The document discusses the classification of natural resources into renewable and non-renewable categories, highlighting their roles in sustaining ecosystems and human livelihoods while addressing issues like overexploitation and deforestation. It covers the importance of forests in ecological balance, economic development, and cultural significance, as well as the detrimental effects of deforestation, water scarcity, and pollution on the environment. Additionally, it emphasizes the need for sustainable resource management practices and community participation in conservation efforts.

1. Dr S V Vageesha
Campus Director, CHAMPS

2.  Natural Resources Resource- Concept of Stock,
Source, resource and resistance
 Natural Resources- classification’s criteria
Renewable and Non-renewable Resources:
 (a) Natural Resources and associated problems
(b) Uses and overexploitation of: (i) Forest Resources (ii) Water
Resources (iii) Mineral Resources: (iv) Food Resources: (v)
Energy Resources: (vi) Land Resources:
 (c) Role of individual in conservation of natural
resources.
 (d) Equitable use of resources for sustainable
lifestyles.
 (e) Discussion of specific case studies

3.  A natural resource may be defined as any material
given to us by nature which can be transformed in
a way that it becomes more valuable and useful.
 variety of goods and services necessary for our day
to day lives.
 natural resources include, air, water, soil, minerals,
along with the climate and solar energy, which
form the non-living or ‘abiotic’ part of nature.
 The ‘biotic’ or living parts of nature consists of
plants and animals
 Any material may be called, as a resource
provided and appropriate technology is available
to transform that into more valuable goods.

4.  Renewable and Non-renewable Resources on the basis of continuity :
 Renewable Resources
 Non-renewable Resources.
 Renewable Resources
 Resources, which can be renewed along with their exploitation, are always
available for use.
 For instance, forests are renewable. If trees are felled for wood, original forest
covers may be maintained through planning new trees
 i.e. a forestation.
 Likewise, solar energy and wind energy are examples of renewable resources.
 Non-renewable Resources
 The formation of some resources like iron ore, coal, mineral oil etc. has taken
several thousand years.
 Once they are used in unlimited way, they cannot be easily replaced.
 Thus, their exploitation at large scale will result in their fast depletion.
 Cyclic Resources
 For resources there is no final use as they can be used continuously.
 For example, water used in industry and domestic ways can be cleaned and
used again for similar or other purpose.

5.  Water and biological living resources are considered
renewable.
 ………. in fact renewable only within certain limits.
 They are linked to natural cycles such as the water cycle.
 Fresh water (even after being used) is evaporated by the sun’s energy,
forms water vapor and is reformed in clouds and falls to earth as rain.
However, water sources can be overused or wasted to such an extent that
they locally run dry. Water sources can be so heavily polluted by sewage
and toxic substances that it becomes impossible to use the water.
 Forests, once destroyed take thousands of years to regrow into fully
developed natural ecosystems with their full complement of species.
Forests thus can be said to behave like non-renewable resources if over-
used.
 Fish are today being over-harvested until the catch has become a fraction
of the original resource and the fish are incapable of breeding successfully
to replenish the population.
 The output of agricultural land if mismanaged drops drastically.

7.  Ecological Balance: Forests and wildlife are essential to maintain ecological balance of an area.
 Renewable Natural Resources: Forests are an important renewable natural resources.
 Eco-system: Trees dominate forest ecosystem; their species content varieties in different parts of the
world.
 Economic Development: Forest contributes to the economic development of the country because
they provide goods and services to the people and industry.
 Environment Quality: The forest enhance the quality of environment by influencing the life
supporting system.
 Safeguard against Pollution: Forest check air pollution and soil erosion. Thus, they exercise safety
and against pollution.
 Soil Conservation: Forest save the hill-slopes from landslides.
 Wind Erosion: In deserts, trees reduce wind erosion by checking wind velocity.
 Check the Extension Balance: The forest checks strong gales and keeps the soil intact beneath the
roots of trees and thus checks extension of desert.
 Maintains Ecological Balance: The forest check pollution of air through increasing oxygen content of
the air.
 Attract Rainfall: By causing condensation of water vapour in clouds, forests attract rains.
 Control Floods: The floods are controlled because forests dry up rainwater like sponge.
 Linked with Cultural and Civilization: Forests are linked with our cultural and civilization.
 Supply of Raw Material: Forest supply wood, which is used as under:
 Fuel,
 Raw material for various industries as pulp, paper, newsprint, board;
 Timber for furniture items;
 To be used in packing articles like fruits, tea etc.
 For preparing matches, sport goods etc.

8.  Minor forest products: Some examples of minor forest
products, are canes, gums, resins, dyes, flocks, medicines,
tannins, lac, fibres, katha etc.
 Employment opportunities: About eight crore people are
employed in wood based industries like paper and match
and small and cottage industries. Besides, those who are
employed in the forest department in various states.
 Revenue Receipts: The forest provide Rs. 400 crores per
year as revenue to the government.
 Fodder for Cattle: Forest provide fodder to cattle.
 Foreign Exchange Earners: Forest produce a great number
of articles like essential oils, resins and dyes. Which find
market in foreign countries. Nearly Rs. 50 crores are
earned in foreign exchange through selling lac, terpentine
oil and sandal wood oil to abroad.

12.  The Western Himalayan region
 Kashmir Kumaon.
 forest of pine, confers and broad-leaved temperate trees.
 Higher up, forests of blue pine spruce and silver fir occur.
 The Eastern Himalayan region
 Darjeeling, Kureseong and the adjacent tract.
 The temperate zone has forests of oaks, laurels, rhodendrons, maples, alder and brich.

