Class 12-science NCERT Solutions Economics Chapter 9 - Environment and Sustainable Development

The environment refers to the total planetary inheritance and all the resources. It includes all the biotic and abiotic factors which influence each other. This means that both biotic (living) and abiotic (physical) elements of the environment impact the survival and quality of human life. Physical elements include air, water, land, Sun, mountains and minerals which are gifts of nature. Living elements include all the living creatures such as plants, birds and animals which impact the quality of life.

The environment can execute many functions without any disturbance unless the demand for these functions is within the carrying capacity of the environment. The environment includes land, air and water which are ingredients for the sustenance of human life. This function of sustaining life is more important because the absence of these elements will be an end to life. Generally, natural resources were hardly viewed as renewable and non-renewable energy. The main focus was on fuller utilisation rather than rational utilisation of natural resources. Therefore, the rate of extraction of resources exceeds the rate of regeneration. This leads to environmental crisis which affects the whole world. In this situation, water will become an economic good. A large amount will be spent on research and technology to find new resources and more expenditure will be incurred on health aspects.

Trees, fish and water are renewable resources which are found abundantly in nature. These resources can be renewed and replenished with the help of physical, chemical or mechanical processes. Although these resources are found abundantly in nature, some of them may take longer time in getting replenished. For example, water and forests take a longer time in getting replenished.

Petroleum, coal and iron ore are non-renewable resources which occur over long geological time, i.e. takes millions of years for their formation. Some resources such as metals can be recycled, while resources such as coal and other fossil fuels cannot be recycled. At present, the main energy sources used by humans are generally non-renewable resources such as coal and petroleum.

Two major environmental issues facing the world today are global warming and ozone depletion.

Global warming refers to an increase in the temperature of the Earth resulting from certain gases (particularly carbon dioxide) which trap the heat of the Sun. For example, the most serious consequence of industrial pollution is global warming. Emission of various greenhouse gases such as CO₂ and methane has raised the temperature of the Earth, leading to global warming. Global warming causes various health hazards and diseases such as malaria, dengue and cholera. It also results in the melting of glaciers and snow-capped mountains, causing an increase in the water levels in seas and rivers, leading to the possibility of floods.

Ozone depletion refers to the phenomenon of reduction in the amount of ozone in the stratosphere. It is caused by high levels of chlorine and bromine compounds in the stratosphere. Origins of these compounds are chlorofluorocarbons which are used as cooling substances in air conditioners and refrigerators.

