BIOLOGY FOLIO

CHAPTER 8:ENDANGERED ECOSYSTEM

NAME : MEGAT AHMAD KAMARUL BIN MEGAT

ZULKIFLI

CLASS : 402

TEACHER : MISS ZALILI

SCHOOL : MRSM PENGKALAN HULU

NO CONTENT PAG

E

I. Introduction

II. Objective

III. Human Activities That Endanger An

Ecosystem

i. Cause

ii. Source

IV. Greenhouse Effects And The Thinning Of

Ozone layer

V. Steps To Maintain stable Environment

VI. Conclusion

VII. Reference

CONTENT

INTRODUCTION

A healthy yet picturesque environment is always a significant dream to others . However numerous negative impact from un responsible human activities has

greatly affect our dream environment . It has not only cause in balance in environment but also causes various environmental problem besides endangering the ecosystem. The only way for us and the future generation to have a sense of peace mind living in the dream picturesque environment is mainly by planning development activities with great care which will possibly not affecting the environment at all. After all environment is our main home. So the environment should be preserved starting from now onwards so that the future generation will be able to feel the environment which we are experiencing now .

THE REASON FOR THE PAPERWORK IS BEING DONE IS DUE TO SEVERAL OBJECTIVES AS STATED BELOW :

To in still awareness among human about the importance of the preservation and the conservation of the ecosystem .

To sensitize humans on various type of negative effects of their activities towards the environment .

To raise the efforts of creating a convenient , safer yet conducive environment for ourselves and the future generations .

To deduce the time for the depletion and the destruction of the environment due to the environmental problems caused by human beings .

APPRECIATION

I , Megat Ahmad Kamarul Bin Megat Zulkifli from 402 would like those who have been indirectly or directly involved in the making of this folio titled “ENDANGERED ECOSYSTEM” . Ministry Of Education’s effort in organizing the making of this folio is highly appreciated in a way of increasing students understanding in biology .Hence, not only increasing student’s level of understanding , but also increasing the value of studying biology as it is related to our living .

By doing this folio, it does not only increase my understanding towards biology ,also it makes me grow enthusiastic towards the

intriguing subject, biology .I have now completed a paperwork on the topic “ENDANGERED ECOSYSTEM” based on the last chapter in the form 4 syllabus.

Nevertheless ,I felt relief and grateful upon having such fabulous companion and references who were my biology teacher Miss Zalili ,my parents ,helpful friends also siblings .I was really thankful to those who have helped me out ,being supportive yet helpful especially in providing extra information on the topic which is given to in the making of this folio .Without their help surely I will not be able to make this folio as a satisfying piece.

Human activities that threaten the ecosystem

The worlds population might reach to 10 billions in the next fifty years .Hence, when there are increments in the number of the worlds population , it generally means that there is an increasing demand for shelter, food, medicine, transport and raw materials .

Today, due to expectation of modern living and industrial revolution, the world has to confront the destruction of forests to build more houses, to being use as plantation areas and build roads, just to fulfil humans needs .

1.0 - HUMAN ACTIVITIES THAT ENDANGER THE ECOSYSTEM

Unplanned developments and mismanagement of ecosystem give rise to vast amounts of environmental crisis. Among those environmental problems are greenhouse effect, global warming, pollution, soil erosion, landslide, flash flood and ozone depletion .

The human activities that we are talking about are like agriculture, burning or combustion, industrialization, urbanization and last but not least, deforestation.

Large agriculture of forests are cleared for extracting timber of fuel wood , agriculture needs, and for the sake of urbanization. The impacts are enormous and outrageous. Let see what are the drawbacks of deforestation .

1. LANDSLIDES Soil erosion is blocked. Thus, water flows inland and causes flash

flood and landslides. When it rains for a long time especially during rainy season, the

top layer of soil loosens and slides down , thus causing landslides.

DEFORESTATION

2. SOIL EROSION leaning of trees causes the loss of tree leaves that protect the soil

from a massive impulsive force of heavy raindrops and also causes the loss of tree roots that hold the soil in place

The wide exposure to the raindrops forces, give arise to soil erosion. Here ,the top layer of soil is easily being washed away by heavy rainfall. The eroded soil, is then, deposited in rivers or streams.

