Environment and Sustainable Development NCERT Solutions Class 12 Economics PDF Download 2026

Ans: The environment performs four vital functions:
1. Supplies Resources: It provides both renewable (water, forests) and non-renewable (fossil fuels, minerals) resources for production.
2. Assimilates Waste: It absorbs the waste generated by production and consumption activities.
3. Sustains Life: It provides essential elements like sun, soil, water, and air, which are necessary to sustain human life and biodiversity.
4. Provides Aesthetic Services: It offers scenic beauty (mountains, rivers) that enhances the quality of life.

Ans: When resource extraction exceeds regeneration, it breaches the environment's carrying capacity. This leads to the depletion of vital resources (like groundwater and forests), environmental crises, and an inability of the environment to assimilate waste, ultimately halting economic development and threatening survival.

Ans: The opportunity cost of negative environmental impact refers to the massive financial resources spent on curing health problems caused by pollution and on cleaning up polluted rivers/air. These funds could have otherwise been used for productive economic development (like building schools or hospitals) had the environment not been degraded.

Ans: As defined by the United Nations' Brundtland Commission (1987), sustainable development is "development that meets the needs of the present without compromising the ability of future generations to meet their own needs." It aims to balance economic growth with environmental conservation.

Ans:
1. Use of Non-conventional Sources of Energy: Shifting from fossil fuels (coal, oil) to cleaner, renewable sources like wind and solar energy.
2. Organic Farming: Avoiding chemical fertilizers and pesticides to restore soil health and maintain ecological balance.

Ans: The Central Pollution Control Board (CPCB), set up in 1974, is the apex body responsible for addressing water and air pollution issues in India.

Ans: Absorptive capacity means the ability of the environment to absorb degradation or assimilate the waste created by human activities without suffering long-term damage.

Ans: The primary cause of ozone depletion is the high level of chlorine and bromine compounds in the stratosphere. The major culprits are Chlorofluorocarbons (CFCs) used in air conditioners, refrigerators, and aerosol propellants.

Ans:
Renewable Resources: Those that can be replenished by nature in a short time and are not depleted by use (e.g., trees, fish, solar energy).
Non-Renewable Resources: Those that have a fixed stock and cannot be replenished within a human lifespan once depleted (e.g., coal, petroleum).

Ans: The Montreal Protocol (signed in 1987) is an international treaty designed to protect the ozone layer by phasing out the production and consumption of numerous substances (like CFCs) that are responsible for ozone depletion.

Ans:
In the past (before industrialization), the demand for environmental resources and services was much less than their supply. The environment could easily replenish extracted resources and assimilate the waste.
However, with rapid population growth and the Industrial Revolution, the demand for resources skyrocketed. We are now extracting resources faster than they regenerate, and producing more waste than the environment's absorptive capacity. This has caused a supply-demand reversal, where the demand for environmental resources is far greater than their supply, leading to today's environmental crisis.

Ans:
1. Global Warming: It is the gradual increase in the Earth's average temperature. It is caused by the emission of greenhouse gases (CO2, Methane) from burning fossil fuels and deforestation. It leads to melting polar ice caps, rising sea levels, and extreme weather events.
2. Ozone Depletion: The ozone layer protects the Earth from harmful UV radiation. The release of CFCs depletes this layer. Depletion increases the risk of skin cancer, cataracts, and damages aquatic life (phytoplankton) and crop yields.

Ans:
1. Population Explosion: A large population puts immense pressure on land, leading to deforestation and over-extraction of groundwater.
2. Poverty: The rural poor rely heavily on nature for survival (cutting trees for firewood), contributing to resource depletion.
3. Urbanisation: Rapid and unplanned urbanization leads to air pollution, massive solid waste generation, and slum proliferation.
4. Industrialisation: Unregulated industries discharge toxic effluents into rivers and emit hazardous gases into the air.

Ans:
1. Biocomposting: In the past, farmers used cow dung as fertilizer. The shift to chemical fertilizers destroyed soil health. Biocomposting involves making compost from organic waste (using earthworms or microbes). It naturally replenishes soil fertility without harming the environment.
2. Biopest Control: Heavy reliance on chemical pesticides contaminated food chains. Biopest control uses natural predators (like owls or specific insects) or plant-based pesticides (neem extract) to control pests, ensuring food safety and environmental health.

Ans: Historically, Indians lived in harmony with nature. Our traditional practices were eco-friendly:
1. Agriculture: Use of mixed cropping and organic manure kept soil healthy.
2. Healthcare: Relying on the AYUSH system (Ayurveda, Yoga, Unani, etc.) which uses plant-based medicines, rather than chemical-heavy modern drugs that pollute water systems during manufacturing.
3. Housing: Traditional architecture used local, eco-friendly materials that provided natural cooling, reducing the need for electricity.
Reverting to these practices promotes sustainability.

Ans: High GDP indicates high production of goods and services. However, if this production involves heavy air pollution, water contamination, and deforestation, the resulting environmental degradation causes severe health issues (asthma, waterborne diseases) for the citizens. The money spent treating these illnesses reduces their standard of living. Thus, high GDP accompanied by environmental ruin does not equate to high human welfare.

Ans: Assertion (A) is False, but Reason (R) is True.
Sustainable development does *not* restrict economic growth; rather, it aims for long-term, continuous growth. It simply ensures that growth is achieved through eco-friendly technologies and rational resource use (Reason R is true) so that future generations are not deprived.

Ans: 1. Chipko Movement: Initiated in the Himalayas (Uttarakhand) to prevent contractors from felling trees. 2. Appiko Movement: Initiated in the Sirsi district of Karnataka (Southern India) for the conservation of forests.

Ans: 1. Solar Energy: Utilizing sunlight via photovoltaic cells. 2. Wind Power: Using wind turbines to generate electricity.

Ans: Compressed Natural Gas (CNG) is considered better because it burns cleaner than diesel. It significantly reduces the emission of harmful greenhouse gases and particulate matter, thereby helping to lower air pollution levels in highly congested urban areas (e.g., CNG buses in Delhi).