(As per NTA UGC NET Paper I Syllabus, 2024–25)
🎯 1. Objective of the Unit
This unit tests your awareness about:
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Environment, ecology, and sustainable development
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Human and natural interaction
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Environmental issues, policies, and global initiatives
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Impact of development on the environment
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Renewable energy, climate change, and environmental ethics
In short — “Human–Environment Relationship” and how development can be made sustainable.
🌱 2. Key Concepts
| Concept | Meaning |
|---|---|
| Environment | The sum of all external factors (biotic & abiotic) that affect living organisms. |
| Ecology | Study of relationship between living organisms and their surroundings. |
| Ecosystem | Functional unit consisting of living (biotic) and non-living (abiotic) components. |
| Biosphere | Global ecosystem — sum total of all ecosystems on Earth. |
| Biodiversity | Variety of living organisms (genes, species, ecosystems). |
| Sustainability | Development that meets present needs without compromising future generations. |
🌳 3. Components of Environment
(A) Natural Environment
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Air (atmosphere)
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Water (hydrosphere)
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Land (lithosphere)
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Living organisms (biosphere)
(B) Human-made Environment
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Cities, buildings, infrastructure, industries.
(C) Social & Cultural Environment
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Ethics, values, customs, beliefs, and institutions.
🧬 4. Ecology and Ecosystem
4.1 Levels of Ecological Organization:
Individual → Population → Community → Ecosystem → Biome → Biosphere
4.2 Components:
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Abiotic: Light, temperature, soil, air, water
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Biotic: Producers, consumers, decomposers
4.3 Energy Flow:
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Unidirectional — from sun → producer → consumer → decomposer.
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Governed by 10% Energy Law (only 10% energy transfers to next trophic level).
4.4 Food Chain & Food Web:
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Food Chain: Linear sequence of energy transfer.
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Food Web: Network of interconnected food chains.
🌾 5. Natural Resources and Their Conservation
| Resource Type | Examples | Conservation Methods |
|---|---|---|
| Renewable | Solar, wind, water, biomass | Sustainable use, technology improvement |
| Non-Renewable | Coal, petroleum, minerals | Reduce, recycle, find alternatives |
| Human Resources | Knowledge, labor | Education and skill development |
| Biotic | Forests, animals | Afforestation, wildlife protection |
| Abiotic | Air, water, soil | Pollution control, soil conservation |
🌍 6. Environmental Issues
| Issue | Description | Impact |
|---|---|---|
| Deforestation | Clearing forests for human use | Loss of biodiversity, soil erosion |
| Desertification | Land degradation in arid areas | Reduced productivity |
| Pollution | Contamination of air, water, soil | Health hazards |
| Climate Change | Global temperature rise | Sea-level rise, extreme weather |
| Loss of Biodiversity | Extinction of species | Ecological imbalance |
| Waste Disposal | Improper waste management | Groundwater contamination |
| Urbanization | Expansion of cities | Resource depletion, congestion |
💨 7. Types of Pollution
| Type | Main Cause | Example / Effect |
|---|---|---|
| Air Pollution | Vehicles, industries | Smog, respiratory diseases |
| Water Pollution | Sewage, industrial effluents | Eutrophication, waterborne diseases |
| Soil Pollution | Pesticides, waste dumping | Loss of fertility |
| Noise Pollution | Traffic, machinery | Hearing loss, stress |
| Thermal Pollution | Hot water discharge from industries | Affects aquatic life |
| Nuclear Pollution | Radiation leaks | Genetic disorders |
🌦️ 8. Climate Change and Global Warming
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Climate Change: Long-term alteration in temperature, rainfall, and weather patterns.
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Global Warming: Rise in Earth’s average temperature due to greenhouse gases (GHGs).
Major GHGs:
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Carbon dioxide (CO₂)
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Methane (CH₄)
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Nitrous oxide (N₂O)
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Chlorofluorocarbons (CFCs)
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Ozone (O₃)
Effects:
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Melting glaciers, rising sea levels
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Extreme weather events
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Crop pattern changes
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Loss of biodiversity
⚡ 9. Renewable and Non-Renewable Energy Sources
| Source | Type | Example |
|---|---|---|
| Renewable | Reusable, eco-friendly | Solar, wind, hydro, biomass, geothermal |
| Non-Renewable | Finite, polluting | Coal, petroleum, natural gas, nuclear |
Government Initiatives (India)
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National Solar Mission (2010) – Target 280 GW by 2030
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Wind Energy Mission
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National Hydrogen Mission (2021) – Green hydrogen production
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International Solar Alliance (ISA) – India-led global initiative
🏭 10. Sustainable Development
Definition (Brundtland Commission, 1987):
Development that meets present needs without compromising the ability of future generations to meet their own.
