NCERT Notes for Class 12 Economics Chapter 9 ENVIRONMENT AND SUSTAINABLE DEVELOPMENT, (Economics) exam are Students are taught thru NCERT books in some of the state board and CBSE Schools. As the chapter involves an end, there is an exercise provided to assist students to prepare for evaluation. Students need to clear up those exercises very well because the questions inside the very last asked from those.

Sometimes, students get stuck inside the exercises and are not able to clear up all of the questions.  To assist students, solve all of the questions, and maintain their studies without a doubt, we have provided step-by-step NCERT Notes for the students for all classes.  These answers will similarly help students in scoring better marks with the assist of properly illustrated Notes as a way to similarly assist the students and answer the questions right





  • Environment is defined as the total planetary inheritance and the totality of all resources.
  • It includes all the biotic and abiotic factors that influence each other.
  1. Living elements: the birds, animals and plants, forests, fisheries etc. Are biotic elements, abiotic elements include air, water, land etc.
  2. Rocks and sunlight are all examples of abiotic elements of the environment.

Functions of the Environment

  • The environment performs four vital functions:
  1. It supplies resources

(Resources include both renewable and non-renewable resources. Renewable resources are those which can be used without the possibility of the resource becoming depleted or exhausted. That is, a continuous supply of the resource remains available. Examples of renewable resources are the trees in the forests and the fishes in the ocean. Non-renewable resources, on the other hand, are those which get exhausted with extraction and use, for example, fossil fuel.)

(ii) It assimilates waste

(iii) It sustains life by providing genetic and bio diversity

(iv) It also provides aesthetic services like scenery etc.

  • Environment had generally two capacities:
  1. Carrying capacity and Absorptive capacity
  2. Carrying capacity means resource extraction is not above the rate of regeneration of the resource and the wastes generated are within the assimilating capacity of the environment.
  3. Absorptive capacity means the ability of the environment to absorb degradation.

Global Warming

  • Global warming is a gradual increase in the average temperature of the earth’s lower atmosphere as a result of the increase in greenhouse gases since the Industrial Revolution.
  • Global warming is human induced.
  • It is caused by man-made increases in carbon dioxide and other greenhouse gases through the burning of fossil fuels and deforestation.
  • Some of the longer-term results of global warming are melting of polar ice with a resulting rise in sea level and coastal flooding, extinction of species, frequent tropical storms; and an increased incidence of tropical diseases.
  • A UN Conference on Climate Change, held in Kyoto, Japan, in 1997, resulted in an international agreement to fight global warming.

Ozone Depletion

  • Ozone depletion refers to the phenomenon of reductions in the amount of ozone in the stratosphere.
  • The problem of ozone depletion is caused by high levels of chlorine and bromine compounds in the stratosphere.
  • The origins of these compounds are chlorofluorocarbons (CFC), used as cooling substances in air conditioners and refrigerators.
  • As a result of depletion of the ozone layer, more ultraviolet (UV) radiation comes to Earth and causes damage to living organisms.
  • UV radiation seems responsible for skin cancer in human beings.


  • India has abundant natural resources in terms of rich quality of soil, hundreds of rivers and tributaries, lush green forests, plenty of mineral deposits beneath the land surface, vast stretch of the Indian Ocean, ranges of mountains, etc
  • The Indo-Gangetic plains spread from the Arabian Sea to the Bay of Bengal are one of the most fertile, intensively cultivated and densely populated regions in the world.
  • Large deposits of iron-ore, coal and natural gas are found in the country.
  1. Air pollution, water contamination, soil erosion, deforestation and wildlife extinction are some of the most pressing environmental concerns of India.
  • The priority issues identified are
  1. land degradation
  2. biodiversity loss
  3. air pollution with special reference to vehicular pollution in urban cities
  4. management of fresh water
  5. solid waste management.


Some of the factors responsible for land degradation are :

(i) loss of vegetation occurring due to deforestation

(ii) unsustainable fuel wood and fodder extraction

(iii) shifting cultivation

(iv) encroachment into forest lands

(v) forest fires and over grazing

(vi) non-adoption of adequate soil conservation measures

(vii) improper crop rotation

(viii) indiscriminate use of agro-chemicals such as fertilisers and pesticides

(ix) improper planning and management of irrigation systems

(x) Extraction of ground water in the competing uses of land for forestry, agriculture, pastures, human settlements and industries etc.


