Ocean Acidification

Graphic by Hyunjoon Rha

The Industrial Revolution was a time of both great progress and technological advances during the 1800s. Indeed, the event led to the invention of the steam engine, locomotives, internal combustion engines, and brickworks. The main source of energy for these inventions was coal, the most common fossil fuel used during the period. A common pollutant of coal is carbon dioxide, and the poisonous gas has escalated in concentration within the Earth’s atmosphere ever since the Revolution.

According to the Global Carbon Project, the global carbon emissions from fossil fuels have reached a record high in 2024 at 37.4 billion tonnes. As a result, the annual global mean surface sweater pH has dropped from 8.11 to less than 8.05, signifying a 15 percent rise in acidity since 1985. 

Ocean acidification occurs due to the rapid absorption of carbon dioxide into the ocean. This happens due to the combined formation of both water and carbon dioxide molecules, ultimately creating carbonic acid. Then, the compound decomposes into a hydrogen ion and bicarbonate. The decomposed hydrogen ion then bonds with a free carbonate which synthesises into another bicarbonate. This increase in the concentration of bicarbonate molecules will impact the availability of carbonate for the synthesis of calcium carbonate, which is essential for shellfish and coral health. Coral health is important because it helps to protect habitats, such as meadows and mangroves, which are essential for the absorption of carbon dioxide.

As carbon dioxide concentrations increase within the ocean, the availability of carbonate decreases. Carbonate is essential for shellfish due to the compound’s ability to bond with calcium to form calcium carbonate which helps to create thick and healthy shells. An increase in acidity will also impact the population of other marine organisms. Just like humans can experience seizures, comas, and even death by a 0.2-0.3 decrease of pH in the blood, fish experience this gradual but harmful change by showing a reduction in energy and slow growth. Consequently, this decline in marine organisms will cause a ripple effect amongst marine organisms. Eventually, a change in one species’ population impacts the population of all the animals that feed on it. 

Around 30 percent of the world’s population relies on food from the ocean as not only for protein supplement but also for employment. Therefore, an increase in carbon dioxide production not only hurts the population of shellfish and coral reefs, but also the human population that consumes them. By and large, fish are the main support of the seafood industry, sustaining more than 1.2 million jobs. Thus, without a stable marine ecosystem, coastal and developing countries will be heavily impacted for their livelihoods and food security.

Ocean acidification is a product of human pollution. Therefore, the increase in carbon dioxide production should not be pinpointed on a myopic, domestic scope, but on a global, international consideration in which every nation takes initiatives in resolving so. Help to fight ocean acidification by being conscious of one’s energy consumption, participate in local beach cleanups, and have a good understanding about the environment to truly make a difference.