UPSC Prelims 2019 Question:

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 the atmosphere oxidizes to carbon dioxide after a decade or two.
   
   

Select the correct answer using the code given below.

Explanation: 

• Enormous amounts of methane hydrate have been found beneath Arctic permafrost and beneath Antarctic ice. Methane hydrate is an "ice" that only occurs naturally in subsurface deposits where temperature and pressure are favorable. So, in the context of global warming, temperature rise might invoke the release of methane gas from these deposits. So, statements 1 and 2 are correct.
  
  
• The main component of methane hydrate is methane. Methane is relatively short-lived in the atmosphere. A molecule of methane is oxidized to water and carbon dioxide after a decade. Hence, if the methane hydrate is removed from this temperature/pressure environment, it becomes unstable and oxidises to carbon dioxide which effectively contributes to climate change. So, statement 3 is  correct.
  
  

Therefore, option (4) is the correct answer.

Subject: Environment | Pollution