3. FLASH FLOOD During heavy rains, rainwater flows harshly into rivers because

there is a non-existence of retention of water by plant roots as well as proper water catchments areas

Due to silting in the rivers, the water flow is blocked. Thus, water flows inland and causes flash floods in low areas.

In addition, soil erosion contributes in the depletion of minerals in the soil, causing the land trouble to be used as a place of cultivation.

4. FARMING

In order to full fill the demands of todays food supplement, large areas of lands have been used and will be used for farming purposes.

Excessive use of land for farming and stock rearing lead to infertile land and may expose the soil to erosion by wind or heavy rainfalls.

Inorganic fertilizers usage in farming also results to eutrophication.

5. URBANISATION

Industrialisation give off industrial waste and heated waste water causing water pollution and thermal pollution.

Toxic gases released by industries contribute to a major concerning problem ; air pollution.

What Is A Greenhouse Effects?

The greenhouse effect is a process by which radioactive energy leaving a planetary surface is absorbed by some atmospheric gases, called greenhouse gases. They transfer this energy to other components of the atmosphere, and it is re-radiated in all directions, including back down towards the surface. This transfers energy to the surface and lower atmosphere, so the temperature there is higher than it would be if direct heating by solar radiation were the only

3.0 THE GREENHOUSE EFFECTS

warming mechanism. This mechanism is fundamentally different from that of an actual greenhouse, which works by isolating warm air inside the structure so that heat is not lost by convection.

Who Discovered the Greenhouse Effects?

The greenhouse effect was discovered by Joseph Fourier in 1824, first reliably experimented on by John Tyndall in 1858, and first reported quantitatively by S vante Arrhenius in 1896.If an ideal thermally conductive blackbody was the same distance from the Sun as the Earth, it would have an expected blackbody temperature of 5.3 °C. However, since the Earth reflects about 30% (or 28%) of the incoming sunlight, the planet's actual blackbody temperature is about -18 or -19 °C, about 33°C below the actual surface temperature of about14 °C or 15 °C.

The mechanism that produces this difference between the actual temperature and the blackbody temperature is due to the atmosphere and is known as the greenhouse effect

Global warming, a recent warming of the Earth's surface and lower atmosphere, is believed to be the result of a strengthening of the greenhouse effect mostly due to human-produced increases in atmospheric greenhouse gases.

 The ozone layer protects the Earth from the ultraviolet rays sent down by the sun. If the ozone layer is depleted by human action, the effects on the planet could be catastrophic. Ozone is present in the stratosphere. The stratosphere reaches 30 miles above the Earth, and at the very top it contains ozone. The sun’s rays are absorbed by the ozone in the stratosphere and thus do not reach the Earth. Ozone is a bluish gas that is formed by three atoms of oxygen. The form of oxygen that humans breathe in consists of two oxygen atoms, 2.When

4.0 THE THINNING OF THE OZONE LAYER

found on the surface of the planet, ozone is considered a dangerous pollutant and is one substance responsible for producing the greenhouse effect.

The highest regions of the stratosphere contain about 90% of all

In recent years, the ozone layer has been the subject of much discussion. And rightly so, because the ozone layer protects both plant and animal life on the planet .The fact that the ozone layer was being depleted was discovered in themid-1980s. The main cause of this is the release of CFCs (chlorofluorocarbons) .Antarctica was an early victim of ozone destruction. A massive hole in the ozone layer right above Antarctica now threatens not only that continent, but many others that could be the victims of Antarctica's melting icecaps. In the future, the ozone problem will have to be solved so that the protective layer can be conserved.

5.1 Managing development activities to ensure a balanced ecosystem.

1. Enforcement of   the environmental laws Environment quality act, 1974 Controls and prevents the pollution of the environment Controls the type of licensing, contentand quality of environment Tests and examines the samples of substances and gas from industries Natural forestry act, 1984

-Aims at protecting and preserving our forests and wildlife Pesticides act, 1974

5.0 THE IMPORTANCE OF PROPER MANAGEMENT OF DEVELOPEMENTACTIVITIES AND ECOSYSTEM

-Aims at controlling the use of pesticides Protection of wildlife act, 1972

-Aims at protecting wildlife animals, birds and plants Fisheries act, 1985

-Aims at controlling marine pollution

2. Use Of Technology

Use modern equipment and chemicals to control oil spills. Recycle rubbish. To look for methods to do research. Change organic rubbish to biogas. Use less polluting and clean fuels in motor vehicles. Control and treat the toxic and dangerous waste before disposing.

