EVS Exam Notes

UNIT V

Global Environmental Issues & Policies

L13 Sustainable Development & Sustainability

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Definition (Brundtland Report, 1987): "Development that meets the needs of the present without compromising the ability of future generations to meet their own needs."

Key idea: Balance between economic development, environmental protection, and social well-being.

3 Types of Sustainability

🌿 Environmental

Conservation of biodiversity
Safeguard water, save energy, reduce waste
Recyclable packaging, sustainable transport
Example: Stockholm city — low emissions, excellent air quality

💰 Economic

Long-term responsible profit generation
Example: Unilever (2010) — recycled packaging, renewable materials
Suez: 95% reduction in electricity-related emissions

👥 Social

Strengthen cohesion & stability of social groups
Example: CEMEX — decent housing through self-building programmes

EIA: Every development project must have an Environmental Impact Assessment before clearance. Large dams, highways, mining, industries must comply.

L14 Global Environmental Issues

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Climate Change

Global avg surface temp ↑ 0.6°±0.2°C over last century
1998 = warmest year; 1990s = warmest decade on record
IPCC projects rise of 1.4°–5.8°C in near future
Sea level projected to rise 9–88 cm by 2100
Vulnerable regions: Nile delta, Ganges-Brahmaputra delta, Marshall Islands, Maldives
More than half world's population lives within 200 km of coastline
Diseases spread: malaria, dengue, filariasis, tick-borne encephalitis

Global Warming

~75% solar energy absorbed at Earth's surface
Average surface temp = 15°C (without greenhouse = -18°C)
Greenhouse effect raises temp by 33°C
CO₂ increased by 31% since pre-industrial times
Main gas: Carbon dioxide from burning fossil fuels

Acid Rain

Causes

Burning fossil fuels → SO₂ + NOₓ
React with water → H₂SO₄ + HNO₃
US: coal plants = 70% SO₂
Canada: industries = 61% SO₂
Motor vehicles = main source of NOₓ

Effects

Leaches soil nutrients, releases Al & Hg
Brown dead spots on leaves
Acidifies lakes/rivers (pH ↓)
pH 6.0 kills clams & mayflies
Damages buildings (Parthenon, Taj Mahal)

Solutions: Scrubbers in smokestacks (water + limestone), catalytic converters in cars, liming of soil (neutralises acidity), low-sulfur fuels.

Ozone Layer Depletion

Ozone layer at 20–50 km above Earth's surface
Ozone = 3 oxygen atoms (O₃); poisonous at ground level
Culprits: CFCs (refrigerants, aerosols), bromine, halocarbons, nitrous oxides
CFCs → stratosphere → UV breaks → releases Cl atoms → destroys O₃
Thinning first detected over Antarctica in early 1980s
Effects: skin cancer, cataracts, crop damage, plankton damage
Montreal Protocol (1987) — CFCs banned by 2000; recovery expected in ~50 years

Nuclear Accidents

Hiroshima & Nagasaki (1945) — only use of nuclear weapons in war
Effects: cancer, genetic mutations, radiation fallout for decades
Nuclear energy = clean & cheap but disasters exceed natural calamities in impact

L15 Environmental Laws & Legislations in India

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Act	Year	Key Features
Wildlife Protection Act	1972	Regulates hunting & trade; establishes sanctuaries/NPs; penalty for violations. Amended 1982 (animal capture for science), 1991 (plant protection & zoo regulation). Projects: Lion (1972), Tiger (1973), Crocodile (1974), Brown Antlered Deer (1981)
Water (Prevention & Control of Pollution) Act	1974	Created CPCB (Central Pollution Control Board) + SPCBs. Defines water pollution. Industries need consent to discharge waste. Standards for streams/wells.
Forest (Conservation) Act	1980	Prevents deforestation; no state can de-reserve forest without Central Govt approval. Non-forest use (mining, cash crops) needs prior clearance. 1992 Amendment allowed limited non-forest use.
Air (Prevention & Control of Pollution) Act	1981	Enacted under Article 253. CPCB+SPCBs implement it. Defines air pollutant (including noise). Standards for automobile emissions.
Environment (Protection) Act	1986	Umbrella legislation; came after Bhopal Gas Tragedy. Defines environment & hazardous substance. Central Govt coordinates all environmental laws. Hazardous Waste Rules 1989.
Scheduled Tribes & Forest Dwellers Act	2006	Protects forest rights of forest-dwelling tribes & traditional communities.

EPA 1986 definition: "Environment includes water, air and land and the inter-relationship which exists among and between water, air and land, and human beings, other living creatures, plants, micro-organism and property."

UNIT VI

Biodiversity & Conservation

L11 Biodiversity & Its Threats

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Definition (E.O. Wilson, 1988): Variability among all living organisms from all sources including terrestrial, marine, and other aquatic ecosystems and ecological complexes of which they are part.

