What is a waste?

“ Waste is excess of material , useless by-products or damaged products , garbage or rubbish.”

Waste is any substance which is discarded after primary use, or it is worthless, defective and of no use.

Domestic waste - Solid waste comprising of garbage and rubbish (such as bottles, cans, clothing, compost, disposables, food packaging, food scraps, newspapers and magazines, and yard trimmings) that originates from private homes or apartments. It may also contain household hazardous waste. Also called Domestic waste or residential waste.

- The term ‘Municipal waste ‘ applies to those wastes generated by households and to wastes of similar character derived from shops , offices and other commercial units. Many small business , commercial units and hospitals , especially those in developing countries rely on municipal waste Municipal waste services .

Agricultural waste - Agricultural waste is waste produced as a result of various agricultural operations. It includes manure and other wastes from farms, poultry houses and slaughterhouses; harvest waste; fertilizer run- off from fields; pesticides that enter into water, air or soils; and salt and silt drained from fields.

Bio-medicinal waste - “Any waste which is generated during the diagnosis, treatment or immunization of human beings or animals or in research activities pertaining thereto or in the production or testing of biologicals.”

Industrial waste - Industrial waste is the waste produced by industrial activity which includes any material that is rendered useless during a manufacturing process such as that of factories, mills, and mining operations.

Nuclear waste - Radioactive and extremely toxic byproducts of nuclear fuel processing plants, and nuclear medicine and nuclear weapons industries. Nuclear wastes remain radioactive for thousands of years.

AFFECTS OUR HEALTH

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DNA damage

Lung cancer

Damage to Heart , Liver and Spleen

Chronic damage to Brain

Asthmatic bronchitis

MANAGEMENT METHODS

• Sanitary landfill dumping

A sanitary landfill is a waste disposal facility where layers of compacted garbage are covered with layers of earth. When the facility reaches capacity, a cap is applied to close the site. Sanitary landfills are one of the most popular methods for disposing of waste, although they have some distinct drawbacks. This technique for waste management was developed in the 1930s, in response to growing pressures created by a growing population.

• Incineration

Incineration is a process of burning waste materials under oxidizing conditions and at high temperatures. The efficiency of incineration depends on combustion conditions that in turn demands.

• Recycling

Recycling is a process to convert waste materials into new products to prevent waste of potentially useful materials, reduce the consumption of fresh raw materials, reduce energy usage, reduce air pollution (from incineration) and water pollution (from landfilling) by reducing the need for "conventional" waste disposal and lower greenhouse gas emissions as compared to plastic production. Recycling is a key component of modern waste reduction and is the third component of the "Reduce, Reuse and Recycle" waste hierarchy.

• Plasma gasification

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Plasma gasification is a process which converts organic matter into synthetic gas, electricity, and slag using plasma. A plasma torch powered by an electric arc, is used to ionize gas and catalyze organic matter into synthetic gas and solid waste (slag)

• Sustainability

The management of waste is a key component in a business. Many companies are encouraged to improve their environmental efficiencies each year by eliminating waste through resource recovery practices , which are Sustainability related activities. One way to do this is by shifting away from waste management to resource recovery practices like Recycling materials such as glass , food , scraps , paper and cardboard , plastic bottles and metals.

• Hazardous waste management –

• COMPOSTING - Composting is a easy and natural bio-degradation process that takes organic wastes i.e. remains of plants and garden and kitchen waste and turns into nutrient rich food for your plants. Composting, normally used for organic farming, occurs by allowing organic materials to sit in one place for months until microbes decompose it. Composting is one of the best method of waste disposal as it can turn unsafe organic products into safe compost. On the other side, it is slow process and takes lot of space.

• BURIAL PITS - Burial is the placement of waste in man-made or natural excavations, such as pits or landfills. Burial is the most common onshore disposal technique used for disposing of drilling wastes (mud and cuttings). Generally, the solids are buried in the same pit (the reserve pit) used for collection and temporary storage of the waste mud and cuttings after the liquid is allowed to evaporate. Pit burial is a low-cost, low-tech method that does not require wastes to be transported away from the well site, and, therefore, is very attractive to many operators.

• ENCAPSULATION - Packing of hazardous waste in containers make of impervious and non-reactive material (such as glass or dense plastic) and sealing of this container in another one of concrete, plastic, or steel for burial or storage.Cement –lined pits or high density plastic container or drums are filled to 75% capacity with health care waste. The container is them filled with plastic foam, sand, cement or clay to immobilize the waste. The encapsulated waste is them disposed of in a landfill or left in place if the container is constructed in the ground.

• BURN AND BURY - Pit burning is a low-cast but relatively ineffctive means of waste disposal. A fence should surround the pit to prevent children, animals and others from coming into contact with the waste. The pit location should avoid walking paths (high traffic areas). The fire usually started with a petroleum-based fuel and allowed to burn, should be supervised by the designated staff and located down-wind of the facility and residential areas. The low-temperature fire emits pollutants, and the ash and remaining materials should be covered with 10-15 cm of dirt.

• Waste to Energy (Recover Energy)

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Waste to energy(WtE) process involves converting of non-recyclable waste items  into useable heat, electricity, or fuel through a variety of processes.

This type of source of energy is a renewable energy source as non-recyclable waste can be used over and over again to create energy. It can also help to reduce carbon emissions by offsetting the need for energy from fossil sources. Waste-to-Energy, also widely recognized by its acronym WtE is the generation of energy in the form of heat or electricity from waste.

• Avoidance/Waste Minimization

The most easier method of waste management is to reduce creation of waste materials thereby reducing the amount of waste going to landfills. Waste reduction can be done through recycling old materials like jar, bags, repairing broken items instead of buying new one, avoiding use of disposable products like plastic bags, reusing second hand items, and buying items that uses less designing.

Environment legislation

Environment legislation is a collection of many lows and regulations aimed at protecting the environment from harmful action.

The umbrella of environmental legislation covers many laws and regulations, yet they all work together toward a common goal , which is regulating the interaction between man and natural world.

In 1992 June 3rd to 14th at Rio-de-jeneiro (brazil) during the united nations sponsored conference on environment and development, more than 100 world leaders and 3000 delegates from 178 countries

ENVIRONMENT LAWS IN INDIA

• Have enacted 200 laws for the protection and improvement for environment

• Article 48A of Indian constitution , incorporated in 1976 through 42nd amendment

• Article 51-A , clause(g)

• Article 253 of Indian constitution empower the Indian parliament to make any law for the whole country

• The wildlife protection act of 1972

Is an act of parliament of India enacted for protection of plant, animal species. The act provides a comprehensive schedule of mammals, amphibian, reptiles ,birds ,crustaceans, insects, beetles etc.. which have been provided legislative protection. The act has 66 sections

Constitution of authorities for wildlife preservation(section 3-8), Protection for specified plants(section 17 A)

Prohibition of hunting of wild animal(section 9 and 11), Recognition of zoo(section 38 H )

Granting license for hunting of animal (section 44 48 49)

Penalties of violation of various types(section 51)…etc..

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• The water prevention and control of pollution act of 1974

Act formulated in 1974 for prevent the pollution of water by industrial , agricultural and household waste water that contaminate our fresh water resources.

Waste waters with high level of pollutants that enter wetlands , river, lakes, wells as seas are serious health hazards. Promote cleanliness of stream and wells (section 16)

to advise central or state governments on matters relating to water pollution (section 16)

To promote research with a view to controlling water pollution (section 16)

To take samples of effluents (section 21)

To prohibit the use of any stream or well for disposing the effluents (section 24)

To undertake any emergency measures in case of any accidental pollution of water (section 33) etc.…

• The forest conservation act of 1980

It extends to whole of India . It should be deemed to have come in to force on the 25th day of October ,1980

It enacted with the objectively checking the deforestation under the directives of article 48A of the Indian constitution. Article 51-A(g) protect forests , wildlife, lakes, rivers etc..

Under section 2 permission for ( any de reservation of forests)and (use of any forests land for non-forests purposes

• The air prevention and control of pollution act of 1981

Enacted on 29th march 1981. Prevention ,control , and abatement of air pollution through the air pollution control boards. Section 11, section 12,section 17, 18

Functions

Declaring any area as air pollution control area(section 19)

Fixing up of the emission levels from the automobiles (section 29)

Location of industry from the point of view of pollution (section 21)

Approaching the court against any polluter(section 22)

Taking samples from concerned unit(section 26)

Section 23 and section 38

• The environment protection act of 1986

The chief objective is the protection and improvement of environment and matters connected therewith

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It applicable to entire country

Section 3 Execute a programme to control of environmental pollution

To lay down standards for the quality of environments in its various aspects

To restrict the areas in which no industrial process operation could be carried

To lay down procedures and safeguards for the handling of hazardous substances

To inspect any premises , industrial plant , equipment , machinery etc.. And to issue directions necessary for controlling environmental pollution

To prepare manuals ,codes ,guidelines ,relating to prevention and control of environment pollution.

• The national environment tribunal act of 1995

Act enacted by the parliament on 17th June 1995

It is effective and expeditious disposal of cases arising out of any accident while handling any hazardous material with immediate relief and compensation for damage persons

Protect health and persons economic things .

Effective and expeditious relief and compensation for damages to human health , property and environment caused by industrial accident and disasters.

Water pollution is contamination of water bodies (e g: lakes, rivers, oceans, aquifers and groundwater) .This form of environmental degradation occurs when pollutants are directly or indirectly discharged into water bodies without adequate treatment to remove harmful compounds.

• WATER POLLUTION

• SURFACE WATER POLLUTION

• POINT SOURCES(SEWAGE,OIL SEEPAGE ETC)

• NON POINT SOURCES(ARGICULTURAL RUNOFF)

• GROUND WATER POLLUTION

SURFACE WATER CONTAMINATION

Surface water is usually rain water that collects in surface water bodies, like oceans, lakes, or streams.

.Surface water pollution occurs when hazardous substances come into contact and either dissolve or physically mix with the water.

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Because of the close relationship between sediments and surface water, contaminated sediments are often considered part of surface water contamination.

SURFACE WATER CONTAMINATION BY INDUSTRIES .

Industries produce huge amount of waste which contains toxic chemicals and pollutants which can cause water pollution.

Industries discharge a variety of pollutants including heavy metals , resin pellets, organic toxins, oils, nutrients, and solids.

The toxic chemicals have the capability to change the color of water, increase the amount of minerals, also known as Eutrophication.

SURFACE WATER CONTAMINATION BY URBANIZATION

Urban areas have the potential to pollute water in many ways.

Untreated or poorly treated sewage can be low in dissolved oxygen and high in pollutants such as fecal colliform bacteria, nitrates, phosphorus, chemicals, and other bacteria.

Garbage dumps, toxic waste and chemical storage and leaking house hold actives .

SURFACE WATER CONTAMINATION BY AGRICULTURE

Over the past few decades, the increase in population and advances made in farming technology has increased the demand for crops and livestock .This growth in agricultural production has resulted in an increase in contaminants polluting soil and water ways.

Chemical fertilizers and pesticides are used by farmers to protect crops from insects and bacteria.They are useful for the plants growth.When these chemicals are mixed up with water they are harmful for plants and animals.

When rains comes, the chemicals mixes up with rainwater and flow down into rivers and canals which pose serious damages for aquatic

GROUND WATER CONTAMINATION

• Groundwater is also one of our most important sources of water for irrigation. Unfortunately, groundwater is susceptible to pollutants .

• Groundwater contamination occurs when man-made products such as gasoline, oil, road salts and chemicals get into the groundwater and cause it to become unsafe and unfit for human use.

GROUND WATER CONTAMINATION BY INDUSTRISES

Processing water and water for cleaning purposes from manufacturing industries when returned to the hydrological cycle causes contamination.

Disposal of wastes associated with spillage and leaks sources to groundwater contamination.

Underground and above ground storage tanks holding petroleum products, acids, solvents and chemicals can develop leaks from corrosion, defects, improper installation, or mechanical failure of the pipes and fittings.

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Mining of fuel and non-fuel minerals can create many opportunities for groundwater contamination.

GROUND WATER CONTAMINATION BY URBANIZATION

As the population increases requirement of basic needs also increases. Water requirement also gradually increases for various purposes.

Residential waste water systems can be a source of many categories of contaminants, including bacteria, viruses, nitrates from human waste, and organic compounds.

Injection wells used for domestic wastewater disposal (septic systems, cesspools, drainage wells for storm water runoff, groundwater recharge wells) are of particular concern to groundwater quality if located close to drinking water wells.

GROUND WATER CONTAMINATION BY AGRICULTURE

Pesticides, fertilizers, herbicides and animal waste are agricultural sources of groundwater contamination.

spillage of fertilizers and pesticides during handling, runoff from the loading and washing of pesticide sprayers or other application equipment.

EFFECTS OF WATER POLLUTION

80% of all illness in developing countries is caused by water related diseases.

90% of waste water in developing countries is discharged directly into rivers and streams without treatment.

40% of deaths caused by water contamination in the world

REMEDIAL MEASURES

Locate the point sources of pollution.

Work against acid rain.

Educate your community.

Ensure sustainable sewage treatment.

Watch out for toxins.

Be careful what you throw away.

Use water efficiently.

Prevent pollution .

Think globally, act locally.

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Environmental Pollution

Environmental pollution has existed for centuries but only started to be significant following the industrial revolution in the 19th century. Pollution occurs when the natural environment cannot destroy an element without creating harm or damage to itself. The elements involved are not produced by nature, and the destroying process can vary from a few days to thousands of years (that is, for instance, the case for radioactive pollutants). In other words, pollution takes place when nature does not know how to decompose an element that has been brought to it in an unnatural way.

Pollution must be taken seriously, as it has a negative effect on natural elements that are an absolute need for life to exist on earth, such as water and air. Indeed, without it, or if they were present on different quantities, animals – including humans – and plants could not survive. We can identify several types of pollution on Earth: air pollution, water pollution and soil pollution.

Environmental pollution is an incurable disease. It can only be prevented -Barry Commoner.

Causes of Environmental Pollution

Let us first take a look at the causes of environmental pollution:

1. Industries: Industries have been polluting our environment especially since the beginning of the industrial revolution, as mentioned above, notably due to the increasing use of fossil fuels. In the 19th century and for a significant part of the 20th century, coal has been use to make machines work faster, replacing human force. Though pollution by industries mainly causes air pollution, soil and water contamination can also occur. This is particularly the case for power-generating industries, such as plants producing electricity (May they be a dam, a nuclear reactor or some other type of plant).

Also, the transportation of this energy can be harmful to the environment. We can take as an example the transportation of petrol through pipelines; if there is a leak in the pipeline, soil will automatically be polluted. At the same time, if the tanker transporting the petrol from its production plant to the place where it will be consumed leaks or sinks, the water will get contaminated.

2. Transportation: Ever since men abandoned animal power to travel, pollution of the environment has become higher and higher. Its levels have only been increasing until now. Similarly to industries, pollution caused by transport can mainly be attributed to fossil fuels. Indeed, humans went from horse carriages to cars, trains (which, before electricity, used to be propelled by coal), and airplanes. As the traffic is increasing every day, pollution follows that evolution.

3. Agricultural Activities: Agriculture is mainly responsible for the contamination of water and soil. This is caused by the increased use of pesticides, as well as by the intensive character of its production. Almost all pesticides are made from chemical substances and are meant to keep diseases and threatening animals away from the crops. However, by keeping these forms of life away, harm is almost always made to the surrounding environment as well.

Furthermore, as agriculture gets more and more intensive to feed the increasing world population, more environments and ecosystems are destroyed to make space for the crops. Some of them, like rapeseed –used to make oil – demand a lot of space for a relatively small output.

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4. Trading Activities: Trading activities including the production and exchange of goods and services. Concerning goods, pollution can be caused by packaging (which often involves the use of plastic, which is made from fossil fuels) or transport, mainly.

5. Residences: Finally, residential areas provide their fair share of pollution as well. First, to be able to build homes, natural environment has to be destroyed in one way or another. Wildlife and plants are driven away and replaced by human constructions. As it requires the work of industries, construction itself is also a source of contamination of the environment. Then, when people settle in, they will produce waste every day, including a part that cannot be processed by the environment without harm yet.

Effects of Environmental Pollution

Now that we have identified the main causes of environmental pollution, let us study the negative effects it has:

1. Effects on Humans: The effects of environmental pollution on humans are mainly physical, but can also turn into neuro-affections in the long term. The best-known troubles to us are respiratory, in the form of allergies, asthma, irritation of the eyes and nasal passages, or other forms of respiratory infections. Notably, these well spread affections can be observed when air pollution is high in cities, when the weather gets hot, for instance. On top of that, environmental pollution has been proven to be a major factor in the development of cancer. This can happen for example when we eat reminiscences of pollutants used in the production of processed foods, or pesticides from the crops. Other, rarer, diseases include hepatitis, typhoid affections, diarrhoea and hormonal disruptions.

2. Effects on Animals: Environmental pollution mainly affects animal by causing harm to their living environment, making it toxic for them to live in. Acid rains can change the composition of rivers and seas, making them toxic for fishes, an important quantity of ozone in the lower parts of the atmosphere can cause lung problems to all animals. Nitrogen and phosphates in water will cause overgrowth of toxic algae, preventing other forms of life to follow their normal course. Eventually, soil pollution will cause harm and sometimes even the destruction of microorganisms, which can have the dramatic effect of killing the first layers of the primary food chain.

3. Effects on Plants: As for animals, plants, and especially trees, can be destroyed by acid rains (and this will also have a negative effect on animals as well, as their natural environment will be modified), ozone in the lower atmosphere block the plant respiration, and harmful pollutants can be absorbed from the water or soil.

4. Effects on the Ecosystem: In short, environmental pollution, almost exclusively created by human activities, has a negative effect on the ecosystem, destroying crucial layers of it and causing an even more negative effect on the upper layers.

Types of Pollution

There are several types of pollution, and while they may come from different sources and have different consequences, understanding the basics about pollution can help environmentally conscious

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individuals minimize their contribution to these dangers. In total, there are nine recognized sources of pollution in the modern world. These sources of pollution don't simply have a negative impact on the natural world, but they can have a measurable effect on the health of human beings as well.

Different Types of Pollution

Air Pollution

Air pollution is defined as any contamination of the atmosphere that disturbs the natural composition and chemistry of the air. This can be in the form of particulate matter such as dust or excessive gases like carbon dioxide or other vapors that cannot be effectively removed through natural cycles, such as the carbon cycle or the nitrogen cycle.

Air pollution comes from a wide variety of sources. Some of the most excessive sources include:

Vehicle or manufacturing exhaust

Forest fires, volcanic eruptions, dry soil erosion, and other natural sources

Building construction or demolition

Depending on the concentration of air pollutants, several effects can be noticed. Smog increases, higher rain acidity, crop depletion from inadequate oxygen, and higher rates of asthma. Many scientists believe that global warming is also related to increased air pollution.

Water Pollution

Water pollution involves any contaminated water, whether from chemical, particulate, or bacterial matter that degrades the water's quality and purity. Water pollution can occur in oceans, rivers, lakes, and underground reservoirs, and as different water sources flow together the pollution can spread.

Causes of water pollution include:

Increased sediment from soil erosion

Improper waste disposal and littering

Leaching of soil pollution into water supplies

Organic material decay in water supplies

The effects of water pollution include decreasing the quantity of drinkable water available, lowering water supplies for crop irrigation, and impacting fish and wildlife populations that require water of a certain purity for survival.

Soil Pollution

Soil, or land pollution, is contamination of the soil that prevents natural growth and balance in the land whether it is used for cultivation, habitation, or a wildlife preserve. Some soil pollution, such as the creation of landfills, is deliberate, while much more is accidental and can have widespread effects.

Soil pollution sources include:11

Hazardous waste and sewage spills

Non-sustainable farming practices, such as the heavy use of inorganic pesticides

Strip mining, deforestation, and other destructive practices

Household dumping and littering

Soil contamination can lead to poor growth and reduced crop yields, loss of wildlife habitat, water and visual pollution, soil erosion, and desertification.

Noise Pollution

Noise pollution refers to undesirable levels of noises caused by human activity that disrupt the standard of living in the affected area. Noise pollution can come from:

Traffic

Airports

Railroads

Manufacturing plants

Construction or demolition

Concerts

Some noise pollution may be temporary while other sources are more permanent. Effects may include hearing loss, wildlife disturbances, and a general degradation of lifestyle.

Radioactive Pollution

Radioactive pollution is rare but extremely detrimental, and even deadly, when it occurs. Because of its intensity and the difficulty of reversing damage, there are strict government regulations to control radioactive pollution.

Sources of radioactive contamination include:

Nuclear power plant accidents or leakage

Improper nuclear waste disposal

Uranium mining operations

Radiation pollution can cause birth defects, cancer, sterilization, and other health problems for human and wildlife populations. It can also sterilize the soil and contribute to water and air pollution.

Thermal Pollution

Thermal pollution is excess heat that creates undesirable effects over long periods of time. The earth has a natural thermal cycle, but excessive temperature increases can be considered a rare type of

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pollution with long term effects. Many types of thermal pollution are confined to areas near their source, but multiple sources can have wider impacts over a greater geographic area.

Thermal pollution may be caused by:

Power plants

Urban sprawl

Air pollution particulates that trap heat

Deforestation

Loss of temperature moderating water supplies

As temperatures increase, mild climatic changes may be observed, and wildlife populations may be unable to recover from swift changes.

Light Pollution

Light pollution is the over illumination of an area that is considered obtrusive. Sources include:

Large cities

Billboards and advertising

Nighttime sporting events and other nighttime entertainment

Light pollution makes it impossible to see stars, therefore interfering with astronomical observation and personal enjoyment. If it is near residential areas, light pollution can also degrade the quality of life for residents.

Visual Pollution

Visual pollution - eyesores - can be caused by other pollution or just by undesirable, unattractive views. It may lower the quality of life in certain areas, or could impact property values and personal enjoyment.

Sources of visual pollution include:

Power lines

Construction areas

Billboards and advertising

Neglected areas or objects such as polluted vacant fields or abandoned buildings

While visual pollution has few immediate health or environmental effects, what's causing the eyesore can have detrimental affects.

Personal Pollution

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Personal pollution is the contamination of one's body and lifestyle with detrimental actions. This may include:

Excessive smoking, drinking or drug abuse

Emotional or physical abuse

Poor living conditions and habits

Poor personal attitudes

In some cases, personal pollution may be inflicted by caregivers, while in other cases it is caused by voluntary actions. Taking positive steps in your life can help eliminate this and other sources of pollution so you can lead a more productive, satisfying life.

Fighting Pollution

All types of pollution are interconnected. For example, light pollution requires energy to be made, which means the electric plant needs to burn more fossil fuels to supply the electricity. Those fossil fuels contribute to air pollution, which returns to the earth as acid rain and increases water pollution. The cycle of pollution can go on indefinitely, but once you understand the different pollution types, how they are created, and the effects they can have, you can make personal lifestyle changes to combat poor conditions for yourself and others around you.

Environment is divided in following segments:

1. Lithosphere

2. Hydrosphere

3. Atmosphere

4. Biosphere

(i) Lithosphere: Lithosphere is related with edaphic factor. The solid component of earth is known as lithosphere. Lithosphere means the mantle of rocks constituting the earth's crust.

It includes the soil, which covers the rock crust.

Soil plays an important role as it provides food for man and animals.

Soil is usually defined as "any part of earth's crust in which plants root."

Muddy bottoms of ponds, ravines or glacial deposits, porous rock surface, bottoms of lakes peat etc., all are thus soil.

A typical productive soil contains approximately 95 per cent inorganic matter and 5 per cent organic matter. Organic matter in the soil provides food for microorganism. This matter includes amino sugars, organic sulphur, organic phosphate, and polysaccharides.

Soil contains silicate minerals, which includes nearly 74 per cent Silicon and Oxygen, common elements in the soil are 46.4 per cent Oxygen, Silicon 27.7 per cent, Aluminium 8.1 per cent, Iron 5.6

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per cent, Calcium 3.6 per cent, Sodium 2.8 per cent, Potassium 2.6 per cent, Magnesium 2.1 per cent. In some soils, manganese oxide and titanium oxide are also available.

(ii) Hydrosphere: This includes all the surface and ground water resources such as oceans, seas, rivers, streams, lakes, reservoirs, glaciers, polar ice caps, ground water and water locked in rock and crevices and minerals laying deep below the earth's crust.

1. Earth is called blue planet because 80 per cent of its surface is covered by water (97 per cent of the earth's water resources is locked up in the oceans and seas, 2.4 per cent is trapped is giant glaciers and polar ice caps.)

2. Water is universal solvent.

3. Water is also the main medium by which chemical constituents are transported from one part of an ecosystem to others.

4. Water has high specific heat, latent heat and relatively high freezing point.

5. Surface water contains a lot of organic matter and mineral nutrients, which feed large bacteria population and algae.

(iii) Atmosphere: The gaseous envelope surrounding the earth is composed of an entire mass of air containing N2, 02, H20, C02 and inert gases is known as atmosphere.

1. Soil contains silicate minerals, which includes nearly 74 per cent Silicon.

2. The atmosphere is a reservoir of several elements essential to life and serves many purposes and functions.

3. The atmosphere is mobile, elastic, compressible and expansible.

4. Atmosphere serves many purposes and functions.

5. It absorbs most of the harmful radiations.

6. It maintains the heat balance of the earth.

7. Different cycles those are present in the atmosphere in the form of water cycle, carbon, oxygen, nitrogen cycle etc. related to the movement of matter been an organism and its environment.

8. Atmosphere can be divided into several layers on the basic of temperature variations. They are troposphere, stratosphere, mesosphere and thermosphere.

9. (iv) Biosphere: The biosphere is the part of the earth in which life exists.

10. Biosphere is biological envelope that surrounds the globe, containing and able to support.

11. It penetrates into and is dependent on the atmosphere, hydrosphere and lithosphere. This denotes the relating of living organism and their interactions with the environment. The biosphere is a relatively thin and incomplete envelope covering most of the world.

The basic approach to the study of man-environment relationship and the core of the environment is ecological analysis of spatial attributes of inter-relationship between technologically advanced man and natural environment of the earth in terms of ecosystem.

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Thus, broadly speaking, environment may be defined as the study of spatial attributes of interrelationship between living organisms and the natural environment in general and technologically advanced 'economic man and his natural environment in particular.

The definition of environmental science may be further broadened to make it more flexible so that it may very precisely reveal the scope of the subject.

Thus, environmental science may be defined as that which studies characteristics, composition and functions of different components of the natural environment-system (including man as a biological organism - a physical man), natural dependence of different components, various processes that link the components, the interactions of different components with each other and among themselves and consequent responses in spatial and temporal contexts in terms of geoecosystem, as well as interactions of technologically advanced economic men with different components of the natural geoecosystem and resultant modifications and changes in the natural geoecosystem, leading to environmental degradation and pollution, the techniques and strategies of pollution control measures and management of ecological resources.

Introduction - What is an Ecosystem?An ecosystem consists of the biological community that occurs in some locale, and the physical and chemical factors that make up its non-living or abiotic environment. There are many examples of ecosystems -- a pond, a forest, an estuary, a grassland. The boundaries are not fixed in any objective way, although sometimes they seem obvious, as with the shoreline of a small pond. Usually the boundaries of an ecosystem are chosen for practical reasons having to do with the goals of the particular study.

The study of ecosystems mainly consists of the study of certain processes that link the living, or biotic, components to the non-living, or abiotic, components. Energy transformations andbiogeochemical cycling are the main processes that comprise the field of ecosystem ecology. As we learned earlier, ecology generally is defined as the interactions of organisms with one another and with the environment in which they occur. We can study ecology at the level of the individual, the population, the community, and the ecosystem.

Studies of individuals are concerned mostly about physiology, reproduction, development or behavior, and studies of populations usually focus on the habitat and resource needs of individual species, their group behaviors, population growth, and what limits their abundance or causes extinction. Studies of communities examine how populations of many species interact with one another, such as predators and their prey, or competitors that share common needs or resources.

In ecosystem ecology we put all of this together and, insofar as we can, we try to understand how the system operates as a whole. This means that, rather than worrying mainly about particular species, we try to focus on major functional aspects of the system. These functional aspects include such things as the amount of energy that is produced by photosynthesis, how energy or materials flow along the many steps in a food chain, or what controls the rate of decomposition of materials or the rate at which nutrients are recycled in the system.  

Components of an Ecosystem

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You are already familiar with the parts of an ecosystem. You have learned about climate and soils from past lectures. From this course and from general knowledge, you have a basic understanding of the diversity of plants and animals, and how plants and animals and microbes obtain water, nutrients, and food. We can clarify the parts of an ecosystem by listing them under the headings "abiotic" and "biotic".    

ABIOTIC COMPONENTS BIOTIC COMPONENTS

Sunlight Primary producers

Temperature Herbivores

Precipitation Carnivores

Water or moisture Omnivores

Soil or water chemistry (e.g., P, NH4+) Detritivores

etc. etc.

All of these vary over space/time

By and large, this set of environmental factors is important almost everywhere, in all ecosystems.

Usually, biological communities include the "functional groupings" shown above. A functional group is a biological category composed of organisms that perform mostly the same kind of function in the system; for example, all the photosynthetic plants or primary producers form a functional group. Membership in the functional group does not depend very much on who the actual players (species) happen to be, only on what function they perform in the ecosystem.  

Processes of EcosystemsThis figure with the plants, zebra, lion, and so forth illustrates the two main ideas about how ecosystems function: ecosystems have energy flows and ecosystems cycle materials. These two processes are linked, but they are not quite the same (see Figure 1).

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Figure 1. Energy flows and material cycles.

Energy enters the biological system as light energy, or photons, is transformed into chemical energy in organic molecules by cellular processes including photosynthesis and respiration, and ultimately is converted to heat energy. This energy is dissipated, meaning it is lost to the system as heat; once it is lost it cannot be recycled.  Without the continued input of solar energy, biological systems would quickly shut down. Thus the earth is an open system with respect to energy.

Elements such as carbon, nitrogen, or phosphorus enter living organisms in a variety of ways. Plants obtain elements from the surrounding atmosphere, water, or soils. Animals may also obtain elements directly from the physical environment, but usually they obtain these mainly as a consequence of consuming other organisms. These materials are transformed biochemically within the bodies of organisms, but sooner or later, due to excretion or decomposition, they are returned to an inorganic state. Often bacteria complete this process, through the process called decomposition or mineralization (see previous lecture on microbes).

During decomposition these materials are not destroyed or lost, so the earth is a closed system with respect to elements (with the exception of a meteorite entering the system now and then). The elements are cycled endlessly between their biotic and abiotic states within ecosystems. Those elements whose supply tends to limit biological activity are callednutrients.  

The Transformation of EnergyThe transformations of energy in an ecosystem begin first with the input of energy from the sun. Energy from the sun is captured by the process of photosynthesis. Carbon dioxide is combined with hydrogen (derived from the splitting of water molecules) to produce carbohydrates (CHO). Energy is stored in the high energy bonds of adenosine triphosphate, or ATP (see lecture on photosynthesis).

The prophet Isaah said "all flesh is grass", earning him the title of first ecologist, because virtually all energy available to organisms originates in plants. Because it is the first step in the production of energy for living things, it is called primary production (click here  for a primer on

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photosynthesis). Herbivores obtain their energy by consuming plants or plant products,carnivores eat herbivores, and detritivores consume the droppings and carcasses of us all.   

Figure 2 portrays a simple food chain, in which energy from the sun, captured by plant photosynthesis, flows fromtrophic level to trophic level via the food chain. A trophic level is composed of organisms that make a living in the same way, that is they are all primary producers(plants), primary consumers (herbivores) or secondary consumers (carnivores). Dead tissue and waste products are produced at all levels. Scavengers, detritivores, and decomposers collectively account for the use of all such "waste" -- consumers of carcasses and fallen leaves may be other animals, such as crows and beetles, but ultimately it is the microbes that finish the job of decomposition. Not surprisingly, the amount of primary production varies a great deal from place to place, due to differences in the amount of solar radiation and the availability of nutrients and water.

For reasons that we will explore more fully in subsequent lectures, energy transfer through the food chain is inefficient. This means that less energy is available at the herbivore level than at the primary producer level, less yet at the carnivore level, and so on. The result is a pyramid of energy, with important implications for understanding the quantity of life that can be supported.

Usually when we think of food chains we visualize green plants, herbivores, and so on. These are referred to asgrazer food chains, because living plants are directly consumed. In many circumstances the principal energy input is not green plants but dead organic matter. These are called detritus food chains. Examples include the forest floor or a woodland stream in a forested area, a salt marsh, and most obviously, the ocean floor in very deep areas where all sunlight is extinguished 1000's of meters above. In subsequent lectures we shall return to these important issues concerning energy flow.

 Finally, although we have been talking about food chains, in reality the organization of biological systems is much more complicated than can be represented by a simple "chain". There are many food links and chains in an ecosystem, and we refer to all of these linkages as a food web. Food webs can be very complicated, where it appears that "everything is connected to everything else", and it is important to understand what are the most important linkages in any particular food web.  

BiogeochemistryHow can we study which of these linkages in a food web are most important? One obvious way is to study the flow of energy or the cycling of elements. For example, the cycling of elements is controlled in part by organisms, which store or transform elements, and in part by the chemistry and geology of the natural world. The term Biogeochemistry is defined as the study of how living systems influence,

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and are controlled by, the geology and chemistry of the earth. Thus biogeochemistry encompasses many aspects of the abiotic and biotic world that we live in.

There are several main principles and tools that biogeochemists use to study earth systems. Most of the major environmental problems that we face in our world toady can be analyzed using biogeochemical principles and tools. These problems include global warming, acid rain, environmental pollution, and increasing greenhouse gases. The principles and tools that we use can be broken down into 3 major components: element ratios, mass balance, and element cycling.

1. Element ratiosIn biological systems, we refer to important elements as "conservative". These elements are often nutrients. By "conservative" we mean that an organism can change only slightly the amount of these elements in their tissues if they are to remain in good health. It is easiest to think of these conservative elements in relation to other important elements in the organism. For example, in healthy algae the elements C, N, P, and Fe have the following ratio, called theRedfield ratio after the oceanographer who discovered it: C : N : P : Fe = 106 : 16 : 1 : 0.01Once we know these ratios, we can compare them to the ratios that we measure in a sample of algae to determine if the algae are lacking in one of these limiting nutrients.  

2. Mass BalanceAnother important tool that biogeochemists use is a simple mass balance equation to describe the state of a system. The system could be a snake, a tree, a lake, or the entire globe. Using a mass balance approach we can determine whether the system is changing and how fast it is changing. The equation is:

NET CHANGE = INPUT + OUTPUT + INTERNAL CHANGEIn this equation the net change in the system from one time period to another is determined by what the inputs are, what the outputs are, and what the internal change in the system was. The example given in class is of the acidification of a lake, considering the inputs and outputs and internal change of acid in the lake.  

3. Element CyclingElement cycling describes where and how fast elements move in a system. There are two general classes of systems that we can analyze, as mentioned above: closed and open systems.

A closed system  refers to a system where the inputs and outputs are negligible compared to the internal changes. Examples of such systems would include a bottle, or our entire globe. There are two ways we can describe the cycling of materials within this closed system, either by looking at the rate of movement or at the pathways of movement.

1. Rate = number of cycles / time * as rate increases, productivity increases

2. Pathways-important because of different reactions that may occur

In an open system  there are inputs and outputs as well as the internal cycling. Thus we can describe the rates of movement and the pathways, just as we did for the closed system, but we can also define a

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new concept called the residence time. The residence time indicates how long on average an element remains within the system before leaving the system.

1. Rate

2. Pathways

3. Residence time, Rt

Rt = total amount of matter / output rate of matter

(Note that the "units" in this calculation must cancel properly)

Controls on Ecosystem FunctionNow that we have learned something about how ecosystems are put together and how materials and energy flow through ecosystems, we can better address the question of "what controls ecosystem function"? There are two dominant theories of the control of ecosystems. The first, called bottom-up control, states that it is the nutrient supply to the primary producers that ultimately controls how ecosystems function. If the nutrient supply is increased, the resulting increase in production of autotrophs is propagated through the food web and all of the other trophic levels will respond to the increased availability of food (energy and materials will cycle faster). 

The second theory, called top-down control, states that predation and grazing by higher trophic levels on lower trophic levels ultimately controls ecosystem function. For example, if you have an increase in predators, that increase will result in fewer grazers, and that decrease in grazers will result in turn in more primary producers because fewer of them are being eaten by the grazers. Thus the control of population numbers and overall productivity "cascades" from the top levels of the food chain down to the bottom trophic levels.

