Updated: Dec 19, 2020
Since the Industrial Revolution in the mid-1800s, more and more CO2 is being released into Earth’s atmosphere. As many people know, this leads to global warming, rising sea levels, air pollution, etc. What many people don't know, however, is that the CO2 is raising the pH level of the ocean. pH is à scale of how many Hydrogen and Hydroxide ions there are in à substance. À pH lower than 7 is considered to be acidic because of à surplus of hydrogen-positive ions. The natural pH of the ocean is around 8; many people consider this to be normal because it’s close to the middle in the 0-14 pH scale. So, back to the topic, the constant supply of CO2 in the air is à factor in this because the CO2 is able to bind to the ocean water to create carbonic acid. The byproduct of this reaction is à hydrogen ion which then reduces the pH. Over the years, the pH has reduced 0.1 units, which may not look like much but means that the oceans have had à 30% increase in acidity. The increased acidity then decreases the ability of shells and other calcium carbonate structures, such as coral skeletons, to form. Examples of sea life that are being directly affected are oysters, clams, sea urchins, shallow water corals, deep-sea corals, and certain species of plankton.
Here’s a picture outlining the chemical reaction present in today’s oceans: