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?

1. A. (a) Only one
2. B. (b) Only two
3. C. (c) All three
4. D. (d) None

Answer: C

Explanation

All three activities are indeed discussed as methods for carbon capture and sequestration. 1. Spreading finely ground basalt rock on farmlands (enhanced rock weathering) accelerates natural geological processes to absorb CO2 from the atmosphere. 2. Increasing ocean alkalinity by adding lime (ocean fertilization) enhances the ocean’s capacity to absorb atmospheric CO2. 3. Carbon capture and storage (CCS) involves capturing CO2 from industrial sources and injecting it into deep geological formations, such as abandoned mines or saline aquifers, often in a supercritical or carbonated water form, for long-term storage. All these are active areas of research and discussion in climate change mitigation, relevant for UPSC Environment and Science & Technology.