Topic-Wise UPSC Mains PYQ Analysis
GS Paper III — Environment
Complete Question Bank with Answer Frameworks (2010–2023)
Topic-Wise Navigation
Climate Change
6 QuestionsQuestion Snapshot
Open with IPCC AR6 prediction of ~1m sea-level rise by 2100. India’s 7,500+ km coastline with 170+ million people in low-lying areas makes it among the most vulnerable.
- Impact on India:
- Submergence — Mumbai, Kolkata, Chennai, Kochi; Sundarbans erosion
- Displacement of coastal communities, climate refugees
- Saline intrusion in groundwater, agricultural productivity loss
- Infrastructure damage — ports, power plants, railways
- Ecological — mangrove destruction, coral bleaching (Lakshadweep, A&N)
- Indian Ocean Region:
- Maldives, Seychelles face existential threat (SIDS)
- Bangladesh — massive displacement potential
- Geopolitical — migration, resource conflicts, maritime disputes
- Governance:
- NAPCC missions, CRZ notifications
- Regional cooperation — IORA, SAARC initiatives
Urgency of climate adaptation + mitigation. India’s NDCs, Loss & Damage Fund (COP27), mangrove restoration, early warning systems. SDG 13 & 14.
Case Study: Sundarbans — Ghoramara island submerged. Data: ~40 million Indians at risk by 2050 (World Bank).
Question Snapshot
Cloudburst — sudden intense rainfall (≥100 mm/hr in ~30 sq km). Climate change increasing frequency in Himalayan region.
- Mechanism: Warm moist air rises rapidly along steep terrain → cumulonimbus clouds → orographic barriers block movement → sudden condensation & downpour.
- India’s Vulnerability: Himalayan topography, Western Ghats, monsoon dynamics, urbanization.
- Recent Examples: Uttarakhand 2021 (Chamoli, Nainital); Amarnath 2022 (flash floods, casualties).
- Impacts: Flash floods, landslides, loss of life & property, infrastructure damage.
Need Doppler radar expansion, early warning systems, climate-resilient hill infrastructure. SDG 11.
Question Snapshot
Global warming — rise in Earth’s average temperature due to GHG accumulation. ~1.1°C rise since pre-industrial era. Kyoto Protocol (1997) was first binding treaty.
- Effects: Rising sea levels, glacial retreat, extreme weather, ocean acidification, biodiversity loss, desertification, food security threats.
- Kyoto Mechanisms:
- CBDR-RC principle
- CDM — developed nations invest in developing country projects
- Joint Implementation between Annex I nations
- Emissions Trading — carbon market
- Limitations: US non-ratification, limited coverage → led to Paris Agreement (2015) with NDCs.
- India’s Steps: NAPCC (8 missions), INDC targets, ISA, LiFE initiative.
Kyoto was a landmark first step; Paris Agreement now central. India’s 50% non-fossil capacity by 2030 & net-zero by 2070. SDG 13.
Question Snapshot
Climate change is global but impacts are localized. India’s diverse geography — Himalayan glaciers to vast coastline — faces multi-dimensional vulnerability.
- General Impact: Rising temps, erratic monsoons, extreme weather, agricultural decline, water stress.
- Himalayan States: Glacial retreat (Gangotri, Siachen), GLOF risk, landslides, permafrost melting, river flow disruption, livelihood loss.
- Coastal States: Sea level rise, cyclone intensification (Amphan, Tauktae), saltwater intrusion, Sundarbans erosion, coral bleaching, urban flooding.
- Socio-economic: Climate migration, vector-borne diseases, food insecurity.
Region-specific adaptation needed. NAPCC missions, CRZ regulations, climate-resilient agriculture, early warning systems. SDG 13, 15.
Question Snapshot
India receives 80% rainfall in 4 months. Climate change disrupts this fragile hydrological cycle, threatening water security for 1.4 billion.
- Glacial Melt: Himalayan glaciers receding → short-term flow increase, long-term scarcity for Ganga, Indus, Brahmaputra.
- Monsoon Variability: Erratic rainfall — droughts in some regions, floods in others. Fewer rainy days but higher intensity.
- Groundwater: Reduced recharge, over-extraction worsened by climate stress.
- Quality: Saline intrusion in coastal aquifers, flood-related contamination.
Integrated water resource management, rainwater harvesting, micro-irrigation, NAPCC Water Mission. SDG 6, 13.
Question Snapshot
Sikkim became India’s first fully organic state in 2016, converting 75,000+ hectares. Won FAO’s Future Policy Gold Award (2018).
- Ecological: Elimination of chemicals, improved soil health & biodiversity, reduced water pollution, carbon sequestration.
- Economic: Premium pricing, eco-tourism boost, reduced input costs, global market access, brand value.
- Social: Better health outcomes, food safety, employment in organic processing.
- Challenges: Initial yield drop, certification costs, scale-up difficulty.
Replicable through PKVY and ZBNF. SDG 2, 12, 15.
Biodiversity & Conservation
7 QuestionsQuestion Snapshot
Wetlands cover ~4.6% of India’s area. NWCP launched 1985-86. India has 75+ Ramsar Sites (2023), 2nd highest globally.
- NWCP Features: Identification, management action plans, community participation, pollution control, research.
- Key Ramsar Sites: Chilika (Odisha), Keoladeo (Rajasthan), Loktak (Manipur), Vembanad-Kol (Kerala), Sambhar (Rajasthan), Deepor Beel (Assam), Wular (J&K).
- Ecological Importance: Flood control, groundwater recharge, biodiversity hotspot, carbon sink, livelihood support.
- Challenges: Encroachment, pollution, invasive species, siltation, weak enforcement.
Rapid Ramsar expansion is positive. Need integrated management, community stewardship, stricter 2017 Rules enforcement. SDG 6, 14, 15.
Question Snapshot
Wetlands are transitional zones between land and water. Ramsar Convention (1971) is the oldest intergovernmental environmental treaty. ‘Wise use’ is its cornerstone.
- ‘Wise Use’: Maintaining ecological character while allowing sustainable human use. Balance between conservation and livelihoods.
- Components: Sustainable extraction, ecosystem-based management, stakeholder participation, regular monitoring.
- Indian Examples: Chilika Lake — restored from Montreux Record via community management; Vembanad-Kol — largest Indian Ramsar site, supports Kuttanad rice cultivation & fisheries.
Wise use aligns conservation with development — relevant for India’s densely populated wetland areas. SDG 6, 15.
Question Snapshot
India is one of 17 mega-diverse countries, hosting ~8% of global biodiversity on 2.4% land. 4 biodiversity hotspots. BD Act 2002 provides institutional framework.
- Variation: Himalayan alpine to tropical rainforests (W. Ghats, NE India), Thar desert, Sundarbans mangroves, coral reefs. 33% flora endemic.
- BD Act 2002:
- Three-tier: NBA (National), SBB (State), BMC (Local)
- Regulates foreign access to biological resources
- Access and Benefit Sharing — aligned with Nagoya Protocol
- People’s Biodiversity Registers (PBRs)
- Biopiracy protection
- Challenges: Weak enforcement, under-resourced BMCs, slow PBR creation, integration gaps with forest/wildlife laws.
Progressive legislation needing strengthened implementation. Kunming-Montreal GBF (2022) reinforces commitments. SDG 15.
Question Snapshot
Large projects (dams, mines, highways) displace communities. Narmada, POSCO illustrate the development-displacement tension.
- Mitigation Measures: Comprehensive EIA with social impact assessment, FPIC, land-for-land compensation, livelihood restoration, monitoring.
- Legal Framework: RFCTLARR Act 2013, Forest Rights Act 2006, EIA Notification 2006.
- Best Practices: Participatory planning, phased relocation, community development funds, skill training.
- Challenges: Inadequate compensation, delayed rehabilitation, cultural loss, weak enforcement.
Development must not marginalize communities. Robust SIA, community-driven rehabilitation, judicial oversight needed. SDG 10, 11, 16.
Question Snapshot
Pithead thermal plants reduce transport costs but concentrate environmental damage. EIA mandatory under 2006 notification.
- Air Pollution: SO₂, NOx, PM, fly ash; respiratory health impacts.
- Water: Thermal discharge, heavy metal leaching, ash pond contamination.
- Land: Fly ash dumps, coal ash ponds, subsidence.
- Ecological: Forest diversion, biodiversity loss in tribal/forested coal areas.
