UPSC Prelims 2019 · Question 94 of 99
UPSC Prelims 2019 question on Methane Hydrate
- ExamUPSC CSE
- Year2019
- PaperGeneral Studies Paper I
- SubjectEnvironment and Ecology
- TopicClimate Change
- DifficultyMedium
- TypeStatement
Which of the following statements are correct about the deposits of 'methane hydrate'?
1. Global warming might trigger the release of methane gas from these deposits.
2. Large deposits of 'methane hydrate' are found in Arctic Tundra and under the seafloor.
3. Methane in atmosphere oxidizes to carbon dioxide after decade or two.
Select the correct answer using the code given below.
Show answer
Answer: D. 1, 2 and 3
Verdict
All three statements are correct → Option (d).
Statement by statement
Statement 1 – CORRECT: Methane hydrate is a crystalline solid that consists of a methane molecule surrounded by a cage of interlocking water molecules. Methane hydrate is an 'ice' that only occurs naturally in subsurface deposits where temperature and pressure conditions are favorable for its formation. Owing to melting of ice, global warming might trigger the release of methane gas from these deposits.
Statement 2 – CORRECT: Four Earth environments have the temperature and pressure conditions suitable for the formation and stability of methane hydrate: 1) sedimentary and rock units below Arctic permafrost; 2) sedimentary deposits along continental margins; 3) deep-water sediments of inland lakes and seas; and 4) under Antarctic ice.
Statement 3 – CORRECT: Methane is relatively short-lived in the atmosphere; a molecule of methane is oxidized to water and carbon dioxide after a decade or so, mainly by reaction with another trace gas, the hydroxyl radical OH-. Thus, unlike the case of carbon dioxide (which stays in the atmosphere longer than methane), a concerted effort to reduce methane emissions would have almost immediate results in terms of reduction of greenhouse effect.
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← Full 2019 question paper · All Environment and Ecology questions