1. Increasing population: Population growth is one of the causes of depletion of natural resources. Because of an increase in population, there will be more demand for goods and services to satisfy their wants. More natural resources are required to produce goods and services and more land for housing and agricultural activities. This increase in population has led to depletion of natural resources in the environment. Indiscriminate use of the available energy sources is responsible for their rapid depletion. Thus, the government took efforts to make equitable distribution of resources for meeting the requirements of the current and future generations without causing damage to the environment. Also, the government created social awareness among the people about the threats of increasing population and needs to check the hazard to protect the environment.
2. Air pollution: In India, vehicles are the major contributors to air pollution in urban areas and a high concentration of industries and thermal power plants in certain other areas. Vehicular emissions are of particular concern because these being ground level sources have the maximum impact on the general population. In India, the total number of motor vehicles has increased from about 3 lakh in 1951 to 67 crore in 2003. Personal transport vehicles constitute about 80% of the total number of registered vehicles and thus contribute significantly to air pollution. CPCB has identified 17 categories of large and medium scale industries which are significantly polluting the environment. India is one of the top 10 industrialised countries in the world. So, there are unwanted, unanticipated consequences such as unplanned urbanisation, occurrence of accidents and pollution. This leads to environmental and health hazards such as acid rain and skin disorders in individuals and factories. Thus, the government took steps to enforce laws pertaining to the control of air pollution such as the Air (Prevention and Control of Pollution) Act.
3. Water pollution: Water pollution has also increased enormously with an increase in the number of industries and factories. Dumping of industrial waste products into water resources and improper treatment of industrial wastes results in water pollution. This polluted water causes diseases such as diarrhoea and hepatitis. Thus, the government took initiatives involving huge investment to control wastewater disposal.
4. Affluent consumption standards:  Affluent consumption style has become a heavy burden on nature. People are using nature beyond the carrying capacity of the environment. Rivers are drying up because of the overuse of water from rivers through dams and reservoirs. The excess use of electricity leads to depletion of resources such as coal and water from which electricity is generated. This leads to excess absorptive capacity of the environment. Thus, the government made huge investment on research and technology to explore new resources.
5. Illiteracy: Illiterate people are not aware of the limited supply of resources, and growth of human wants leads to resource depletion. They are unable to manage the available resources more efficiently and thus led to misuse of resources. So, the government created awareness among the people regarding the different methods to conserve natural resources.
6. Industrialisation: Industrialisation is a process in which a country transforms itself from an agricultural society to an industrial one. It implies creation and growth of manufacturing units. Because of the progress of industries such as iron and steel, chemical, coal, cement and thermal power, non-renewable resources are depleted at a rapid pace. Thus, the government initiated measures to control the depletion and degradation of resources.
7. Urbanisation: Urbanisation is a process of relative growth in a country's urban population. Because of urbanisation, there is a change in land use, depletion of water resources, use of large quantities of building materials for construction purposes and development of slums. More use of land for housing and industries has caused the loss of biological diversity. Widespread construction leads to a decline in the local groundwater level and cities have to make provision for external sources of water. So, the government promoted small and cottage industries to control the migration of people from rural to urban areas.
8. Reduction in forest coverage: Deforestation arises because of increased demand for fibre and fuel to human beings. Forests give us oxygen and take in carbon dioxide. Reduction of forest coverage will increase the carbon dioxide level in the atmosphere. So, the government initiated extensive afforestation campaigns to protect the environment. Central and state governments have established many wildlife sanctuaries and national parks to protect forests and wildlife.
9. Poaching:  People poach animals because animal products such as hide, ivory, horn, teeth and bone are useful to make jewellery, clothes and other materials. So, the government passed an act to ban hunting and poaching of animals and provided legal protection to their habitats.
10. Global warming: Global warming refers to increase in the temperature of the Earth resulting from certain gases particularly carbon dioxide which trap the heat of the Sun. For example, the most serious consequence of industrial pollution is global warming. Emission of various greenhouse gases such as CO₂ and methane has raised the temperature of the Earth, leading to global warming. Global warming causes various health hazards and diseases such as malaria, dengue and cholera. It also results in the melting of glaciers and snow-capped mountains, causing an increase in the water levels in seas and rivers, leading to the possibility of floods.  

Functions of the environment:

1. Supply of resources: The environment includes physical elements such as air, water, land, Sun, mountains and minerals. They are a gift of nature and used as raw material in production.
2. Assimilates waste: Production and consumption activities generate wastes in the form of garbage which is absorbed by the environment.
3. Sustains life: Sun, soil, air and water are the essential ingredients of the environment and are required to sustain human life. Absence of these elements will lead to an end of life on the Earth.
4. Aesthetic services: The environment provides aesthetic services such as scenery which includes rivers, oceans, mountains and deserts. These add to the quality of life. 

Six factors which are responsible for land degradation in India:

1. Shifting cultivation: The practice of shifting cultivation is an extravagant and unscientific form of land use. The effects of shifting cultivation are devastating in degrading the environment and ecology of a region. The previous 15-20 year cycle of shifting cultivation on a particular land has now reduced to 2-3 years as it resulted in large-scale deforestation, soil and nutrient loss and invasion by weeds and other harmful species. Also, the indigenous biodiversity of a region has been affected to a large extent. 
2. Soil erosion: Soil is an important resource. It is the medium of plant growth and supports various kinds of living organisms on the Earth. We cannot imagine plant and human life without soil. Soil erosion refers to the wearing away of a field's topsoil by the forces of water and wind leading to desertification. The erosion of soil is caused by faulty agricultural practices, overgrazing and deforestation. This results in major loss in nutrients for the growth of land. 
3. Desertification: Desertification refers to land degradation in arid, semiarid and dry sub-humid areas resulting from various factors including climatic variations and human activities. It is the most dangerous ecosystem change impacting the life of the poor. Constant reduction of ecosystem services as a result of desertification links land degradation to loss of human well-being. 
4. Deforestation: Deforestation is undertaken to accommodate more agricultural activity, human settlement and construction of dams. This leads to soil erosion which in turn causes climatic change.
5. Alkalinity and salinity of soil: Over irrigation of land leads to waterlogging resulting in the salinity of soil. This has degraded land mainly in Punjab and Haryana.
6. Overgrazing: The number of domestic animals, especially cattle, is the highest in the world. The cattle freely graze in open lands making them bare of their green cover. After this happens, the wind carries away the dry soil particles from the bare landscape. In many parts of Rajasthan, this has exposed the topsoil to denudation. Thus, land degradation also occurs because of uncontrolled grazing

Opportunity cost is not an actual cost because it is the cost of the next best alternative available but not actually opted in decision-making. For example, a farmer using a piece of land for the production of wheat indicates foregoing the opportunity cost of using a piece of land for the production of pulses. Thus, loss in the production of pulses is the opportunity cost of producing wheat on a given land. Opportunity cost of negative environmental impact is the heavy medical expenditure incurred on health-related problems and research to explore new resources.

