UPSC Prelims 2017 · Question 100 of 99
UPSC Prelims 2017 question on Carbon Capture Storage Options
- ExamUPSC CSE
- Year2017
- PaperGeneral Studies Paper I
- SubjectEnvironment and Ecology
- TopicClimate Change
- DifficultyMedium
- TypeStatement
In the context of mitigating the impending global warming due to anthropogenic emissions of carbon dioxide, which of the following can be potential sites for carbon sequestration?
1. Abandoned and uneconomic coal seams
2. Depleted oil and gas reservoirs
3. Subterranean deep saline formations
Select the correct answer using the code given below:
Show answer
Answer: D. 1, 2 and 3
Verdict
The answer is 1, 2 and 3. Abandoned coal seams, depleted oil and gas reservoirs and deep saline formations are all potential carbon sequestration sites.
Analysis
Carbon sequestration involves capturing carbon dioxide and storing it for the long term, and geological sequestration stores it underground in depleted oil and gas reservoirs, saline formations and deep unmineable coal beds. All three work for the same reason: each is a porous rock formation capped by an impermeable layer that has already demonstrated its ability to hold buoyant fluids underground for geological time, which is exactly the property required to retain injected carbon dioxide.
Source
The Hindu reporting on enhancing carbon dioxide sinks.
How to crack it
Derive the answer from one physical requirement rather than from a list of sites. Storage needs porosity to hold the gas and an impermeable cap to trap it, and any formation that has held oil, gas or brine for millions of years has already proved both. Ask of each candidate whether it has demonstrably retained a fluid, and all three qualify. Note also that depleted hydrocarbon reservoirs carry a commercial bonus through enhanced oil recovery.
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