Correct Option (D)
Explanation
All three statements regarding methane hydrates are correct.
- Statement 1: Methane hydrates are stable under specific conditions of high pressure and low temperature. Global warming, through processes like rising ocean temperatures or melting permafrost, can destabilize these deposits. This destabilization can lead to the release of methane gas, a potent greenhouse gas, into the atmosphere, thereby contributing to further warming in a positive feedback loop.
- Statement 2: The largest known natural reservoirs of methane hydrate are primarily located beneath the Arctic permafrost (which includes the Arctic Tundra regions) and within marine sediments under the seafloor, particularly along continental margins.
- Statement 3: Methane (CH₄) has a relatively short atmospheric lifespan, typically persisting for about 9 to 12 years. During this period, it undergoes oxidation, primarily reacting with hydroxyl (OH) radicals, eventually converting into carbon dioxide (CO₂) and water (H₂O). Although its atmospheric lifetime is shorter than CO₂, methane is a significantly more potent greenhouse gas over a 20-year period.
Incorrect Options
Options A, B, and C are incorrect because they do not include all the correct statements. Since statements 1, 2, and 3 are all factually accurate regarding methane hydrates, the option encompassing all three is the correct choice.