EDU
- 11
DEVELOPMENTAL PERSPECTIVES OF EDUCATION.
UNIT 3
ENVIRONMENTAL AWARENESS AND IMPORTANCE OF ENVIRONMENTAL EDUCATION
Concept and components of Environment
Natural and Manmade Environment Environmental resources- types
Biodiversity-types and significance
Environmental education-concept and
importance Need of incorporating EE at various levels-Primary, Secondary and
Tertiary level. Objectives and Principles of EE
Human interventions, its impact on
Environment and measures of Environmental protection Deforestation, Quarrying
and Mining, Destruction of mangroves, sacred groves and wetlands, Population
Explosion, Pollution types, causes and effects.
Depletion of Biodiversity, Extinction of
species- Climate change, water scarcity, loss of arable soil, global warming,
ozone depletion, greenhouse effect.
Waste management, wildlife and forest
conservation, water conservation, green culture, alternative sources of energy,
organic farming, vermi composting.
3.
B) Education for sustainable development-
Concept and
significance
Sustainable practices and role of
students. Role of Governmental agencies and NGO s in environmental
protection.
Environmental laws and rights- Air act,
Water act, Wildlife Protection act, Forest Conservation act , Articles 48 A, 51
A(g),
International Protocols- Earth Summit, Kyoto
Protocol, Montreal Protocol, Stockholm Conference.
CONCEPT
AND COMPONENTS OF ENVIRONMENT
v Meaning and Definition
The term environment has been
derived from a French word “Environia” means to surround.
It refers to both abiotic (physical
or non-living) and biotic (living) environment. The word environment means
surroundings in which organisms live.
Environment is the sum total of
physical, biological and cultural elements which are interlinked both individually
and collectively. It influences the growth and development of living forms.
Definitions
of Environment
1. According to P. Gisbert
“Environment is anything immediately surrounding an object and exerting a
direct influence on it.”
2. According to E. J. Ross
“Environment is an external force which influences us.”
Thus, environment refers to anything
that is immediately surrounding an object and exerting a direct influence on
it.
COMPONENTS
OF ENVIRONMENT
Environment mainly consists of
atmosphere, hydrosphere, lithosphere and biosphere. But it can be roughly
divided into two types such as
(a)
Micro environment
Micro environment refers to the
immediate local surrounding of the organism.
(b)
Macro environment.
Macro environment refers to all the
physical and biotic conditions that surround the organism externally.
It can also be divided into two
other types such as
(c)
Physical environment
Physical environment refers to all
abiotic factors or conditions like temperature, light, rainfall, soil, minerals
etc. It comprises of atmosphere, lithosphere and hydrosphere.
(e) Manmade environments
They
are artificially made environments made by man resembling natural environment.
eg:
Fish tanks which are created by man and they resemble natural aquatic
reservoirs.
(f) Natural environment
Natural
environment refers to the natural biotic and abiotic components of the
environment which are naturally occurring. It
includes all vegetation, microorganisms, soil, rocks, atmosphere and natural
phenomena.
For
example : Pond , Lake , grassland , etc
Based on the source of origin, state of development and the
renewability of the resources we can classify natural resources.
Classification of
natural resources based on source of origin
Biotic
environment.
Biotic environment includes all
living forms like plants, animals, micro organisms. It also includes fossil fuels such
as coal and petroleum which are formed from organic matter that has decayed.
Abiotic
environment:
These resources come
from non-living and non-organic material. Examples of these resources include
land, fresh water, air, and heavy metals (gold, iron, copper, silver, etc.)
Classification of
natural resources based on source of state of development
Potential
resources
These are resources
that exist in a region and may be used in the future.
For example, if a
country has petroleum in sedimentary rocks, it is a potential resource until it
is actually drilled out of the rock and put to use.
Actual
resources
These are resources
currently surveyed. Their quantity, quality and the development is dependent on
technology.
Reserve
resources
This is the part of an
actual resource that can be developed profitably in the future.
Stock
resources
These are resources
that have been surveyed, but cannot be used due a lack of technology. An
example of a stock resource is hydrogen.
Classification of
natural resources based on their renewability
Renewable
natural resources
These are resources
that can be replenished and are available continuously and their quantity is
not noticeably affected by human consumption.
Eg. sunlight, air, and
wind .
Non-renewable
natural resources
These resources form
extremely slowly in the environment. A resource is considered to be
non-renewable when their rate of consumption exceeds the rate of recovery.
eg minerals and fossil
fuels.
Biodiversity
The term biodiversity was coined as a
contraction of biological diversity by E.O. Wilson in 1985. Biodiversity may be
defined as the variety and variability of living organisms and the ecological
complexes in which they exist.
In other words, biodiversity is the
occurrence of different types of ecosystems, different species of organisms
adapted to different climates, environments along with their interactions and
processes.
Types of Biodiversity
1.
Genetic diversity
It describes the variation in the
number and types of genes as well as chromosomes present in different species.
Genetic diversity has the
following importance:
(i) It helps in
speciation or evolution of new species
(ii) It is useful in adaptation to changes in
environmental conditions
(iii) It is important for agricultural productivity
and development.
2.
Species diversity
It describes the variety in the
number and richness of the species with in a region. The species richness
depends largely on climatic conditions.