  • Sustainable development aims at promoting the kind of development that minimises environmental problems and meets the needs of the present generation without compromising the ability of the future generation to meet their own needs.
  • The concept of sustainable development was emphasised by the United Nations Conference on Environment and Development (UNCED).
  • which defined it as: ‘Development that meets the need of the present generation without compromising the ability of the future generation to meet their own needs’.
  • Sustainable development aims at decreasing the absolute poverty of the poor by providing lasting and secure livelihoods that minimise resource depletion, environmental degradation, cultural disruption and social instability.
  • Sustainable development is a development that meets the basic needs of all, particularly the poor majority, for employment, food, energy, water, housing, and ensures growth of agriculture, manufacturing, power and services to meet these needs.
  • The Brundtland Commission emphasises on protecting the future generation.
  • The present generation can promote development that emphasis on
  1. conservation of natural assets
  2. preservation of the regenerative capacity of the world’s natural ecological system
  3. avoiding the imposition of added costs or risks on future generations.
  • According to Herman Daly, a leading environmental economist, to achieve sustainable development, the following needs to be done
  1. limiting the human population to a level within the carrying capacity of the environment. (The carrying capacity of the environment is like a ‘plimsoll line’ of the ship which is its load limit mark)
  2. technological progress should be input efficient and not input consuming
  3. renewable resources should be extracted on a sustainable basis, that is, rate of extraction should not exceed rate of regeneration
  4. for non-renewable resources rate of depletion should not exceed the rate of creation of renewable substitutes
  5. Inefficiencies arising from pollution should be corrected.


Use of Non-conventional Sources of Energy: India hugely dependent on thermal and hydro power plants to meet its power needs. Both of these have adverse environmental impacts.

  1. Wind power and solar rays are good examples of non-conventional energy sources and they are more eco-friendly.

LPG, Gobar Gas in Rural Areas: Households in rural areas generally use wood, dung cake or other biomass as fuel.

  1. This practice has several adverse implications like deforestation, reduction in green cover, wastage of cattle dung and air pollution.
  2. To rectify the situation, LPG, gobar gas plant is being provided through easy loans and subsidy.
  3. It reduces household pollution to a large extent. Also, energy wastage is minimised.

CNG in Urban Areas: In Delhi, the use of Compressed Natural Gas (CNG) as fuel in public transport system has significantly lowered air pollution.

Wind Power: In areas where speed of wind is generally high, windmills can provide electricity without any adverse impact on the environment.

Solar Power through Photovoltaic Cells: India is naturally endowed with a large quantity of solar energy in the form of sunlight.

  1. Now, with the help of photovoltaic cells, solar energy can be converted into electricity.
  2. These cells use special kind of materials to capture solar energy and then convert the energy into electricity. This technique is also totally free from pollution.

Mini-hydel Plants: In mountainous regions, streams can be found almost everywhere.

  1. By using these streams, we can construct Minihydel power Plants.
  2. Such power plants are environment friendly as they do not change the land use pattern in areas where they are located more over they generate enough power to meet local demands.

Traditional Knowledge and Practices: Traditionally, Indian people have been close to their environment. They practiced environment friendly agriculture system, healthcare system, housing, transport etc.

Biocomposting: In our quest to increase agricultural production during the last five decades we almost totally neglected the use of compost and completely switched over to chemical fertilisers.

  1. It adversely affected, our land, health, water bodies due to chemical contamination.
  2. Now Farmers, in large numbers all over the country, have started using compost made from organic wastes of different types.
  3. Earthworms can convert organic matter into compost faster than the normal composting process. This process is now being widely used.

Biopest Control: With the advent of green revolution our farmers use more and more chemical pesticides for higher yield.

  1. As a result, food products, soil, water bodies and even ground water were polluted with pesticides.
  2. Even milk, meat and fishes were also contaminated.
  3. To meet this challenge now better methods of eco-friendly pest control measures were used.
  4. One such step is the use of pesticides based on plant products.
  5. Mixed cropping and growing different crops in consecutive years on the same land have also helped farmers.

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