So, which theory is correct? Well, as is often the case when there is a clear dichotomy to choose from, the answer lies somewhere in the middle. There is evidence from many ecosystem studies that BOTH controls are operating to some degree, but that NEITHER control is complete. For example, the "top-down" effect is often very strong at trophic levels near to the top predators, but the control weakens as you move further down the food chain. Similarly, the "bottom-up" effect of adding nutrients usually stimulates primary production, but the stimulation of secondary production further up the food chain is less strong or is absent.

Thus we find that both of these controls are operating in any system at any time, and we must understand the relative importance of each control in order to help us to predict how an ecosystem will behave or change under different circumstances, such as in the face of a changing climate.  

The Geography of EcosystemsThere are many different ecosystems: rain forests and tundra, coral reefs and ponds, grasslands and deserts. Climate differences from place to place largely determine the types of ecosystems we see. How terrestrial ecosystems appear to us is influenced mainly by the dominant vegetation.

The word "biome" is used to describe a major vegetation type such as tropical rain forest, grassland, tundra, etc., extending over a large geographic area (Figure 3). It is never used for aquatic systems,

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such as ponds or coral reefs. It always refers to a vegetation category that is dominant over a very large geographic scale, and so is somewhat broader than an ecosystem.

We can draw upon previous lectures to remember that temperature and rainfall patterns for a region are distinctive. Every place on earth gets the same total number of hours of sunlight each year, but not the same amount of heat. The sun's rays strike low latitudes directly but high latitudes obliquely. This uneven distribution of heat sets up not just temperature differences, but global wind and ocean currents that in turn have a great deal to do with where rainfall occurs. Add in the cooling effects of elevation and the effects of land masses on temperature and rainfall, and we get a complicated global pattern of climate.

A schematic view of the earth shows that, complicated though climate may be, many aspects are predictable (Figure 4). High solar energy striking near the equator ensures nearly constant high temperatures and high rates of evaporation and plant transpiration. Warm air rises, cools, and sheds its moisture, creating just the conditions for a tropical rain forest. Contrast the stable temperature but varying rainfall of a site in Panama with the relatively constant precipitation but seasonally changing temperature of a site in New York State. Every location has a rainfall- temperature graph that is typical of a broader region.

Figure 4. Climate patterns affect biome distributions.

We can draw upon plant physiology to know that certain plants are distinctive of certain climates, creating the vegetation appearance that we call biomes. Note how well the distribution of biomes plots on the distribution of climates (Figure 5). Note also that some climates are impossible, at least on our planet. High precipitation is not possible at low temperatures -- there is not enough solar energy to power the water cycle, and most water is frozen and thus biologically unavailable throughout the year. The high tundra is as much a desert as is the Sahara. 

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   Figure 5. The distribution of biomes related to temperature and precipitation.

   Summary Ecosystems are made up of abiotic (non-living, environmental) and biotic components, and

these basic components are important to nearly all types of ecosystems.  Ecosystem Ecology looks at energy transformations and biogeochemical cycling within ecosystems.

Energy is continually input into an ecosystem in the form of light energy, and some energy is lost with each transfer to a higher trophic level. Nutrients, on the other hand, are recycled within an ecosystem, and their supply normally limits biological activity.  So, "energy flows, elements cycle".

Energy is moved through an ecosystem via a food web, which is made up of interlocking food chains. Energy is first captured by photosynthesis (primary production). The amount of primary production determines the amount of energy available to higher trophic levels.

The study of how chemical elements cycle through an ecosystem is termed biogeochemistry. A biogeochemical cycle can be expressed as a set of stores (pools) and transfers, and can be studied using the concepts of "stoichiometry", "mass balance", and "residence time".

Ecosystem function is controlled mainly by two processes, "top-down" and "bottom-up" controls.

A biome is a major vegetation type extending over a large area. Biome distributions are determined largely by temperature and precipitation patterns on the Earth's surface.

Concept of an Ecosystem:

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The term ecosystem was coined in 1935 by the Oxford ecologist Arthur Tansley to encompass the

interactions among biotic and abiotic components of the environment at a given site. The living and

non-living components of an ecosystem are known as biotic and abiotic components, respectively.

Ecosystem was defined in its presently accepted form by Eugene Odum as, “an unit that includes all the

organisms, i.e., the community in a given area interacting with the physical environment so that a flow

of energy leads to clearly defined trophic structure, biotic diversity and material cycles, i.e., exchange

of materials between living and non-living, within the system”.

Smith (1966) has summarized common characteristics of most of the ecosystems as follows:

1. The ecosystem is a major structural and functional unit of ecology.

2. The structure of an ecosystem is related to its species diversity in the sense that complex ecosystem

have high species diversity.

3. The function of ecosystem is related to energy flow and material cycles within and outside the

system.

4. The relative amount of energy needed to maintain an ecosystem depends on its structure. Complex

ecosystems needed less energy to maintain themselves.

5. Young ecosystems develop and change from less complex to more complex ecosystems, through the

process called succession.

6. Each ecosystem has its own energy budget, which cannot be exceeded.

7. Adaptation to local environmental conditions is the important feature of the biotic components of an

ecosystem, failing which they might perish.

8. The function of every ecosystem involves a series of cycles, e.g., water cycle, nitrogen cycle, oxygen

cycle, etc. these cycles are driven by energy. A continuation or existence of ecosystem demands

exchange of materials/nutrients to and from the different components.

Types of Ecosystem:

We can classify ecosystems as follows:

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(a) Natural Ecosystems:

These ecosystems are capable of operating and maintaining themselves without any major interference

by man.

A classification based on their habitat can further be made:

1. Terrestrial ecosystems: forest, grassland and desert.

2. Aquatic ecosystems: fresh water ecosystem, viz. pond, lake, river and marine ecosystems, viz. ocean,

sea or estuary.

(b) Artificial Ecosystem:

These are maintained by man. These are manipulated by man for different purposes, e.g., croplands,

artificial lakes and reservoirs, townships and cities.

Basic Structure of an Ecosystem:

Every ecosystem has a non-living (abiotic) and living (biotic) components.

Abiotic Components:

Basic inorganic compounds of an organism, habitat or an area like carbon dioxide, water, nitrogen,

calcium, phosphorus, etc. that are involved in the material cycles are collectively called as abiotic

component. The amount of these inorganic substances present at any given time, in an ecosystem is

called as the standing state or standing quality of an ecosystem.

Whereas, organic components e.g., proteins, amino acids, carbohydrates and lipids that are synthesized

by the biotic counterpart of an ecosystem make the biochemical structure of the ecosystem. The

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physical environment, viz. climatic and weather conditions are also included in the abiotic structure of

the ecosystem.

Biotic Components:

From the trophic (nutritional) point of view, an ecosystem has autotrophic (self-nourishing) and a

heterotrophic (other nourishing) components:

(a) Autotrophic component (Producers):

This component is mainly constituted by the green plants, algae and all photosynthetic organisms.

Chemosynthetic bacteria, photosynthetic bacteria, algae, grasses, mosses, shrubs, herbs and trees

manufacture food from simple inorganic substances by fixing energy and are therefore called as

producers.

(b) Heterotrophic component (Consumers):

The members of this component cannot make their own food. They consume the matter built by the

producers and are therefore called as consumers. They may be herbivores, carnivores or omnivores.

Herbivores are called as primary consumers whereas carnivores and omnivores are called as secondary

consumers. Collectively we can call them as macro-consumers.

(c) Decomposers:

Heterotrophic organisms chiefly bacteria and fungi that breakdown the complex compounds of dead

protoplasm, absorb some of the products and release simple substances usable by the producers are

called as decomposers or reducers. Collectively we call them as micro consumers.

