Internal Evs Notes

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Agriculture

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Modern methods of agriculture have resulted in use of fertilisers and pesticides to increase the

yield of the crops. Most of them are synthetic and chemicals-based. They are collectively calledagro-chemicals. These chemicals enter into the water bodies with the rain water flow and theground water by seepage. The chemicals remain in the environment for a long time and can enter

the food chain. They cause a number of problems in the animals.

Oil

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Oil spill is a major problem in the oceans and seas. The oil tankers and offshore petroleum

refineries cause oil leakage into the waters. This pollutes the waters. Oil floats on the watersurface and prevents the atmospheric oxygen from mixing in the water. The oil enters the bodyof the organisms. It also coats the body of the aquatic animals and birds which may also kill

them.

Pollutant Source/Cause Effect

Sewage that includesdomestic wastes, hospital

wastes, excreta, etc.

Sewarage of rural

and urban areas.Oxygen depletion Spread of diseases/ epidemics

Metals-Mercury Industnal wastes

Minamata disease (resulted from the

contaminated waters of the Minamata bay in

Japan in 1953) - causes numbness of limbs, lips

and tongue, blurred vision, deafness and mental

derangement.

Lead Industrial wastes

Absorbed into blood and affects PBCs, liver,

kidney, bone, brain and the penpheral nervous

system. Lead poisoning can even lead to coma.

Cadmium Cadmium

industnes,

Deposited in organs like the kidney, pancreas,

liver, intestinal mucosa, etc. Cadmium poisoning
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Pollutant Source/Cause Effect

fertilisers causes headache, vomiting, bronchial

pneumonia, kidney necrosis, etc.

Arsenic Fertilisers

Arsenic poisoning causes renal failure and

death, It can cause nerve disorder, kidney and

liver disorders, muscular atrophy, etc.

Agrochemicals like DDT Pesticides

Accumulates in the bodies of fishes, birds,

mammals including man. Adversely affects the

nervous system, fertility. Causes thinning of egg

shells in birds.

Effects of Water Pollution

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Eutrophication

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Water bodies are being constantly polluted by dumping of sewage which includes organic matterand by the runoff from the agricultural fields that contains fertilisers. Pollutants like sewage,

organic wastes and fertilisers contain good amount of inorganic nutrients like nitrates andphosphates.

These nutrients enrich the water promoting the growth of algae. The water turns green. This is

called algal bloom. Rich algal growth leads to great increase in the number of the decomposers.

All these life forms-decomposers, algae, other plants, fishes and other aquatic animals, use the

oxygen in the water for respiration. This causes great demand for oxygen and results in depletion

of oxygen.

Pollution is measured by knowing the biological oxygen demand (BOD). Low BOD means littlepollution and high BOD means higher pollution.

Eutrophication also results in overgrowth of plants like Eicchornia that covers the entire surface

of water. This reduces the light reaching the lower layers in water.
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Control of Water Pollution

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Sewage Treatment

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The sewage before being let into the water bodies must be purified.

This is done in three steps as follows:

Primary treatment Secondary treatment Tertiary treatment Effluent treatment

Primary Treatment

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The water is sieved through coarse sieves and made to stand in sedimentation tanks. This makesthe heavy suspended matter settle down. It is then passed through a bed of rocks.

Secondary Treatment

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The organic materials that are biodegradable are treated with the help of decomposers andoxygen. Then, the water is also chlorinated to remove the germs.

Tertiary Treatment

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This step removes the inorganic pollutants like the nitrates, phosphates, detergents, metal ions,etc. by passing the water through activated charcoal that acts as a filter.

Effluent Treatment

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The industrial wastes should be treated before being let into the water bodies. The toxic materialsshould be removed, the metallic compounds should be precipitated, the acids and alkalis should

be neutralized and the temperature of the hot waters should be reduced.

Public Awareness

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The public should be made aware of the dangers of water pollution. This will ensure that thewater bodies are not contaminated and are maintained clean.

BIODIVERSITY:

Biodiversity is the number of different species within an area and also the genetic variation that

exists within each species. It also includes the range of habitats and communities that are present

in an area.

