Environment and Natural Resources

What to remember

• Natural resources are gifts of nature. Renewable resources can be replaced in a human lifetime; non-renewable resources cannot. We must use both wisely.
• Conservation means careful use, saving and protecting resources. Pollution harms air, water, soil and living things.
• Ecosystem balance depends on food chains, biodiversity and the carbon and other cycles. Laws, protected areas and public action help protect the environment.

Natural resources

A natural resource is any material from nature that people use.

Soil is a natural resource formed slowly by the breakdown of rocks, helped by climate and living things. A mix of sand, silt and clay in good proportion gives loamy soil, which is good for crops. Soil erosion is the removal of the top layer by wind and water. Plant cover, terracing, contour ploughing and shelter belts prevent it. Black soil (regur) holds moisture and is good for cotton. Red soil is rich in iron. Alluvial soil is formed by rivers and is the most fertile and widespread soil in India.

Water: only a small part of Earth's water is fresh and usable. Sources are rivers, lakes, ponds, groundwater and rain. Water-harvesting methods save rainwater: rooftop collection, check dams, farm ponds and percolation tanks. Groundwater is recharged by rain soaking into the ground. Over-pumping lowers the water table.

Forests: give wood, fruit, medicines, shelter to wildlife and soil protection. They absorb carbon dioxide and affect rainfall. Deforestation (clearing forests) causes soil erosion, loss of habitat, floods and climate change. Afforestation means planting trees in a new area; reforestation means replanting where forests were cut.

Minerals and energy

• Fossil fuels: coal, petroleum and natural gas. They took millions of years to form. Burning them gives carbon dioxide.
• Renewable energy: solar, wind, hydro, biomass and geothermal. They are cleaner.
• Natural gas is the cleanest fossil fuel. CNG (compressed natural gas) and LPG (liquefied petroleum gas) are common fuels.
• India has a long coastline, and Andhra Pradesh has strong solar and wind projects. Coal, iron ore, limestone and bauxite are important minerals.

Conservation of resources

The 5 R's: Refuse, Reduce, Reuse, Recycle, Recover. Reduce first, because producing less waste is better than managing waste.

• Energy saving: switch off unused lights, use LED bulbs, public transport and efficient appliances.
• Water saving: fix leaks, reuse greywater, drip irrigation.
• Soil saving: crop rotation, mulching, organic manure, terrace farming.
• Wildlife saving: national parks, wildlife sanctuaries and biosphere reserves.
• In-situ conservation means protecting species in their natural homes (national parks, sanctuaries, biosphere reserves). Ex-situ conservation is outside the natural home (zoo, botanical garden, seed bank).

Chipko Movement: a village movement in the Himalayan region in which people hugged trees to stop felling. Appiko in Karnataka is a similar movement. The Bishnoi community of Rajasthan is known for protecting trees and animals. Sustainable development means meeting the needs of the present without harming the needs of future generations.

Important laws and bodies: The Environment (Protection) Act, 1986, the Wildlife (Protection) Act, 1972, the Water Act, 1974, the Air Act, 1981 and the Forest (Conservation) Act, 1980. The Ministry of Environment, Forest and Climate Change handles environment policy. The National Green Tribunal (NGT) hears environment cases. Project Tiger (started 1973) protects tigers. Environment Day is on 5 June; Wildlife Week is in October; Earth Day is 22 April; World Water Day is 22 March.

Ecosystem basics

An ecosystem includes all living things in an area and their non-living surroundings. Producers (green plants) make food; consumers (herbivores, carnivores, omnivores) eat; decomposers (bacteria, fungi) break down dead matter and return nutrients to soil.

• Food chain: grass, grasshopper, frog, snake, eagle. Each step is a trophic level.
• Food web: many food chains linked together.
• Only about 10 per cent of the energy passes from one trophic level to the next. This is the 10 per cent law, so food chains are short.
• Biodiversity is the variety of life. Biodiversity hotspots have many species that are found nowhere else and are under threat. India has several, including the Western Ghats.
• Endangered species are at high risk of extinction. The Red Data Book lists threatened species.

Cycles: the water cycle moves water through evaporation, condensation and rain. The carbon cycle moves carbon between air, plants, animals and soil. The nitrogen cycle involves nitrogen-fixing bacteria in the soil and root nodules.

Pollution

Pollution is the addition of harmful substances to the environment. A harmful substance is a pollutant.

Air pollutants: carbon monoxide (from incomplete burning of fuel; it binds haemoglobin and is poisonous), sulphur dioxide, nitrogen oxides and particulate matter. Smog is smoke plus fog. Acid rain forms when sulphur and nitrogen oxides dissolve in rainwater. It harms plants, soil, buildings and the Taj Mahal marble.

Greenhouse effect: gases such as carbon dioxide, methane, nitrous oxide and water vapour trap heat. A natural greenhouse effect keeps Earth warm; an excess leads to global warming. The rise in sea level, melting of glaciers and changes in rainfall follow.

Ozone layer: a layer of ozone (O3) in the stratosphere that absorbs harmful ultraviolet rays from the sun. Chemicals called chlorofluorocarbons (CFCs) damage it. The Montreal Protocol (1987) is the global agreement to phase out ozone-damaging substances.

Water pollution measures: sewage treatment, ban on dumping waste in rivers, and less use of chemical fertilisers. BOD (Biochemical Oxygen Demand) shows the pollution load in water; high BOD means more pollution. Eutrophication is the overgrowth of algae in a water body due to extra nutrients, which reduces oxygen and kills fish.

Waste: Biodegradable waste (food, paper) decays by microbes. Non-biodegradable waste (plastic, glass, metals) does not. Segregation into wet and dry waste helps in recycling and composting. Plastic is a big problem because it lasts for a very long time.

Global agreements: the Kyoto Protocol and Paris Agreement are about climate change. The Convention on Biological Diversity (CBD) is about biodiversity.

Energy resources and waste management

Conventional sources: Coal and petroleum are widely used but cause air pollution and release carbon dioxide. Hydropower uses falling water, but big dams can displace people and change river life.

Non-conventional sources: Solar panels change sunlight to electricity. Wind turbines work best in windy coastal and hilly areas. Biomass and biogas use cow dung and farm waste. Tidal and geothermal energy are used in some places. These sources cause little pollution but may be costly or depend on place and weather.

Waste management steps: collect, segregate, treat and dispose. Wet waste can be made into compost or biogas. Dry waste such as paper, metal and glass can be recycled. E-waste from old phones and computers holds harmful metals and should go to authorised recyclers. Vermicomposting uses earthworms to turn kitchen waste into manure. Burning plastic is harmful because it releases poisonous gases.

Individual actions: use cloth bags, plant trees, use public transport, switch off lights, avoid wasting water and keep surroundings clean. The Government of India's Swachh Bharat Mission works for cleanliness and sanitation.

Exam traps

• Renewable does not mean unlimited; forests and groundwater can be overused.
• Biotic includes fossil fuels because they come from once-living matter.
• In-situ means in the natural habitat; ex-situ means outside it (zoo).
• Carbon monoxide comes from incomplete burning; carbon dioxide from complete burning.
• The ozone layer is damaged by CFCs; global warming is caused by greenhouse gases. These are different problems.
• Montreal Protocol is about the ozone; Kyoto and Paris are about climate change.
• Afforestation is planting in new areas; reforestation is replanting where forests were removed.
• 10 per cent energy transfer is between trophic levels, not the amount of plants eaten.

One-liners

• 1. Coal, petroleum and natural gas are fossil fuels.
• 2. Alluvial soil is the most widespread soil in India.
• 3. Black soil suits cotton.
• 4. Rooftop rainwater harvesting recharges groundwater.
• 5. Chipko Movement was about saving trees.
• 6. Project Tiger began in 1973.
• 7. World Environment Day is on 5 June.
• 8. Ozone absorbs ultraviolet rays.
• 9. CFCs damage the ozone layer.
• 10. Acid rain is caused by sulphur and nitrogen oxides.
• 11. Only about 10 per cent of energy passes to the next trophic level.
• 12. Decomposers return nutrients to the soil.