3. Ecosystem diversity
It describes the assemblage and
interaction of species living together and the physical environment in a given
area. It relates to varieties of habitats, biotic communities, ecological
processes in biosphere. It also tells about the diversity within the ecosystem.
It is referred as Land escape diversity because it includes placement and size
of various ecosystems.
Eg, the landscapes like grass lands,
deserts, mountains etc. show ecosystem diversity.
Importance of Biodiversity:
1. Productive values
Biodiversity produces a number of products harvested
from nature and sold in commercial markets. So it provides economic benefits to
people
2. Consumptive value:
The consumptive value can be assigned to goods such as
fuel woods, leaves, forest products etc.
3. Social value:
The loss of biodiversity directly influences the
social life of the country possibly through influencing ecosystem functions
(energy flow and biogeochemical cycle). This can be easily understood by
observing detrimental effects of global warming and acid rain which cause an
unfavorable alteration in logical processes.
4. Aesthetic value:
The earth’s natural beauty with its colour and hues,
thick forest, and graceful beasts have aesthetic values. Also refreshing
fragrance of the flowers, taste of berries, melodious songs of birds, etc.
compel the human beings to preserve them. Similarly botanical and zoological
gardens are the means of biodiversity conservation and are of aesthetic values.
5. Legal values:
All living organisms have equal right to coexist on
the surface of earth with all benefits. Unless some legal value is attached to
biodiversity, it will not be possible to protect the rapid extinction of
species.
6. Ethical value
It should be prime responsibility and moral obligation
of man to preserve and conserve other organisms which will directly or
indirectly favour the existence of the man.
7. Ecological value:
Biodiversity holds great ecological value because it
is indispensable to maintain the ecological balance, otherwise will lead to
severe problems, which may threaten the survival of human beings.
8. Economic value:
Biodiversity has great economic value because economic
development depends upon efficient and economic management of biotic resources.
Uses of Biodiversity:
(i) It provides
food of all types.
(ii) It provides fibres, sources for the preparation
of clothes.
(iii) It provides different types of oil seeds for the
preparation of oils.
(iv) It provides new varieties of rice, potato etc.
through the process of hybridization.
(v) It provides different drugs and medicines which
are based on different plant products.
(vi) It is very essential for natural pest control,
maintenance of population of various species, pollination by insects and birds,
nutrient cycling, conservation and purification of water, formation of soil
etc.
Threats to Biodiversity
The different factors responsible for causing threat to biodiversity
1. Habitat destruction
Due to the large industrial and commercial activities
associated with agriculture, irrigation, construction of dams, mining, fishing
etc leads to habitat destruction.
2. Habitat fragmentation:
With increased population, the habitats are fragmented
into pieces by roads, fields, canals, power lines, towns etc. The isolated
fragment of habitats restricts the potential of species for dispersal and
colonization. Also it brings microclimatic changes in light, temperature, wind etc.
3. Pollution
It includes air pollution, water pollution, industrial
pollution, pollution due to chemical wastes, pesticides, radioactive materials
etc. Pollution of air, water and soil has a direct or indirect impact on the
human, animal and plant life. Pollutants like pesticides, radioactive material,
SO2, oxides of nitrogen, heavy metals, chlorofluorocarbon, chlorofluoromethane,
silt and sewage etc., have become a cause for elimination many sensitive life
forms
4. Over exploitation:
The natural resources are over exploited to meet
growing rural poverty, intensive technological growth and globalization of
economy. All these factors together may be responsible for the extinction of a
number of species.
5. Introduction of exotic species
The introduction of exotic species are due to
(i) horticulture
(ii) agriculture;
(iii) European colonisation and
(iv) accidental transport.
Some exotic species may kill or eat the native species
thereby causing its extinction.
6. Diseases
Since the animals are more vulnerable to infection,
the anthropological activities may increase the incidence of diseases in wild
species, leading to their extinction.
7. Shifting or Jhum cultivation:
The shifting or Jhum cultivation by poor tribal people
greatly affects the forest structure which is a store house of biodiversity.
8. Poaching of wild life:
A number of wildlife species are becoming extinct due
to poaching and hunting.
9. Natural Calamities: Fire,
landslides, soil erosion, wind, etc., occur erratically in the forested zone of
the Highlands of the State. They act as driving forces to devastate the
biodiversity and disturb the environment of the region.
10.
Urbanization:
It refers to the process of increased concentration of human population in
large cities. Increased human population has put a great strain on agricultural
land and forest. Clearing of forests and conversion of agricultural lands for
human habituation has a direct impact on biodiversity as it destroys natural
habitat eliminating important plant and animal species
11.
Acidification of Soil and Water: It refers to decrease in pH of soil and water. Generally
most of the soil and water are found to be slightly alkaline or neutral. Human
activities like excessive use of nitrogen based chemical fertilizers, acid rain
due to SO2 and Oxides of Nitrogen pollution cause acidification of soil and
water. Many plant and animal species are sensitive to acidic condition and such
species are eliminated from the habitat causing biodiversity depletion
12.
Mining Activity:
Mining is the process of excavating non-renewable resources like coal and
minerals from the earth. Surface mining or Open pit mining activity has direct
impact on the fauna and flora of the area and also causes environmental pollution.
Also to store mined material and to dump the residue left after extracting the
ore requires huge land area. Thus mining has a worst impact on the environment
and it biodiversity.
13.
