Reducing CO2 emissions is the primary method mentioned in the text to mitigate ocean acidification. Ocean acidification is a process in which the pH of seawater decreases due to the absorption of carbon dioxide (CO2) from the atmosphere. This increased acidity can have detrimental effects on marine ecosystems, including coral reefs, shellfish, and other marine organisms that rely on calcium carbonate for their shells and skeletons.

- Reducing CO2 emissions is the most effective way to mitigate ocean acidification because it addresses the root cause of the problem. By reducing the amount of CO2 released into the atmosphere, we can limit the amount that is absorbed by the oceans and subsequently lowers the pH.

- This can be achieved through various means, such as transitioning to renewable energy sources like solar and wind power, improving energy efficiency to reduce overall energy consumption, and implementing policies that promote sustainable practices and reduce greenhouse gas emissions.

- Transitioning to renewable energy sources helps to reduce the burning of fossil fuels, which is a major contributor to CO2 emissions. By relying less on fossil fuels and more on clean, renewable energy, we can significantly reduce the amount of CO2 released into the atmosphere.

- Improving energy efficiency also plays a crucial role in reducing CO2 emissions. By using energy more efficiently and reducing waste, we can decrease the demand for energy and, in turn, reduce the amount of CO2 emitted during energy generation.

- Policies and initiatives that promote sustainable practices and reduce greenhouse gas emissions can also contribute to mitigating ocean acidification. These can include regulations on industrial emissions, incentives for renewable energy adoption, and international agreements to limit CO2 emissions.

- It is important to note that while reducing CO2 emissions is the primary method mentioned in the text, it should be combined with other efforts to address ocean acidification comprehensively. These can include promoting research and monitoring of ocean acidification, implementing marine protected areas, and reducing other sources of pollution that can exacerbate the effects of acidification.

In conclusion, reducing CO2 emissions through the use of renewable energy, improving energy efficiency, and implementing sustainable practices is the primary method mentioned in the text to mitigate ocean acidification. By addressing the root cause of the problem, we can work towards preserving the health and biodiversity of our oceans.