Key Principles:
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Conservation of resources
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Environmental protection
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Social equity and economic growth
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Intergenerational responsibility
Indicators of Sustainable Development:
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Human Development Index (HDI)
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Ecological Footprint
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Environmental Sustainability Index
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Green GDP
🌏 11. Environmental Management and Protection
| Area | Description |
|---|---|
| Environmental Impact Assessment (EIA) | Predicting impact of development projects before approval |
| Environmental Education | Promoting awareness and eco-friendly behavior |
| Environmental Ethics | Moral principles guiding human interaction with nature |
| Eco-restoration | Rebuilding degraded ecosystems |
🧾 12. Major International Environmental Conventions
| Convention / Summit | Year | Objective |
|---|---|---|
| Stockholm Conference | 1972 | First global conference on environment |
| Brundtland Report | 1987 | Concept of Sustainable Development |
| Rio Earth Summit (UNCED) | 1992 | Agenda 21, Biodiversity Convention |
| Kyoto Protocol | 1997 | Legally binding GHG reduction |
| Montreal Protocol | 1987 | Control of ozone-depleting substances |
| Paris Agreement | 2015 | Limit global warming below 2°C |
🇮🇳 13. Environmental Policies and Acts (India)
| Act / Policy | Year | Objective |
|---|---|---|
| Water (Prevention & Control of Pollution) Act | 1974 | Control of water pollution |
| Air (Prevention & Control of Pollution) Act | 1981 | Control of air pollution |
| Environment Protection Act | 1986 | Umbrella law for environment |
| Wildlife Protection Act | 1972 | Protection of wildlife and biodiversity |
| Forest Conservation Act | 1980 | Prevent deforestation |
| National Green Tribunal (NGT) | 2010 | Judicial body for environmental disputes |
💚 14. Biodiversity and Its Conservation
Levels of Biodiversity:
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Genetic diversity – variation within species
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Species diversity – variety among species
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Ecosystem diversity – variety of habitats
Conservation Approaches:
| Type | Method | Example |
|---|---|---|
| In-situ | Conservation in natural habitat | National Parks, Sanctuaries |
| Ex-situ | Outside natural habitat | Zoos, Seed banks, Botanical gardens |
🌿 15. Important Environmental Terms
| Term | Meaning |
|---|---|
| Carbon Footprint | Total GHG emissions caused by an individual/activity |
| Carbon Credit | Tradable certificate representing 1 ton of CO₂ reduced |
| Ozone Hole | Depletion of ozone layer due to CFCs |
| Acid Rain | Rain with pH < 5.6 caused by SO₂ and NOx |
| Eutrophication | Nutrient enrichment of water bodies causing algal bloom |
| Desertification | Land degradation in arid regions |
| Carrying Capacity | Maximum population sustainable by environment |
| Biomagnification | Accumulation of toxins in food chain at higher levels |
☀️ 16. Renewable Energy in India
| Source | Capacity Trend | Example Project |
|---|---|---|
| Solar | Rapid growth (ISA, Solar Mission) | Pavagada Solar Park (Karnataka) |
| Wind | Coastal and desert regions | Tamil Nadu, Gujarat |
| Hydro | Major renewable source | Tehri Dam |
| Biomass | Rural energy | Bagasse, crop residue |
| Geothermal | Under exploration | Himalayas, Gujarat |
♻️ 17. Environmental Movements in India
| Movement | Leader | Aim |
|---|---|---|
| Chipko Movement | Sunderlal Bahuguna | Forest conservation |
| Narmada Bachao Andolan | Medha Patkar | Against displacement due to dam |
| Silent Valley Movement | Kerala activists | Save tropical forest |
| Appiko Movement | Karnataka | Forest protection |
| Save Ganga Movement | Various NGOs | River conservation |
🧩 18. Population and Environment
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Population growth increases demand for resources.
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Causes deforestation, urban congestion, pollution.
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Education and family planning promote sustainable population growth.
⚙️ 19. Environmental Management Tools
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Environmental Audit
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Environmental Accounting
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Life Cycle Assessment (LCA)
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Green Building Rating (LEED, GRIHA)
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Sustainable Development Goals (SDGs, UN 2015–2030)
🌏 20. Sustainable Development Goals (SDGs)
UN’s 17 Global Goals (2015–2030):
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No Poverty, Zero Hunger, Good Health
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Quality Education, Gender Equality
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Clean Water & Sanitation, Affordable Energy
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Climate Action, Life Below Water, Life on Land
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Responsible Consumption, Peace & Justice, etc.
India’s nodal agency: NITI Aayog
✅ 21. Quick Summary for Revision
| Theme | Core Points |
|---|---|
| Environment & Ecology | Interaction of biotic and abiotic components |
| Pollution Types | Air, water, soil, noise, nuclear |
| Climate Change | Due to GHGs and human activity |
| Energy | Renewable vs Non-renewable |
| Sustainable Development | Balance of economic, social, environmental goals |
| Conventions & Acts | Stockholm, Rio, Paris; EPA 1986, Air/Water Acts |
| Biodiversity | In-situ & Ex-situ conservation |
| Environmental Movements | Chipko, Narmada Bachao |
| SDGs | 17 global goals by UN |
| Indian Initiatives | NGT, ISA, National Missions |