Transition to cleaner energy, supercritical tech, fly ash utilization, robust EIA enforcement. SDG 7, 13, 15.
Question Snapshot
Endosulfan — organochlorine pesticide. Devastating health impacts in Kerala’s Kasaragod district. Listed under Stockholm Convention on POPs (2011).
- Health Impacts: Kasaragod — neurological disorders, birth defects, cancer; bio-accumulation.
- Environmental: Soil/water contamination, toxic to aquatic life & pollinators; persistent organic pollutant.
- For Ban: Irreversible damage, international obligations, safer alternatives available.
- Against Ban (then): Cost-effective for farmers, India was top producer, lack of affordable alternatives.
India banned Endosulfan (SC 2011, global 2013). Need IPM, bio-pesticides, victim compensation. SDG 3, 12, 15.
Question Snapshot
- Cause: Diclofenac (veterinary NSAID) caused renal failure in vultures feeding on treated carcasses. 99%+ decline.
- Consequences: Loss of scavengers → feral dog increase → rabies risk; Parsi sky burial affected.
- Conservation: Diclofenac veterinary ban (2006), Jatayu Breeding Centres, Vulture Safe Zones, Meloxicam as alternative.
Pollution
7 QuestionsQuestion Snapshot
Oil pollution — contamination by petroleum hydrocarbons from spills, shipping, offshore drilling. India imports ~85% crude oil via sea.
- Marine Impacts: Oil slicks block sunlight → phytoplankton death → food chain disruption. Toxic to fish, seabirds, mammals. Coral smothering, mangrove damage.
- India-Specific: Major shipping route (Hormuz → Indian Ocean); Mumbai/Kochi/Chennai ports; Lakshadweep reefs & Sundarbans vulnerable; 7,500 km coastline fishing communities.
- Incidents: Mumbai spill (2010), Chennai MV Rak spill (2017).
- Governance: National Oil Spill Disaster Contingency Plan, MARPOL compliance, Coast Guard role.
Stronger spill response, green shipping, enhanced coastal surveillance needed. SDG 14.
Question Snapshot
Photochemical smog — secondary pollutant from NOx + VOCs + sunlight → ground-level ozone & PAN. Major urban air quality issue.
- Formation: Vehicle NOx + industrial VOCs + sunlight → O₃, PAN, formaldehyde. Worse in summer/tropical regions.
- Effects: Respiratory diseases, eye irritation, crop damage, reduced visibility, material degradation.
- Mitigation: BS-VI norms, catalytic converters, EVs, public transport, industrial VOC controls, green belts.
- Gothenburg Protocol: Under UNECE’s CLRTAP — reduces SO₂, NOx, VOCs, NH₃. Multi-pollutant approach. Revised 2012 to include PM2.5.
India not party to Gothenburg but can draw lessons for NCAP. Integrated multi-pollutant reduction is key. SDG 3, 11.
Question Snapshot
India’s construction boom drives massive sand demand. Coastal mining — often illegal — threatens shorelines, marine ecosystems, communities.
- Environmental: Coastal erosion, loss of storm barriers (dunes), groundwater salinization, turtle nesting habitat loss, mangrove disruption.
- Examples: Kerala — severe beach erosion; Tamil Nadu — Ennore creek damage; Maharashtra — illegal creek mining affecting Mumbai.
- Socio-economic: Fishing community losses, sand mafia violence, livelihood disruption.
- Regulatory: CRZ provisions, Sustainable Sand Mining Guidelines (2016), NGT orders, weak enforcement.
M-sand promotion, satellite monitoring, UNEP guidelines on sustainable extraction. SDG 14, 15.
Question Snapshot
- Consequences: Deforestation, biodiversity loss, land degradation, water contamination, air pollution, tribal displacement, revenue loss, mafia violence.
- Go/No-Go Zones: MoEFCC categorized forests by canopy density. No-Go (>10% canopy) — mining barred; Go — allowed with conditions. Balances energy security with forest conservation.
- Challenges: Norm dilution under industry pressure, reclassification controversies, weak monitoring.
Question Snapshot
- NWP 2012: Water as economic good, ecological needs, minimum flow, river basin approach, participatory management, pricing reforms.