3. Preservation And Conservation Of The Ecosystem

Force the development companies to replant the forest trees after deforestation.

Remaining the mangrove swamps area so that the ecosystem is protected. Restore the mining and used land for agriculture. Put effort in rivers cleaning to ensure there is sufficient supply of water in

future) Practice of biological control. A method of controlling the animal pests by using natural predators

instead of using chemical substances. Factors to choose the animals predators.

4. Biological Control

Pesticides are expensive and toxic to non-pest,while pests may build up stronger resistance to the pesticides used.Pesticide also contributes water and air pollution

Biological control is an alternative method to control pest.It involves the use of the pest’s natural predator to keep the population of the pest at a minimum level.

Female overfly is used to control the population of aphids which suck the nutrient of wheat plants

5. Use of renewable energy

Renewable enery is an energy that occurs naturally and is inexhaustible. It does not contribute to any type of pollution.

Examples are solar energy,wind energy and hydroelectric.

The effects of unplanned development and mismanagement of the ecosystem can lead to damaging consequences such as soil erosion, flash floods, landslides, eutrophication ,pollution global warming, ozone depletion, climatic changes and loss of biodiversity. There are four types of pollution which are air ,water, thermal, and noise pollution. Greenhouse gases released by various human activities can trap heat in the atmosphere and raise the Earth’s average temperature. Such an overall rise in the Earth’s temperature can leads to global warming. The thinning of ozone

Conclusion

layer is mainly due to the accumulation of chloroflurocarbon (CFCs) in the atmosphere. Sustainable development must take into consideration of proper management of the ecosystem to ensure a balance of nature is maintained.

Biology Form 4 Text Book. Success (Oxford Fajar) Biology < 2012 edition > reference books.

REFERENCES

2.1 Air pollution

Air pollution is the introduction of chemicals, particulate matter,

or biological materials

that cause harm or discomfort to humans or other living organisms, or

damages the natural

environment into the atmosphere.

The atmosphere is a complex dynamic natural gaseous system that

is essential to support life on planet Earth. Stratospheric ozone depletion

due to air pollution has long been recognized as a threat to human health

as well as to the Earth's ecosystems.

Air pollution from World War II production

Pollutants

An air pollutant is known as a substance in the air that can cause harm to

humans and the

environment. Pollutants can be in the form of solid particles, liquid

droplets, or gases. In addition,they may be natural or man-made.

Pollutants can be classified as either primary or secondary. Usually,

primary pollutants aresubstances directly emitted from a process, such as

ash from a volcanic eruption, the carbon

monoxide gas from a motor vehicle exhaust or sulfur dioxide released

from factories.Secondary pollutants are not emitted directly. Rather, they

form in the air when primary pollutantsreact or interact. An important

example of a secondary pollutant is ground level ozone— one of the

many secondary pollutants that make up photochemical smog. Note that

some pollutants may be both primary and secondary: that is, they are

both emitted directly and formed from other primary pollutants.About 4

percent of deaths can be attributed to air pollution, according to the

Environmental Science Engineering Program at the Harvard School of

Public Health.

causes and effects of air pollution: (1) greenhouse effect, (2) particulate contamination,

(3) increased UV

radiation, (4) acid rain, (5) increased ozone concentration, (6) increased levels of

nitrogen oxides

Major primary pollutants produced by human activity include:

Sulphur oxides  (SOx) - especially sulfur dioxide, a chemical

compound with the formula SO2. SO2 is produced by volcanoes and

in various industrial processes. Since coal and petroleum often

contain sulfur compounds, their combustion generates sulfur

dioxide. Further oxidation of SO2, usually in the presence of a

catalyst such as NO2, forms H2SO4, and thus acid rain. This is one

of the causes for concern over the environmental impact of the use

of these fuels as power sources.

Nitrogen oxides (NOx) - especially nitrogen dioxide are emitted from

high temperature combustion. Can be seen as the brown haze

dome above orpl ume downwind of cities.

Nitrogen dioxide is the chemical compound with the formula NO2.

It is one of the several nitrogen oxides. This reddish-brown toxic gas has

a characteristic sharp, biting odor.NO2 is one of the most prominent air

pollutants.