Instance to justify that the opportunity costs of negative environmental impact are high: The environment can execute many functions without any disturbance unless the demand for these functions is within the carrying capacity of the environment. The environment includes land, air and water which are ingredients for the sustenance of human life. This function of sustaining life is more important because the absence of these elements will be an end to life. Hence, the rate of extraction of the resource exceeds the rate of regeneration. This leads to environmental crisis which affect the whole world. In this situation, water will become an economic good, a large amount will be spent on research and technology to find new resources and more expenditure will be incurred on health aspects. Thus, it is justified that the opportunity costs of negative environmental impact are high.

Sustainable development refers to human development where resources are used for satisfying human needs without causing any harm to the surrounding environment and without compromising the needs of future generations.

Steps involved in attaining sustainable development in India:

1. Measures to control population: The government initiated measures to control birth and created awareness among the people to protect the environment. Thus, they attempted to control the increased population to a level within the carrying capacity of the environment.
2. Use of non-conventional sources of energy: Thermal and hydro power plants are the two non-conventional sources of energy which has negative impacts on the environment. Thermal power plants emit enormous quantities of carbon dioxide in the environment. Hydro power plants inundate forests and obstruct the natural water flow in catchment areas and river basins. Hence, the use of non-renewable resources should deplete at a rate not exceeding the rate of creation of renewable substitutes.
3. Mini hydel plants in mountainous regions: Mini-hydel plants are environment-friendly as they do not change the land-use pattern in the mountainous regions. They always do with the need of large-scale transmission loss and generate power to meet local demands. 
4. Use of LPG and gobar gas in rural areas: Wood, cow dung and other biomass are used as fuel by households in rural areas. Because of the adverse effects such as deforestation and reduction in green cover, subsidised liquefied petroleum gas (LPG) is being provided along with gobar gas plants through easy loans and subsidy in rural areas. 
5. Use of CNG as fuel in urban areas: In urban areas, compressed natural gas (CNG) is used as fuel in public transport vehicles. This significantly lowers air pollution. 
6. Technological knowledge: Technological progress needs to be input efficient rather than input consuming. This implies the maximisation of output which moderates the stress on resources endowment per unit of output.
7. Convert sunlight to solar energy: India has plenty of sunlight which is a rich source of energy. This sunlight is an eco-friendly and non-exhaustible source of energy which can be converted to solar energy and then converted to electricity through photovoltaic cells. 
8. Segregation of waste: First, non-hazardous wastes are separated from hazardous wastes rather than dumping them together. Then a small amount of hazardous waste can be treated and a large amount of non-hazardous waste can be destroyed by traditional methods.

India has a wide range of natural resources which are the foundation for the prosperity of the country. Land greatly influences natural vegetation. Vegetation differs according to landforms such as mountains, plains and plateaus. While the fertile lands of the plains are used for agricultural activities, the grasslands are used for providing pastures for animals. Various kinds of soil support different vegetation. While alluvial soil is fertile and supports extensive agricultural activities, sandy soil of the desert region supports cactus and thorny bushes. In India, alluvial soil is deposited by Rivers Ganga and Brahmaputra. It is found in the North Indian Plains extending to some parts of Rajasthan and Gujarat. It is also found in the eastern coastal plains, especially in the delta of Mahanadi, Krishna, Godavari and Kaveri. India, being a tropical country, has ample sunlight, water and wind energy. These natural resources are a gift of nature and pollution-free. Cotton is largely produced in the black soil of the Deccan plateau. Large deposits of iron ore, coal and natural gas are found in India.

Yes, the environmental crisis is a very recent phenomenon. The environment can execute many functions such as supply of resources, assimilates waste and sustains life and aesthetic services without any disturbance unless the demand for these functions is within the carrying capacity of the environment. The environment includes land, air and water which are ingredients for the sustenance of human life. This function of sustaining life is more important because the absence of these elements will be an end to life. Growing population and the advent of the Industrial Revolution to meet the requirement of increasing population raised the demand for resources for production and consumption. Hence, the rate of extraction of resources exceeds the rate of regeneration. This leads to an environmental crisis which affects the whole world. So, the pressure on absorptive capacity has increased tremendously in recent years.