Desertification:
Desertification is the process leading to desert formation. Deforestation and
overgrazing brings about marked changes in the climate of the area like changes
in rainfall, temperature and wind velocity causing soil erosion and increased
dust particles in the atmosphere. This causes desertification. As a result
critical habitat for fauna and flora will be lost
14. Loss of Arable
land: The loss of arable land has been
caused by a number of factors, many or most of which are tied to human
development. The primary causes are deforestation, overexploitation for
fuelwood, overgrazing, agricultural activities and industrialization.
Conservation of Biodiversity
Biodiversity is being depleted by the
loss of habitat, fragmentation of habitat, over exploitation of resources,
human sponsored ecosystems, climatic changes, pollution invasive exotic spices,
diseases, shifting cultivation, poaching of wild life etc.
Human being should prevent the
degradation and destruction of the habitats thereby maintaining the
biodiversity at its optimum level. Conservation of biodiversity is protection,
upliftment and scientific management of biodiversity so that it gives maximum
benefits for the present generation and to meet the needs of the future
generations.
Conservation of biodiversity
has three basic objectives
(a) To maintain essential ecological processes and
life supporting systems.
(b) To preserve the diversity of species.
(c) To make sustainable utilisation of species and
ecosystems.
Strategies for Conservation of
Biodiversity:
(1) All the
possible varieties (old or new) of food and timber plants, live stock,
agriculture animals and microbes should be conserved.
(2) All the economically important organisms in
protected areas should be identified and conserved.
(3) Critical habitats for each species should be
identified and safeguarded.
(4) Priority should be given to preserve unique
ecosystems.
(5) There should be sustainable utilisation of
resources.
(6) International trade in wild life should be highly
regulated.
(7) The poaching and hunting of wildlife should be
prevented as far as practicable.
(8) Care should be taken for the development of
reserves and protected areas.
(9) Efforts should be made to reduce the level of
pollutants in the environment.
(10) Public awareness should be created regarding
biodiversity and its importance for the living organisms.
(11) Priority should be given in wildlife conservation
programme to endangered species over vulnerable species and to vulnerable
species over rare species.
(12) The habitats of migratory birds should be
protected by bilateral and multilateral agreement.
(13) The over exploitation of useful products of wild
life should be prevented.
(14) The useful animals, plants and their wild
relatives should be protected both in their natural habitat (in-situ) and in
zoological botanical gardens (ex-situ)
(15) Efforts should be made for setting up of National
parks and wild life sanctuaries to safeguard the genetic diversity and their
continuing evolution.
(16) Environmental laws should be strictly followed.
Conservation Methods
There are two types of conservation
methods namely in-situ and ex-situ conservations.
(a) In situ conservation
The conservation of species in their
natural habitat or natural ecosystem is known as in situ conservation. It is a
cheap and convenient way of conserving biological diversity and can preserve
large number of organisms which are known and unknown to us. It helps to adjust with different
environmental conditions and to evolve into a better life form.
The protection and management of
biodiversity through in situ conservation involve certain specific areas known
as protected areas which include national parks, Sanctuaries and Biosphere
reserves.
(b) Ex-situ conservation:
Ex-situ conservation involves
maintenance and breeding of endangered plants and animals under partially or
wholly controlled conditions in specific areas like zoo, gardens, nurseries
etc. That is, the conservation of selected plants and animals in selected
areas outside their natural habitat is known as ex-situ conservation.
Some important areas under
these conservation are:
(i) Seed gene bank,
(ii) Field gene bank;
(iii) Botanical gardens;
(iv) Zoos.
Environmental education-concept and
importance. Need of incorporating EE at various levels-Primary, Secondary and
Tertiary level. Objectives and Principles of EE
ENVIRONMENTAL
EDUCATION-CONCEPT AND IMPORTANCE
“Environmental
education provides important opportunities for students to become engaged in
real world issues that transcend classroom walls. They can see the relevance of
their classroom studies to the complex environmental issues confronting our
planet and they can acquire the skills they’ll need to be creative problem
solvers and powerful advocates.”
— Ms. Campbell, California’s Superintendent of San Mateo County Schools
— Ms. Campbell, California’s Superintendent of San Mateo County Schools
Environmental
Education is a holistic, lifelong learning process which creates responsible individuals
who explore and identify environmental issues, engage in problem solving, and
take action effectively to improve the environment.
Environmental Education can be taught
formally, informally and through various
non-formal education programs such as experiential outdoor education,
workshops, outreach programs and community education.
Environmental Education develops
problem-solving and investigation skills in children. Qualified environmental
educators should work in the field, conducting programs, involving and
collaborating with local communities, and using strategies to link the
environmental awareness, building skills, and responsible action.
The education system in India had incorporated certain
aspects of environment in school curricula as early as 1930. The Kothari
commission (1964-66) also suggested that basic education had to offer EE and
relate it to the life needs and aspirations of the people and the nation.
At the primary stage, the report recommended that " the
aims of teaching science in the primary schools should be to develop proper
understanding of the main facts, concepts, principles and processes in physical
and biological environment”
Environmental education is an essential part of every
pupil's learning. It helps to encourage awareness of the environment, leading
to informed concern for active participation in resolving environmental
problems. It was introduced without any delay from class –1 as EVS, as a
subject so that right from their childhood, the right attitudes towards
environment will be nurtured in the young minds.