Carbon monoxide - is a colourless, odourless, non-irritating but very

poisonous gas. It is a product by incomplete combustion of fuel such

as natural gas, coal or wood. Vehicular

exhaust is a major source of carbon monoxide.

Carbon dioxide (CO2) - a greenhouse gas emitted from combustion

but is also a gas vital to living organisms. It is a natural gas in the

atmosphere.

Volatile organic compounds - VOCs are an important outdoor air

pollutant. In this field they are often divided into the separate

categories of methane (CH4) and non-methane (NMVOCs). Methane

is an extremely efficient greenhouse gas which contributes to

enhanced global warming. Other hydrocarbon VOCs are also significant

greenhouse gases via their role in creating ozone and in prolonging the

life of methane in the atmosphere, although the effect varies depending

on local air quality. Within the NMVOCs, the aromatic compounds

benzene, toluene and xylene are suspect carcinogens and may lead to

leukemia through prolonged exposure. 1,3-butadiene is another

dangerous compound which is often associated with industrial uses.

Particulate matter - Particulates, alternatively referred to as

particulate matter (PM) or fine particles, are tiny particles of solid or

liquid suspended in a gas. In contrast, aerosol refers to particles and

the gas together. Sources of particulate matter can be man made or

natural. Some particulates occur naturally, originating from

volcanoes, dust storms, forest and grassland fires, living vegetation,

and sea spray. Human activities, such as the burning of fossil fuels

in vehicles, power plants and various industrial processes also

generate significant amounts of aerosols. Averaged over the globe,

anthropogenic aerosols—those made by human activities—currently

account for about 10 percent of the total amount of aerosols in our

atmosphere. Increased levels of fine particles in the air are linked to

health hazards such as heart disease, altered lung function and lung

cancer

Minor air pollutants include:

A large number of minor hazardous air pollutants.

A variety of persistent organic pollutants, which can attach to

particulate matter.

Persistent organic pollutants (POPs) are organic compounds that are

resistant to environmental

degradation through chemical, biological, and photolytic processes.

Because of this, they have been observed to persist in the environment,

to be capable of long-range transport, bioaccumulate in human and

animal tissue, biomagnify in food chains, and to have potential significant

impacts on human health and the environment.

Natural sources

Effects

Air pollution is responsible for major health effects.Every year, the health of

countless people is ruined or endangered by air pollution.

Many different chemicals in the air affect the human body in negative

ways.Just how sick people will get depends on what chemicals they are exposed

to, in what concentrations, and for how long.

Studies have estimated that the number of people killed annually in the US

alone could be over 50,000.

Older people are highly vulnerable to diseases induced by air

pollution.Those with heart or lung disorders are under additional risk.Children

and infants are also at serious risk. Because people are exposed to so many

potentially dangerous pollutants, it is often hard to know exactly which

pollutants are responsible for causing sickness.Also, because a mixture of

different pollutants can intensify sickness, it is often difficult to isolate those

pollutants that are at fault.

Many diseases could be caused by air pollution without their becoming

apparent for a long time.Diseases such as bronchitis, lung cancer, and heart

disease may all eventually appear in people exposed to air pollution.

Air pollutants such as ozone, nitrogen oxides, and sulfur dioxide also have

harmful effects on Natural eco systems.They can kill plants and trees by

destroying their leaves, and can kill animals, especially fish in highly polluted

rivers.

ACID RAIN

Acid rain is a result of air pollution. When any type of fuel is burnt, lots of different chemicals are produced. The smoke that comes from a fire or the fumes that come out of a car exhaust don't just contain the sooty grey particles

that you can see - they also contains lots of invisible gases that can be even more harmful to our environment. Power stations, factories and cars all burn fuels and therefore they all produce polluting gases. Some of these gases (especially nitrogen oxides and sulphur dioxide) react with the tiny droplets of water in clouds to form sulphuric and nitric acids. The rain from these clouds then falls as very weak acid - which is why it is known as "acid rain".How acidic is acid rain? Acidity is measured using a scale called the pH scale. This scale goes from 0 to 14. 0 is the most acidic and 14 is the most alkaline (opposite of acidic). Something with a pH value of 7, we call neutral, this means that it is neither acidic nor alkaline.Very strong acids will burn if they touch your skin and can even destroy metals. Acid rain is much, much weaker than this, never acidic enough to burn your skin.