Practice questions

1. Which of the following is a renewable resource?

   1. Natural gas
   2. Coal
   3. Wind energy
   4. Petroleum
   Answer

   C. Wind energy

   Wind is naturally replaced; fossil fuels are not.

2. Which is a non-renewable resource?

   1. Sunlight
   2. Petroleum
   3. Wind
   4. Flowing water
   Answer

   B. Petroleum

   Petroleum took millions of years to form.

3. Coal and petroleum are called

   1. Biofuels only
   2. Nuclear fuels
   3. Fossil fuels
   4. Renewable fuels
   Answer

   C. Fossil fuels

   They come from remains of ancient life.

4. The most fertile and widespread soil in India is

   1. Black soil
   2. Red soil
   3. Desert soil
   4. Alluvial soil
   Answer

   D. Alluvial soil

   Rivers deposit alluvial soil.

5. Black soil is best known for growing

   1. Tea
   2. Cotton
   3. Coconut only
   4. Apple
   Answer

   B. Cotton

   Black (regur) soil holds moisture and suits cotton.

6. Removal of the top layer of soil by wind and water is

   1. Eutrophication
   2. Afforestation
   3. Percolation
   4. Soil erosion
   Answer

   D. Soil erosion

   Plant cover reduces erosion.

7. Planting trees in an area that had no forest earlier is

   1. Desertification
   2. Afforestation
   3. Reforestation
   4. Deforestation
   Answer

   B. Afforestation

   Reforestation means replanting where forest was cut.

8. Which method helps to recharge groundwater?

   1. Burning waste
   2. Deforestation
   3. Over-pumping
   4. Rainwater harvesting
   Answer

   D. Rainwater harvesting

   Harvested rain soaks into the ground.

9. The cleanest fossil fuel among the following is

   1. Coal
   2. Diesel
   3. Natural gas
   4. Petrol
   Answer

   C. Natural gas

   Natural gas gives the least pollution on burning.

10. The first step among the 5 R's, which is the best way to cut waste, is to

    1. Recycle
    2. Reduce
    3. Recover
    4. Reuse only after dumping
    Answer

    B. Reduce

    Making less waste is better than managing it.

11. Protecting species in their natural habitat is called

    1. In-situ conservation
    2. Ex-situ conservation
    3. Captive breeding only
    4. Seed storage
    Answer

    A. In-situ conservation

    National parks and sanctuaries are in-situ.

12. A zoo or a botanical garden is an example of

    1. In-situ conservation
    2. Sacred grove
    3. Biosphere reserve
    4. Ex-situ conservation
    Answer

    D. Ex-situ conservation

    Species are kept outside their natural habitat.

13. The Chipko Movement was started to

    1. Build dams
    2. Clean rivers
    3. Protect tigers only
    4. Stop the cutting of trees
    Answer

    D. Stop the cutting of trees

    Villagers hugged trees to save them.

14. The Bishnoi community of Rajasthan is known for

    1. Mining coal
    2. Building canals
    3. Protecting trees and animals
    4. Growing only cotton
    Answer

    C. Protecting trees and animals

    They have a long tradition of protecting nature.

15. Project Tiger began in

    1. 1986
    2. 1973
    3. 2001
    4. 1947
    Answer

    B. 1973

    It was launched to protect the tiger.

16. World Environment Day is celebrated on

    1. 2 October
    2. 22 March
    3. 5 June
    4. 22 April
    Answer

    C. 5 June

    22 April is Earth Day; 22 March is World Water Day.

17. The Environment (Protection) Act was passed in

    1. 1981
    2. 1972
    3. 1986
    4. 2002
    Answer

    C. 1986

    The 1986 Act is the umbrella law for the environment.