IMPORTANCE OF ENVIRONMENTAL EDUCATION
- Breaking
Indoor Habit.
- Improving
Student Health.
- Supporting
STEM. EE
offers an engaging platform for gaining and applying knowledge and skills
in science, technology, engineering, and mathematics (STEM).
- Meeting
21st Century Needs.
- Cultivating
Leadership Qualities. Improving Focus and Cognition.
- Creating Enthusiastic Students.
- Fostering Innovative Teacher-Leaders.
- Saving
Schools Money.
- Fostering Healthier Schools.
- Supporting
Sound Decision-Making.
- Contributing
to Sustainability.
- Conserving
our Natural Resources.
AIMS AND OBJECTIVES FOR
ENVIRONMENTAL EDUCATION
·
The
environment as a common heritage of mankind.
·
The
common duty of maintaining, protecting & improving the quality of
environment, as a contribution to the protection of human health and
safeguarding the ecological balance
·
The
need for a prudent and rational utilization of resources
·
The
way in which each individual can contribute to the protection of
environment;
·
To
improve management of environment and provide satisfactory solutions to
environmental issues.
·
Provide
opportunities to acquire the knowledge, values, attitudes, commitment and
skills needed to protect and improve the environment.
·
Encourage
pupils to examine and interpret the environment from a variety of
perspectives-physical, geographical, biological, sociological, economic,
political, technological, historical, esthetic and ethical.
·
Arouse
pupil's awareness and curiosity about the environment and encourage active
participation in resolving environmental problems.
·
Environmental
education is closely linked to the other cross circular themes of other subject
areas.
·
Appreciations
of care and concern for environment.
·
Concern
for other living things on earth.
·
Independent
thought on environmental issues.
·
Respect
for others opinion.
·
Respect
for rational argument and evidence.
·
Tolerance
to face others views.
Thus Environmental education can be thought of as comprising
three linked components:
- Education
about the environments (Knowledge).
- Education
for the environment (Values, Attitudes & Positive actions).
- Education
through the environment (A Resource).
Environmental
knowledge contributes to an understanding and appreciation of the society,
technology and productivity and conservation of natural and cultural resources
of their own environment. It can solve the societal needs, the needs of a
community problem and their solutions and workforce for tackling cooperative
minds. So we need the school children to share and develop the motivation from
school about various environmental issues, which are the challenges of today
and prepare them for the future.
Environmental education becomes a major part of EE in both
primary and upper primary stages of school education.
The components of
environmental education objectives are:
·
Awareness—to help social groups and
individuals acquire an awareness and sensitivity to the total environment and
its allied problems.
·
Knowledge—to help social groups and
individuals gain a variety of experience in, and acquire a basic understanding
of, the environment and its associated problems.
·
Attitudes—to help social groups and individuals
acquire a set of values and feelings of concern for the environment and the
motivation for actively participating in environmental improvement and
protection.
·
Skills—to help social groups and
individuals acquire the skills for identifying and solving environmental
problems.
·
Participation—to provide social groups
and individuals with an opportunity to be actively involved at all levels in
working toward resolution of environmental problems.
Human interventions, its impact on
Environment
1. Overpopulation
Overpopulation results when mortality rates have decreased,
medicine has improved, and methods of industrial farming were introduced, thus
keeping humans alive for much longer and increasing the total population.
The effects of overpopulation are problems in space, so cutting
of trees, damaging eco systems, increase in CO₂ levels, reducation of coal and fossil fuels for energy.
2. Pollution
3. Global Warming
Humans are consistently increasing CO₂ levels globally due to burning fossil fuels and
deforestation. The increase of CO₂
emissions has contributed to the planet's average temperature
increasing almost a whole degree. As the Temperature increases,
arctic land ice and glaciers melt which causes the ocean levels to rise at a
rate of 3.42mm per year.
4. Climate Change
Climate changes due to industrial and technological
development. As global temperatures increases, Earth's weather patterns will
drastically change. The increase will impact weather patterns, promising more
intense hurricanes in both size and frequency, as well as intensifying and prolonging droughts and heat waves. But
air pollution does not just affect the environment.
5. Genetic Modification
6. Ocean Acidification
Ocean acidification is caused when CO₂ dissolves into the ocean bonding with sea water creating
carbonic acid. The acid reduces the pH levels in the water. The acidity
depletes the calcium concentrations, making it difficult for crustaceans to
build their shell, leaving them vulnerable without their armor. Coral reefs are
home to 25% of aquatic life, many of which are responsible for
the natural
filtration of the ocean and production of necessary nutrients
that are vital for life under the sea. However, acidification is not the only
watery threat as there are other human activities causing severe changes.
7. Deforestation
Forests are cleared to make way for new humans, is a
major threat to the survival of animals and others which becomes a big
conservation issue. It also increases the greenhouse gases within the
atmosphere which leads to further global warming. Such human activities need to
stop if we wish to survive.
8. Acid Rain
When humans burn coal, sulphur dioxide and nitrogen oxides are released
into the atmosphere where they rise up and accumulate in the clouds until the
clouds become saturated and rain as acid, causing burns. It is harmful to lakes
and small bodies of water. The ground surrounding the water soaks up the acid,
depleting the soil of essential nutrients. Trees that absorb the acid
accumulate toxins that damage leaves and
slowly kills large areas of forest.