Rain is always slightly acidic because it mixes with naturally occurring oxides in the air. Unpolluted rain would have a pH value of between 5 and 6. When the air becomes more polluted with nitrogen oxides and sulphur dioxide the acidity can increase to a pH value of 4. Some rain has even been recorded as being pH2. Vinegar has a pH value of 2.2 and lemon juice has a value of pH2.3. Even the strongest recorded acid rain is only about as acidic as lemon juice or vinegar and we know that these don't harm us - so why do we worry about acid rain?

The Effects of Acid Rain

Acid rain can be carried great distances in the atmosphere, not just between countries but also from continent to continent. The acid can also take the form of snow, mists and dry dusts. The rain sometimes falls many miles from the source of pollution but wherever it falls it can have a serious effect on soil, trees, buildings and water.Forests all over the world are dying, fish are dying. In Scandinavia there are dead lakes, which are crystal clear and contain no living creatures or plant life. Many of Britain's freshwater fish are threatened, there have been reports of

deformed fish being hatched. This leads to fish-eating birds and animals being affected also. Is acid rain responsible for all this? Scientists have been doing a lot of research into how acid rain affects the environment.

ForestsIt is thought that acid rain can cause trees to grow more slowly or even to die but scientists have found that it is not the only cause. The same amount of acid rain seems to have more effect in some areas than it does in others.As acid rain falls on a forest it trickles through the leaves of the trees and runs down into the soil below. Some of it finds its way into streams and then on into rivers and lakes. Some types of soil can help to neutralise the acid - they have what is called a "buffering capacity".Other soils are already slightly acidic and these are particularly susceptible to the effects of acid rain.Acid rain can effect trees in several different ways, it may:• dissolve and wash away the nutrients and minerals in the soil which help the trees to grow.• cause the release of harmful substances such as aluminium into the soil.• wear away the waxy protective coating of leaves, damaging them and preventing them from being able to photosynthesise properly.

2.2 Water Pollution

Water pollution is the contamination ofwater bodies (e.g.lakes,ri ve

rs,oceans andgro undwater). Water pollution affects plants and organisms living

in these bodies of water; and, in almost all cases the effect is damaging not only

to individualspecie s and populations, but also to the natural biological

communities.

Water pollution occurs whenpollutants are discharged directly or indirectly

into water bodies

without adequatet r e atm ent to remove harmful compounds.

Pollutants

Water pollution is usually caused by human activities. Different human sources

add to the

pollution of water. There are two sorts of sources, point and nonpoint

sources.Point sources discharge pollutants at specific locations through

pipelines or sewers into the surface water. Nonpoint sources are sources that

cannot be traced to a single site of discharge.

Pb poisoning is another serious source of environmental pollution which

causes water pollution. Pb poisoning is characterized by CNS damage, anaemia

and deposition of Pb in bones and teeth. The major sources of this pollutant are

paint manufacturing industries/factories, lead smelting works; petrol engines

discharged inorganic Pb salts, metallic Pb and organic Pb respectively. Pb

(C2H4)4 – is used as an anti knock in petrol engines and is a pollutant. The

anaemia caused by Pb is due to inhibition of haem biosynthesis. Inorganic Pb

inhibits aminolaevulinic acid dehydratase and ferrochetalase (haem synthetase)

which catalyses the formation of the pyrrole porphobilinogen and incorporation

of Fe 2+ into protoporphyrin IX respectively.

There are a lot of types of water pollution. One of them is caused by toxic

substances. This is when someone dumps out a chemical pollutant into water.

One of the greatest contributors to toxic pollution is a factory compound.

Once water is contaminated, it is difficult, expensive, and sometimes

impossible to remove pollutants. Technologies to remove contaminants from

groundwater are air stripping, granular activated carbon, and advanced

oxidation. Air stripping involves pumping out the contaminated

water, then heating it to evaporate the contaminant. The cleaned water is

reinjected into the ground. Pumping out contaminated water and absorbing the

pollutant on activated charcoal can remove less volatile compounds.

Pollutants in water include a wide spectrum of chemicals, pathogens,

and physical chemistry or sensory changes.Many of the chemical substances

are toxic. Pathogens can produce waterborne diseases in either human or

animal hosts. Alteration of water's physical chemistry include acidity,

electrical conductivity, temperature, and eutrophication. Eutrophication is

the fertilisation of surface water by nutrients that were previously scarce. Even

many of the municipal water supplies in developed countries can present health

risks.

One class of water pollutants are nutrients; they are water-soluble nitrates

and phosphates that cause excessive growth of algae and other water plants,

which deplete the water's oxygen supply. This kills fish and, when found in

drinking water, can kill young children.

Heat is a water pollutant—increased water temperatures result in the

deaths of many aquatic organisms. These increases in temperature are most

often caused by discharges of cooling water by factories and power plants.

At industrial sites, chemical spills that contain toxic substances, smoke

stacks that spew emissions and uncovered or unprotected outdoor storage or

waste areas can contribute pollutants to storm water runoff.

Sources

The specific contaminants leading to pollution in water include a wide spectrum

of chemicals, pathogens, and physical or sensory changes such as elevated

temperature and discoloration. While many of the chemicals and substances that

are regulated may be naturally occurring (calcium,so di um,iron,m angane se,

etc.) theconcentration is often the key in determining what is a natural

component of water, and what is a contaminant.

Oxygen-depleting substances may be natural materials, such

as plant matter (e.g. leaves and grass) as well as man-made chemicals. Other

natural and anthropogenic substances may cause turbidity (cloudiness) which

blocks light and disrupts plant growth, and clogs the gills of some fish species.

Many of the chemical substances are toxic. Pathogens can

produce waterborne diseases in either human or animal hosts. Alteration of

water's physical chemistry includes acidity (change in pH), electrical

conductivity, temperature, and eutrophication. Eutrophication is an increase in

the concentration of chemical nutrients in an ecosystem to an extent that

increases in the primary productivity of the ecosystem. Depending on the degree

of eutrophication, subsequent negative environmental effects such

asanoxia (oxygen depletion) and severe reductions in water quality may occur,

affecting fish and other animal populations.

2.3 Thermal Pollution

Thermal pollution is the degradation of water quality by any process that

changes ambient water temperature.

A common cause of thermal pollution is the use of water as aco o l

ant by power plants and

industrial manufacturers. When water used as a coolant is returned to the natural

environment at a higher temperature, the change in temperature (a)

decreasesoxy gen supply, and (b) affects ecosystemco m po sitio n. Urban

runoff--stormwater discharged to surface waters from roadsand parking lots--

can also be a source of elevated water temperatures.

When a power plant first opens or shuts down for repair or other causes, fish

and other organisms adapted to particular temperature range can be killed by the

abrupt rise in water temperature known as 'thermal shock'.

Pollutant

Sources

The major sources of thermal pollution are electric power plants and industrial

factories. In most electric power plants, heat is produced when coal, oil, or

natural gas is burned or nuclear fuels undergo fission to release huge amounts of

energy. This heat turns water to steam, which in turn spins turbines to produce

electricity. After doing its work, the spent steam must be cooled and condensed

back into water. To condense the steam, cool water is brought into the plant and

circulated next to the hot steam. In this process, the water used for cooling

warms 5 to 10 Celsius degrees (9 to 18 Fahrenheit degrees), after which it may

be dumped back into the lake, river, or ocean from which it came. Similarly,

factories contribute to thermal pollution when they dump water used to cool

their machinery.

The second type of thermal pollution is much more widespread. Streams and

small lakes are naturally kept cool by trees and other tall plants that block

sunlight. People often remove this shading vegetation in order to harvest the

wood in the trees, to make room for crops, or to construct buildings, roads, and

other structures. Left unshaded, the water warms by as much as 10 Celsius

degrees (18 Fahrenheit degrees). In a similar manner, grazing sheep and cattle

can strip streamsides of low vegetation, including young trees. Even the

removal of vegetation far away from a stream or lake can contribute to thermal

pollution by speeding up the erosion of soil into the water, making it muddy.

Muddy water absorbs more energy from the sun than clear water does, resulting

in further heating. Finally, water running off of artificial surfaces, such as

streets, parking lots, and roofs, is warmer than water running off vegetated land

and, thus, contributes to thermal pollution.

Effects

Elevated temperature typically decreases the level of dissolved oxygen (DO) in

water. The

decrease in levels of DO can harm aquatic animals such as fish,am phi bi a

ns andco pepo ds. Thermal pollution may also increase them etabo lic rate of

aquatic animals, asenzym e activity, resulting in these organisms consuming

more food in a shorter time than if their environment were not changed. An

increased metabolic rate may result in fewer resources; the more adapted

organisms moving in may have an advantage over organisms that are not used

to the warmer temperature. As a result one has the problem of

compromising food chains of the old and new environments. Biodiversity can

be decreased as a result.

