Environment, Ecology, Biodiversity and Climate Change

What the official syllabus says

UPSC Civil Services (Preliminary) Examination, General Studies Paper I:

General issues on Environmental ecology, Bio-diversity and Climate Change - that do not require subject specialization.

Topics in detail

Ecology

• Ecosystem structure and function: producers, consumers, decomposers
• Food chains, food webs, trophic levels, ecological pyramids, energy flow and the ten per cent law
• Biogeochemical cycles: carbon, nitrogen, phosphorus, sulphur and water
• Ecological succession; population interactions (mutualism, commensalism, parasitism, predation, competition); ecotone and edge effect

Ecosystems

• Forests, grasslands, deserts and mountains
• Aquatic ecosystems: wetlands, lakes, estuaries, mangroves, coral reefs and the open ocean
• Eutrophication and ecosystem services

Biodiversity

• Levels of biodiversity: genetic, species and ecosystem; India as a megadiverse country
• Biodiversity hotspots: 36 in the world, four in India (Himalaya, Indo-Burma, Western Ghats and Sri Lanka, Sundaland)
• Threats: habitat loss, invasive species, overexploitation, pollution, climate change
• IUCN Red List categories; endemic, keystone, flagship and indicator species
• In-situ conservation: national parks, wildlife sanctuaries, conservation and community reserves, biosphere reserves, tiger reserves
• Ex-situ conservation: zoos, botanical gardens, gene and seed banks
• Projects for species: Project Tiger (1973), Project Elephant (1992) and other recovery programmes

Pollution and waste

• Air pollution: pollutants, PM2.5 and PM10, the Air Quality Index
• Water pollution: BOD and COD, eutrophication; soil, noise, thermal and radioactive pollution
• Solid, plastic, electronic, biomedical and hazardous waste and their management rules
• Bioaccumulation and biomagnification

Climate change

• Greenhouse effect, greenhouse gases and global warming potential
• Effects: sea-level rise, glacier retreat, ocean acidification, extreme weather, impacts on agriculture
• Mitigation and adaptation: carbon sinks, carbon markets and credits, renewable energy, climate finance
• Ozone depletion, the Montreal Protocol (1987) and the Kigali Amendment (2016) on HFCs
• UNFCCC (1992), Kyoto Protocol (1997), Paris Agreement (2015) and nationally determined contributions; the IPCC
• India's National Action Plan on Climate Change (2008) and its eight national missions

Laws and institutions in India

• Wildlife (Protection) Act, 1972; Water Act, 1974; Air Act, 1981; Environment (Protection) Act, 1986
• Forest (Conservation) Act, 1980 (renamed the Van (Sanrakshan Evam Samvardhan) Adhiniyam in 2023); Biological Diversity Act, 2002; Forest Rights Act, 2006; National Green Tribunal Act, 2010
• Environmental impact assessment; Central and State Pollution Control Boards
• National parks and wildlife sanctuaries under the Wildlife (Protection) Act; eco-sensitive zones; Coastal Regulation Zone
• Biosphere reserves in UNESCO's Man and the Biosphere network; Ramsar sites and the Montreux Record

Sustainable use of resources

• Renewable energy: solar, wind, small hydro, biomass, green hydrogen; energy efficiency
• Sustainable agriculture: organic and natural farming, integrated pest management, biofertilisers, agroforestry
• Afforestation, desertification and land degradation; water conservation and rainwater harvesting
• Sustainable consumption, recycling and the circular economy

International conventions

• Ramsar Convention on wetlands (1971); CITES; Convention on Migratory Species
• Convention on Biological Diversity (1992) with the Cartagena and Nagoya Protocols
• UN Convention to Combat Desertification
• Chemicals and waste conventions: Basel, Rotterdam, Stockholm and Minamata

Overlaps

Conservation, environmental pollution and degradation, environmental impact assessment and disaster management are part of Mains General Studies III. Species, protected areas and climate conferences in the news are covered with Current Events.