Acid rain has also been known to completely eliminate
entire species of fish, causing a snowball effect of damage to
the ecosystem that relies on diverse organisms to sustain the environment.
9. Ozone Depletion
The ozone layer is renowned for its ability to absorb
harmful UV rays that would otherwise be detrimental to the health of all walks
of life. Without an ozone layer, walking outside would be unbearable.
10. Reduction and fragmentation of habitats and
landscapes
The expansion of humans activities into
the natural environment, manifested by urbanisation, recreation,
industrialisation, and agriculture, results in increasing uniformity in
landscapes and consequential reduction, disappearance, fragmentation or
isolation of habitats and landscapes.
11. Loss of Species of Fauna and Flora
Modern
agriculture is responsible for the loss of much wildlife and their habitats and
fragmentation of habitats and wildlife populations. The drainage of wetlands,
the destruction of hedgerows and the intensive use of fertilizers and
pesticides can all pose a threat to wildlife.
13. Energy
The
sustainability of the natural environment will be improved as trends away from
damaging energy uses and extractive methods reduce and whilst real cost market
forces and the polluter pays principle take effect.
Almost
all forms of industry have an impact on the natural environment and its
sustainability. The impact varies at different stages in the life cycle of a
product, depending upon the raw materials used through to the final end use of
the product for waste residue, re-use or recycling. Industrial accidents and
war damage to industrial plants can also endanger the natural environment.
some
forms of tourism can be extremely detrimental to ecologically sensitive areas,
resulting in habitat degeneration or destruction, in the disturbance or hunting
even rare or threatened species.
Transport
is perhaps the major contributor to pollution in the world today, particularly
global environmental issues such as the greenhouse effect. The key impacts of
transportation include fragmentation of habitats and species and genetic
populations, disruption of migration and traffic mortalities to wildlife.
17.Land Degradation
Deforestation occurs when humans clear forests to use the
land either for agriculture or for habitation. Consequently, forest cover
dwindles significantly, leading to soil erosion and extinction of plant
species. Land animals also decline in numbers and even face extinction due to
human expansion that encroaches on their natural habitat and limits their
ability to spread geographically.
18. Air Pollution
One of the biggest environmental impacts of human activities
is air quality. The transportation sector, industry etc causes an imbalance in
the quality and composition of air. Some air pollutants deplete the ozone layer
and expose the Earth to dangerous radiation from the sun.
19. Water Contamination
Human intervention in the environment also jeopardizes the
supply and flow of clean drinking water. Activities like waste disposal from
residential, commercial and industrial areas, oil spills and runoff from
agriculture all contaminate bodies of water. The direct deposit of pollutants
into lakes, rivers, seas and streams and indirect runoff of hazardous
substances during the rainy seasons both impact water sources. Another
environmental issue impacting water systems is overfishing, which causes a
reduction in diversity of marine life.
DeforestationDeforestation means unwanted cutting of trees including repeated lopping, felling, removal of forest litter, browsing, grazing and trampling of seedlings. It results mainly from
1) shifting
cultivation
2) development projects
3) demand for fuel wood
4) demand for wood for industry and for commercial purposes
5) other causes.
2) development projects
3) demand for fuel wood
4) demand for wood for industry and for commercial purposes
5) other causes.
1)Shifting
cultivation
In this practice a patch of land is cleared, vegetation is burned and the ash is mixed with the soil thus adding nutrients to the soil. This patch of land is used for raising crops for 2 to 3 years, and this yield is modest. In India it is widely practiced in North Eastern and in Andaman Nicobar islands.
2)
Development projects
The use of science and technology support the process of development at a rapid rate. Development projects like the hydroelectric projects, large dams and reservoirs, laying down Railway lines and roads etc results in deforestation effects
3)
Demand for fuel wood
The increasing demand for fuel wood results in deforestation. Increasing demand for firewood from forest which is used for lighting, cooking or heating purposes pressures on the forests increased intensity of deforestation.
4)
Raw materials
Raw materials used in making boxes, crates, packing cases, paper etc also demands deforestation. Since large number of industries dependent on forests, thoughtless and unrestricted exploitation of forest for raw materials results in degradation of the forest ecosystem.
5)
Other causes
·
Natural enemies like termites, pests and
several kinds of diseases affect the forests adversely.
·
Due to floods and fires.
·
Overgrazing and Agriculture
·
Deforestation and overgrazing
·
Rate of water infiltration is
proportionally related to grazing intensity. Water infiltration is low in
heavily grazed areas and high in lightly grazed areas. Heavily grazed areas
also have high rates of runoff.
·
Changes in environment caused by man
·
cultivating the land intensely without
proper soil management, leads to problems like soil erosion, desertification
and depletion of plant nutrient.
·
Irrigation without sufficient drainage
leads to excessive accumulation of water (water logging) or salts
(salinization), rise in water table in the soil, ultimately leading to the
degradation of quality of soil.
·
Indiscriminate use of agrochemicals -
fertilizers and pesticides
·
Mining
Effects of deforestation
1. Soil
erosion
2.
Water Cycle
3.
Loss of Biodiversity
4.
Climate Change
Plants absorb Carbon Dioxide CO2 from the atmosphere and gives off Oxygen. Destroying the forests mean CO2 will remain in the atmosphere and in addition, destroyed vegetation will give off more CO2 stored in them as they decompose. This will alter the climate of that region. Cool climates may get a lot hotter and hot places may get a lot cooler.