3 Types of Biodiversity

Genetic Diversity

Variation at individual gene level
Raw material for new species (evolution)
Used to breed disease-resistant crops

Species Diversity

Number of species in a region
Areas rich in species = hotspots
Countries with most hotspots = mega-diversity nations
India = among world's 15 mega-diversity nations

Ecosystem Diversity

Variation in structure & functions of ecosystems. Describes niches, trophic levels, energy flow, food webs, nutrient recycling. Keystone species (fig, peepal) = determine ability of large no. of other species to persist.

Measuring Biodiversity

α Alpha diversity

Diversity within a community/habitat. Species richness + evenness.

β Beta diversity

Diversity between communities. Species change along gradients (altitude, moisture).

γ Gamma diversity

Diversity over total landscape. = Sum of α + β diversities.

India's 10 Biogeographic Zones

Trans-Himalayan (Ladakh) | Himalayan ranges | Terai | Gangetic-Brahmaputra plains
Thar Desert (Rajasthan) | Deccan plateau semi-arid | North-eastern states
Western Ghats (Maharashtra, Karnataka, Kerala) | Andaman & Nicobar Islands | Coastal belt

Values of Biodiversity

Type	Key Points & Examples
Consumptive	Food, drugs (75% world population uses plant-based medicines), fuel. Penicillin (Penicillium fungus), Quinine (cinchona bark → malaria), Tetracycline (bacteria)
Productive	Commercially marketed: elephant tusks, musk, silk, wool, fur. Pyrethrum (daisy plants → mosquito coils), Bacillus thuringiensis (kills insects)
Social	Sacred plants (Tulasi, Mango, Banana leaves); sacred animals (cow, peacock, snake)
Ethical	Species should exist even if not used (Dodo, Pigeon – extinct examples)
Aesthetic	Eco-tourism = $12 billion annually. Kaplan & Kaplan (1989): nature relieves job stress.

Threats to Biodiversity

Extinction rate: 10,000–20,000 species/year = 1000–10,000× faster than natural rate. Human actions may exterminate 25% species in next 20–30 years.

Habitat loss = single greatest threat. Deforestation, wetland drainage, mangrove clearing for prawn farming.
Exotic invasives: Lantana, Eupatorium, Congress grass
Poaching: tiger skin/bones, elephant ivory, rhino horn, musk deer, corals, orchids
Man-wildlife conflict: Sambhalpur — 195 humans killed by elephants in 5 yrs; 98 elephants killed in retaliation
One adult elephant needs 200 kg fodder + 150 L water/day

Endangered & Endemic Species

Categories: Vulnerable → Rare → Intermediate → Threatened
Threatened animals: Tiger, Rhino, Elephant, Siberian crane, Great Indian Bustard, Florican, Vultures
Endemic species (India-specific): Indian wild ass, Kashmiri stag (Hangul), Golden langur, Pigmy hog

L12 Biodiversity Conservation

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In-Situ Conservation (On-site)

Conservation in natural habitat
India: 589 PAs — 89 National Parks + 500 Wildlife Sanctuaries
100+ PAs in Andaman & Nicobar
Examples: Kaziranga (elephant, gaur, swamp deer), Manas (golden langur, pigmy hog), Dachigam (Hangul/Kashmiri stag), Great Himalayan NP (snow leopard)

Ex-Situ Conservation (Off-site)

Outside natural habitat (zoos, botanical gardens, gene banks)
Last resort or supplement to in-situ
Examples: Madras Crocodile Trust (3 species, 2 clutches/yr), Guchali Zoo (pigmy hog), Delhi Zoo (Manipur brow antlered deer)
World's 1500 botanic gardens maintain 12,000–15,000 threatened plant species

Ex-Situ Techniques

Technique	Details
Captive Breeding	Zoos/NGOs; e.g., cheetah
Embryo Transfer	Developed for lab & farm animals; useful for endangered mammals
Artificial Insemination	Black-footed ferret (from 6 individuals → 16 kittens); elephants, cheetahs
Somatic Cell Cloning	First done at Roslyn Institute, Edinburgh (Dolly the sheep). Rare cattle "Lady" rescued this way.
Fostering	Peregrine falcon (huge success); Whooping crane: from 21 birds (1941) → 300+ (1996)
Translocation	Moving individuals to another habitat
Introduction	Releasing species outside historical range (needs extreme care)
Reintroduction	Restoring species within historical range
Seed Banks	Gene banks for plant germplasm; dormancy feature allows long-term storage

Project Tiger — Case Study

Launched: 1 April 1973 (centrally sponsored)
Initially: 9 reserves, 16,339 sq km, 268 tigers
Currently: 27 reserves, 37,761 sq km, 2967 tigers (1.14% of India's area)
Core-Buffer Strategy: Core = no biotic disturbance; Buffer = multiple use area

Biological Diversity Act, 2002

Passed: Lok Sabha — 2 Dec 2002; Rajya Sabha — Dec 2002. Implementing Rules: 2004.

