Ocean Acidification
What is it?
There are many harmful and negative side effects of climate change that can seriously impact biodiversity and the earth’s ecosystems -- ocean acidification happens to be one of the unfortunate byproducts of climate change and increased levels of carbon dioxide (CO2) in the atmosphere. Simply put, when CO2 gases in the atmosphere combine with the H2O of the ocean, they form carbonic acid and releases hydrogen ions. As its name affirms, the molecules decrease the pH level of the water, causing a rise in the ocean's acidity.
Where does the CO2 come from?
Each year, 43 billion tonnes of CO2 is released into the atmosphere. These gases are a result of several human activities including, but not limited, to the following: transportation, electricity, and agriculture. These activities involve burning fossil fuels like coal and gas or from other chemical reactions which produce greenhouse gases (United States Environmental Protection Agency). As climate change becomes more prevalent, CO2 levels will increase and ocean acidification becomes more of an issue.
What are pH levels?
A pH scale is a 1-14 numeric indicator of a liquid's acidity. A lower pH level means the liquid is acidic, a neutral level would be 7, and a higher pH level means the liquid is basic or has high alkalinity. Additionally, the pH scale is heavily influenced by the concentration of hydrogen ions -- as these ions increase, the acidity also increases and the pH level decreases (Bennet). The scale is also logarithmic, meaning a pH of 4 would be 10 times more acidic than a pH of 5, which would be 100 times more acidic than pH level of 6 (National Oceanic and Atmospheric Association [NOAA]). This means that changes in the ocean's acidity levels would drastically affect the chemical reactions necessary for marine life.
How does ocean acidification affect marine wildlife?
Ocean acidification negatively affects species that build hard shells, such as sea snails and corals. This is because these critters require carbonate to make their shells, but as mentioned previously, lower pH means more hydrogen ions. These "loose" hydrogen molecules bond together with carbonate, meaning that shell-creating species do not have as much carbonate in the ocean to pull from (Bennet). This damages the organisms shell during its chemical production, but if acidity levels increase even further, their shells can actually dissolve.
This does not only affect shell-creating species. For example, clownfish have a difficult time detecting predators in acidic waters and show less effective metabolic systems. Other studies show that acidification may limit coral growth, leading to erosion that would impact entire ecosystems (NOAA).
By destroying species' protective shells, harming their metabolisms, and erroding living spaces like coral reefs, ocean acidification is clearly an issue that must be addressed. This, however, is just one many unforeseen environmental impacts of global warming and human activities. Nonetheless, learning about environmental issues is an important step towards progress and eventually reducing one's own carbon footprint.