What is blue carbon?
Answer & explanation
Answer: (a) Carbon captured by oceans and coastal ecosystems
'Blue carbon' is the carbon taken up and stored by the ocean and by coastal ecosystems such as mangroves, tidal marshes and seagrass meadows. Per unit area these habitats lock away more carbon than land forests, mostly in their waterlogged soils.
- ✓ (a) The term refers to carbon stored in marine and coastal ecosystems; the colour 'blue' signals water.
- ✗ (b) Carbon held in forests and farm soils on land is usually called 'green carbon', not blue carbon.
- ✗ (c) Carbon in petroleum and natural gas is fossil carbon; burning it releases carbon dioxide rather than storing it.
Remember · Blue carbon = carbon stored by oceans and coastal ecosystems (mangroves, salt marshes, seagrasses); green carbon = land vegetation and soils.
Sources
- IUCN Issues Brief: Blue carbon ↗ “Blue carbon is the carbon stored in coastal and marine ecosystems. Coastal ecosystems such as mangroves, tidal marshes and seagrass meadows sequester and store more carbon per unit area than terrestrial forests”
- NOAA National Ocean Service: What is Blue Carbon? ↗ “Blue carbon is the term for carbon captured by the world's ocean and coastal ecosystems.”
Question and answer: UPSC's official GS Paper I (2021, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). ·