5.
Loss of ecological balance:
6.
Air pollution:
7.
Water pollution:
8.
Increased consumption of natural resources:
9.
Production of waste:
10. Extinction
of Wildlife:
11. Habitual
destruction:
12. Noise
pollution:
13. Radiation
pollution:
14.
Soil erosion
How can we preserve forests
1.
laws, rules and regulations should be there to enforce
the preservation of forests.
2.
Make a conscious effort to share information with
others on deforestation and its' effects.
3.
Join organizations, forest-preservation societies and
pressure groups that aim to help preserve the rest of our natural resources.
When more people work together, the impact is greater.
4.
Reduce the use of artificial items, recycle more and
re-use items.
5.
Wood, paper, plastics and many other things we use
everyday at home can be linked to natural resources being destroyed. This means
that if we all recycle more, there will be less dependence on the environment
(and trees).
Quarrying
It's a process of cutting into rock or ground
to extract stone or other materials.
Quarrying Methods
1. Excavating
Excavating stones from earth by
Shovels, pick axes, hammers chisels, machinery etc
2. Wedging
This method is suitable for quarrying
soft stratified rocks. Steel hammers called sledge, hammers etc split the slab
along the line of holes drilled.
3. Heating
This method is suitable where only
smaller blocks of more or less regular shape are required. It consists in
piling a heap of fuel on a small area of the exposed face of rock and burning a
steady fire for some hours. It results in uneven expansion because of unequal
heating of the two layers and consequent separation of the upper and lower
layers.
4. Blasting
It is quarrying stones with
explosives. Blasting is to excavate foundations for buildings road structures
in rock works and for tunneling.
Advantages of quarrying:
- enhancing trade
- creating jobs for people around
- creating new habitats
- sometimes new roads are built
- after the removal of extracted material , the site can
be used for leisure and sports activities
Disadvantages of qurraying:
·
air
pollution
·
noise
pollution
·
destruction
of habitats
·
destruction
of natural beauty
·
producing
waste, creating a menace if not disposed off wisely
·
contamination
of water
·
production
of bacteria, germs and insects around which can be harmful for people
·
often
leaves an open pit that can become a dumping ground for others
·
affects
the weather of the surrounding
Mangroves and Coral
Reefs
The greatest benefit of mangroves is their ability to reduce
storm surge. This benefit is long-term and requires no maintenance. Mangroves
are destroying because of clearing for development, logging, and shrimp
farming.
Coral reefs are lost by mining sedimentation from agriculture
on the upland, bad fishing techniques that kill corals , sedimentation from
nourished beaches and a host of other natural and global warming-related
causes. Mangroves and coral reefs often provide protection for nearby beaches.
Their destruction harms the beach as well.
Importance of Reefs and Mangroves
Mangroves
- The only species of tree which
flourishes in sea water.
- Regenerate quickly from propagules.
- Provide vital structure to
coastlines, their arching roots trap sediment that would otherwise be
washed back by the waves.
- Act as a barrier between sea and
land, protecting vulnerable coastal communities from the impact of waves.
- Mangroves and their root systems
provide habitats for; bats, spawning fish, lobsters, manatees and birds.
Threats to and Mangroves
1.
Mangroves thrive in brackish, nutrient-rich
waters. It purifies the water of silt, human waste and nutrients
2.
Anthropogenic
Impacts
·
destroyed to make way for tourist resorts, or
cut for firewood.
·
Chemical Pollution
·
Pesticides and fertilisers used in agricultural
development projects
·
Industrial practices such as mining, dredging
and refining all release heavy metals into coastal waters.
·
Nutrients
Loading/Sewage
The introduction of organic compounds
results in eutrophication and subsequent oxygen depletion. Europhication is
where the nutrient load gets to an extent that the community becomes dominated
by algal/seaweed, exceeding the capacity to control by grazing organisms. This
leads to oxygen and light reduction and perhaps death of the communities living
there.
·
Overfishing
·
Construction
and Sedimentation
·
Mangrove
cutting
·
Rubbish/Litter
·
Tourists
MINING
Mining may be defined
as the removal of minerals and other materials from Earth's crust for the
welfare and prosperity of man. Modern industrial, economic and commercial
activity depends a lot on the exploitation and consumption of minerals. The
recovery of minerals and construction material require removing the vegetative
cover on land with underlying soil mantle and excavating overlying rock masses
The result
- is
reshaping of the topography,
- generation
of great volumes of debris and
- disruption
of surface and ground water circulations.
- These
further lead to soil erosion,
- increased
incidences of landslides and ultimately Land Degradation.
- affect
ocean ecosystems
Pollution
It is an unconcerned
and uncontrolled contamination of natural resources. Its effects are hazardous
for the healthy survival. Pollution is drastically rising in all the
countries associated with modern technology and population growth. Even
the daily normal livelihood requirements are high contributing factors to never
ending pollution of all sorts. Pollution poses health hazards, endangers wild
life and makes the planet unsafe for future human survival.