1. Overuse of environmental resources: 

1. Rivers dried up: Rivers dried up because of overuse of water from rivers through dams and reservoirs.
2. Soil erosion: Erosion of soil is caused by faulty agricultural practices, overgrazing and deforestation. This implies a major loss in nutrients of the land. 

2. Misuse of environmental resources: 

1. Use of electricity: Excess use of electricity leads to depletion of resources such as coal and water from which electricity is generated.
2. Use of wood: Wood, cow dung and other biomass are used as fuel by households in rural areas, and therefore, it has adverse effects on the environment such as deforestation and reduction in green cover. 

Four pressing environmental concerns of India:

1. Global warming and ozone depletion
2. Land degradation 
3. Management of freshwater and solid waste management
4. Air pollution in urban cities

Correction of environmental damages involves opportunity cost as explained below: 

• Similarly, the correction for environmental damages involves opportunity costs. It requires huge investments to explore new resources. For example, thermal power plants emit enormous quantities of carbon dioxide in the environment. Hydropower plants inundate forests and obstruct the natural water flow in catchment areas and river basins. Wind power and solar rays are conventional energy resources which are cleaner and greener. Such energy is not explored on a large scale because the cost involved in using advanced technological devices is high. Thus, the government needs to incur huge expenditures to explore new resources which is the opportunity cost of rectifying environmental damages.
• The health costs of degraded environment quality are also present as a decline in air and water quality has resulted in an increased incidence of respiratory and water-borne diseases. 
• Industrial activities have polluted water bodies. Cleaning up the polluted water and replenishing water resources require a huge investment.

Before industrialisation the demand for satisfying human wants required less input for production. So, the rate of extraction of the resource was lesser than the rate of regeneration. However, the growing population and the advent of the Industrial Revolution to meet requirements raised the demand for resources for production and consumption. This increased the rate of extraction of the resource compared to the rate of regeneration, and the pressure on absorptive capacity has increased tremendously in recent years. This leads to an environmental crisis which affects the whole world. Thus, the relationship between supply-demand for environmental resources is in reverse because the demand for environmental resources is higher than supply. The main cause for this reversal operation of supply-demand relationship is over use and misuse of environmental resources. 

Population growth and affluent consumption style are causes of depletion of natural resources. Expansion of production activities is equally important when it comes to the degradation of environmental resources. Industrial smoke pollutes air and industrial waste pollutes water. In the wake of urbanisation, the expansion of vehicular traffic generates air pollution, global warming and noise pollution. This leads to excessive exploitation of natural resources to achieve a higher rate of growth and sometimes resources are diverted to wrong use causing environmental degradation. Thus, the environment does not perform the function of sustaining life. The main focus was given to fuller utilisation rather than rational utilisation of these resources. Hence, the rate of extraction of the resource exceeds the rate of regeneration. This leads to environmental crisis which affected the whole world. Currently, two major environmental issues facing the world today are global warming and ozone depletion.

1. Global warming refers to increase in temperature of the Earth resulting from certain gases particularly carbon dioxide which traps the heat of the Sun. For example, the most serious consequence of industrial pollution is global warming. The emission of various greenhouse gases such as CO₂ and methane has raised the temperature of the Earth, leading to global warming. Global warming causes various health hazards and diseases such as malaria, dengue and cholera. It also results in the melting of glaciers and snow-capped mountains, causing an increase in the water levels in seas and rivers, leading to the possibility of floods.
2. Ozone depletion refers to the phenomenon of reduction in the amount of ozone in the stratosphere. It is caused by high levels of chlorine and bromine compounds in the stratosphere. The origin of these compounds is chlorofluorocarbons which are used as cooling substances in air conditioners and refrigerators. 

Two serious adverse environmental consequences of development in India are land degradation and air pollution.