- Ganga Strategies: Namami Gange — STPs, industrial regulation, riverfront development, dolphin conservation, afforestation, Ganga Task Force.
- Hazardous Waste: HW Rules 2016, E-waste Rules, Basel Convention compliance, CPCB oversight, polluter pays principle.
Question Snapshot
- Evolution: BS-I (2000) → BS-II (2005) → BS-III (2010) → BS-IV (2017) → BS-VI (2020, skipping BS-V). Based on Euro norms.
- BS-VI Features: 70% NOx reduction for diesel, 25% for petrol. OBD, real driving tests, particulate filters mandatory.
- Impact: Significant urban air quality improvement potential, fuel quality upgrade (10 ppm sulfur), technology push.
Question Snapshot
- HFC-23 is potent GHG (14,800x CO₂), byproduct of HCFC-22 production.
- Companies allegedly increased HCFC-22 to generate more HFC-23 for CDM credits — perverse incentive.
- EU banned HFC-23 credits. Kigali Amendment (2016) now phases down HFCs globally.
Environmental Acts & Policies
6 QuestionsQuestion Snapshot
EIA is a preventive governance tool under EPA 1986. Draft EIA 2020 attracted widespread debate on dilution of safeguards.
- Post-facto Clearance: Draft 2020 allows ex-post-facto clearance on penalty — incentivizes violations; 2006 had no such provision.
- Public Consultation: Reduced 30→20 days; expanded exemptions from public hearings (B2 category).
- Compliance Reports: Changed half-yearly→annual — reduces monitoring.
- Exemptions: Defence & national security projects exempted — blanket exemption concerns.
- Positives: Digitized process, increased penalties, district monitoring cells.
EIA reform must strengthen, not dilute, governance. Need robust public participation, independent assessment. SDG 16.
Question Snapshot
- Features: Campaign-based (not scheme), 256 water-stressed districts, 5 interventions: rainwater harvesting, traditional water body renovation, reuse & recharge, watershed development, afforestation.
- Implementation: Central officers deployed, convergence with MGNREGA & Jal Jeevan Mission.
- Significance: NITI Aayog: 21 cities may run out of water by 2030. Creates urgency and community awareness.
- Limitations: Short campaign duration, sustainability concerns, needs structural reforms.
Question Snapshot
Launched January 2019 — India’s first comprehensive long-term air pollution strategy. Targets 20-30% PM reduction by 2024, revised to 40% by 2025-26.
- Coverage: 131 non-attainment cities exceeding NAAQS.
- Features: City-specific action plans, augmented monitoring, source apportionment, technology assessment, public awareness.
- Implementation: Convergence with Smart Cities, AMRUT, Swachh Bharat. 15th FC grants linked to air quality.
- Challenges: Non-binding targets, funding gaps, inter-state sources (crop burning), weak enforcement capacity.
NCAP needs legal teeth, adequate funding, airshed management approach. SDG 3, 11.
Question Snapshot
- Previous Failures (GAP I & II): Only STPs, ignored industrial effluents, no community ownership, corruption, poor maintenance.
- Namami Gange (2014): Integrated: sewage management, surface cleaning, biodiversity conservation (dolphin, turtle), afforestation, community participation, industrial monitoring.
- Quantum Leaps: Zero liquid discharge for industries, decentralized sewage treatment, ecological flow enforcement, river-centric urban planning, bioremediation, real-time water quality monitoring.
Question Snapshot
- World’s largest wildlife survey — All India Tiger Estimation every 4 years under NTCA.
- Phase IV: camera traps, DNA analysis, GIS mapping, double-sampling framework.
- Recovery: 1,411 (2006) → 3,167 (2022) — conservation success.
- Challenges: habitat fragmentation, human-wildlife conflict, poaching, corridor connectivity.
Question Snapshot
- Spatial Components: Collection points, transfer stations, processing facilities, landfill sites — all need spatial planning based on density, land use, transport.
- Challenges: NIMBY for landfills, inadequate land, informal sector not integrated, lack of decentralized processing.
- Way Forward: GIS-based route optimization, decentralized composting, waste-to-energy, segregation at source, EPR.
Renewable & Energy Resources
7 QuestionsQuestion Snapshot
Transport = ~24% global CO₂. EVs are zero tailpipe emissions with higher energy efficiency. India’s FAME-II driving adoption.
