Blue Carbon: Mangroves, Seagrasses, and Climate Mitigation

TOPIC CLASSIFICATION

Subject: Environment & Ecology — Coastal and Marine Ecosystems
Sub-topic: Blue Carbon — Mangroves, Seagrasses, Salt Marshes as Carbon Sinks; Role in Climate Mitigation; India's Blue Carbon Potential
Mains GS Paper-III: Environment — conservation of coastal ecosystems, climate change mitigation, carbon sequestration.

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EXAMINER REASONING

Blue carbon is a high-yield emerging topic — the examiner is increasingly testing it because it connects ocean ecosystems, carbon cycles, and climate policy. Prelims tests: definition of blue carbon, examples (mangroves, seagrasses, salt marshes), why they are important (5-10x more carbon stored per ha than terrestrial forests), Ramsar sites. Mains demands: (a) the science of blue carbon — why coastal ecosystems are superior carbon sinks, (b) India's blue carbon assets — Sundarbans (mangroves), Chilika/Pulicat (seagrasses), Gulf of Kutch, (c) threats — coastal development, aquaculture, pollution, climate change (sea level rise), (d) blue carbon in climate policy — Paris Agreement, NDCs, Green Credit Programme, (e) conservation measures — MISHTI scheme, Coastal Regulation Zone (CRZ) norms. The examiner's favourite framing is: "Can blue carbon ecosystems help India meet its NDC targets?"

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Core Concept

What is Blue Carbon?

Blue carbon is the carbon stored in coastal and marine ecosystems — primarily mangroves, seagrass meadows, and tidal salt marshes. These ecosystems sequester and store carbon at rates 5-10 times higher than terrestrial forests and can store it for millennia (in deep sediments).

Types of Blue Carbon Ecosystems: