Consider the following activities : 1. Spreading finely ground basalt rock on farmlands extensively 2. Increasing the alkalinity of oceans by adding lime 3. Capturing carbon dioxide released by various industries and pumping it into abandoned subterranean mines in the form of carbonated waters How many of the above activities are often considered and discussed for carbon capture and sequestration?
- (a) Only one
- (b) Only two
- (c) All three ✓ UPSC's answer
- (d) None
Why the answer is (c)
• All three activities are proposed carbon dioxide removal or storage techniques.
• Spreading finely ground basalt on farmland is 'enhanced rock weathering': the rock reacts with CO2 and rainwater to form bicarbonates that are locked away in soils and oceans (activity 1).
• Adding lime or other alkaline minerals to the sea is 'ocean alkalinity enhancement', which increases the ocean's capacity to absorb and store CO2 (activity 2).
• Capturing industrial CO2 and injecting it, including as carbonated water, into depleted mines or geological formations is carbon capture and storage (activity 3).
• Hence all three, option (c).
Why the other options are wrong
- (a) Only one
- All three are recognised carbon removal approaches, not one.
- (b) Only two
- All three are discussed for sequestration, not two.
- (d) None
- Each is an established carbon capture or removal method.
Asked in the GS Paper I of the UPSC Civil Services Preliminary Examination 2023, held on 28 May 2023. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.