The weight of Environment in UPSC Prelims has climbed steadily—contributing 15–20 questions every year. Its dynamic, interdisciplinary nature demands both strong fundamentals and up-to-date current affairs.
Table of Contents
Key Static Topics
These foundational areas form the bedrock of UPSC Environment questions:
1. Basics of Ecology & Ecosystems
- Definitions: ecosystem, ecology, biodiversity, species richness/evenness (α/β/γ)
- Ecosystem functions: trophic levels, food chains/webs, nutrient cycles
2. Biodiversity Conservation
- Protected areas: National Parks, Wildlife Sanctuaries, Tiger & Elephant Reserves, Biosphere Reserves
- Government initiatives: Project Tiger, Project Elephant, National Biodiversity Action Plan
- International frameworks: CBD, CITES, Ramsar Convention, IUCN Red List
3. Climate Change & Global Agreements
- Key agreements: Kyoto Protocol, Paris Agreement, IPCC reports, major COP outcomes
- National policies: National Action Plan on Climate Change, climate finance mechanisms
- Phenomena: coral bleaching, ocean acidification, greenhouse gases
4. Pollution & Waste Management
- Pollutants: air (PM₂.₅, SO₂, NOₓ), water (BOD, Eutrophication), soil (heavy metals, pesticides)
- Legislation: Air (Prevention & Control of Pollution) Act, Water (Prevention & Control) Act, Basel Convention
- Emerging themes: microplastics, e-waste rules
5. International & National Bodies
- UN bodies: UNEP, UNFCCC, UNCCD, Global Environment Facility
- Indian agencies: CPCB, NGT, NTCA, Wildlife Crime Control Bureau, BNHS
Must-Know Map Topics
UPSC loves integrating geography with environment—so your map work must be razor-sharp:
- Rivers & National Parks: e.g., Satpura NP on the Betwa, Valley of Flowers on the Pushpawati
- Tiger & Elephant Reserves: pointers like Kanha, Kaziranga, Nagarhole
- Ramsar & Biosphere Sites: Chilika Lake, Sunderbans, Nilgiri Biosphere Reserve
- Global hotspots: Aral Sea, Great Barrier Reef (map context for climate change)
Current Affairs Since Jan 2024
Keep an eye on these dynamic developments and reports:
| Topic/Report | Relevance |
| CBD CoP 16 Outcomes | Biodiversity targets for 2030 |
| UNFCCC CoP 29 Highlights | India’s NDC updates, climate finance pledges |
| World Wildlife Crime Report 2024 | Trends in illegal wildlife trade |
| Emissions Gap Report 2024 | Global GHG gap analysis, mitigation strategies |
| Water (Amendment) Act 2024 | Changes in water resource governance |
| “Green Credit” & Aravalli Green Wall | India’s nature-based solutions initiatives |
| Species & Sites in News | Indian Wild Ass, Neelakurinji bloom, Kuttanad wetlands |
Top Sources & Study Materials
| Source | Use Case |
| NCERT Class 12 Biology (Ch. 15–17) | Basic ecology & environment theory |
| Oxford Atlas | All the map-related topics |
Prelims Question Trends
- Volume: ~ 15–20 questions (~ 30–40 marks) every year
- Current affairs weightage: 60–70% from post-2019 developments
- Interdisciplinary overlap: Geography, Science & Tech, Agriculture
- Emerging areas: animal behaviour, ecosystem services, environmental economics
4 Actionable Preparation Tips
- Build a rock-solid foundation
- Read NCERTs once for concepts.
- Read NCERTs once for concepts.
- Master PYQs & MCQs
- Solve 15+ years of Environment questions. Use our Daily MCQ Practice to hone speed.
- Solve 15+ years of Environment questions. Use our Daily MCQ Practice to hone speed.
- Stick to curated sources
- Over-reading kills retention. Limit yourself to the five materials listed above.
- Over-reading kills retention. Limit yourself to the five materials listed above.
- Integrate map & theory
- Every time you read about a park or reserve, mark it on your atlas. Look for river-park linkages.