18. The Wildlife (Protection) Act was passed in

    1. 1986
    2. 1972
    3. 1991
    4. 2005
    Answer

    B. 1972

    It gives legal protection to wild animals.

19. In a food chain, green plants are

    1. Parasites
    2. Consumers
    3. Decomposers
    4. Producers
    Answer

    D. Producers

    They make food by photosynthesis.

20. Bacteria and fungi that break down dead matter are

    1. Herbivores
    2. Decomposers
    3. Carnivores
    4. Producers
    Answer

    B. Decomposers

    They return nutrients to the soil.

21. Many interlinked food chains form a

    1. Food pyramid of money
    2. Trophic cycle of rocks
    3. Water table
    4. Food web
    Answer

    D. Food web

    A food web shows connections among chains.

22. A gas formed by incomplete burning of fuel that binds haemoglobin is

    1. Carbon dioxide
    2. Ozone
    3. Carbon monoxide
    4. Methane
    Answer

    C. Carbon monoxide

    Carbon monoxide is poisonous.

23. Acid rain is mainly caused by

    1. Carbon dioxide and oxygen
    2. Helium and neon
    3. Sulphur and nitrogen oxides
    4. Ozone only
    Answer

    C. Sulphur and nitrogen oxides

    They dissolve in rain to form acids.

24. The ozone layer protects life by absorbing

    1. Infrared rays only
    2. Radio waves
    3. Ultraviolet rays
    4. Sound waves
    Answer

    C. Ultraviolet rays

    Ozone in the stratosphere absorbs UV radiation.

25. Chemicals that damage the ozone layer are

    1. CFCs
    2. CNG
    3. Nitrogen
    4. LPG
    Answer

    A. CFCs

    Chlorofluorocarbons release chlorine in the stratosphere.

26. The global agreement to phase out ozone-depleting substances is the

    1. Ramsar Convention
    2. Kyoto Protocol
    3. Paris Agreement
    4. Montreal Protocol
    Answer

    D. Montreal Protocol

    Montreal Protocol dates from 1987.

27. Excess nutrients causing algal overgrowth and loss of oxygen in a lake is

    1. Biomagnification only
    2. Percolation
    3. Transpiration
    4. Eutrophication
    Answer

    D. Eutrophication

    Fish die when dissolved oxygen falls.

28. A high BOD value in water indicates

    1. Cleaner water
    2. More pollution
    3. More ozone
    4. No microbes
    Answer

    B. More pollution

    BOD is oxygen needed by microbes to break down waste.

29. Which of these is non-biodegradable?

    1. Plastic
    2. Paper
    3. Cotton cloth
    4. Vegetable peel
    Answer

    A. Plastic

    Microbes cannot break plastic down quickly.

30. Smog is a mixture of

    1. Steam and dust only
    2. Smoke and fog
    3. Rain and hail
    4. Ozone and nitrogen
    Answer

    B. Smoke and fog

    The word is smoke plus fog.

31. Which gas is a major greenhouse gas?

    1. Methane
    2. Argon
    3. Oxygen
    4. Nitrogen
    Answer

    A. Methane

    Carbon dioxide, methane and nitrous oxide trap heat.

32. Consider the statements about resources. 1. Fossil fuels are renewable within a human lifetime. 2. Solar energy is a renewable resource.

    1. 1 only
    2. 2 only
    3. Both 1 and 2
    4. Neither 1 nor 2
    Answer

    B. 2 only

    Fossil fuels take millions of years to form.

33. Consider the statements about conservation. 1. A national park is an example of in-situ conservation. 2. A seed bank is an example of in-situ conservation.

    1. 1 only
    2. 2 only
    3. Both 1 and 2
    4. Neither 1 nor 2
    Answer

    A. 1 only

    A seed bank is ex-situ.

34. Consider the statements about the greenhouse effect. 1. A natural greenhouse effect keeps Earth warm. 2. Excess greenhouse gases lead to global warming.