- Emission Reduction: Zero tailpipe; lifecycle 50-70% lower than ICE; improves as grid greens.
- Benefits over ICE: 85-90% energy efficiency vs 20-35%, lower running costs, less noise pollution, reduced PM2.5/NOx, cuts oil import dependency.
- Challenges: Battery manufacturing footprint, charging infra gaps, grid capacity, upfront cost, battery recycling.
- India’s Initiatives: FAME-II, National Electric Mobility Mission, PLI for Advanced Chemistry Cells, state EV policies, battery swapping.
Critical for NDCs and net-zero. Need circular economy for batteries, RE-powered charging, affordable models. SDG 7, 11, 13.
Question Snapshot
At COP26: 500 GW non-fossil capacity by 2030, 50% energy from renewables. Currently ~180+ GW RE — ambitious but achievable.
- Positive Signs: Solar tariffs at ₹2/kWh, massive solar parks, PM-KUSUM, green hydrogen mission, ISA leadership, private investment surge.
- Challenges: Land acquisition, grid integration of intermittent RE, storage gaps, China dependency for solar cells, DISCOM health, just transition for coal regions.
- Subsidy Shift: India spends ~₹2L cr on fossil subsidies. Redirecting to RE funds grid storage, EV infra, rooftop solar. Creates level playing field, accelerates private investment.
Ambitious but achievable with political will, subsidy reform, storage investment, manufacturing push (PLI). SDG 7, 13.
Question Snapshot
- Benefits: Zero emissions, abundant (300+ sunny days), declining costs, decentralized generation (rooftop), reduced imports, jobs, scalable.
- Vs Conventional: No fuel cost, no water use (unlike thermal), no air/water pollution, no mining impacts.
- Govt Initiatives: JNNSM (100 GW target), PM-KUSUM (solar pumps), rooftop solar scheme, solar parks (Bhadla, Pavagada), ISA, PLI for solar manufacturing, Green Energy Corridor.
Question Snapshot
- Cost Decline Factors: China’s manufacturing scale, technology improvement, competitive bidding, policy support (RPOs), global oversupply, Swanson’s law.
- Thermal Implications: Stranded assets risk, financial stress on generators, just transition needs, coal-state revenue loss, banking NPAs from thermal loans.
- Way Forward: Retrofitting, coal gasification, just transition framework, worker retraining.
Question Snapshot
- Dedicated transmission infrastructure to evacuate RE power from generation hubs to load centres.
- Two components: Intra-state (8 RE-rich states) and Inter-state (PGCIL — national grid connection).
- Solves intermittency via grid balancing, reduces RE curtailment, enables larger RE integration.
- Complemented by battery storage and smart grid initiatives.
Question Snapshot
- Run-of-river: Uses natural river flow, minimal/no storage, diverts water through turbines and returns downstream.
- Vs Conventional: No large dam/reservoir → less displacement, lower ecological impact, less submergence. But output varies seasonally, less flood control.
- Examples: NE India, Himachal Pradesh small hydro projects.
Question Snapshot
- CSP: Mirrors/lenses concentrate sunlight → heat fluid → steam → turbine. Advantage: thermal storage for night generation. Needs direct sun, large land, water.
- PV: Semiconductor cells convert sunlight to electricity directly. Scalable, declining costs, no water needed, works in diffused light. Dominant globally.
- India: Largely favours PV due to cost advantage and versatility.
Sustainable Development
3 QuestionsQuestion Snapshot
Carrying capacity — maximum population an ecosystem can sustain indefinitely. When exceeded, ecosystem services collapse.
- Concept: Determined by resource availability, waste absorption, regenerative ability. Dynamic — changes with technology and consumption.
- Planning Relevance: Tourism CC (Shimla overcrowding), urban CC (Delhi’s air/water limits), agricultural CC (Punjab groundwater). Exceeding leads to ecological overshoot.
- Application: EIA studies, CRZ regulations, eco-sensitive zones, groundwater regulation — all implicitly use this concept.
- Global Context: Ecological Footprint — humanity uses 1.75 Earths. Earth Overshoot Day arrives earlier each year.
Development planning must respect ecological limits. Integrating carrying capacity into EIA and urban planning is imperative. SDG 11, 15.