It is known that temperature changes of even one to two

degreesCelsius can cause significant changes in organism metabolism and other

adverse cellular biology effects. Principal adverse changes can include

rendering cell walls less permeable to necessaryo smo sis, coagulation of

cellprote ins, and alteration of enzyme metabolism. These cellular level effects

can adversely affectmortality andrepro duction.

Primary producers are affected by warm water because higher water

temperature increases plant growth rates, resulting in a shorter lifespan and

species overpopulation. This can cause an algae bloom which reduces oxygen

levels.

A large increase in temperature can lead to the denaturing of life-supporting

enzymes by breaking downhy dro gen- and disulphide bonds within the

quaternary structure of the enzymes. Decreased enzyme activity in aquatic

organisms can cause problems such as the inability to break downlipids, which

leads tom alnutrition.

In limited cases, warm water has little deleterious effect and may even lead

to improved function of the receiving aquatic ecosystem. This phenomenon is

seen especially in seasonal waters and is known as thermal enrichment. An

extreme case is derived from the aggregational habits of them anatee, which

often uses power plant discharge sites during winter. Projections suggest that

manatee populations would decline upon the removal of these discharges.

2.4 Noise Pollution

Noise pollution(orenvironmental noise) is displeasing human, animal or

machine-created sound that disrupts the activity or balance of human or animal

life. The wordnoise comes from the Latin wordnause as, meaning seasickness.

The source of most outdoor noise worldwide is

mainlyconstruction andtransportatio n

systems, including motor vehicleno ise, aircraft noiseand rail noise. Poor urban

planning may give rise to noise pollution, since side-by-side industrial and

residential buildings can result in noise pollution in the residential area.

Indoor and outdoor noise pollution sources include car alarms, emergency

servicesirens,

mechanical equipment,fi rew or ks, compressed air horns, groundskeeping

equipment, barking dogs, appliances,lighting hum, audio entertainment systems,

electricm egapho nes, and loud people.

Sources

Noise becomes irritating if you're in the comfort of your home and an endless

drone of low

flying airplanes will pass overhead. It causes your blood pressure to rise since

the occurrence can shake your walls and rattle you window panes. On top of

that, you have read so many incidents about how accidents can happen; that by

some stroke of misfortune any one of these planes may accidentally use your

roof as landing pads.

Noise becomes a form of pollution if you're living in the city and the traffic

could bring a lot of cars honking simultaneously as their way of trying to protest

the long

hours they have been waiting in queue. Add the multitudes of pedestrians who'd

rather walk than wait it out in the city traffic, most of them talking

simultaneously,

enough to create a din. Noise in the city can disrupt your sleep, invade your

privacy when you find it hard to carry on with a simple conversation or create

an unpleasant atmosphere for work done at home.

Efects

Human health

Noise health effects are both healthand behavioral in nature. The unwanted

sound is called noise. This unwanted sound can damage physiological and

psychological health. Noise pollution can cause annoyance and aggression,hy

pertension, high stress levels,tinnitus, hearing loss, sleep disturbances, and other

harmful effects.Furthermore, stress and hypertension are the leading causes to

health problems, whereas tinnitus can lead to forgetfulness, severe depression

and at times panic attacks.

Chronic exposure to noise may cause noise-induced hearing loss. Older

males exposed to significant occupational

noise demonstratesignificantly reduced hearing sensitivity than their non-

exposed peers, though differences in hearing sensitivity decrease with time and

the two groups are indistinguishable by age 79.

High noise levels can contribute tocardio v ascular effects and exposure to

moderately high levels during a single eight hour period causes a statistical rise

in blood pressure of five to ten points and an increase instress[3] andv aso

constrictio n leading to the increased blood pressure noted above as well as to

increased incidence of coronary artery disease.

Noise pollution is also a cause of annoyance.

Environment

Noise can have a detrimental effect on animals by causing stress, increasing risk

of death by changing the delicate balance in predator/prey detection and

avoidance, and by interfering with their use of sounds in communication

especially in relation to reproduction and in navigation. Acoustic overexposure

can lead to temporary or permanent loss of hearing.

