UPSC Mains 2025 GS3 Q7: model answer

CCUS captures carbon dioxide from large sources such as power plants, steel and cement, or from air, and then uses it or stores it permanently underground.

Process: capture (post-combustion, pre-combustion, oxy-fuel) → transport by pipeline or ship → use (urea, methanol, building materials, enhanced oil recovery) or storage in deep saline aquifers and old oil fields. Norway's Sleipner project has stored CO₂ since 1996.

Role in climate action

• Cuts emissions from 'hard-to-abate' industries where renewables alone cannot help: cement and steel.
• Allows existing coal plants to run with lower emissions during transition; useful for India where coal gives most power.
• Negative emissions through direct air capture and bioenergy with CCS.
• IPCC pathways for 1.5°C include some carbon removal.

India: NITI Aayog's CCUS policy report (2022); pilot plants by NTPC and Tata Steel; ONGC studies on storage.

Limits: high cost and energy penalty, leakage risk, small global scale today, may delay phase-out of fossil fuels.

CCUS is a complement, not a substitute, for renewables and efficiency.