Biodiversity can be defined as the number of plant and animal life that lives in a certain area or

habitat. It can refer to a small area (biome) or the entire planet. A good way to remember this is

that the prefix bio is a Greek word meaning life and diversity means variety or assortment. So

biodiversity therefore means the variety of life found in an area.

. What is Biodiversity?

What is biological diversity ? In its narrowest sense this term refers to the number of species on

the planet, and it also is used more broadly as an umbrella term.

Biological diversity refers to the variety and variability among living organisms and theecological complexes in which they occur. Diversity can be defined as the number of different

items and their relative frequency. For biological diversity, these items are organized at many

levels, ranging from complete ecosystems to the chemical structures that are the molecular basis

of heredity. Thus, the term encompasses different ecosystems, species, genes, and their relativeabundance (Office of Technology Assessment, 1987). Or to paraphrase: number and variety of

species, ecological systems, and the genetic variability they contain.
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Threats to Biodiversity

These include:

The unsustainable harvesting of natural resources, including plants, animals and marinespecies.

The loss, degradation or fragmentation of ecosystems through land conversion foragriculture, forest clearing etc.

Invasive non-native or 'alien' species being introduced to ecosystems to which they arenot adapted i.e. where they have no, or not enough, predators, to maintain an ecological

balance.

Pollution Climate change

The first two have taken place throughout human history, although not on the current scale. The

introduction of invasive species is certainly facilitated, if not caused, by the level of internationaltransport and traffic of goods of our trade system. The latter two are definitely products of an

industrial age.

Habitat loss and fragmentation is considered by conservation biologists to be the primary

cause of biodiversity loss. Clearance of native vegetation for agriculture, housing, timber and

industry, as well as draining wetlands and flooding valleys to form reservoirs, destroys thesehabitats and all the organisms in them. In addition, this destruction can cause remaining habitats

to become fragmented and so too small for some organisms to persist, or fragments may be too

far apart for other organisms to move between.

Invasive alien species are the second greatest threat to biodiversity worldwide. Whether

introduced on purpose or accidentally, non-native species can cause severe problems in the

ecosystems they invade, from affecting individuals to causing huge changes in ecosystemfunctioning and the extinction of many species. Virtually all ecosystems worldwide have

suffered invasion by the main taxonomic groups. This problem will probably get worse during

the next century driven by climate change, and an increase in global trade and tourism. As wellas the risks to human health, alien species inflict massive economic costs to agriculture, forestry,

fisheries and other human activities.


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Preventing Species IntroductionsIt is often much easier and less expensive to prevent a problem from developing in the first place than t

try to fix it once it occurs. This is the case with invasive species, which can wreak havoc when introducto ecosystems that arent prepared to deal with them. Many governments prohibit bringing foreign plan

and animals into their countries without authorization; some even go so far as to disinfect landing plane

and the shoe-bottoms of people on them.

Informing / EducatingEducation is a powerful tool, and the more people know about biodiversity loss, the more they will be

prepared to help slow it. Spreading the word about detrimental human effects on plants and animals canencourage people to change their ways and effect changes to preserve biodiversity.

Slowing Climate Change

Climate change is the documented cause of several extinctions that we know about, and has likely caushundreds of species to go extinct about which we may never know. Any efforts as individuals,

organizations, or governments, to slow current human-caused global warming is a step towards slowing

biodiversity loss.

Promoting Sustainability

Sustainable agriculture is much better for the environment than grazing and cropping that rely on cleari

swathes of forest or field.


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SUSTAINABLE DEVELOPMENTHuman greed must be controlled and human wants and needs must be restricted. We must

treat our environment and resources with respect and stop their reckless exploitation ofnatural resources.

Sustainable development emphasizes that rate of consumption and use of natural resources

must balance. The rate at which these resources can be either substituted or replaced.

Economic and industrial development must go on in such a way that no irreparable damagebe done to the environment. The World Commission on Environment and developmentdefined sustainable development as Development that meets the needs of the present

without compromising the ability of the future generations to meet their own needs. This definition emphasizes two important points. One, the natural resources are important for

our present day survival as for the survival of our future generations. Two, any present

developmental activity or programme must take into account, its future consequences.