Question Snapshot
- Advantages: Flood mitigation in surplus basins, drought relief in deficit areas, irrigation expansion, hydropower generation, inland navigation, groundwater recharge.
- Environmental Concerns: Massive ecological disruption, river ecosystem fragmentation, wetland destruction, displacement, downstream impacts, inter-state water disputes, climate change uncertainty.
- Ken-Betwa Link: First project approved — links surplus Ken (MP) to deficit Betwa. Concerns about submergence of Panna Tiger Reserve forest.
Need comprehensive EIA, cumulative impact assessment, and climate-proofing. Demand-side management (micro-irrigation, crop diversification) should complement supply augmentation. SDG 6, 15.
Question Snapshot
- Environmental Sustainability: Maintaining ecological processes and natural resources for future generations within planetary boundaries.
- Sustainable Development of People: UNDP’s human development approach — expanding choices (health, education, livelihood) while ensuring environmental integrity.
- Linkage: Both converge in SDGs — 17 goals integrating social, economic, and environmental dimensions.
Environmental Organisations & Conventions
10 QuestionsQuestion Snapshot
- Green Grid Initiative (GGI): ‘One Sun One World One Grid’ — interconnected global solar energy grid to ensure 24/7 clean energy. Launched at COP26 by India-UK.
- Purpose: Enable cross-border RE trade, balance supply-demand across time zones, accelerate clean energy access globally, reduce storage needs.
- ISA Origin: Concept first floated by PM Modi at ISA Assembly (2018). ISA (HQ: Gurugram) launched 2015 in Paris.
Question Snapshot
- Revised AQGs (2021): PM2.5 annual: 5 μg/m³ (was 10); PM10 annual: 15 (was 20); NO₂ annual: 10 (was 40); SO₂ 24-hr: 40 (was 20). Much stricter based on new health evidence.
- Key Difference: 2021 guidelines are significantly tighter, reflecting evidence that health damage occurs at lower levels than previously thought.
- NCAP Changes Needed: Revise NAAQS to align with WHO, strengthen monitoring network, source apportionment in all cities, sector-specific interventions (transport, industry, construction, biomass), airshed approach, legally binding targets.
Question Snapshot
COP26 (Glasgow, 2021) was pivotal — first explicit mention of fossil fuels in a COP decision.
- Major Outcomes: Glasgow Climate Pact — ‘phase down’ coal, methane pledge, deforestation halt by 2030, Article 6 carbon market rules finalized, enhanced NDC submissions, climate finance push.
- India’s Panchamrit:
- 500 GW non-fossil capacity by 2030
- 50% energy from renewables by 2030
- Reduce carbon intensity by 45% (vs 2005)
- Reduce 1 billion tonnes CO₂ by 2030
- Net-zero by 2070
- Assessment: India’s commitments ambitious for a developing nation. Coal phase-down (not phase-out) language reflects India’s energy transition reality.
India playing leadership role while balancing development needs. SDG 7, 13, 17.
Question Snapshot
- CDM Benefits for India: Revenue from emission reduction projects, technology transfer, sustainable development co-benefits, incentive for cleaner production.
- Challenges: Carbon credit price collapse (~€0.50 from €30+), additionality concerns, bureaucratic complexity, limited environmental impact.
- India’s Perspective: CDM projects generated billions; but India needs massive energy expansion. Balance between climate commitments and growth is critical.
- Evolution: Paris Agreement’s Article 6 replaces CDM with new market mechanisms. India should shape new carbon market rules to its advantage.
Question Snapshot
- CBD: Broad biodiversity conservation, sustainable use, access & benefit sharing (ABS). Nagoya Protocol operationalizes ABS.
- FAO ITPGRFA: Specific to crop genetic resources. Multilateral System — facilitated access to 64 crops. Standard Material Transfer Agreement (SMTA).
- Interlinkages: Both address ABS but different scope. ITPGRFA is ‘lex specialis’ for crops. Potential conflicts in ABS provisions. Need harmonization for farmers’ rights and food security.
Question Snapshot
- CDM under Kyoto Protocol: allows Annex I (developed) countries to invest in emission reduction projects in developing countries.
- Generates Certified Emission Reductions (CERs) — carbon credits tradeable in carbon markets.
