreased from 8.25 to 8.14). If we continue emitting CO2 at the same rate, by 2100 ocean’s acidity will increase by about 150%. Such an immense alteration in ocean chemistry is likely to impact ocean life, especially coral reefs, and molluscs severely.
This increasing acidity holds a direct relationship with the production of shells out of calcium carbonate sediments in the ocean (known as calcification). Though they are formed, such structures are vulnerable to dissolution unless the surrounding seawater contains saturating concentrations of carbonate ions.
Apart from slowing and reversing of calcification, there are other unpleasant effects such as reproductive disorders in fish, acidification of body fluids (hypercapnia), reduction in metabolic rates, depression of the immune responses, a longer incubation period of eggs, and an increase in red tide events which leads to the accumulation of toxins in certain organisms. In addition to these, it is expected that OA will lead to a significant decrease in carbonate sediments.
Experiments were conducted to see the reaction of animals shells to ocean acidification. One of them was to see the behavior of pteropods (these are eaten by organisms ranging from tiny krill to whales!) shells under the conditions expected to exist in 2100. The shell slowly dissolved over a period of 45 days! This could mean a catastrophe as pteropod is at the lower end of the food chain (something like a huge building with crumbled foundation!).
OMG, it seems pretty dangerous! What now?
Ocean acidification is an emerging global problem and requires immediate attention. Solutions have been put forward such as climate engineering, iron fertilization, carbon-negative fuels, etc. Still, none could provide a promising and permanent solution to this problem without any side effects.
Ocean acidification is because of CO2 emissions from industries, and there is nothing we could do about it. If this is your conclusion, then please reconsider. It is everyone’s responsibility as a parasite of the ocean’s treasures to spread awareness and do as much to stop this dangerous phenomenon from further advancement. Invigorate the efforts for the reduction of CO2 in the atmosphere, and your contribution IS PRETTY SIGNIFICANT.
Imagine a person who you have helped to conspire against you. How cruel and stupid! This is exactly what we are doing to the oceans. With his exceptional intelligence, the human being is pathetically trying to cut the branch of the tree on which he is sitting!