Types of pollution:
1. Air
pollution: This is a contamination of natural air with dangerous
gases. Many gases like carbon monoxide, carbon dioxide, sulfur dioxide, methane
and other harmful gases are emitted from automobiles (powered by petroleum),
industries and sometimes by natural calamities like volcanoes. It is also
caused by emissions from manufacturing industries and power plants, smoking,
natural events such as volcanic eruptions and wildfire, and burning of waste
materials such as wood, rubber and plastics. The common air pollutants include hydrocarbons, volatile organic
compounds (VOCs), dust particles, carbon monoxide, sulfur oxides, particulate
matter, chlorofluorocarbons (CFCs), and nitrogen oxides. There is some sort of
particulate dust from the chimneys of the factory. This is harmful especially
to the respiratory system are it is directly exposed. This air pollution can be
minimized by filtration of effluents, decrease in use of petroleum related
automobiles and also sufficient growth of trees.
- Water pollution:
After air, water is resource which is highly contaminated. Both drinking
water from rivers, ponds and also sea water are contaminated by discharge
of large amounts of human and industrial wastes. The causes of water pollution
include:
·
The
discharge of industrial waste in water bodies
·
Agricultural
pollution: practices such as the use of pesticides and other agrochemicals that
get washed into water systems or infiltrate into groundwater
·
Discharge
and dumping of waste materials and home made products such as plastics and
detergents into water bodies
·
Oil
spills
·
Natural
disasters such as floods and hurricanes that lead to intermixing of water with
dangerous substances on the land
3. Land
pollution:
It also occurs when
people dump chemical products to soils in the form of herbicides, fertilizers,
pesticides, or any other form of the consumer by-products. Mineral exploitation
equally leads to the decline in quality of the earth’s land surfaces. In this
regard, it has grave consequences for human health, plant life, and soil
quality. Acid rain, construction sites, solid waste, mineral
exploitation, agricultural chemicals, and deforestations are the primary causes of land pollution.
- Sound pollution:
Also called as noise pollution is a disturbance of silent
environment with harsh loud noises. Noise pollution is mostly an undesirable
sound or sound which generates horrible discomfort on the ears. It is
measured in decibels (dB) and sound levels beyond 100 dB can cause
permanent hearing loss. The industrial sound limit according to the World
Health Organization (WHO) is 75 dB. In the contemporary society, noise has
become a permanent aspect owing to the daily activities such as
transportation including airports, traffic and railroads, industrial
manufacturing, construction works, and concerts. This
is mostly due to automobile sounds, by the audio systems used for fun
or public speeches, temples, mosques, churches etc. This pollution has
severe impact especially on the old people, small children. Even sound
from industrial sirens, vehicle movements also contribute to this noise
pollution.
5. Dust
pollution: This is pollution where in the contamination is due to dust
particles in air. This can be from soil, roads, farming, and even due to
mining etc. From farms this dust pollution occurs due to pollen grains as a
part of pollination. While on the roads it is due to unclean road over run by
vehicles. This air contamination by dust creates trouble for proper breathing
leading to infections, congestion of breath etc.
6. Radiation
pollution: This is the pollution due to abnormal radiation in the
environment. This occurs due to use of radioactive elements from atomic energy
stations. From cell and mobile towers, by use of wireless Internet access
modems etc. . Due to its intensity, it can cause massive human death, cancers,
serious lung disease, organ damage, birth defects, and grave destruction to
plant life and animals.
7. Thermal pollution:
This pollution arises due to release of excess heat from thermal
power plants, industries involved in metals molding etc. The
heat is released into the surrounding water rising the temperature of the
locality drastically. This can be especially troublesome water and marine
animals as the heat deprives them of oxygen and also changes the environment
around them.
8. Light
pollution: Light pollution effects especially at night as it
disturbs the sleep of humans, birds and other animals. This might sometimes
affect the natural body rhythm or circadian clock. It is believed
that light pollution is one of the causes of obesity, insomnia and other health
issues. The types of light pollution include glare, light trespass, and sky
glow. City lighting, advertising and billboards, and nighttime entertainments
are some of the main contributors of light pollution
9. Plastic
pollution: The plastic and polythene due to their ability to withstand
decomposition for years together add up to pollution. Plastic pollution can
contribute to air, water and soil pollution.
10. Industrial
Pollution
Industrial pollution is the release of wastes and
pollutants generated by industrial activities into the natural environment
including air, water, and land. The pollutants and wastes from industries
encompass air emissions, deposit of used water into water resources, landfill
disposal, and injection of toxic materials underground. Industrial pollution can adversely damage plants, kill
animals, cause ecosystem imbalance, and degrade the quality of life. Leading
industries such as power plants, steel mills, sewage treatment plants, heating
plants, and glass smelting among other production, processing and manufacturing
companies are the contributors to industrial pollution.
EFFECTS
OF DEPLETION OF BIODIVERSITY
Extinction of
species
Even though a species
is not eliminated from the ecosystem or from the biosphere, its niche (the role
the species play in the ecosystems it inhabits) diminishes as its numbers fall.
If it is suddenly declining in numbers, it may produce significant changes in
the ecosystem’s structure. For example, if trees are cut from
forests it eliminates the shading, temperature,
and moisture regulation, animal habitat, and nutrient transport services they
provide to the ecosystem.
CLIMATE
CHANGE
Climate means the average weather conditions in an area over
a long period of time usually 30 years or longer. It includes systems in the
air, water, land and living organisms. Climate change is the shift or abnormal
change in climate patterns. Ecosystems and biodiversity will be forced to
fluctuate along with the regional climate, and that could harm many species.