- Dual purpose: helps developed nations meet targets cost-effectively + promotes sustainable development in host countries.
- India was 2nd largest CDM host (after China). Projects in wind, biomass, energy efficiency, waste management.
Question Snapshot
- BWC Status: In force since 1975. Bans development/production/stockpiling of biological weapons. 183 states parties. Key weakness: no verification mechanism.
- Issues for Review: Verification protocol (US opposition), dual-use technology governance, bioterrorism threats, synthetic biology developments, capacity building for developing nations.
Question Snapshot
- Eight Ramsar Sites: Chilika (Odisha), Keoladeo (Rajasthan), Wular (J&K), Loktak (Manipur), Harike (Punjab), Sambhar (Rajasthan), Vembanad-Kol (Kerala), Deepor Beel (Assam).
- Montreux Record: Register of Ramsar sites where ecological character has changed or is changing due to human interference. A ‘red flag’ list.
- Indian Sites on Montreux: Keoladeo (Rajasthan) and Loktak Lake (Manipur) were listed. Chilika was removed after successful restoration.
Question Snapshot
- Rotterdam Convention (1998, force 2004): governs international trade in hazardous chemicals and pesticides.
- Prior Informed Consent (PIC) procedure — exporting country must get importing country’s consent before shipping listed hazardous chemicals.
- Promotes shared responsibility and informed decision-making. Covers ~50 chemicals including asbestos, pesticides.
Question Snapshot
- Annex I: Industrialized countries + economies in transition (41 countries). Have binding emission reduction targets under Kyoto Protocol.
- Annex II: Subset of Annex I — only developed (OECD) countries. Additional obligation: provide financial resources and technology transfer to developing nations.
- Key Distinction: All Annex II are Annex I, but not vice versa. Russia, Ukraine are Annex I but not Annex II. Reflects CBDR principle.
Wetlands, Ecology & Ecosystems
4 QuestionsQuestion Snapshot
Wetlands are transitional zones (marshes, swamps, bogs, floodplains). Ramsar Convention (1971) — ‘wise use’ is its cornerstone.
- ‘Wise Use’: Maintaining ecological character while allowing sustainable human use. Balance conservation and livelihoods. People-wetland interdependence recognized.
- Components: Sustainable extraction, ecosystem management, stakeholder participation, ecological monitoring.
- Indian Examples: Chilika Lake — community-led restoration, removed from Montreux Record; Vembanad-Kol — largest Indian Ramsar site, Kuttanad farming.
Wise use aligns conservation with development. SDG 6, 15.
Question Snapshot
- Definition: Use of plants to remove, degrade, or contain environmental contaminants (heavy metals, pesticides, solvents) from soil, water, or air.
- Types: Phytoextraction (metal uptake), phytostabilization (immobilize contaminants), phytodegradation (break down organics), rhizofiltration (root absorption from water).
- Applications: Mine site remediation, industrial wastewater treatment, constructed wetlands for sewage, radioactive site cleanup, agricultural runoff treatment.
- Advantages: Cost-effective, eco-friendly, aesthetically pleasing, applicable to large areas. Limitations: slow, species-specific, seasonal.
Question Snapshot
- E-waste — discarded electronic devices (phones, computers, TVs). India generates ~3.2 million tonnes/year.
- Hazards: lead, mercury, cadmium, BFRs; informal recycling exposes workers (Seelampur, Delhi) to toxic fumes.
- E-waste Rules 2016: Extended Producer Responsibility (EPR), authorized dismantlers, collection targets.
- Need: formal recycling infrastructure, urban mining for resource recovery, consumer awareness.
Question Snapshot
- Impediments: Lack of segregation at source, inadequate processing infrastructure, NIMBY for landfills, poor ULB capacity, informal sector not integrated, low awareness, funding gaps.
- Toxic Waste Solutions: Secured landfills, high-temperature incineration, bioremediation, chemical treatment, phytoremediation, common hazardous waste treatment facilities (CHTWFs).
- Governance: SWM Rules 2016, HW Rules 2016, Swachh Bharat Mission, Extended Producer Responsibility, polluter pays principle.
Circular economy approach — reduce, reuse, recycle. Waste-to-wealth mindset needed. SDG 11, 12.