    1. 1 only
    2. 2 only
    3. Both 1 and 2
    4. Neither 1 nor 2
    Answer

    C. Both 1 and 2

    Both are correct.

35. Consider the statements about the ozone layer. 1. It lies in the stratosphere. 2. It is damaged mainly by carbon dioxide from respiration.

    1. 1 only
    2. 2 only
    3. Both 1 and 2
    4. Neither 1 nor 2
    Answer

    A. 1 only

    CFCs, not respiration, damage ozone.

36. Consider the statements about the food chain. 1. Energy is lost at each trophic level. 2. Food chains are usually very long because of energy gain.

    1. 1 only
    2. 2 only
    3. Both 1 and 2
    4. Neither 1 nor 2
    Answer

    A. 1 only

    Energy loss keeps chains short.

37. Consider the statements about soil. 1. Terracing helps to prevent soil erosion. 2. Loamy soil is a mix of sand, silt and clay.

    1. 1 only
    2. 2 only
    3. Both 1 and 2
    4. Neither 1 nor 2
    Answer

    C. Both 1 and 2

    Both are correct.

38. Consider the statements about pollution. 1. Noise is a form of pollution. 2. Thermal pollution is caused by cold water discharge only.

    1. 1 only
    2. 2 only
    3. Both 1 and 2
    4. Neither 1 nor 2
    Answer

    A. 1 only

    Thermal pollution is mostly from hot water discharge.

39. Consider the statements about environment laws. 1. The Air Act was passed in 1981. 2. The Water Act was passed in 1986.

    1. 1 only
    2. 2 only
    3. Both 1 and 2
    4. Neither 1 nor 2
    Answer

    A. 1 only

    The Water Act is of 1974.

40. Consider the statements about biodiversity. 1. Biodiversity means the variety of life. 2. The Western Ghats are considered a biodiversity hotspot.

    1. 1 only
    2. 2 only
    3. Both 1 and 2
    4. Neither 1 nor 2
    Answer

    C. Both 1 and 2

    Both are correct.

41. Match the pollutant or cause (left) with the problem (right). P. CFC Q. SO2 and NOx R. Sewage S. Loudspeaker

    1. P-acid rain, Q-ozone depletion, R-water pollution, S-noise pollution
    2. P-ozone depletion, Q-water pollution, R-acid rain, S-noise pollution
    3. P-ozone depletion, Q-acid rain, R-noise pollution, S-water pollution
    4. P-ozone depletion, Q-acid rain, R-water pollution, S-noise pollution
    Answer

    D. P-ozone depletion, Q-acid rain, R-water pollution, S-noise pollution

    Each cause is matched to its problem in option A.

42. Match the day (left) with the date (right). P. World Environment Day Q. Earth Day R. World Water Day

    1. P-5 June, Q-22 March, R-22 April
    2. P-5 June, Q-22 April, R-22 March
    3. P-22 April, Q-5 June, R-22 March
    4. P-22 March, Q-22 April, R-5 June
    Answer

    B. P-5 June, Q-22 April, R-22 March

    These are the standard dates.

43. Match the soil (left) with its feature (right). P. Alluvial Q. Black R. Red S. Loamy

    1. P-river-deposited, Q-iron-rich, R-holds moisture, S-sand, silt and clay mix
    2. P-river-deposited, Q-holds moisture, R-sand, silt and clay mix, S-iron-rich
    3. P-holds moisture, Q-river-deposited, R-iron-rich, S-sand, silt and clay mix
    4. P-river-deposited, Q-holds moisture, R-iron-rich, S-sand, silt and clay mix
    Answer

    D. P-river-deposited, Q-holds moisture, R-iron-rich, S-sand, silt and clay mix

    Option A gives the correct feature of each soil.

44. Which body hears and decides cases on the environment in India?

    1. Finance Commission
    2. Competition Commission
    3. Election Commission
    4. National Green Tribunal
    Answer

    D. National Green Tribunal

    The NGT deals with environment disputes.