The Problem With Fossil Fuels and Climate Change

Burning any carbon based fuel converts carbon to carbon dioxide. Unless it is captured and stored, this carbon dioxide is usually released to the atmosphere. Burning fossil fuels releases carbon that was removed from the amosphere millions of years ago by animal and plant life. This leads to increased concentrations of carbon dioxide in the atmosphere.

The problem with burning fossil fuels

Why is Carbon Dioxide a problem?

Carbon dioxide (CO2) is one of a number of gases that are transparent to the visible light falling on the Earth from the Sun, but absorb the infra-red radiation (heat) emitted by the warm surface of the Earth,

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preventing its loss into space. During the geological history of the Earth the level of atmospheric CO2 has varied considerably and this has had an impact on the global temperature. A significant amount of this atmospheric carbon was sequestered or (removed from the atmosphere) and turned into inert material (coal, and oil) typically 300-360 Million years ago. All of the global ecosystems and species have adapted to a lower level of atmospheric CO2 and critically, human civilisation has also grown since that period.

Since the industrial revolution humans have been burning sequestered CO2 in the form of coal, oil, and natural gas which has the result of releasing energy but also releases CO2 back into the atmosphere.

Other “greenhouse” gasses include

Carbon dioxide (CO2)

Methane (CH4)

Nitrous oxide (N2O)

Water vapour (H2O).

This increase of atmospheric CO2 and other gasses has the effect of changing the global climate back towards the point when they were originally sequestered. This climate was characterised by higher average global temperatures and higher sea levels. Furthermore, the rapidity of the change (about 200 years) is having additional impacts. This period of time is extremely short in context of the global climate and is not much more than a single generation for some long lived species leaving them very little time to adapt.

Volcanic Gases and Climate Change OverviewVolcanoes can impact climate change. During major explosive eruptions huge amounts of volcanic gas, aerosol droplets, and ash are injected into the stratosphere. Injected ash falls rapidly from the stratosphere -- most of it is removed within several days to weeks -- and has little impact on climate change. But volcanic gases like sulfur dioxide can cause global cooling, while volcanic carbon dioxide, a greenhouse gas, has the potential to promote global warming.

Eruption of Mount Pinatubo on June 15, 1991.The most significant climate impacts from volcanic injections into the stratosphere come from the conversion of sulfur dioxide to sulfuric acid, which condenses rapidly in the stratosphere to form fine sulfate aerosols. The aerosols increase the reflection of radiation from the Sun back into space, cooling the Earth's lower atmosphere or troposphere. Several eruptions during the past century have caused a decline in the average temperature at the Earth's surface of up to half a degree (Fahrenheit scale) for periods of one to three years. The climactic eruption of Mount Pinatubo on June 15, 1991, was one of the largest eruptions of the twentieth century and injected a 20-million ton (metric scale) sulfur dioxide cloud into the stratosphere at an altitude of more than 20 miles. The Pinatubo cloud was the largest sulfur dioxide cloud ever observed in the stratosphere since the beginning of such observations by satellites in 1978. It caused what is believed to be the largest aerosol disturbance of the stratosphere in the twentieth century, though probably smaller than the disturbances from eruptions of Krakatau in 1883 and Tambora in 1815. Consequently, it was a standout in its climate impact and cooled the Earth's surface for three years following the eruption,

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by as much as 1.3 degrees at the height of the impact. Sulfur dioxide from the large 1783-1784 Laki fissure eruption in Iceland caused regional cooling of Europe and North America by similar amounts for similar periods of time.

Deforestation An estimated 13 million hectares of forests were lost each year between 2000 and 2010 due to deforestation.* In tropical rainforests particularly, deforestation continues to be an urgent environmental issue that jeopardizes people’s livelihoods, threatens species, and intensifies global warming. Forests make a vital contribution to humanity, but their full potential will only be realized if we halt deforestation and forest degradation.

Forests impact our daily lives in more ways than we can imagine. Just think of how forests have affected your life today: Have you had your breakfast? Read a newspaper? Switched on a light? Travelled to work in a bus or car? Made a shopping list? Got a parking ticket? Blown your nose into a tissue? All these activities directly or indirectly involve forests. Some are easy to figure out – fruits, paper and wood come from trees. Others are less obvious – by-products that go into everyday items like medicines, cosmetics and detergents. 

From the air we breathe to the wood we love, human beings are heavily dependent on forests and the products and services they provide. Forests provide habitats to diverse animal species; they form the source of livelihood for many different human settlements; they offer watershed protection, timber and non-timber products, and various recreational options; they prevent soil erosion, help in maintaining the water cycle, and check global warming by using carbon dioxide in photosynthesis. 

Yet we are losing forests. Over the past 50 years, about half the world's original forest cover has been lost, mainly because of unsystematic use of its resources. When we take away the forest, it is not just the trees that go. The entire ecosystem begins to fall apart, with dire consequences for all of us.

What is deforestation?

Deforestation is the conversion of forest to another land use or the long-term reduction of the tree canopy cover. This includes conversion of natural forest to tree plantations, agriculture, pasture, water reservoirs and urban areas but excludes timber production areas managed to ensure the forest regenerates after logging. 

What is forest degradation?

Forest degradation happens when changes within the forest negatively affect the structure or function of the stand or site, and thereby lower the capacity to supply products and/or ecosystem services. Forest degradation creates less resilient and less productive forests and in some countries, it can be nearly as harmful as deforestation, carving "death by a thousand cuts" that eventually leads to deforestation. Forest degradation often begins the slippery slope to deforestation: large canopy gaps can dry out rainforests leaving them vulnerable to fire; abandoned logging roads provide access to settlers; and authorities are often more willing to grant conversion permits in heavily logged forests. 

What are the effects of deforestation and forest degradation?28

Reduced biodiversity: Deforestation and forest degradation can cause wildlife to decline. When forest cover is removed, wildlife is deprived of habitat and becomes more vulnerable to hunting. Considering that about 80% of the world's documented species can be found in tropical rainforests, deforestation poses a serious threat to the Earth’s biodiversity. 

Release of greenhouse gas emissions: Forests are the largest terrestrial store of carbon and deforestation is the third-largest source of greenhouse gas emissions after coal and oil. Deforestation causes 15% of global greenhouse gas emissions. Of these, carbon dioxide emissions represent up to one-third of total carbon dioxide emissions released because of human causes. Find out more about climate change and deforestation. 

Disrupted water cycles: As a result of deforestation, trees no longer evaporate groundwater, which can cause the local climate to be much drier. 

Increased soil erosion: Deforestation accelerates rates of soil erosion, by increasing runoff and reducing the protection of the soil from tree litter. 

Disrupted livelihoods: Millions of people rely directly on forests, through shifting cultivation, hunting and gathering, and by harvesting forest products such as rubber. Deforestation continues to create severe social problems, sometimes leading to violent conflict.

What can we do?

Current deforestation trends point toward catastrophic and irreversible losses of biodiversity and runaway climate change. With better governance and smarter land use, it would be possible to meet global demand for food and forest products without any further loss of forests between now and 2030, but urgent action is needed. Actions to tackle deforestation will require new policies and laws, better implementation of existing laws, tough crackdowns on corruption, and economic opportunities for local communities, whether they be the 300 million people living in forests and the more than 1 billion directly dependent on forests. 

Mineral Resources: Definition, Types, Use and Exploitation (with statistics and diagram)

Definition:

Minerals provide the material used to make most of the things of industrial- based society; roads, cars,

computers, fertilizers, etc. Demand for minerals is increasing world wide as the population increases

and the consumption demands of individual people increase. The mining of earth’s natural resources is,

therefore accelerating, and it has accompanying environmental consequences.

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A mineral is a pure inorganic substance that occurs naturally in the earth’s crust. All of the Earth’s

crust, except the rather small proportion of the crust that contains organic material, is made up of

minerals. Some minerals consist of a single element such as gold, silver, diamond (carbon), and

sulphur.

More than two-thousand minerals have been identified and most of these contain inorganic compounds

formed by various combinations of the eight elements (O, Si, Al, Fe, Ca, Na, K, and Mg) that make up

98.5% of the Earth’s crust. Industry depends on about 80 of the known minerals.

A mineral deposit is a concentration of naturally occurring solid, liquid, or gaseous material, in or on

the Earth’s crust in such form and amount that its extraction and its conversion into useful materials or

items are profitable now or may be so in the future. Mineral resources are non-renewable and include

metals (e.g. iron, copper, and aluminum), and non-metals (e.g. salt, gypsum, clay, sand, phosphates).

Minerals are valuable natural resources being finite and non-renewable. They constitute the vital raw

materials for many basic industries and are a major resource for development. Management of mineral

resources has, therefore, to be closely integrated with the overall strategy of development; and

exploitation of minerals is to be guided by long-term national goals and perspectives.

Types of Mineral Resources:

Minerals in general have been categorized into three classes’ fuel, metallic and non-metallic. Fuel

minerals like coal, oil and natural gas have been given prime importance as they account for nearly

87% of the value of mineral production whereas metallic and non-metallic constitutes 6 to 7%.

(A) Fuel Minerals:

Coal, oil and natural gas are the basic fossil fuel. We have good reserves for coal but are very poor in

more essential fuel — oils and natural gas.

(i) Coal:

Proven coal reserves of the country as on January 1994 (estimated by GSI) is about 68 billion tonnes.

We are mining about 250 tonnes annually and this rate is expected to go by 400 – 450 tonnes by 2010

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A.D. If we could maintain our mining rate of 400 tonnes per year then the coal reserves might last for

about 200 years taking proven reserves as 80 billion tonnes.

The calorific value of coal varies with percentage of carbon present in it. Coal depending upon

variation in percentage carbon, can be divided into three categories as follows (bituminous /

anthracite type is the most abundant form present in Indian coal):

Table 2.3: Categories of Coal

Type % Carbon % Volatile Matter % Moisture

Lignite 38 19 43

Bituminous 65 10 25

Anthracite 96 1 3

(ii) Crude Oil (Petroleum):

It is believed that petroleum has been formed over a period of millions of years, through conversion of

remains of micro organisms living in sea, into hydrocarbon by heat, pressure and catalytic action. The

petroleum on fractional distillation and further processing provides us numerous products and by-

products.

Some of the common products obtained on fractional distillation are given in Table 2.4, along with the

temperature (just below the boiling point) at which they tend to liquefy after crude oil feed at the base

is heated to about 400°C. One million tonne of crude oil on fractional distillation provides about 0.8

million tonnes of petroleum products.

The percentage composition varies with the quality of crude oil or it could be varied up to a certain

limit depending upon the requirement or demand. On an average the percentage composition of the

common product with their number of carbon atoms is given in table 2.4.

Table 2.4.: Average % Composition of Petroleum products (with no. of C atoms) obtained

through fractional distillation.31

S. No. % Composition Name of products No. of carbon atoms with average value

1. 25 Petrol C6-C12 (C8)

2. 45-60 Diesel & C6– C22 (C14)

Kerosene

a3. 15-20 Naphtha

4. 8- 10 Fuel oil C30 – C80(C40)

5. 2-5 Asphalt C50 -C100(C100)

We have very poor reserves for petroleum just limited to 700 million tonnes. About 40% of the total

consumption of the overall petroleum products of the country is used in road transport sector (in case of

diesel, consumption of road transport sector is to the extent of 70% of the total diesel consumption of

the country).

Rest 60% of the petroleum products are used in industries including power generation, domestic and

for miscellaneous purposes. In view of rapid growth of these vital sectors, the consumption of

petroleum products has been increasing consistently over a period of last few years and is bound to

increase at rapid pace in near future.

(iii) Natural Gas:

The proven reserve for natural gas on April 1993 works out to be approx. 700 billion cubic meter

(BCM). As regard to production vis a vis utilization aspect in earlier years, more than half of gas

coming out of the wells remained unutilized. However, in recent years, we have achieved a utilization

rate of 80 – 90%. Keeping in view the future demands and proven gas reserves, it is unlikely that our

gas reserves might last for more than 20 years.

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(B) Metallic and Non-metallic Minerals:

India is poorly endowed with mineral wealth. Except for iron ore and bauxite our share of world

reserves of every other mineral is one percent or less. However, there has been a phenomenal growth in

production since independence. As per estimates if the present trend of production continues, we will

exhaust our reserves of all the important minerals and fuels, except coal, iron ore, limestone and

bauxite, in 25 to 30 years.

Use and Exploitation:

The use of minerals varies greatly between countries. The greatest use of minerals occurs in developed

countries. Like other natural resources, mineral deposits are unevenly distributed around on the earth.

Some countries are rich in mineral deposits and other countries have no deposits. The use of the min-

eral depends on its properties. For example aluminum is light but strong and durable so it is used for

aircraft, shipping and car industries.

Recovery of mineral resources has been with us for a long time. Early Paleolithic man found flint for

arrowheads and clay for pottery before developing codes for warfare. And this was done without

geologists for exploration, mining engineers for recovery or chemists for extraction techniques. Tin and

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copper mines were necessary for a Bronze Age; gold, silver, and gemstones adorned the wealthy of

early civilizations; and iron mining introduced a new age of man.

Human wealth basically comes from agriculture, manufacturing, and mineral resources. Our complex

modern society is built around the exploitation and use of mineral resources. Since the future of

humanity depends on mineral resources, we must understand that these resources have limits; our

known supply of minerals will be used up early in the third millennium of our calendar.

Furthermore, modern agriculture and the ability to feed an overpopulated world is dependent on

mineral resources to construct the machines that till the soil, enrich it with mineral fertilizers, and to

transport the products.

We are now reaching limits of reserves for many minerals. Human population growth and increased

modern industry are depleting our available resources at increasing rates. The pressure of human

growth upon the planet’s resources is a very real problem.

The consumption of natural resources proceeded at a phenomenal rate during the past hundred years

and population and production increases cannot continue without increasing pollution and depletion of

mineral resources.

The geometric rise of population as shown in Fig. 2.3 has been joined by a period of rapid

industrialization, which has placed incredible pressure on the natural resources. Limits of growth in the

world are imposed not as much by pollution as by the depletion of natural resources.

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As the industrialized nations of the world continue the rapid depletion of energy and mineral resources,

and resource-rich less-developed nations become increasingly aware of the value of their raw materials,

resource driven conflicts will increase.

In Fig. 2.4., we see that by about the middle of the next century the critical factors come together to

impose a drastic population reduction by catastrophe. We can avert this only if we embark on a planet-

wide program of transition to a new physical, economic, and social world that recognizes limits of

growth of both population and resource use.

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In a world that has finite mineral resources, exponential growth and expanding consumption is

impossible. Fundamental adjustments must be made to the present growth culture to a steady-state

system.

This will pose problems in that industrialized nations are already feeling a loss in their standard of

living and in non-industrialized nations that feel they have a right to achieve higher standards of living

created by industrialization. The population growth continues upward and the supply of resources

continues to diminish. With the increasing shortages of many minerals, we have been driven to search

for new sources.

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