 The Assam region
 Brahamputra and the Surma valleys and the intervening hill ranges.
 region has evergreen forests, occasional thick clumps of bamboos and tall grasses.
 The Ganga plain region
 region covers the area from the Aravali rangers to Bengal and Orissa.
 Widely different types are found only in small areas in the forests.
 The Deccan region
 region has various kinds from scrub jungles to mixed decidous forests.
 The Malabar region
 This region is rich in forest vegetation.
 Besides, it produces important commercial crops, such as cocount pepper, coffee, tea. Besides, rubber,
cashewnut and eucalyptus trees.
 The Andaman region
 rich in evergreen, semi-evergreen, mangrove, beach and diluvial forests.
 SUMMARY :
 Nearly 45,000 species of plants including shrubs in the country.
 vascular flora, which forms the conspicuous vegetation cover itself
comprises 15,000 species.

13.  Fuel wood, Timber and Pulpwood
 The data show that (FAO, 1981) consumption of wood in
developing countries is exactly the reverse of the developed ones.
In the former, wood is used 82% for firewood and 18%
respectively, In India, firewood demand is mostly in rural areas
because the alternative source of energy, are yet to reach there.
 Wood for Packing Purposes
 Wood is needed, on a large scale, for our fruit industry, tea etc. It is
estimated that for wooden crates nearly 0.5 Mm3 of wood is need.
 Paper Board and Newsprint
 With the rapidly increasing population growth our per capita
consumption of paper is increasing from 2 kg to 4.5 kg per year.
 Bamboos and hardwood are the chief sources (70%) of raw
materials for paper and board.
 Growing demand for 2.45 Mt will enhance dependence on bamboo
and hardwood.

14.  Deforestation is the process of felling trees
indiscriminately resulting in nude or semi- nude
surface of the hill hitherto covered by thick forests.
 India’s serious environmental problems is forest
degradation due to timber extraction and our
dependence on fuel wood.
 poor rural people are still highly dependent on
wood to cook their meals and heat their homes.
 The National Forest Policy of 1988 now gives an
added importance to JFM. Another resolution in
1990 provided a formal structure for com- munity
participation though the formation of Village
Forest Committees

15.  Felling of trees to meet the ever increasing demand of the cities.
 Grazing by the local cattle, goats, sheep etc.
 Meeting out the growing hunger for land. It has hit the ecology of
the country badly very soon India is likely to have more of
wasteland than productive land.
 Large scale deforestation has badly affected the weather facing
almost each year more of bleak than the normal weather.
 The increase in shifting (jhum) cultivation in North east and
Orissa has also laid large in forest tracts bare. As the jhum cycle is
shortened to six years only (in some districts, even 2-3 years only),
too short period does not provide enough time for natural repair
of damaged ecosystem.
 A major cause of deforestation has been the construction of hill
roads. About a decade back, they were about 30, 000 km long.
Most of these roads are in state and most fragile belt of Himalayas.
Road construction damaged the protective vegetation cover both
above and below roads. It blocked natural and pollution streams.

16.  Adverse Effect on Productivity
 The deforestation increase the soil erosion increase manifold. The
soil so washed leads to an accentuated cycle of floods and drought.
 Deforestation creates to use cowdung and crop wastes as fuel
mainly for cooking. As a result no part of the plant goes back to
loss in soil fertility.
 Land/Erosion and Landslides
 Deforestation has been causing tremendous land erosion and
landslides.
 Data reflect that about 6,000 million ton of topsoil is lost annually
due to water erosion in the absence of trees.
 Low Per Capita Forestland
 As far as per capita forestland is concerned, India today is the
poorest in the world.
 The per capita forestland in India is 0.10 hectare compared to the
world average of 1 hectare.

17.  Timber extraction, mining and dams are in- variably parts of the needs of
a developing country.
 If timber is overharvested the ecological functions of the forest are lost.
 Unfortunately forests are located in areas where there are rich mineral
resources. Forests also cover the steep embankments of river valleys,
which are ideally suited to develop hydel and irrigation projects.
 Thus there is a constant conflict of interests between the conservation
interests of environmental scientists and the Mining and Irrigation
Departments.
 What needs to be understood is that long-term ecological gains cannot be
sacrificed for short-term economic gains that unfortunately lead to
deforestation.
 These forests where development projects are planned, can displace
thousands of tribal people who lose their homes when these plans are
executed.
 This leads to high levels of suffering for which there is rarely a
satisfactory answer.

18.  Effects :
 thinning of forests
 loss of biodiversity, particularly tree breading species
 soil erosion and loss of soil fertility
 migration of tribal people from one place to another in
search of new forest
 extinction of tribal people and their culture

19.  .
 Mining is a process of removing ores from area
which is very much below the ground level. Mining is
done for the extraction of several minerals of metals like
Fe, Mn, Au, Ag, etc. The minerals are especially found
in thick forests.
 Mining is a process of removing ores from area
which is very much below the ground level. Mining is
done for the extraction of several minerals of metals like
Fe, Mn, Au, Ag, etc. The minerals are especially found
in thick forests.

21.  Mining can be carried out in two ways
 Surface mining
 Underground mining or sub-surface mining
 The effects of underground mining on forest
reserves is comparatively less than that of
surface mining

22.  Forests both influence and influenced by climate change.
 They play an important role in the carbon cycle and the way we manage
forests could significantly affect global warming.
 Forests hold more than 50 per cent of the carbon that is stored in
terrestrial vegetation and soil organic matter. Hence, deforestation contributes
significantly to net emissions of carbon di oxide into the atm.
 If the predicted global warming occurs, the impact on forests is likely to
be regionally varied, dramatic, and long-lasting.
 Even now, we can see how any extreme weather has great impact on
forests. For example, the 1999 storms in Europe caused heavy damage to
forests and also to trees outside forest areas.
 The Kyoto Protocol on climate change may have a great impact on forest
management. Under the Protocol, a country with forests earns emission
credits, since its forests absorb carbon di oxide.
 These credits are tradable, that is, a developing country can sell its credits to an
industrialized country that has exceeded its quota of emissions. The latter would invest
in afforestation and reforestation projects in the developing country.

