Crack Prelims
← Climate change · Greenhouse gases & climate science
Prelims 2019 · Q34 · Greenhouse gases & climate science

Which of the following statements are correct about the deposits of 'methane hydrate'?

  1. 1.Global warming might trigger the release of methane gas from these deposits.
  2. 2.Large deposits of 'methane hydrate' are found in Arctic Tundra and under the seafloor.
  3. 3.Methane in atmosphere oxidizes to carbon dioxide after a decade or two.

Select the correct answer using the code given below.

Show answer

Answer: D. Statement 1 is correct: warming can destabilise methane hydrates (methane trapped in ice) and release methane. Statement 2 is correct: large deposits lie under Arctic permafrost and on the seafloor along continental margins. Statement 3 is correct: methane lasts about a decade in the air before it oxidises to carbon dioxide and water. So all three.

Watch for: Statement 3 sounds too precise, so students drop it, but methane's lifetime in air is about 9-12 years.

Why the other options are wrong
  • A. Wrong because statement 3 is also correct.
  • B. Wrong because statement 1 is also correct.
  • C. Wrong because statement 2 is also correct.

Source to check: IPCC Fifth Assessment Report (2013), Working Group I, chapter on carbon and other biogeochemical cycles; US Geological Survey gas hydrates programme

Answer from the official UPSC key. Written and fact-checked by AI against the official key. Spotted a mistake? Report it.