The main cause of unsustainability is in ever increasing human population and overexploitation of resources. In developing countries, resource exploitation occurs mainly to

meet the needs of human population for food, fodder, fuel, wood and shelter. Human

activities affect the sustainability of biosphere. The various human activities meant to improve

the quality of life are usually accompanied by environmental degradation. Such activities asoverfishing, agriculture, over use of fresh water supply, deforestation and industrialization cause

environmental degradation and social stress because of negative changes in the ecosystem.

What is global warming?

Global warming is when the earth heats up (the temperature rises). It happens when greenhouse

gases (carbon dioxide, water vapor, nitrous oxide, and methane) trap heat and light from the sun

in the earths atmosphere, which increases the temperature. This hurts many people, animals,

and plants. Many cannot take the change, so they die.


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water, and land) are sent into the air when fossil fuels are burned. Some of these chemicals are

called greenhouse gasses.

When we throw our garbage away, the garbage goes to landfills. Landfills are those big hills that

you go by on an expressway that stink. They are full of garbage. The garbage is then sometimes

burned. This sends an enormous amount of greenhouse gasses into the air and makes global

warming worse.

Another thing that makes global warming worse is when people cut down trees. Trees and other

plants collect carbon dioxide (CO2), which is a greenhouse gas.

What is Acid Rain?

Acid rain is the term used in environmental science that represents mixing of environmentalpollutantswith the rain water. The mixing raises the acidity of rain water by formations of acids

following chemical reactions involving pollutant gases and water. The major pollutants that

cause acid rain are sulfur dioxide (SO2) and nitrogen oxides (NOx) produced during the

combustion of fossil fuels.

When these gases are released into atmosphere afterthe combustion of fossil fuels, these gases accumulates in the atmosphere. After that the

chemical reaction starts between the gases and the water vapours. The oxidation of the gases

converts sulfur dioxide (SO2) into sulfuric acid (H2SO4) and nitrogen oxides (NOx) to nitricacid (HNO3). When rain falls, these dissolved deposits are returned back to earths surface in the

form of acid rain.

Most of these gases are released into atmosphere by the electrical utilities during combustion of

coal. Electrical utilities contribute about 70% of sulfur dioxide (SO2) and 30% of nitrogenoxides (NOx). The other source is the automobile sector that contributes about 40% of the

nitrogen oxides (NOx).
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The acidity of the acid rain is measured by its pH. pH value is represented by a scale of 1-14.

The lesser the pH value is, more acidic is the water. pH value 7 represents neutral solution i.e.

neither acidic nor base. The pH of the non polluted rain lies between 5-5.6. The reason being thenatural processes also emits these pollutant gases into the atmosphere. The pH of the acid rain

may fall to 4.0 or even less depending on the intensity of pollution.

Effects of Acid Rain on Environment:

The acid rain cause threat to forests and water bodies. The pollutants gets deposited on thesurface of the plants and interfere with photosynthesis. This abruptly cause death of the plants.

Acid deposition due to rainfall has the potential to affect sensitive forests.

Acid rain also affects buildings and monuments. The Taj Mahal in Agra, which is among worlds

seven wonders is losing its shine because of acid rain. Exposure of building materials used in

monuments (e.g., zinc, marble, limestone etc.) to acidic rainfall can result in deterioration of thesurface.

The other devastating effect of acidic deposition in the water bodies is the declining biodiversityin the lakes and ponds. Many marine species that are part of food chain can not survive below

pH value of 6. This further affects the other members of the food chain and the food chain is

destroyed.

Ozone Depletion

Meaning, Term, and Glossary Definition - What is Ozone Depletion?

Destruction of the stratospheric ozone layer which shields the earth from ultraviolet radiationharmful to life. This destruction of ozone is caused by the breakdown of certain chlorine and/orbromine containing compounds (chlorofluorocarbons or halons), which break down when they

reach the stratosphere and then catalytically destroy ozone molecules.

Causes: Chlorofluorocarbons (CFCs) and other halogens (all man-made gases) emitted from

industry rise to the stratosphere where ultraviolet radiation breaks them up and releases their

chlorine. Chlorine destroys the ozone layer.

Effects: Decreasing ozone means increases in melanoma (skin cancer), cataracts, famine (loss of


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arable land, and damage to crops). This would only occur in areas that had this thinning or hole

in the ozone.

More detail

Causes:

CFCs and related halocarbon gases are the main cause of ozone depletion all over the world.CFCs released from Western countries take several years to reach the stratosphere where the

ozone layer is. During that time winds spread them all over the world. In the presence of

ultraviolet light these gases release chlorine and bromine atoms which destroy some of the ozonein the ozone layer. This is called ozone depletion. The ozone hole is a related but different

phenomenon.

Effects:Earth's surface receives more UltraViolet-B, as ozone is the only gas currently in our atmosphere

that absorbs UltraViolet-B. UltraViolet-B is also absorbed by soil, meters depth of water, and

directly by the DNA of all surface life. DNA absorbing UltraViolet-B ends up increasing rates

of cancer, mutation, and decreases crop yields. UltraViolet-B also causes cataracts to form ineye structures in animals (including Man).

. International Efforts on environmental management(agenda 21)

Introduction

Mans concern for natural environment has always been there but his serious concern about the

issues of resource depletion and degrading environment/ecosystem began after World War II

when industrialisation started vigorously. However, nothing tangible was done to control damage

afflicted to environment till 1960s.

In the early decades industry, trade and business resisted efforts aimed at environmental

protection and resource conservation because money spent on such efforts would diminish profit.

However, the attitude is changing, not because of legal action only but also due to realisation that

cutting down on raw material and generating less waste could be a financial gain. Also, there was

an International angle to environment which could not be ignored. It became clear that problems

like Ozone Depletion or Global Warming cannot be tackled at national level alone. Leaders,

politicians and people in general, therefore, started looking up at organisations like UN for

environmental issues.

United Nations Conference on Human Environment, 1972

It was in the light of above mentioned scenario that the United Nations Conference on Human

Environment was held in 1972 at Stockholm. It marked the beginning of organised international


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efforts for comprehensive programme to safeguard environment while also promoting economic

development. The following two strategies emerged in this conference.

1. The principles and action plan were evolved for controlling and regulatinghuman environment.

2.

Institutional and financial arrangements were proposed for achieving the goalfor regulating human environment. This has been called theMagna Carta on

environment. It declared:

a) Humans have the fundamental right to freedom, equality and adequateconditions of life in an environment of quality that permits a life of dignity

and well-being.

b) Human beings have responsibility to protect and improve the environment forpresent and future generations.

General Assemblys Resolution of December, 1972

Stockhom Conference was followed by the United Nations General Assembly resolution on

December 15, 1972 emphasising the need of active cooperation among the States in the sphere ofhuman environment. The Resolution designated June 5 as the World Environment Day and urged

governments and organisations in the United Nations system to undertake on that day every year

worldwide activities reaffirming their concern for the protection of the environment. Another

resolution was passed which provided for institutional and financial arrangements for

international cooperation for environment. Amongst other decisions, provisions were made for

establishing a Governing Council for Environmental Programme (Headquarter at Nairobi)

leading to establishment of Environment Secretariat and Environment Fund. The Governing

Council formulated long-term and short-term plans for the protection of environment particularly

relating to development.

Charter of Economic Rights and Duties of States, 1974

The Charter of Economic Rights and Duties of States 1974 is a document of UN. One of its

articles states that:

The protection, preservation and the enhancement of the environment for the present and future

generations is the responsibility of all States. All States have the responsibility to ensure that the

activities within their jurisdiction or control do not cause damage to the environment of other

States or of areas beyond the limits of national jurisdiction. All States should cooperate in

evolving international norms and regulations in the field of the environment.

UN-Habitat Conference on Human Settlement of 1976, World Water Conference of 1977

and Other Conferences

The international efforts at the protection and preservation of environment became vigorous in

1970s and 1980s. Most important efforts are the following:

1. UN Habitat Conference on Human Settlements in Vancouver, Canada in 1976.


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2. World Water Conference in Mardel Plata, Argentina in 1977. The World WaterConference called upon the UN to establish a programme with a goal of providing

clean drinking water and sanitation to all.3. The UN Desertification Conference held in Nairobi in 1977.4. Paris Conference, held in 1986 called for saving trees and forests. The

Conference was attended by Heads of States and Government officials from36 countries.

Environmental Education Conference

In 1977, United Nations Environment Programme (UNEP) and United Nations Educational,

Scientific and Cultural Organisation (UNESCO) organised an Intergovernmental Education

Conference at Georgia. The Conference was attended by over 400 delegates from 74 countries.

The UNEP Executive Director underscored that environmental education was a matter of life and

death and that problems of environment were jeopardising the development of mankind.

World Commission on Environment and Development

In 1980s, international community became seriously concerned with increasing problems of

environment. Problems of ozone depletion, climate change (global warming), declining of

fisheries and forest cover, loss of biodiversity, pollution and hazardous wastes attracted the

attention at global level. Equally, issues of sustainable development became of paramount

importance especially for the developing countries.

Earth Summit 1992*

Introduction

UN convened a United Nations Conference on Environment and Development (UNCED) at Riode Janerio in 1992. It is called Earth Summit. An eight hundred page document, called Agenda

21, was issued at this Conference. It contains comprehensive blueprint for governments on

everything from population strategy, management of hazardous wastes, recycling, energy

conservation, renewable energy, business strategies to role of women in environment.

Rio Declaration

Having met at Rio de Janerio from 3 to 14 June, 1992:

Reaffirming the Declaration of the United Nations Conference on the HumanEnvironment, adopted at Stockholm on 16 June, 1972, and seeking to build uponit;

With the goal of establishing a new and equitable global partnershipthrough the creation of new levels of cooperation among States, key sectorsof societies and people;

Working towards international agreements which respect the interests of all andprotect the integrity of the global environmental and developmental system;

Recognising the integral and interdependent nature of the Earth, our home;


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Earth Summit +5 *

The governments acknowledged that global environment has continued todeteriorate since Earth Summit 1992 with increasing emissions of greenhouse

gases and generating of more solid wastes. Also pollution and effluent treatmentcontinue to be major problems.

Renewable resources like fresh water, forests, fish continue to be used at anunsustainable rate. On the positive side it is noted that:

i) World population is slowing, ii) Food protection is rising, iii) Life span has

increased.

Ear th Summit +5 addressed itself the above concerns and the participating governments took

action on several fr onts and agreed to the foll owing:

Reconfirm the political commitment to sustainable development from allmembers of the international community, as well as from all major groups of

civil society; Reconfirm the financial commitments and targets for official development

assistance (ODA) made by industrialised countries at the Earth Summit, and

call for intensified efforts to reverse the downward trend in ODA;

Earth Summit 2002- Johannesburg Summit

The summit reaffirmed sustainable development as a central elements of theinternational agenda and gave a new impetus to global action to protect environment

and fight poverty. It was decided to establish World Solidarity Fund for eradication

of poverty. The linkages between poverty and environment/resource use was re-

examined to strengthen this relationship.

Governments agreed to reaffirm the targets and commitments for action forbetter implementation of sustainable development.

Energy and sanitation issues became important elements of negotiation thanprevious international meetings.

It was decided to pay special attention and support for development of Africa. Key role of Civil society and NGO's was recognised in promoting partnership

among business, Governments and society. Many partnerships were announced

during the Summit.

Specif icall y, Johannesburg outl ined the foll owing key commitments, targets and time tables:

1. Poverty Reduction2. Water and Sanitation3. Sustainable Production and Consumption4. Energy5. Chemicals6. Management of Natural Resource Base7. Corporate Responsibility8. Health9. Sustainable Development of Small Island Developing States


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10. Sustainable Development for Africa

SHORT NOTES:

What is meant by ecosystem?

The term ecosystem refers to the combined physical and biological components of an

environment. An ecosystem is generally an area within the natural environment in which

physical (abiotic) factors of the environment, such as rocks and soil, function together along withinterdependent (biotic) organisms, such as plants and animals, within the same habitat to create a

stable system. Ecosystems can be permanent or temporary. Ecosystems usually form a number of

food webs.

