Q.Which of the following gases is/are the main cause of air pollution ?
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🔒 Start your 14-day free trial to unlock the full solution →Concept understanding — Environmental Degradation
Environmental Degradation: When Nature's Balance Sheet Goes Red
Think of the environment as a bank account that gives you free withdrawals every day. Clean air, fertile soil, fresh water, forests — these are deposits built over millions of years. Environmental degradation is what happens when you start withdrawing faster than the account can replenish itself. The balance turns negative, and the services nature once provided for free now cost you — in health, in money, in lost opportunities.
The Precise Meaning
In economics, environmental degradation refers to the deterioration of the environment through the depletion of resources (air, water, soil) and the destruction of ecosystems. It happens when economic activity — production and consumption — imposes costs on nature that are not accounted for in market prices.
The key economic idea is this: markets fail to price environmental goods correctly. A factory that dumps waste into a river pays for labour, raw materials, and electricity, but it pays nothing for the clean water it destroys. That cost — called a negative externality — is shifted onto society. The river becomes polluted, fishing communities lose their livelihood, and someone else must pay to clean it up.
Why It Matters: The Link to National Income
Here is where the concept connects directly to what you study in macroeconomics. The standard measure of a country's output is Gross Domestic Product (GDP):
GDP=C+I+G+(X−M)
where C is consumption, I is investment, G is government spending, and (X−M) is net exports.
Notice what is missing. When a forest is cut down and the timber is sold, GDP rises — the wood adds to consumption or investment. But the loss of the forest's other services — carbon absorption, rainfall regulation, soil conservation — is subtracted from nature's capital without any entry in GDP. The national income accounts record the gain but ignore the loss.
This is the defensive expenditure problem. If pollution makes people sick, the money spent on hospital bills and medicines adds to GDP. The economy looks like it is growing, but the growth is actually compensating for damage. You are running just to stay in place.
The Three Dimensions of Degradation
1. Land degradation. Over-farming, deforestation, and improper irrigation turn fertile soil into desert. In India, this is visible in the loss of topsoil and falling groundwater tables. The immediate effect is lower agricultural output; the long-term effect is that future generations inherit land that can no longer support them.
2. Air and water pollution. Industrial emissions, vehicle exhaust, and untreated sewage degrade the quality of air and water. The economic cost shows up as higher healthcare spending, lower labour productivity, and reduced tourism. Clean air and clean water are not free goods anymore — they become scarce, and scarcity means a price must eventually be paid.
3. Loss of biodiversity. When species disappear, ecosystems lose their resilience. A single-crop farm is more vulnerable to pests than a diverse forest. The economic logic is simple: diversity is a form of insurance. Losing it makes the entire system fragile.
A common mistake is to think environmental degradation only matters for "green" reasons. In economics, it matters because it reduces the productive capacity of the economy over time. A degraded environment means lower future output, higher future costs, and a lower quality of life — all of which are economic problems, not just ecological ones.
The Vicious Cycle …
Carbon dioxide released by burning fuels is a major cause of air pollution and the greenhouse effect. …
Carbon dioxide is a main cause of air pollution.
Burning of fossil fuels and other activities release carbon dioxide (and other gases), polluting the air and intensifying the greenhouse effect/global warming. Oxygen and hydrogen are not pollutants …
- CBSE 2024Set ANNUAL1 markMCQQ.Central Pollution Control Board was set up in India in the year _____.(a) 1974(b) 1984
›Reveal solutionSolution
The Central Pollution Control Board was established in 1974, under the Water (Prevention and Control of Pollution) Act of that year.
The Central Pollution Control Board (CPCB) is India's apex statutory body for pollution control, functioning under the Ministry of Environment, Forest and Climate Change. It was constituted in 1974, under the provisions of the Water (Prevention and Control of Pollution) Act, 1974 — its mandate was later expanded by the Air (Prevention and Cont …
- CBSE 2023Set ANNUAL1 markMCQQ.Match the following : A
- Feature of sustainable development
- Water pollution
- Global warming
- Land degradation B A. Industrial waste B. Soil erosion C. No increase in pollution D. Greenhouse gases
(a) 1=A, 2=B, 3=C, 4=D(b) 1=B, 2=A, 3=D, 4=C(c) 1=C, 2=A, 3=D, 4=B(d) 1=D, 2=C, 3=B, 4=A›Reveal solutionSolution
The correct matching is: 1-Feature of sustainable development = C-No increase in pollution; 2-Water pollution = A-Industrial waste; 3-Global warming = D-Greenhouse gases; 4-Land degradation = B-Soil erosion.
Explaining each match:
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1. Feature of sustainable development → C. No increase in pollution. Sustainable development means meeting the needs of the present generation without compromising the ability of future generations to meet their own needs — a central feature of this is that development should NOT keep increasing pollution/environmental damage over time, preserving environmental quality for the future.
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2. Water pollution → A. Industrial waste. Untreated or poorly treated industrial effluents (chemicals, heavy metals, waste water) discharged into rivers, lakes and groundwater are a leading cause of water pollution.
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- CBSE 2022Set ANNUAL1 markMCQQ.Pollution Control Board was set up in _____.(a) 1974(b) 1984
›Reveal solutionSolution
The (Central) Pollution Control Board was established in 1974.
The Central Pollution Control Board (CPCB) was constituted in September 1974 under the Water (Prevention and Control of Pollution) Act, 1974, as India's apex technical body for pollution control, tasked with monitoring and controlling water and (later) air pollution and coordinating the activities of the State Pollution Con …
- CBSE 2021Set ANNUAL1 markQ.OR (Question 25 alternative) What is global warming?
›Reveal solutionSolution
Global warming is the rise in Earth's average temperature due to greenhouse gases trapping heat in the atmosphere.
Global warming refers to the observed long-term rise in the average temperature of the Earth's atmosphere and oceans. It is primarily caused by the greenhouse effect being intensified by human activity: burning fossil fuels (coal, oil, natural gas) for energy and transport, large-scale deforestation (which reduces the planet's capacity to absorb carbon dioxide), and industrial/agricultural emissions release greenhouse gases — principally carbon dioxide, methane, and nitrous oxide — into the atmosphere. These gases trap outgoing infrared heat that would otherwise escape into space, warming the planet over time. Consequences include melting polar ice and glaciers, rising sea leve …
- CBSE 2021Set ANNUAL1 markMCQQ._____ urbanisation causes environment degradation.(a) Decreasing(b) Increasing
›Reveal solutionSolution
Increasing urbanisation causes environmental degradation — as more people crowd into cities faster than infrastructure can keep pace, pollution, waste generation, and pressure on land/water/air all rise.
As India's urban population has grown rapidly, cities have faced mounting environmental stress: vehicular and industrial air pollution, inadequate sewage and solid-waste management, shrinking green cover and water bodies converted to built-up land, and overcrowded, unplanned settlements/slums with poor sanitation. These pressures intensify precisely as the PACE and SCALE of urbanisation increases, overwhelming the carrying capacity of urban infrastructure. …
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