How does increased carbon dioxide affect ocean acidity?

Increased carbon dioxide in the atmosphere leads to higher levels of CO2 dissolving in the ocean, increasing its acidity.

When the concentration of carbon dioxide in the atmosphere rises, more of it dissolves into the ocean. This process is part of the natural carbon cycle, where the ocean acts as a significant carbon sink, absorbing about a quarter of the CO2 that humans release into the atmosphere. However, when the ocean absorbs CO2, it reacts with seawater to form carbonic acid, a weak acid, which subsequently dissociates to form bicarbonate ions and hydrogen ions. The increase in hydrogen ions in the ocean leads to a decrease in pH, making the ocean more acidic. This process is known as ocean acidification.

Ocean acidification is a significant environmental concern because it can have detrimental effects on marine life, particularly organisms that build shells or skeletons from calcium carbonate, such as corals, molluscs, and some types of plankton. The increased acidity can reduce the availability of carbonate ions, which these organisms need to build their shells or skeletons. If the pH of the ocean continues to decrease, it could reach a point where the ocean is corrosive to these structures, leading to their dissolution.

Furthermore, the increased acidity can also affect the behaviour and physiological processes of marine organisms. For example, studies have shown that higher levels of CO2 can interfere with the ability of fish to smell predators, and can also affect their metabolism and immune system. This could have significant implications for marine ecosystems and the millions of people who rely on them for food and livelihood.

In conclusion, the increase in atmospheric CO2 leads to higher levels of dissolved CO2 in the ocean, which increases its acidity. This process, known as ocean acidification, can have significant impacts on marine life and ecosystems. Therefore, it is crucial to reduce CO2 emissions to mitigate the effects of ocean acidification.