Ecosystem is a functional unit consisting of living things in a given area, non-living chemical

and physical factors of their environment, linked together through nutrient cycle and energy

flow.

LEVELS OF BIODIVERSITY:

1. Genetic Diversity: Variation between individuals of same species Genes, made of DNA , are the building blocks that determine how an organism will

develop and what its traits and abilities will be

2.Species Diversity

Variety of species in a given region or area They are easier to conceptualize and have been the basis of much of the evolutionary and

ecological research that biodiversity draws on

3.Ecosystem Diversity Communities of plants and animals, together with the physical characteristics of their

environment interlink together as an ecological system

Ecosystem diversity is more difficult to measure because there are rarely clearboundaries between different ecosystems and they grade into one another


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What is the Water Cycle?

Thewater cycleis also known as thehydrologic cycle. Thereis the same amount of water on the Earth now as there was when the Earth began. The watercycle is how the earth's water recycles itself.

The cycle includesprecipitation,evaporation,condensation, andtranspiration. Earth's water

keeps changing from liquid water to vapor and then back again. This cycle happens because ofthe sun's heat and gravity.

How does the Water Cycle work?

Watermoleculesfrom lakes, rivers, streams, reservoirs, and the ocean getheated by the sun and turn into vapor that rises into the air. [evaporation]

Plants are heated by the sun, too, and send water molecules into the air through

their leaves. [transpiration]

These water molecules form into clouds.

When the air and the water cool, they form drops of water that fall to the earthas rain. If they are frozen, they become snow or sleet. [condensation] The

vapor has changed into a liquid.

Once the water reaches the ground, it can flow across the land until it reaches

rivers, lakes, streams, or the ocean. This is surface water. It can also sink intothe ground and flow with gravity through gaps in rock, gravel, and sand until it

reaches these bodies of water, too. This is groundwater.

The cycle begins again.
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What are renewable and non renewable resources and their uses?

Uses:

All these resources are being mainly used to generate electricity. Oil is also used for transportand the production of plastics. Minerals like iron ore and gold are nonrenewable, but may be

recycled and reused.

Renewable Resources

A renewable resource is something that is being continually replaced faster than we use it up.

Solar energy is considered a renewable source of energy because the sun's energy iscontinuous. (Note that the rest of this list are all forms of solar power.)

Wind Power Water Power (Hydro-electricity from dammed rivers, tidal streams and ocean waves) Thermal Power from the earth (Geothermal: Using the earth's heat to generate electricity) Thermal Power from the ocean Biomass, the burning of plant material, is a renewable resource. Even though the burning

puts carbon dioxide into the atmosphere, it also prevents a much greater amount ofmethane being released by the decomposing vegetation, so it is rated as positive.

Trees are renewable because we can replant them.

Non-Renewable Resources

A non-renewable resource is something that is not being replaced as we consume it.

Oil is a good example of a non-renewable resource. It is used to make gasoline and otherfuels, as well as plastics, such as grocery bags. We are using billions of gallons of oil

every year, but it takes millions of years to be replace. We are using up oil much muchfaster than it is being produced. Once we use up oil from the earth, it 's gone. We can't

wait millions of years for some more.

Coal is non-renewable. Peat is non-renewable.

Uranium is non-renewable.


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Difference between Endangered and extinct species?

Endangered means in danger of being extinct that is there are very few organisms

of that species and it is in the danger of becoming extinct.

Extinct means that there are no more organisms of that species on the earth. We

cannot see them again

And Most importantly let us not weep about the extinct ones but protect the

endangered ones.

Examples for endangered species is the tiger and the asiatic lion while the dodo

bird is an extinct species.

What Is The Difference Between Extinct And Endangered?

The difference between extinct and endangered is that extinct means the specie

that is extinct is completely gone forever, most of the time because of humans

from pollution or from hunting, and endangered means that there are a few of thespecie left but they are nearly extinct

Endangered Species are ones that have a very smallpopulation and that population is at a greater risk ofbecoming extinct. Many species that become extinct never

make to the endangered species list.

Extinct Species are ones that are either known (documented)

to be extinct or are so few in population that a recovery is

considered highly unlikely even under excellent conditions.

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