Quick revision summary of Chapter 7: Environment and Sustainable Development (Indian Economic Development). Read the full notes for the detailed explanation.
Board note: CBSE teaches this book in Class 12; UP, Bihar, Rajasthan and MP Boards teach it in Class 11.
1 Key definitions
Definitions
EnvironmentTotal planetary inheritance and totality of all resources; biotic and abiotic factors
Biotic elementsBirds, animals, plants, forests, fisheries
Abiotic elementsAir, water, land, rocks, sunlight
Renewable resourcesUsed without risk of depletion, continuous supply: trees, fishes
Non-renewable resourcesExhausted with extraction and use: fossil fuel
Carrying capacityExtraction not above regeneration and wastes within assimilating capacity
Absorptive capacityAbility of the environment to absorb degradation
Environmental crisisDemand beyond carrying capacity; life-sustaining function fails
Global warmingGradual rise in average temperature of the earth’s lower atmosphere due to more greenhouse gases since the Industrial Revolution
Ozone depletionReduction in the amount of ozone in the stratosphere
Sustainable developmentMeets present needs without compromising future generations’ ability to meet theirs (UNCED)
2 Four functions of the environment
- Supplies resources
- Assimilates waste
- Sustains life through genetic and bio diversity
- Provides aesthetic services
Stress on the first two: rising population of developing countries + affluent consumption and production of the developed world.
3 Opportunity costs and why the crisis is new
- High opportunity costs: spending on exploring new resources; health costs (seventy per cent of water polluted); financial commitments for global warming and ozone depletion
- Water as an economic good: rivers and aquifers polluted and dried up
- Why the crisis is new: earlier demand < supply; after the population explosion and industrial revolution demand > supply, a reversal of the supply-demand relationship
4 Global warming and ozone depletion
| Basis | Global warming | Ozone depletion |
|---|---|---|
| Causes | Fossil fuels, deforestation, methane from animal waste | CFCs (ACs, refrigerators, aerosols), halons (fire extinguishers) |
| Figures | Since 1750, CO₂ +31%, CH₄ +149%; 0.6°C (1.1°F) in the past century | About 5% fall from 1979 to 1990 |
| Effects | Melting ice, sea-level rise, storms, diseases, extinction | More UV: skin cancer, less phytoplankton |
| International step | Kyoto, Japan, 1997 | Montreal Protocol |
5 State of India’s environment
- Resources: black soil (cotton, textiles), Indo-Gangetic plains, forests, iron-ore (8% of world), coal, natural gas
- Dichotomy: poverty-induced degradation + pollution from affluence and industry
- Most pressing concerns: air pollution, water contamination, soil erosion, deforestation, wildlife extinction
- Five priority issues: land degradation, biodiversity loss, urban vehicular air pollution, fresh water management, solid waste management
- Pressure on land: 17% population, 20% livestock, 2.5% area; per capita forest land 0.06 ha (0.47 needed); 15 million m³ excess felling; 5.3 billion tonnes soil eroded a year
- Vehicles: 3 lakh in 1951, 35 crore in 2022; 85% two-wheelers and cars
- CPCB: 1974; seventeen categories of polluting industries; 125 rivers monitored
- Appiko: 8 September 1983, Salkani forest, Sirsi; 160 people; 12,000 trees saved
Six factors of land degradation to remember: deforestation, unsustainable fuel wood and fodder extraction, shifting cultivation, encroachment into forests, forest fires and over grazing, indiscriminate use of agro-chemicals.
6 Sustainable development: who said what
| Source | Main idea |
|---|---|
| UNCED | Present needs met without compromising future generations; “need” and “future generations” |
| Our Common Future | Basic needs of all; redistribution makes it a moral issue |
| Edward Barbier | Raise the material standard of living of the poor at the grass root level |
| Brundtland Commission | Protect the future generation; leave “quality of life” assets no less than inherited |
| Herman Daly | Population within carrying capacity (plimsoll line); input-efficient technology; extraction ≤ regeneration; depletion ≤ creation of substitutes; correct pollution inefficiencies |
| UN, 2015 | 17 Sustainable Development Goals, by 2030 |
7 Nine strategies
- Non-conventional sources of energy (thermal: CO₂, fly ash; hydro: inundated forests)
- LPG (subsidised) and gobar gas (easy loans) in rural areas; slurry is organic fertiliser
- CNG in urban areas (Delhi’s public transport)
- Wind power (high initial cost easily absorbed)
- Solar power through photovoltaic cells (remote areas, pollution-free; International Solar Alliance)
- Mini-hydel plants (no change in land use, no transmission loss)
- Traditional knowledge and practices (15,000 medicinal species, 8,000 in regular use)
- Biocomposting (earthworms)
- Biopest control (neem, mixed cropping, snakes, owls, peacocks, lizards)
Common Mistake
Wind and solar are non-conventional sources; global warming and ozone depletion are two separate problems; the environment has four functions.
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