Question 25

describe a recent suggestion for alleviating the problem of global warming

The passage primarily discusses the strategy of iron fertilization as a proposed method to combat global warming by enhancing phytoplankton growth in the Southern Ocean. This method aims to increase photosynthesis, thereby reducing atmospheric carbon dioxide levels.

A) compare various methods proven to be effective in helping to clean marine environments

This option is incorrect because the passage does not compare multiple methods for cleaning marine environments; it specifically focuses on a singular approach—iron fertilization—as a potential solution to global warming.

B) explain how single-celled marine organisms photosynthesize

While the passage mentions photosynthesis related to phytoplankton, it does not provide a detailed explanation of the process itself. Instead, it emphasizes the potential benefits of increasing phytoplankton through iron fertilization rather than explaining photosynthesis.

C) describe a recent suggestion for alleviating the problem of global warming

This is the correct option as the passage outlines the concept of iron fertilization and its intended purpose to enhance phytoplankton growth, thereby addressing the issue of global warming through carbon dioxide reduction.

D) account for the relative scarcity of phytoplankton in the Southern Ocean

Although the passage notes the low concentrations of phytoplankton due to iron deficiency, it does not focus on explaining the scarcity itself. Instead, it suggests a method to potentially increase their population, which is not the main purpose of the passage.

E) characterize the difference between the Southern Ocean and other large bodies of water

This option is incorrect because the passage does not explore or compare the Southern Ocean with other bodies of water. Its focus is solely on the implications of iron fertilization for the Southern Ocean in terms of global warming.

Conclusion

The correct answer, option C, captures the essence of the passage, which is centered on proposing iron fertilization as a novel approach to mitigate global warming. All other options either misinterpret the passage's intent or focus on unrelated topics, thereby failing to address the central theme of the text.