23. 1. Provides large scale employment of tribal people and increase
the std. of living of them
2. Contribute for economic uplift and growth
3. Help in checking flood
4. Generate electricity
5. Reduce power and water shortage
6. Provide irrigation water
7. Provide drinking water to remote areas
8. Fisheries

25.  Upstream problems
1. Displacement of tribal people
2. Loss of flora and fauna
3. Siltation and sedimentation near reservoir
4. Stagnation and water logging near reservoir
5. Growth of aquatic weeds
6. Micro climatic changes
7. RIS causes earthquakes
8. Breeding of disease vectors
 Downstream problems
1. Water logging and salinity due to over irrigation
2. Micro climatic changes
3. Salt water intrusion at river mouth
4. Loss of fertility due to sediment deposits
5. Out break of vector born diseases

26.  It is revealed by the history of human civilization that water
supply and civilization are most synonymous.
 Several cities and civilizations have disappeared due to water
shortages originating from climatic changes.
 Millions of people all over the world, particularly in the
developing countries, are losing their lives every year from
water-borne disease.
 An understanding of water chemistry is the basis of knowledge
of the multi- dimensional aspects of aquatic environment
chemistry, which involve the sources, composition, reactions,
and transport of the water.
 About 97% of the earth’s water supply is in the ocean, which is
unfit of the remaining 3%, 2% is locked in the polar ice-caps and
only 1% is available as fresh water in rivers, lakes, streams,
reservoirs and ground water which is suitable for human
consumption.

27.  Continuous overutilization of surface and ground
water has led to virtual water scarcity in the world
today.
 The depleting sources for high growth in human
population over the centuries and increased man-
induced water pollution across the world have
created unforeseen water scarcity around the globe.
 As a result, there has been continuous
overutilization of the existing water sources due to
mammoth growth in world population.
 Groundwater is the major source of water in many
parts of the world.
 However, there has been continuous depletion of this
source due to its overexploitation by rising human
population and the rapid rise in industrialization and
urbanization in modern times.

28.  Agriculture also pollutes surface water and un-
der-ground water stores by the excessive use of
chemical fertilizers and pesticides.
 Methods such as the use of biomass as fertilizer
and non toxic pesticides such as neem products and
using integrated pest management systems reduces
the agricultural pollution of surface and ground
water.

29.  Industry tends to maximise short-term economic
gains by not bothering about its liquid waste and
releasing it into streams, rivers and the sea.
 In the longer term, as people become more
conscious of using ‘green products’ made by
eco-sensitive industries, the polluter’s products
may not be used.

30.  Over utilization of water leads to rapid depletion of water resources, ground
subsidence, lowering of water table and water logging.
 Economic development, rapid industrial growth and population explosion
 Effects :
 Declining of water levels
 Crops failure and reduction in agricultural production
 Over pumping of ground water create drought, famine and food shortage
 Over pumping of ground water sea water intrusion in coastal aquifers
 Land subsidence may due to over pumping of ground water
 River pollution due to industrial activities and dumping of waste into rivers, which
in turn force to utilize the ground water, ultimately leads to over pumping


31.  Water scarcity, water pollution/contamination
 Water logging
 Salination
 Alkalization


32.  Unpredictable delay in climatic condition occurring
due to monsoon rain failure
 Types:
 Meteorological: in order of month or year, actual moisture supply at
a given place consistently falls below critical level.
 Hydrological: deficiency in surface and subsurface water supplies
 Agricultural: inadequate soil moisture to meet the need of a
particular crop at particular time or susceptibility of crops during
different stages in its development
 Socioeconomic: reduction in the availability of food and social
securing of people

33.  Deforestation and poor rainfall
 Over drafting of Ground water, subsidence of
soil
 Pollution of soil with solid waster and
industrial effluents etc. makes land useless
 Shifting of Cultivation

34. 1. Rain water harvesting
2. Drip irrigation technology
3. Mixed cropping and dry farming
4. Construction of reservoirs to improve groundwater
level

35.  Building several small reservoirs instead of few mega projects.
 Develop small catchment dams and protect wetlands.
 Soil management, micro catchment development and afforestation permits recharging of underground aquifers thus reducing
the need for large dams.
 Treating and recycling municipal waste water for agricultural use.
 Preventing leakages from dams and canals.
 Preventing loss in Municipal pipes.
 Effective rain water harvesting in urban environments.
 Water conservation measures in agriculture such as using drip irrigation.
 Pricing water at its real value makes people use it more responsibly and efficiently and reduces water wasting.
 In deforested areas where land has been degraded, soil management by bunding along the hill slopes and making ‘nala’
plugs, can help retain moisture and make it possible to re-vegetate degraded areas.

41.  Minerals are naturally occurring substances having
definite chemical composition and physical properties.
 An ore is a mineral or com- bination of minerals from
which a useful sub- stance, such as a metal, can be
extracted and used to manufacture a useful product.
 The economic development of a country depends, to a
great extent on the availability of minerals, got as ores
from the earth by mining Coal and iron are the basic
minerals which man needs to develop iron and steel
industry.
 Minerals like mica, copper, lead and zinc are of vast
economic importance. Thorium and uranium are
atomic energy minerals.

42.  Minerals are formed over a period of millions of
years in the earth’s crust.
 Iron, aluminum, zinc, manganese and copper
are important raw materials for industrial use.
 Important non-metal resources include coal,
salt, clay, cement and silica.
 Stone used for building material, such as
granite, marble, limestone, constitute another
category of minerals.

43.  Development of industrial plants and machinery. Examples - Iron, aluminium,
copper, etc.,
 Construction, housing, settlements. Example - Iron, aluminium, nickel, etc.,
 Generation of energy. Example – Coal, Lignite, Uranium etc
 Designing of defense equipment's, weapons, ornaments
 Jewelerry – Example - Gold, silver, platinum and diamond.
 Making of alloys for various purposes. Examples - Phosphorites.
 Communication purposes. Examples – Telephone wires, cables, electronic
devices.
 Medicinal purposes – particularly in ayurvedic system – Example – Sulphur
pyrites

44.  Extraction of minerals is carried out
through mining (Underground or
Surface)
 Mineral resources, however, are
exhaustible and finite, which means
excessive use may affect their availability
in the future.

45.  Environmental damage, caused by mining activities, are as follows.
1. Devegetation and defacing of landscape: Large scale deforestation or
devegetation leads to several ecological losses and also landscape gets
badly affected.
2. Groundwater contamination: Mining disturbs and also pollutes the
ground water. Some heavy metals also get leached into groundwater.
3. Surface water pollution: Drainage of acid mines often contaminates the
nearby streams and lake water and kill many aquatic animals.
4. Air pollution: Smelting and roasting are done to purify the metals, which
emits enormous amounts of air pollutants damaging the nearby vegetation
and public suffer from several health problems.
5. Subsidence of land: It is mainly associated with underground mining.
Subsidence of mining area results in cracks in houses, tilting of buildings,
bending of rail tracks.

46. • Deforestation and desertification
• Extinction of species
• Rapid depletion of high grade minerals
• Forced migration
• Wastage of upper soil layer and vegetation
• Soil erosion and oil depletion
• Ozone depletion
• Greenhouse gas increase
• Environmental pollution
• Natural hazards, etc.

53.  Food is an essential requirement for the human
survival.
 Each person has a minimum food requirement.
 The main components of food are carbohydrates,
fats, proteins, minerals and vitamins.
 food comes almost entirely from agriculture,
animal husbandry and fishing

54. • Global food production would not meet the food requirements of the world’s estimated 7.8 billion
people by 2020.
• Food prices are expected to jump by 20% in the next ten years as prolonged droughts and floods
take their toll on food production.
• The report, which looked at the impact of climate change on four cereals - wheat,`rice, maize and
soybean - pointed out that global wheat production will experience a 14 percent deficit
between production and demand
• Rice production will experience 11 percent deficit, and percent deficit in maize production.
• Soybean is the only crop showing an increase in global production, with an estimated five percent
surplus.
• Current wheat production is estimated to decline to 663 million tons by 2020 yet772.3 million tons
is the estimated need at that time, creating a gap of 109 million tons.
• Rice is estimated to grow to 692.1 million tons by 2020 yet demand at that time is estimated at
775.1 million –creating a shortage of 82.9 million tons.
• Maize production stands at 826.2 million tons and is estimated to grow to 849.1 million tons by
2020 yet demand at that time is estimated at 933.7 million ton, creating a shortage of 85 million
tons.

55.  Population growth: Food production in 64 of the 105 developing countries is
lagging behind their population growth levels.
 Poor agricultural practices: Poor environmental agricultural practices such as
slash and burn, shifting cultivation, or ‘rab’ (wood ash) cultivation degrade
forests.
 Degradation of agricultural lands: Globally 5 to 7 million hectares of farmland is
degraded each year. Loss of nutrients and overuse of agricultural chemicals are
major factors in land degradation. Water scarcity is an important aspect of poor
agricultural outputs. Salinization and water logging has affected a large amount
of agricultural land worldwide.
 Our fertile soils are being exploited faster than they can recuperate.
 9) Loss of Genetic Diversity: Modern agricultural practices have resulted in a
serious loss of genetic variability of crops. India’s distinctive traditional varieties
of rice alone are said to have numbered between 30 and 50 thousand. Most of
these have been lost to the farmer during the last few decades as multinational
seed companies push a few commercial types. This creates a risk to our food
security, as farmers can loose all their produce due to a rapidly spreading disease.
A cereal that has multiple varieties growing in different locations does not permit
the rapid spread of a disease.

56.  Forests, grasslands and wetlands have been converted to
agricultural use, which has led to serious ecological
questions.
 Use of genetically modified seed variety, without minding
the conducive environment for such experimentation, will
seriously affect the land ecosystem.
 Our fish resources, both marine and inland, show evidence
of exhaustion.
 There are great disparities in the availability of nutritious
food. Some communities such as tribal people still face
serious food problems leading to malnutrition especially
among women and children.

57.  It is the ability of all people at all times to access enough food for
an active and healthy life.
 It is estimated that 18 million people worldwide, most of whom
are children, die each year due to starvation or malnutrition, and
many others suffer a variety of dietary deficiencies.
 The earth can only supply a limited amount of food. If the world’s
carrying capacity to produce food cannot meet the needs of a
growing population, anarchy and conflict will follow.
 The following 3 conditions must be fulfilled to ensure food security
 - Food must be available
 - Each person must have access to it.
 - The food utilized must fulfill nutritional requirements

58. 1) Institutional support for small farmers: A major concern is the support needed for
small farmers so that they remain farmers rather than shifting to urban centers as
unskilled industrial workers.
2) Trade related issues: International trade policies in regard to an improved flow of
food across national borders from those who have surplus to those who have a deficit
in the developing world is another issue that is a concern for planners who deal with
International trade concerns. ‘Dumping’ of under priced foodstuffs produced in the
developed world, onto markets in undeveloped countries undermines prices and
forces farmers there to adopt unsustainable practices to compete.
3) Protecting genetic diversity: The most economical way to prevent loss of genetic
diversity is by expanding the network and coverage of our Protected Areas.
Collections in germplasm, seed banks and tissue culture facilities, are other possible
ways to prevent extinction but are extremely expensive. The most effective method to
introduce desirable traits into crops is by using characteristics found in the wild
relatives of crop plants. As the wilderness shrinks, these varieties are rapidly
disappearing. Once they are lost, their desirable characteristics cannot be introduced
when found necessary in future.
4) Ensuring long-term food security may depend on conserving wild relatives of crop
plants in National Parks and Wildlife Sanctuaries

59. 5) Environmental friendly farming methods: Shift
from chemical agriculture to organic farming,
practicing integrated nutrient management
(INM), integrated pest management (IPM).
6) Several crops can be grown in urban settings,
including vegetables and fruit which can be
grown on waste household water and fertilizers
from vermi-composting pits.

60. 7)Prevention of water and land degradation: Pollution of water sources, land degradation and
desertification must be rapidly reversed. Adopting soil conservation measures, using
appropriate farming techniques, especially on hill slopes, enhancing the soil with organic
matter, crop rotation and managing watersheds at the micro level are a key to agricultural
production to meet future needs.
8) Population control: Most importantly food supply is closely linked to the effectiveness of
population control programs worldwide.
9) Education: Educating women about nutrition, who are more closely involved with feeding
the family, is an important aspect of supporting the food needs/security of many developing
countries.
10) Changing food habits : Today the world is seeing a changing trend in dietary habits. As
living standards are improving, people are eating more non-vegetarian food. As people change
from eating grain to meat, the world’s demand for feed for livestock based on agriculture
increases as well. This uses more land and water per unit of food produced and the result is
that the world’s poor do not get enough to eat.
11) Women play an extremely vital role in food production as well as cooking the meal and
feeding children. In most rural communities they have the least exposure to technical training
and to health workers trained in teaching/learning on issues related to nutritional aspects.
Women and girls frequently receive less food than the men. These disparities need to be
corrected.
12) Alternate Food Source: Food can be innovatively produced if we break out of the current
agricultural patterns.

61.  Fisheries: Fish is an important protein food in many
parts of the world. This includes marine and fresh
water fish.
 While the supply of food from fisheries increased
phenomenally between 1950 and 1990, in several parts
of the world fish catch has since dropped due to
overfishing.
 Modern fishing technologies using mechanized
trawlers and small meshed nets lead directly to
overexploitation, which is not sustainable.
 It is evident that fish have to breed successfully and
need to have time to grow if the yield has to be used
sustainably. The worst hit are the small traditional
fishermen who are no match for organized trawlers.

62.  Food can be innovatively produced if we break
out of the current agricultural patterns.
 This includes working on new avenues to
produce food, such as using forests for their
multiple non-wood forest products, which can
be used for food if harvested sustainably.
 This includes fruit, mushrooms, sap, gum, etc.
This takes time, as people must develop a taste
for these new foods.

63.  Energy consumption of a nation is usually considered as an
index of its development, because almost all the development
activities are directly or indirectly dependent upon energy.
 Power generation and energy consumption are crucial to
economic development as economy of any nation depends upon
availability of energy resources.
 There are wide disparities in per capita energy use of
developed and the developing nations. With increased speed of
development in the developing nations energy needs are also
increasing.
 Population explosion, Luxurious life, Industries, Agriculture,
mining, transportation, lighting, cooling, heating, building all need
energy. Fossil fuels like coal, oil, natural gas produce 95% of energy

64.  Primary- Renewable energy-resources which can
be generated continuously in nature and are in
exhaustible and can be used again endlessly.
wood, Tidal, Solar, wind, hydropower, biomass,
biofuel, geothermal, hydrogen
 Non – renewable energy- Resources which have
accumulated in nature over along span of time and
cannot be quickly replenished when exhausted.
coal, petroleum, natural gas
 Secondary-petrol, electrical energy, coal burning

67.  Renewable energy resources:
 These energy resources are also known as non conventional
energy resource, which can be regenerated continuously.
 It can be used again and again in an endless manner because
these resources are available in large amount.
 For example, solar energy, wind energy, bio-fuels, hydro
energy, geothermal energy, wave & tidal energy.
 Non renewable resources:
 These energy resources are also known as conventional
(traditional) energy resources.
 It cannot be replenished when these sources are exhausted
because these resources are present in limited amount and take
a long period of time to re- synthesize.
 For example, nuclear energy, coal, petroleum, natural gas etc

68.  Alternative energy is energy that does not comes from fossil fuels and
thus produces little to no greenhouse gases.
 This means that energy produced from alternative sources does not
contribute to the greenhouse effect that causes climate change.
 These energy sources are referred to as “alternative” because they
represent the alternative to coal, oil, and natural gas, which have been
the most common sources of energy since the Industrial Revolution.
 Alternative energy, however, should not be confused with renewable
energy, although many renewable energy sources can also be
considered alternative.
 Solar power, for example, is both renewable and alternative because it
will always be abundant and it emits no greenhouse gases.
 Nuclear power, however, is alternative but not renewable, since it uses
uranium, a finite resource.
 Examples: energy from waste, Hydrogen energy, Fuel cells, Alcohol as
energy source, Energy plantation etc.

69.  considered a reliable source of energy because the technological
development in recent years allowed these clean energy sources to enter
more and more into the global energy.
 good for the environment that produces very low emissions or zero emission.
 represents a renewable energy source that never runs out.
 the solution to getting energy independence for every household. It enables
the poor to stretch their period of economic activity and their children can
help them in daily chores and then study in the evenings.
 Lower dependency on fuel wood and other household fuel sources reduces
the drudgery of women by eliminating the distances they travel for fuel
collection.
 Reduce or eliminate health problems associated with using conventional
cook stoves, including respiratory diseases and eye problems.
 provide local employment opportunities through direct use of energy in
small-scale industry and agriculture, through construction, repair, and
maintenance of energy devices, or through the sale of energy to local
utilities.

70.  HYDROELECTRIC POWER
 It is a form of renewable energy resources. Electricity produced
from water is usually referred as hydro electricity.
 In this process dams are constructed for storage of water and
then water led down through tunnel to lower level which
rotates the turbine to produce mechanical energy.
 The produced mechanical energy can be converted into
electrical energy with the help of generator and again
transformed in alternating current through transformer.
 Once the electricity is produced it can be delivered to homes,
industries etc.
 The output of energy produce by dams is totally depends on
the volume of water released or discharge speed and vertical
distance from where water fall or vertical distance of water
head.

71.  Advantage of hydroelectricity
 It is renewable source of energy. i.e. Non polluting
water
 Once the dams are constructed, electricity can be
produced to many years or decades.
 Hydroelectricity is non polluting sources of energy.
 Dams used in production of hydroelectricity, is also
used in irrigation purposes.
 Disadvantage of hydroelectricity
 Loss of biodiversity.
 Construction of dams is expensive.
 During drought condition electricity cannot be produce
by hydroelectricity plant.

75.  Sun is the primary source of energy. Sun’s energy each day is 600 times greater
than produced from all other sources.
 Solar energy can be used directly (ex. direct heating) or indirectly (ex. biomass
energy) for the human welfare.
 Solar Energy Harvesting Technologies :

76.  Solar heating for homes: In solar heated buildings, sunspaces are
built on the south side of the structure which acts as large heat
absorbers. The floors of sunspaces are usually made of tiles or bricks
that absorb heat throughout the day and then release heat at night
when it’s cold.
 Solar water heating: The solar energy collector heats the water,
which then flows to a well insulated storage tank.
 Solar cookers: The heat produced by the sun can be directly used for
cooking using solar cookers. A solar cooker is a metal box which is
black on the inside to absorb and retain heat. The lid has a reflective
surface to reflect the heat from the sun into the box. The box contains
black vessels in which the food to be cooked is placed.
 Solar desalination: systems for converting saline or brackish water into
pure distilled water.

77.  Photovoltaic energy: The solar technology which has the
greatest potential for use throughout the world is that of solar
photo voltaic cells which directly produce electricity from
sunlight using photovoltaic (PV) (also called solar) cells.
 Solar power plant: Solar energy is harnessed on a large scale by
using conclave reflectors.
 Concentrated Solar Power (CSP): It uses lenses or mirrors
and tracking systems to concentrate sunlight, then use the
resulting heat to generate electricity from conventional steam-
driven turbines. It is also called concentrated solar thermal.
 Biomass Energy: Biomass is organic material which has
stored sun light in the form of chemical energy. Because plants
and trees depend on sunlight to grow, biomass energy is a
form of stored solar energy.

78.  An energy source that has emission provides electricity around the clock
and propels our society into the future.
 Nuclear power is a clean and efficient way of boiling water to make steam,
which turns turbines to produce electricity.
 In all nuclear power plants, the process of making electricity causes
radioactivity.

79. 1. Nuclear Fusion: Breaking a heavy nucleus into 2 or more than 2 smaller
lighter nuclei.
2. Nuclear Fission: Combining 2 lighter nuclei to form a heavy nucleus.
 Uncontrolled chain reaction: A heavy nucleus in bombarded with a
neutron. It splits into lighter nuclei releasing 2 or more neutrons. Each
neutron again bombards nuclei of atom and splits further and further.
The neutrons and thereby the fission reaction exponentially increases.
Ex: Atom bomb.
 Controlled chain reaction: A heavy nucleus in bombarded with a
neutron. It splits into lighter nuclei releasing 2 or more neutrons. But in
this case, except one neutron all the other neutrons are absorbed. So,
only one neutron is left. This single neutron again bombards nuclei of
atom and splits further and further. Again only one neutron is left
behind and the others are absorbed. So, the reaction is controlled. Ex:
Nuclear generator.

80.  Nuclear Technology is used in Industries.
 Agricultural uses of nuclear technology.
 Environmental uses of nuclear technology.
 Biological Experimentations.
 Hospitals, doctors, dentists, and even veterinarians use
to diagnose and treat illnesses, such as cancer. They
are also used to study diseases.
 Scientific institutions use it in laboratory experiments and
research.
 Supply electricity to satellites and to spacecraft that are
sent on missions to the outermost regions of our solar
system.
 Engineering Projects.
 Neutron Activation Analysis.

81. 1. Compared to the surface occupied by a solar power plant, a wind farm or a biomass
facility, a nuclear power station will occupy a smaller surface of land and will generate
huge amounts of clean electricity.
2. Nuclear Energy is Powerful and Efficient: Coal generates 32.5 MJ/kg
(Megajoules/kilogram), while uranium (breeder) generates 810,000,000 MJ/kg, so almost
25,000 times more.
3. The future operational costs of the nuclear power plant will be much smaller.
4. Nuclear Energy is a Cleaner Energy Source.
5. On the energy market today, the price of nuclear energy is stable and pretty low
compared with the price of energy generated from fossil fuels.
6. Nuclear reactors are considered today very reliable machines that can operate in safe
conditions for several decades.
7. Nuclear generates jobs: Nuclear energy provides more than 100,000 well-paid, long-
term jobs and supports local economies.
8. Nuclear boosts international development: Nuclear energy helps developing nations
meet sustainable development goals.
9. Nuclear powers electric vehicles: Electrified transportation promises to reduce carbon
emissions. When powered by carbon-free nuclear energy, electric vehicles can reach

82. 1. It’s not a renewable energy source.
2. The rods need to be changed periodically. This has impacts on the
environment due to disposal of nuclear waste.
3. The reaction releases very hot waste water that damages aquatic ecosystems.
4. Uranium mining can cause high levels of pollution and also health risks for mine
workers.
5. Transport of uranium and nuclear fuels carries potential pollution and
environmental contamination risks.
6. Building new nuclear plants is a huge investment, especially for developing
countries.
7. National Risk: Nuclear Power Plants and Nuclear Waste Facilities Are
Constant Targets for Terrorist Groups.
8. The most severe Nuclear Disasters in the Recent History are the following:
the Three Mile Island nuclear accident in March 28, 1979 (the U.S.), the
Chernobyl disaster in April 26, 1986 (Ukraine), and the Fukushima nuclear
disaster in March 11, 2011 (Japan).

83.  Biogas is a type of biofuel that is produced from the decomposition (anaerobic fermentation) of
organic matter (plant material and animal waste, garbage, waste from households and some
types of industrial wastes, such as fish processing, dairies, and sewage treatment plants) by the
action of bacteria.
 Biogas production is a well-established process for energy generation, nutrient recovery, and
valorization of organic residues. Typically, the biogas is composed of methane, carbon dioxide,
hydrogen sulphide, water vapour and other impurities.
 Due to the high content of methane, typically 50-75%, biogas is flammable and therefore
produces a deep blue flame.
 Biogas is known as an environmentally-friendly energy source because it alleviates two major
environmental problems simultaneously: first, the global waste epidemic that releases dangerous
levels of methane gas every day and second the reliance on fossil fuel energy to meet global
energy demand.
 Biogas plant is a unit which converts organic waste matter into useful gaseous fuel (methane and
carbon dioxide) and organic fertilizer as byproduct in the form of slurry.
 The potential is about 12 million family type biogas plants based on estimated availability of cattle
dung in the country. A total of 4.31 million family type biogas plants have been setup in the
country.
 The cost of biogas plant varies from place to place and size of the plant. Average cost of 2 cubic
meter size biogas plant is about Rs. 17,000.
 The Ministry is implementing a National Biogas and Manure Management Programme

84.  Geothermal energy is the heat that comes from the sub-surface of the earth. To
produce power from geothermal energy, wells are dug a mile deep into underground
reservoirs to access the steam and hot water there, which can then be used to drive
turbines connected to electricity generators.
 There are four major types of geothermal energy resources:
 Hydrothermal,
 Geopressurised brines,
 Hot dry rocks and Magma.
 According to the International Renewable Energy Agency (IRENA), geothermal
energy has grown steadily from around 10GW worldwide in 2010 to 13.3GW in 2018.
 The world’s largest producer of geothermal energy is “The Geysers” in California
(U.S.), spread over 117 square kilometres and formed of 22 power plants, with an
installed capacity of over 1.5 GW.
 The GSI (Geological Survey of India) has identified 350 geothermal energy locations
in the country. The most promising of these is in Puga valley of Ladakh. The
estimated potential for geothermal energy in India is about 10000 MW.
 There are seven geothermal provinces in India: the Himalayas, Sohana, West coast,
Cambay, Son- Narmada-Tapi (SONATA), Godavari, and Mahanadi.

85.  In earth’s core geothermal energy continuously produce due to collision of
tectonic plates and due to decay of radioactive materials. In this process two
tunnels are drilled inside the earth.
 One tunnel used to inject water into the earth. When water injected into the earth,
where water come in contact with hot rocks and produced steam. The generated
steam comes out from the second tunnel where it rotates turbine to produce
mechanical energy.
 The produced mechanical energy can be converted into electrical energy with the
help of generator.

86. a) Flash steam power plant: It take high-pressure hot water (around 180oC) from
deep inside the earth and convert it to steam to drive generator turbines. When the
steam condenses to water then it again injected back into the ground. Most
geothermal power plants are flash steam plants.

87.  Dry steam power plant: In this case underground steam is used to rotate turbine
which derive generator to produce electricity.

88. Advantages
i) It is also a renewable source of energy.
ii) Unlike solar cell, it works all day and night.
iii) Low cost of maintenance.
iv) Geothermal energy is advantageous over fossil fuel.
Disadvantages
i) Underground hot water is necessary for geothermal energy.
ii) Installation cost is high.
iii) Production efficiency is lower.

89.  Biomass is a renewable energy resource, also known as ‘carbon neutral’ (because
biomass formed by sunlight, water, carbon dioxide, so biomass does not increase
carbon dioxide on the earth) or ‘phytomass’.
 It is formed by the excreta or waste materials of living organism (like sewage, cow
dung etc.) and dead plants & trees (firewood, wood shavings, fruit stone etc.).
 The chemical energy released from these molecule when they undergoes digestion or
combustion because chemical bonds between carbon, hydrogen and oxygen are
broken.
 Agricultural residue or agro-residue describes all organic material produced as
by-products after harvesting and processing of agricultural crops.
 Agro-residues are non-wood and a rich source of cellulose with lignin.
 Biomass are of two types :
 Field residues: The materials left in an agricultural field after the crop has
been harvested. It includes leaves, banana pseudo stems and leaves,
cornhusk, seed pods, kapok seed pods and cotton stalks etc.
 Process residues: The materials left after the crop is processed into a
usable resource. Examples: bagasse, pea peel, wheat and rice straw etc.
 In biomass, the energy from the sunlight is stored in the form of cellulose, sugar,
starch, lignin etc.