A. Factors responsible for land degradation

1. Shifting cultivation: The practice of shifting cultivation is an extravagant and unscientific form of land use. The effects of shifting cultivation are devastating and far-reaching in degrading the environment and ecology of a region. The previous 15-20 year cycle of shifting cultivation on a particular land has now reduced to 2-3 years as it resulted in large-scale deforestation, soil and nutrient loss and invasion by weeds and other harmful species. Also, the indigenous biodiversity of a region has been affected to a large extent. 
2. Soil erosion: Soil is an important resource. It is the medium of plant growth and supports various kinds of living organisms on the Earth. We cannot imagine plant and human life without soil. Soil erosion means the wearing away of a field's topsoil by the forces of water and wind leading to desertification. The erosion of soil is caused by faulty agricultural practices, overgrazing and deforestation. This implies the major loss in nutrients for the growth of land. 
3. Desertification: Desertification refers to land degradation in arid, semiarid and dry sub-humid areas resulting from various factors including climatic variations and human activities. It is the most dangerous ecosystem change impacting the life of the poor. Constant reduction of ecosystem services as a result of desertification links land degradation to loss of human well-being. 
4. Deforestation: Deforestation is undertaken to accommodate more agricultural activity, human settlement and construction of dams. This leads to soil erosion which in turn causes climatic change.
5. Alkalinity and salinity of soil: Over irrigation of land leads to waterlogging resulting in the salinity of soil. This has degraded land mainly in Punjab and Haryana.
6. Overgrazing: The number of domestic animals, especially cattle, is the highest in the world. The cattle freely graze in open lands making them bare of their green cover. After this happens, the wind carries away the dry soil particles from the bare landscape. In many parts of Rajasthan, this has exposed the topsoil to denudation. Thus, land degradation also occurs because of uncontrolled grazing.

B. Air Pollution

In India, vehicles are the major contributors to air pollution in the urban areas and a high concentration of industries and thermal power plants in certain other areas. Vehicular emissions are of particular concern because these being ground level sources have the maximum impact on the general population. In India, the total number of motor vehicles has raised from about 3 lakh in 1951-67 crore in 2003. Personal transport vehicles constitute about 80% of the total number of registered vehicles, and thus contribute significantly to air pollution. CPCB has identified 17 categories of large and medium-scale industries which significantly pollute the environment. India is one of the top 10 industrialised countries in the world. So, there are unwanted, unanticipated consequences such as unplanned urbanisation, occurrence of accidents and pollution. This leads to environmental and health hazards such as acid rain and skin disorders in individuals and factories.  

India's environmental problems pose a dichotomy is true. Environmental degradation is occurring and expanding because of poverty and growth of productivity. Deforestation is the consequence of widespread poverty in India. Many poor people in rural areas are forced to fell trees for fuel wood and there is growing demand for natural resources because of affluent consumption style in urban areas. As a result, they get trapped in a situation of severe environmental degradation. In the wake of urbanisation, the expansion of vehicular traffic generates air pollution, global warming and noise pollution. This leads to excessive exploitation of natural resources to achieve a higher rate of growth, and resources are diverted to wrong use causing environmental degradation.

Sustainable development is the judicious or optimum utilisation of resources in such a manner that the pace of economic growth sustains intergenerational equity.

Four strategies of sustainable development:

1. Use of eco-friendly sources of energy: Subsidised liquefied petroleum gas (LPG) is being provided along with gobar gas plants through easy loans and subsidy in rural areas. In urban areas, compressed natural gas (CNG) is used as fuel in public transport vehicles. It significantly lowers air pollution because of which air can become cleaner.
2. Technological knowledge: Technological progress needs to be input efficient rather than input consuming. This implies to the maximisation of output which moderates the stress on resource endowment per unit of output.
3. Convert sunlight to solar energy-renewable source: India has plenty of sunlight which is a rich source of energy. This sunlight is eco-friendly and a non-exhaustible source of energy. Solar energy can be converted to electricity through photovoltaic cells. 
4. Organic farming: Excessive use of chemical fertilisers, insecticides and pesticides has increased their production but there was loss in soil fertility. This implies the loss in the production capacity for future years. Therefore, there is need for organic farming which maintains soil health with sustained productivity. 

Sustainable development stresses its obligation for the development process to meet the needs of the present generation without compromising on the ability of future generations to meet their own needs. It is necessary that the present generation should maintain the Earth in good shape for the future generation. This means that the natural resources should not be used in excess to achieve higher rate of growth and need to divert the resources for appropriate use to avoid environmental degradation. This helps maintain the rate of extraction of the resource by keeping it lower than the rate of regeneration. Sustainable development can maximise the welfare of the present and future generations. Thus, the main focus should be on fuller utilisation rather than rational utilisation of natural resources to have sustained economic growth with intergenerational equity.