3 Objectives: Conserve biodiversity | Sustainable use | Fair & equitable benefit sharing

Hierarchy: National Biodiversity Authority → State Biodiversity Boards → Biodiversity Management Committees (BMC)

International Day for Biological Diversity: 22nd May

Key provisions: Prohibits transfer of Indian genetic material abroad without Govt approval. Prohibits IPR claims on biodiversity without Govt permission. Regulates GMOs. Sets up Biodiversity Funds at national/state/local level.

Hotspots of Biodiversity

Term coined by Norman Myers (British biologist, 1988). Criteria: (1) ≥1500 vascular plant species as endemics (>0.5% of world's total); (2) ≤30% of original natural vegetation remaining.

36 hotspots globally — cover only 2.4% of Earth's land but support >50% of world's plant species and 43% of bird, mammal, reptile, amphibian species as endemics.

India's 4 Hotspots

Himalaya — entire Indian Himalayan region (+ Pakistan, Tibet, Nepal, Bhutan, China, Myanmar)
Indo-Burma — NE India except Assam & Andaman (+ Myanmar, Thailand, Vietnam, Laos, Cambodia, S China)
Sundalands — Nicobar Islands (+ Indonesia, Malaysia, Singapore, Brunei, Philippines)
Western Ghats & Sri Lanka — entire Western Ghats + Sri Lanka

IUCN Red List

IUCN = International Union for Conservation of Nature and Natural Resources. Conducts field surveys globally. Publishes 'Red Data List' with species status.

Wetlands

Functions: Regulate water regime, natural filters, nutrient dynamics, removes toxins/heavy metals
Mangroves = natural bulwark against sea erosion; buffer against Bay of Bengal storms
India has 6,740 sq km of mangroves; 80% in Sunderbans + A&N Islands
First Ramsar Convention: Iran, February 1971; India's delegates: Chilka (Odisha) + Bharatpur
Currently 26 Ramsar sites in India

Conservation of Cultivars

50 years ago: ~30,000 rice varieties in India. Now: only a few. Traditional varieties essential as germplasm for disease-resistant crop development.

UNIT VII

Human Communities & the Environment

L16 Human Communities & the Environment

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Current human population: 7.8 billion. Projected: 9 billion by 2040, 11 billion by 2100.

Factors for Population Growth

↑ Agricultural productivity (agrochemicals, modern machinery)
↓ Death rate & infant mortality (better medicines, vaccines)
Science & Technology → Industrial Revolution
Illiteracy, poverty, lack of family planning awareness

Impacts of Overpopulation

Deforestation: agricultural expansion, urbanisation, industrialisation
Biodiversity loss: habitat destruction → ecological imbalance
Urbanisation: depletes resources, poor sanitation, water scarcity
Land Degradation: soil erosion, salination, desertification
Fresh water: 2/3 world population will face water shortages by 2025
Climate Change: GHG emissions from fossil fuels
Transport: CO, NOₓ, hydrocarbons; oil spills → marine biodiversity loss

Population Control Measures

Minimum marriage age: 21 (men), 18 (women)
Education, employment, family planning awareness
Govt incentives: monetary benefits, tax benefits, leave/promotion for small families

Carbon Footprint

Carbon Footprint = amount of GHGs (mainly CO₂) released by any anthropogenic activity — individual, family, industry, or nation.

Reduce by: electric vehicles, public transport, energy-efficient appliances, local/organic food, carbon credits.

Resettlement & Rehabilitation (R&R)

National Policy on R&R came into force: 2004
R&R Plan = part of EIA & EMP reports
Based on NRRP-2003 and NRRP-2007
Triggers: mining, dam building, industries, declaration of NP/WLS/Biosphere Reserve

CNG Vehicles — Delhi Case Study

Delhi = on WHO's list of 20 most polluted cities
28 July 1998: Supreme Court ordered all commercial vehicles (taxis, buses, 3-wheelers) to convert to CNG
From 5 lakh vehicles (1981) to massive fleet today
~80,000 vehicles travel through Delhi daily between 8pm–6am
Advantages: Reduceds emissions, can be generated from biomethane, renewable
Limitations: High-pressure cylinders take more space, limited fuelling infrastructure

L17 Environmental Movements in India

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Green movement gained worldwide attention after UN Conference on Human Environment, Stockholm, 1972. By 1980s it became a global phenomenon.

