The document “Ocean Acidification” explains the ongoing decrease in ocean pH due to anthropogenic CO₂ absorption – often called the “chemical arm of climate change”. It is a critical topic for UPSC Prelims, Mains GS-3, and Essay.
Key coverage includes:
- Chemical mechanism – stepwise reactions, carbonate ion depletion, pH scale logarithm
- Drivers – fossil fuel combustion, deforestation, acid rain, eutrophication, upwelling (Arabian Sea), riverine input
- Latest developments (2025–26) – planetary boundary breach, 7th breached boundary, State of India’s Environment Report 2026
- Regional focus – Arabian Sea (high acidification), Bay of Bengal (low buffering), Lakshadweep, Gulf of Mannar
- Impacts – coral reefs, pteropods, fisheries decline, food security, coastal livelihoods
- Saturation horizons – lysocline, CCD, aragonite vs calcite
- Ocean deoxygenation – OMZs, feedback loops (DMS → clouds → albedo)
- Governance – SDG 14.3, GOA-ON, IAEA OA-ICC, High Seas Treaty, Paris Agreement
- India-specific vulnerabilities – 14 million+ fishers at risk, coral bleaching, reef degradation
- Mitigation & challenges – CO₂ reduction, blue carbon, MPAs, global commons problem
This PDF is a one-stop revision material for UPSC GS-3 (Conservation, Pollution, Climate Change) and current-linked environment questions.
