Final answer:
The world's oceans reduce global warming by removing CO2, increasing primary productivity, and absorbing heat energy. Although they help mitigate climate change, the oceans' absorption of CO2 leads to acidification, which harms marine life. Efforts to reduce emissions and use sustainable energy are vital. The correct answer is option - removing CO2 and sequestering CO2 above the thermocline.
Step-by-step explanation:
The world's oceans play a critical role in reducing global warming through several mechanisms. One important function is their ability to remove CO2 from the atmosphere, which helps to mitigate the greenhouse effect responsible for global warming. This is achieved through processes such as the absorption of CO2 by the ocean's surface and its subsequent sequestration above the thermocline, where it is stored long-term.
The oceans also absorb surplus heat energy, which is crucial since they collect and transport vast amounts of solar energy across the globe, helping to regulate temperature and climate patterns. However, the increased absorption of CO2 by the oceans is causing their pH levels to drop, leading to acidification that can harm marine ecosystems. Lastly, while not entirely accurate, the notion of trapping CO2 in sea ice does reflect the role of polar regions in climate regulation, but ocean water itself does not trap CO2 in this way.
Despite providing a buffer against climate change, these phenomena have limitations and can lead to negative impacts such as the acidification of the ocean, threatening delicate marine ecosystems. It's crucial to balance the use of natural processes with proactive efforts to reduce carbon emissions and develop sustainable energy sources.