How does climate change affect ocean acidity?

The correct answer highlights a critical process that links atmospheric CO2 levels and ocean chemistry. As the concentration of carbon dioxide (CO2) in the atmosphere increases, a significant portion of this CO2 gets absorbed by the oceans. When CO2 interacts with seawater, it undergoes a chemical reaction to form carbonic acid (H2CO3). This process contributes to a decrease in the pH level of ocean water, indicating an increase in acidity.

The implications of this change are substantial for marine life, as many organisms, particularly those with calcium carbonate shells or skeletons, are sensitive to changes in acidity. Lower pH levels can hinder their ability to form shells and can disrupt various ecological balances within marine environments.

In contrast to the other options, which suggest either no change or a positive change in ocean acidity, the correct answer accurately reflects the established science surrounding the impact of climate change on ocean chemistry, particularly through the lens of carbon cycling and acidification processes.