An impact of noise on animal life is the reduction of usable habitat that

noisy areas may cause, which in the case of endangered species may be part of

the path toe xt inction. Noise pollution has caused the death of certain species of

whales thatbe ache d themselves after being exposed to the loud sound of

military sonar.

Noise also makes species communicate louder, which is called Lombard

vocal response. Scientists and researchers have conducted experiments that

show whales' song length is longer when submarine-detectors are on.If creatures

do not "speak" loud enough, their voice will be masked

by anthropogenic sounds. These unheard voices might be warnings, finding of

prey, or preparations of net-bubbling. When one species begins speaking louder,

it willmask other species' voice, causing the whole ecosystem to eventually

speak louder.

People living in urban environments are more likely to sing at night in

places with high levels of noise pollution during the day, suggesting that they

sing at night because it is quieter, and their message can propagate through the

environment more clearly.The same study showed that daytime noise was a

stronger predictor of nocturnal singing than night-time Light pollution, to which

the phenomenon is often attributed.

Zebra finches become less faithful to their partners when exposed to traffic

noise. This could alter a population's evolutionary trajectory by selecting traits,

sapping resources normally devoted to other activities and thus lead to profound

genetic and evolutionary consequences.

The greenhouse effect is the heating of the surface of a planet or moon due to the presence of an atmosphere containing gases that absorb and emit infrared radiation. Thus, greenhouse gases trap heat within the surface-troposphere system. This mechanism is fundamentally different from that of an actual greenhouse, which works by isolating warm air inside the structure so that heat is not lost by convection. The greenhouse effect was discovered by Joseph Fourier in 1824, first reliably experimented on by John Tyndall in 1858, and first reported quantitatively by Svante Arrhenius in 1896.

The black body temperature of the Earth is 5.5 °C. Since the Earth's surface reflects about 28% of incoming sunlight, the planet's mean temperature would be far lower, about -18 or -19 °C. Along with the added contribution of the

greenhouse effect, it is instead much higher, roughly 14 °C. Global warming, a recent warming of the Earth's surface and lower atmosphere, is believed to be the result of an ‘enhanced greenhouse effect’ mostly due to human-produced increases in atmospheric greenhouse gases. This human induced part is referred to as anthropogenic global warming (AGW).

The Earth receives energy from the Sun mostly in the form of visible light and nearby wavelengths. About 50% of the sun's energy is absorbed at the Earth's surface. Like all bodies with a temperature above absolute zero the Earth's surface radiates energy in the infrared range. Greenhouse gases in the atmosphere absorb most of the infrared radiation emitted by the surface and pass the absorbed heat to other atmospheric gases through molecular collisions. The greenhouse gases also radiate in the infrared range. Radiation is emitted both upward, with part escaping to space, and downward toward Earth's surface. The surface and lower atmosphere are warmed by the part of the energy that is radiated downward, making our life on earth possible.

The distribution of ozone in ionosphere, mesosphere and stratosphere is being depleted. The concentration of ozone is gradually reducing. As the content of ozone is highest in ionosphere and the air itself being very thin, the depletion is negligible in ionosphere. But in mesosphere and stratosphere the air is thicker and ozone content is less. The depletion of ozone is of higher order in these layers. The so called hole in ozone layers simply means that above some continents (specifically Antarctica, Asia and parts of South America) the mesosphere and stratosphere have lost their original level of ozone content.

The depletion of ozone layer is a global phenomena both in terms of cause and effect. The geographical limits of countries are not barriers to either dispersal of

gases in layers of atmosphere or depletion of gases. The causes for depletion may arise in any country. The effects (in terms of depletion) may arise in any other country. The effects (in terms of ozone depletion) need not be exactly above the country causing the depletion.

It is now established that chloroflouro carbon (CFC) chemicals evolved from various refrigerants, coolants and propellants are the primary reasons for depletion of ozone. CFC are a group of chlorine bearing gases of low specific gravity. They rise to stratosphere and mesosphere. Due to ionising solar radiation in these layers, (which is the primary reason for production of ozone) fresh chlorine gas is produced from CFCs. This nascent chlorine gas has the capacity to react with ozone and bring down the level of ozone substantially.

The concept of ozone depletion is new. But study of international ozone trendis being made since 1988, when international ozone commission was established. Extensive ozone assessment facilities were established under International Middle Atmospheric Programme (IMAP) in India to study ozone along with number of other green house gases.