Changes in climate can also intensify droughts, decrease water supply, threaten
food security, erode and inundate coastlines, and weaken natural resilience
infrastructure that humans depend on.
1. TEMPERATURE
·
A number of species cannot control its body
temperature when the ambient temperature rises above 30°C. An extended heat
could kill off a large part of its population.
·
Warmer sea surface temperatures causes coral
bleaching
·
Predicted changes in the intensity, frequency
and extent of disturbances such as fire, cyclone, drought and flood will place.
· Heatwaves
may affect the biodiversity of marine ecosystems
2.
CHANGES IN RAINFALL
·
Predicted decreased rainfall and consequent
lower river flows in both regions would have a major impact on aquatic biota.
3. INCREASED CO2 AND
PLANT GROWTH
·
causes increased growth rates in many plant
species.
·
‘fertilization’ effect is matched by increased CO2, adequate soil moisture and
other nutrients.
·
increased
concentrations of carbon dioxide could diminish the nutritional value of
foliage.
·
resulted in a decrease in the ocean’s pH, which
in turn affects the rate at which many marine organisms build skeletons,
meaning that reefs damaged by bleaching or other agents would recover more
slowly.
4.
EFFECTS OF WATER AND WATER
SCARCITY
·
show a direct correlation to the growth rates
and persistences of plant species in that region.
·
have a direct impact on the soil moisture in an
area.
·
changing the dynamics of the ecosystem as a
whole.
·
Plants rely not only on the total rainfall
during the growing season, but also the intensity and magnitude of each
rainfall event.
·
Environment cannot survive in the absence of
water.
GLOBAL
WARMING
Global warming is the long-term heating of Earth’s climate
system due to human activities, primarily fossil fuel burning, which increases
heat-trapping greenhouse gas levels in Earth’s atmosphere. It occurs when carbon
dioxide (CO2) and other air pollutants and greenhouse gases collect in the
atmosphere and absorb sunlight and solar radiation that have bounced off the
earth’s surface. These pollutants trap the heat and cause the planet to get
hotter. That's what's known as the greenhouse effect. Human activities are
estimated to have increased Earth’s global average temperature by about 1
degree Celsius (1.8 degrees Fahrenheit), a number that is currently increasing
by 0.2 degrees Celsius (0.36 degrees Fahrenheit) per decade.
Natural processes can also contribute to climate change such
as volcanic activity, changes in the Sun’s energy output, and variations in
Earth’s orbit etc
Certain gases in the atmosphere block heat from escaping.
Long-lived gases that remain semi-permanently in the atmosphere and do not
respond physically or chemically to changes in temperature are described as
"forcing" climate change. Gases, such as water vapor, which respond
physically or chemically to changes in temperature are seen as "feedbacks."
Gases that contribute
to the greenhouse effect
- Water vapor. Water vapor increases the possibility of clouds and
precipitation, making these some of the most important feedback mechanisms
to the greenhouse effect.
- Carbon dioxide (CO2). A minor but very important
component of the atmosphere, carbon dioxide is released through natural
processes such as respiration and volcano eruptions and through human
activities such as deforestation, land use changes, and burning fossil
fuels. This is the most important long-lived "forcing" of
climate change.
- Methane. A hydrocarbon gas due to the decomposition of wastes
in landfills, agriculture, rice cultivation, as well as ruminant digestion
and manure management associated with domestic livestock
- Nitrous oxide. Gas produced by soil cultivation practices,
especially the use of commercial and organic fertilizers, fossil fuel
combustion, nitric acid production, and biomass burning.
- Chlorofluorocarbons (CFCs). Of industrial origin used in a number of
applications, but now largely regulated in production and release to the
atmosphere. They are also greenhouse gases.
EFFECTS
·
Earth will become warmer.
·
Warmer conditions will probably lead to
more evaporation and precipitation overall, but individual regions will vary,
some becoming wetter and others dryer.
·
A stronger greenhouse effect will warm
the oceans and partially melt glaciers and other ice, increasing sea level.
·
Ocean water also will expand if it
warms, contributing further to sea level rise.
·
Higher temperatures and shifting climate
patterns may change the areas where crops grow best and affect the makeup of
natural plant communities.
OZONE
DEPLETION
The theory about ozone depletion was
first put forward in 1974 by American scientists Mario Molina and F. Sherwood
Rowland. Ozone
depletion is the thinning of ozone
layer, which is most pronounced in the polar regions, especially over Arctic
and Antarctic region. It is a major environmental problem because it increases
the amount of uv radiation that reaches Earth’s surface, which increases
the rate of skin cancer, cataract and genetic and immune system damage. Ozone layer is expected to recover over
time. Measurements from satellites, aircraft, ground-based sensors, and other
instruments indicate that ozone decreased globally. The largest decreases in
ozone took place in toward the poles and the smallest decreases occurred in
tropical areas. In addition, atmospheric measurements show that the depletion
of the ozone layer increased the amount of UV radiation reaching Earth’s
surface. This global decrease in stratospheric ozone is well correlated
with rising levels of chlorine and bromine stratosphere from the manufacture
and release of CFCs and other halo carbons from refrigerants and large
chillers, propellants for aerosol cans, blowing agents for
making plastic foams, firefighting agents etc.
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