Movement	Year / Place	Leaders	Key Facts
Bishnoi Movement	1700s; Khejarli, Marwar, Rajasthan	Amrita Devi + Bishnoi villagers	Against cutting sacred trees for king's palace. 363 Bishnoi villagers martyred. Guru Jambaji founded Bishnoi faith in 1485. King apologised; designated area as protected.
Chipko Movement	1973; Chamoli & Tehri-Garhwal, Uttarakhand	Sunderlal Bahuguna, Gaura Devi, Chandi Prasad Bhatt	"Hug the tree" movement. Against logging in W Himalayas. Women tied sacred threads on trees. Gained momentum 1978 (police firings). CM Hemwati Nandan Bahuguna set up inquiry → ruled in villagers' favour.
Save Silent Valley	1978; Palakkad, Kerala	KSSP (NGO), poet Sughathakumari	Against hydroelectric dam on Kunthipuzha River (proposed cost Rs. 25 crores; would submerge 8.3 sq km forest). Indira Gandhi halted — Jan 1981. Project officially cancelled Nov 1983. 1985: Rajiv Gandhi inaugurated Silent Valley National Park.
Appiko Movement	1983; Uttara Kannada & Shimoga, Karnataka	Pandurang Hegde (facilitator)	"Appiko Chaluvali" = southern version of Chipko. Against felling of natural forests. Used folk dances, street plays, foot marches. Promoted afforestation & alternative energy. Movement succeeded.
Narmada Bachao Andolan	1985; Narmada River (Gujarat, MP, Maharashtra)	Medha Patker, Baba Amte, adivasis	Against large dams on Narmada (Sardar Sarovar Dam — proposed height 130m). World Bank withdrew. Activists demanded 88m. SC judgment (Oct 2000): allowed up to 90m. Project financed by state govts; expected completion 2025.

L18 Disaster Management

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NDMA (National Disaster Management Authority) headed by the Prime Minister of India = apex body for Disaster Management. Disaster Management Act 2005 = most significant change. Nodal ministry shifted from Agriculture → Home Affairs (2002).

Post Disaster Management vs. Mitigation

Post Disaster (Reactive)

Evacuation, rescue, communications
Medical/psychiatric assistance
Relief, shelter provision
Reactive Mechanism

Mitigation (Proactive)

Sustained action to reduce long-term vulnerability
Repetitive benefits over time
Proactive approach
Prevention, preparedness, response, recovery

Main Elements of Mitigation Strategy

Risk assessment & vulnerability analysis
Applied research & technology transfer
Public awareness & training
Institutional mechanisms (NDMC)
Incentives & resources for mitigation
Land use planning & regulations
Hazard-resistant design & construction
Structural reinforcement of existing buildings

Floods

Only 18% rainwater stored; 82% flows to sea → floods recurrent
Causes: heavy rainfall, breach of dams/tanks, cyclones, river bank erosion, poor drainage
Western Ghats' thick forests = natural buffer against west coast floods
Structural measures: Dams, embankments, sea walls, channel improvement
Non-structural: Flood plain zoning, wetland management, forecasting & warning

Earthquakes

Abrupt release of energy in Earth's crust via tectonic processes
Intensity measured on Richter scale
High-risk zones in India: Assam & Himalayan regions
Gujarat earthquake (2001): 30,000 deaths
Precursors: land deformation/tilt, foreshocks, ↓ electrical resistivity, ↑ Radon gas

Cyclones

Indian Ocean = one of 6 major cyclone-prone regions
India's coastline = 5700 km; eastern coast hit by 80% of total cyclones
Season: April–May and October–December
Bay of Bengal cyclones > Arabian Sea in number & intensity
3 main effects: High-speed winds, Storm surge, Heavy rainfall/floods
Mitigation: early warning systems, shelter belts, permanent houses, community training

Landslides

Recurring in Himalayan region
Geological process: rock falls, slope failures, debris flows
Causes: heavy rains/snowmelt, earthquakes, volcanic eruptions, traffic vibrations, excess weight
Mitigation: drainage measures, bamboo check dams, terracing, jute/coir netting, grass plantation, preventing deforestation

Tsunami

Japanese: tsu (harbor) + nami (wave). Generated when sea floor abruptly deforms. Speed: 500–1000 km/h (commercial jet speed = 800 km/h). Wave height near shore: up to 30 m.

26 December 2004: Indian Ocean earthquake off N Sumatra — magnitude 9.0 (Richter). Aftershocks 6.3–7.0 in 1000 km zone to Andaman Islands. Deaths: ~187,000; ~43,000 missing. Aceh province: 130,000 died, 36,786 missing, 500,000 lost homes. 28 March 2005: follow-up earthquake of 8.7 near Nias.

Caused by: undersea earthquakes (tectonic), volcanic eruptions, submarine landslides
Can cross Pacific Ocean in less than a day
Sea recedes before tsunami hits (warning sign that most didn't recognise in 2004)