90.  Combustion
 burning is most common method to obtain energy
directly from biomass.
 Fermentation:
 biomass (carbohydrate) is converted into alcohol
in presence of bacteria or yeast.
 Biomass gasification:
 biomass is converted into combustible fuel like
producer gas (CO+H2) and small amount of
methane through incomplete combustion.

91.  The production of fuels from biomass energy plantations is comparatively
easy and reliable.
 Agro-residue is highly versatile, easy to store (or to harvest on
demand) and available in almost all geographical locations.
 Many employment opportunities are created in rural communities.
 Options for producing electricity on scales suited to clusters of rural
townships.
 Low capital investment is required, with a relatively fast payback period.
 Local fuels reduce demand for foreign exchange by substituting for imported
fuels/oils.
 Local resources can be exploited to the full with use of local skills and
technologies, and this result in lower energy costs; and helps build a
pool of local experience/expertise.
 Bio-manure is the safest source of plant nutrients, when compared to
inorganic chemical fertilizers.

92.  Local resources can be exploited to the full with use of local
skills and technologies, and this result in lower energy costs;
and helps build a pool of local experience/expertise.
 Bio-manure is the safest source of plant nutrients, when compared
to inorganic chemical fertilizers.
 Biomass is an ideal choice for rural, industrial and domestic
application.
 Agro-residue encourages self-sustaining employment and
income generation with greater opportunities for decentralizing
energy production systems.
 Cleaner environment, better sanitation, improved hygiene and the use of
materials previously wasted

93. 1. In a biomass power plant the agro-residue is burnt in a boiler to produce steam
that then drives a turbine and a generator to produce electricity. Example: The
Indian Government has approved the establishment of two biomass plants at
Ambala and Karnal.These will comprise a 12 MW power plant in Ambala and
fired by agro-residues (i.e. rice straw, rice husk, wheat straw, bagasse and
cotton stalks). The second plant at Karnal will have capacity of 5.5MW and will
also burn agro-residues.
2. Agro-residue can be converted to liquid biofuels such as methanol and ethanol or
used directly as a fuel.
3. Anaerobic digestion is the process of biological
digestion/degradation/decomposition of agro-residue in the absence of oxygen.
During this process a gaseous fuel usually called biogas is produced. The slurry
obtained from anaerobic digestion makes an excellent soil conditioner and plant
food.

94. 1. Consolidating and packaging loose agro-waste into a high
density unit is called biomass ‘briquetting’. Briquettes are an
excellent fuel capable of replacing fossil fuels for a number of
uses.
2. Incineration is the process of directly burning agro-residue in the
presence of excess air (oxygen) at high temperatures (about
8000 0C), which results in heat energy, inert gases and ash.
3. Bio-diesel is the name given to a clean burning fuel produced
from renewable sources such as soybean, vegetable residues.
4. Bio-ethanol is produced from crops with high sugar or starch content.

95. Biomass Briquettes

97. Biomass Power Plant

99.  The biogas generated by anaerobic digestion of organic waste (animal waste,
plant residue, crops) in biogas plant, mainly involve three steps: hydrolysis, acid
formation and gas production.
 Hydrolysis: In this step, macromolecule like fats, proteins, carbohydrates
are broken down through hydrolysis into fatty acids, amino acids and
sugars respectively.
 Acid formation: in this step, fatty acids, amino acids and sugars are
fermented by acid producing bacteria under anaerobic condition into acetic
acid, carbon dioxide and hydrogen.
 Gas production: In this step, methanogenic bacteria produce methane
either by fermenting acetic acid to form methane and carbon dioxide or by
reduction of carbon dioxide into methane.

101. Advantages
i) Produce organic waste
ii) Burn without smoke
iii) Renewable
iv) Help to reduce waste.
Disadvantages
i) Methane is health hazardous.
ii) Not efficient like fossil fuel.

102.  Hydrogen is light in weight, most abundant chemical element (about 90% of
material present on Earth contains hydrogen) of the earth, present in the form of
hydrocarbon, hydrides, organic compounds, water etc.
 Hydrogen is a cleanest (burn without emission of carbon containing gases) and
renewable source of energy.

103.  Electrolysis of water:
 Electrolysis is a process in which electricity is used to decompose
water into hydrogen and oxygen.
 The cell is filled with pure water and two electrodes (cathode and
anode) are connected with external power source.
 When a critical voltage is provide to electrodes then electrodes start to
produce hydrogen gas at cathode and oxygen gas at anode by
electrolysis:

105.  In this process, methane gas is converted into hydrogen gas in presence of steam.
 The process comprises three steps; in first step methane is mixed with steam and
fed in catalytic reactor, where methane is converted in carbon monoxide and
hydrogen.
 In second step, produce carbon monoxide fed in CO catalytic converter, where
CO converts into hydrogen and carbon dioxide in presence of steam.
 In last step, carbon dioxide and other impurities are removed from gas stream and
only pure hydrogen gas remains left.

106.  In fuel cell, electricity produces by combination of hydrogen
with oxygen and only water and heat are generated as by
product.
 Fuel cell consist two electrodes, one cathode and other one is
anode. Hydrogen gases enter through anode side where
catalyst (platinum catalyst) converts hydrogen molecules into
hydrogen ions (protons) and release electrons.
 The electrons go through the external circuit to produce
electricity and hydrogen ions migrate towards cathode side
where hydrogen ions combine with oxygen in presence of
electrons to produce water molecule.

108.  Advantage of hydrogen energy
i) Better energy-to-weight ratio.
ii) Produce zero harmful gas.
iii)Renewable.
iv) High efficiency.
 Disadvantage of hydrogen energy
i) Expensive to extract (because hydrogen does not present in
pure form).
ii) Highly inflammable.
iii) Hydrogen is difficult to storage and transport.