PYQ Heat Map — Pareto Analysis (80:20 Rule)
This heat map shows the frequency of questions from each Environment sub-topic across years. Use the 80:20 Pareto principle — focus on the high-frequency topics that yield maximum marks coverage.
| Sub-Topic | 2010 | 2011 | 2012 | 2013 | 2014 | 2015 | 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 | TOTAL |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Climate Change | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 0 | 0 | 0 | 2 | 1 | 6 |
| Biodiversity & Conservation | 0 | 1 | 2 | 0 | 1 | 0 | 1 | 0 | 2 | 0 | 0 | 0 | 0 | 1 | 8 |
| Pollution | 2 | 0 | 0 | 2 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 0 | 1 | 1 | 7 |
| Env. Acts & Policies | 1 | 1 | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 3 | 0 | 0 | 0 | 6 |
| Renewable & Energy | 0 | 1 | 0 | 2 | 0 | 1 | 1 | 0 | 0 | 0 | 1 | 0 | 1 | 1 | 8 |
| Sustainable Development | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 1 | 0 | 1 | 0 | 0 | 0 | 0 | 3 |
| Organisations & Conventions | 3 | 0 | 2 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 3 | 0 | 0 | 9 |
| Wetlands & Ecosystems | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 2 | 0 | 0 | 0 | 0 | 0 | 4 |
🎯 Pareto Analysis — 80:20 Focus Strategy
Focusing on the top 4 topics covers ~60%+ of all Environment questions asked. These are your high-ROI preparation areas:
- 1Organisations & Conventions 9 Questions
- 2Biodiversity & Conservation 8 Questions
- 3Renewable & Energy Resources 8 Questions
- 4Pollution 7 Questions
Strategy: Master these 4 topics first → then cover Climate Change & Acts/Policies → finally Sustainable Development & Wetlands. This ensures maximum marks with focused effort.
PYQ Trend Insights & Exam Strategy
📊 Topic Frequency Pattern
- Consistently asked: Renewable Energy and Biodiversity appear almost every 2 years
- Cyclical: Organisations & Conventions peaks when global summits happen (COP years: 2010, 2012, 2021)
- Rising: Climate Change questions increasing post-2017 — linked to IPCC reports and COP outcomes
- Declining: Pure conceptual questions (definitions) are being replaced by analytical, policy-oriented questions
🎯 High-Weightage Areas (15 Marks)
- Climate Change + Sea Level Rise / IPCC
- Renewable Energy targets + Government schemes
- COP outcomes + India’s commitments (Panchamrit)
- Biodiversity Act + Conservation programmes
- NCAP, EIA notifications, Namami Gange
- EV adoption + Energy transition
📈 Emerging Themes for 2024-25
- Green Hydrogen Mission & National Green Hydrogen Policy
- Carbon markets — India’s carbon credit trading scheme
- Deep ocean mission & blue economy
- Kunming-Montreal GBF (30×30 targets)
- Climate finance — Loss & Damage Fund operationalization
- Forest Conservation Amendment Act 2023
- Plastic waste management & EPR
- Critical minerals & rare earths for energy transition
📝 UPSC Question Framing Patterns
- Statement + Comment: “IPCC has predicted… What would be its impact?” — needs data-backed analysis
- Scheme evaluation: “Comment on NWCP / NCAP / Namami Gange” — needs features + critique + way forward
- Comparison: “How does draft EIA 2020 differ from 2006?” — tabular approach works well
- Contemporary linkage: Questions tied to recent events (COP26, Chandrayaan, EVs) — stay updated
- Multi-part: Many questions have 2-3 sub-parts — address each explicitly for full marks
✅ Legacy IAS — Exam Day Reminders
- Always open with data/definition/current context — shows knowledge depth
- Use diagrams where possible (flowcharts for mechanisms, maps for regional impacts)
- Cite recent reports — IPCC AR6, UNEP, State of Forest Report, Economic Survey
- Include case studies — Sundarbans, Sikkim Organic, Chilika restoration, Bhadla Solar Park
- End with SDG linkage + Government initiative + Way forward
- For 10-mark questions: ~150 words | For 15-mark questions: ~250 words
Prepared for Legacy IAS
UPSC Mains GS Paper III — Environment | Topic-Wise PYQ Analysis (2010–2023)


