The concentrations of carbon dioxide and other such greenhouse gases in our atmosphere have grown tremendously since the beginning of the industrial era. Ever since the industrial revolution began, global oceans have absorbed an estimated 30% of the CO2 that is released in the atmosphere (National Oceanic and Atmospheric Administration, 2024). As a result of the absorption of carbon dioxide, the chemistry of global oceans has begun to change.

Ocean acidification is the process through which ocean water becomes more acidic due to the excessive amounts of carbon dioxide that is absorbed from the atmosphere. As carbon dioxide is absorbed into ocean water, carbonic acid is produced. Carbonic acid, then releases hydrogen and bicarbonate ions. The excessive quantities of these hydrogen ions are what causes water to become more acidic (Hu & Ireland, 2022). This simple chemistry drives ocean acidification.

Environmental Impact

Carbonate ions are essential to the overall health seashells and coral skeletons. The rapidly increasingly acidic seawater causes carbonate ions to become relatively less abundant. A decrease in carbonate ions can make it very difficult for various marine organisms such as sea urchins, corals, plankton, oysters and clams to build and maintain their shells and other bodily calcium carbonate structures (National Oceanic and Atmospheric Administration, 2024). Additionally, an increased acidity in ocean water could hinder the ability of certain organisms such as fish to detect predators. This could potentially lead to imbalances in marine ecosystems.

Numerous ecosystems globally have been devastated by this acidification, with coral reefs being one of the first ecosystems to be affected (Readfearn, 2024). The Great Barrier Reef is the world’s largest coral ecosystem, and it is composed of nearly 3000 individual coral reefs. There have been mass bleaching events in the reef in 1998, 2002, 2016, 2017, 2020, 2022, and in 2024 (Readfearn, 2024). It is projected that by the year 2050, 90% of the coral reefs globally will experience coral bleaching annually (Coral Reef Alliance, n.d.). To make matters worse, as the oceans get hotter, they are able to hold more carbon dioxide, which will further exacerbate ocean acidification (WHOI, n.d.).

Ocean acidification may also have tremendous impacts on plankton populations and go on to massively disrupt various ecosystems and food chains. An increased rate of ocean acidification will immensely impact global populations of phytoplankton. These organisms are essential to marine ecosystems as they are the primary producers of the sea. (Chu, 2015). It is projected that ocean acidification will cause most disturbance to phytoplankton and to the species that rely on them as a food source. Moreover, the trillions of phytoplankton in our oceans collectively convert immense quantities of CO2 into living matter and release a major percentage of the world’s oxygen into the atmosphere in the process (My NASA Data, n.d.). Due to these changes, both the chemical composition and ecosystems of the world's oceans will undergo significant transformations.

Economic Impact

The dramatic change in the ecosystems of global oceans would impact more than 37.88 million people working in the fishing industry, as well as the 20.67 million people working in aquaculture globally (Statista, 2022). This would lead to dire economic consequences for the livelihoods of the people and the countries whose economies are based on fishing and aquaculture. 

How we can stop it

To further prevent ocean acidification, we must tackle the problem from its root cause. We must drastically reduce our carbon dioxide emissions and decarbonise in all possible sectors like the automotive industry and energy production industries (Anderson, 2024). Through methods such as upgrading to energy efficient appliances, reducing food wastage, using public transportation, we can lower our carbon footprint on an individual scale as well.

Once we have lowered carbon emissions, we must then increase and restore the various other carbon sinks found on Earth. This can be achieved through implementing policies that preserve critical tropical forests such as the Amazon Rainforest. In fact, certain studies estimate that tropical forests are responsible for reducing more than 1 degree celsius of atmospheric warming, this is due in large part to the amount of carbon that they store (Ruiz, 2024). 

Conclusion

In conclusion, ocean acidification is a serious and growing environmental concern that is a result of increased levels of carbon dioxide in the atmosphere. It has profound impacts on various marine ecosystems, ranging from coral reefs to plankton. These disruptions can have detrimental impacts on the various species that depend on them. There are also severe economic consequences as this will impact the livelihoods of millions of people globally, and change global economies. However, stopping ocean acidification is not yet fully outside of our control. Through reducing carbon emissions and protecting carbon sinks such as tropical rainforests, we can reduce the effects of ocean acidification. To make this possible, we must decide as a global community to take action and safeguard the health of our oceans. We must ensure a balanced, and thriving marine environment for future generations.

References

Chu, J. (2015, July 20). Ocean acidification may cause dramatic changes to phytoplankton. MIT News | Massachusetts Institute of Technology. https://news.mit.edu/2015/ocean-acidification-phytoplankton-0720

Coral Bleaching. (n.d.). Coral Reef Alliance. https://coral.org/en/what-we-do/global-conservation/coral-bleaching/

Ireland, P. (2022, October 13). Ocean Acidification: What You Need to Know. Www.nrdc.org. https://www.nrdc.org/stories/ocean-acidification-what-you-need-know

My NASA Data. (n.d.). Mynasadata.larc.nasa.gov. https://mynasadata.larc.nasa.gov/basic-page/global-phytoplankton-distribution

NOAA. (2024, June 16). What Is Ocean Acidification? National Ocean Service; NOAA. https://oceanservice.noaa.gov/facts/acidification.html

NOAA Fisheries. (2017). Understanding Ocean Acidification. Noaa.gov; NOAA. https://www.fisheries.noaa.gov/insight/understanding-ocean-acidification

Number of people working in fishing and aquaculture worldwide 2018. (n.d.). Statista. https://www.statista.com/statistics/248768/number-of-persons-working-in-fishing-and-aquaculture-worldwide/

Ocean. (2022, May 20). Ocean Science Fact - 99% of reef-building corals are at threat due to global warming. YouTube. https://youtu.be/0h4ouyKJq2o

Ocean Acidification: Causes, Issues and Solutions. (n.d.). Greenly.earth. https://greenly.earth/en-gb/blog/ecology-news/ocean-acidification-causes-issues-and-solutions

Readfearn, G. (2024, March 8). Fifth mass coral bleaching event in eight years hits Great Barrier Reef, marine park authority confirms. The Guardian. https://www.theguardian.com/environment/2024/mar/08/coral-bleaching-great-barrier-reef-australia

Ruiz, S. (2024, April 17). Forest Carbon Storage, Explained. Woodwell Climate. https://www.woodwellclimate.org/global-forest-carbon-storage-explained/

US EPA. (2017, January 23). Climate Change Indicators: Atmospheric Concentrations of Greenhouse Gases | US EPA. US EPA. https://www.epa.gov/climate-indicators/climate-change-indicators-atmospheric-concentrations-greenhouse-gases

Woods Hole Oceanographic Institution. (2024). Ocean warming - woods hole oceanographic institution. Https://Www.whoi.edu/. https://www.whoi.edu/know-your-ocean/ocean-topics/climate-weather/ocean-warming/