Free BEVAE-181 Solved Assignment English Medium (2020-21)




1. (a) Explain the importance of environment in day to day life by citing suitable examples in about 120 words. 

Ans – The environment studies enlighten us, about the importance of protection and conservation of environment. At present, due to our aggressive consumerist lifestyle and carbon intensive industrial development we have created a large number of environment issues both in terms of magnitude, intensity and complexity at local, regional and global level. Let us discuss major environmental as issues in the following paragraphs:

  1. Environmental issues are of international importance: It has now been well recognised that environment issues like global warming, climate change, ozone layer depletion, acid rain, marine pollution and loss of biodiversity are not merely national issues but are global issues and hence must be tackled with international efforts and cooperation.
  • Emergence of problems in the wake of modernisation and development: Development in the modern period has given birth to industrialisation,urbanization, modern transportationsystems,Agriculture, Housing etc. When the West developed, it did so perhaps in ignorance of the environmental impact of its activities. Evidently such a path is neither practicable nor desirable. The developing world now faces the challenge ofdeveloping withoutenvironmentaldegradation.
  • Explosive increase in population: World census reflects that one in every seven persons in this planet lives in India.Evidently with 16 per cent of the world’s population and only 2.4 per cent of its land area ,there is a heavy pressure on the natural resources including land. This emphasizes on the need for efficient management of natural resources for the benefits of all.
  • Need for an alternative solution: It is essential, especially for developing countries to find alternative paths to developmental goal.Such a goal would need to be distinct from the developed world in the manner that would conserve natural resources and avoid wasteful consumption.
  • Need for wise planning of development: Resources withdrawal, processing and use of theproducts have all to be synchronised with the ecological cycles in any plan of development. Our actions should be planned for the sustenance of the environment and development.

(b) “Sustainable development is a goal toward which all human societies need to be   moving.” Elaborate the statement in about 120 words. 

Ans – It has been said that sustainable development is an ideal which no societies today have achieved anything resembling it. Nevertheless, as with justice, equality, and freedom, it is important to uphold sustainable development as an ideal – a goal toward which all human societies need to be moving. For example, policies and actions that reduce infant mortality, increase the availabilityof familyplanning,improvethe air quality,providemore abundant and pure water, preserve and protect natural ecosystems, reduce soil erosion and reduce the release of toxic chemicals to the environment, all movea society in the right direction – toward a sustainable future.

To achieve this desired goal, societies have to make certain transitions which are very much essential. There is a broad consensus on the following transition to make future societies:

  • A demographic transition: from a continually growing population toone that is stable.
  • A resource transition to an economy that is not solely obsessed with growth, rather relies more on nature’s income and protects ecosystem capital from depletion.
  • A technological transition from pollution-intensive economic production to environment friendly processes.
  • A political/sociological transition
  • A community transition

2. Differentiate between the following terms by giving suitable examples in about 120 words:

(a) Primary succession and secondary succession

Ans – Primary succession is initiated when a new area that has never previously supported an ecological community is colonized by plants and animals. This could be on newly exposed rock surfaces from landslides or lava flows. Primary succession thus, occurs where no community exists before, such as rocky outcropping, newly formed deltas, sand dunes, emerging volcanic islands and lava flows. An example, which can be used as a model showing development of primary succession, is the invasion and colonisation of bare rock as on a recently created volcanic island.

Secondary succession occurs when a community in an area is drastically disturbed leading to its destruction which results in a new community moving into that area. Secondary succession is more common than primary succession and is often the result of natural disasters such as fires, floods, and winds, as well as human interference such as logging and tree-cutting.

(b) Direct and indirect use value of biodiversity

Ans – Direct use values are for those goods that are ensured directly e.g. food and timber. Maintaining a wide range of components of biological diversity can be of direct use, especially in the fields of agriculture, medicine and industry. Direct use can involve the use of forests, wetlands or other ecosystems for timber extraction, collection of non-timber products, fishing, etc. Direct use values could be due to extractive use where resources are extracted and consumed, or due to non-extractive use when there is no extraction or removal of the resource that is used (e.g. bird watching, scientific research in an ecosystem).

Indirect use value is for those services that support the items that are consumed. Various indirect use values are as follows :

  • Non-consumptive value
  • Aesthetic value
  • Cultural and religious values
  • Ethical values

3. Answer the following questions in about 150 words.

(a) What is biodiversity hotspot? Why is India considered as a mega biodiversity hotspot?

Ans – Hot spots are areas that are extremely rich in species, have high endemism and are under constant threat.

Myers (1988) identified 18 regions or “Hot spots” around the world. Interestingly these areas contain nearly 50,000 endemic plant species, or 20% of the world’s plant species, in just 746,000 km2, or 0.5% of the Earth’s total land surface.

 India is one of the mega-diversity countries because –

  • Four hot spots out of 34 global biodiversity hot spots are in India with itsneighbouring countries.
  • The endemics of Indian biodiversity is high.About 33% of the recorded flora is endemic to the country. Of the 49,219 plant species, 5150 are endemic and distributed into 141 genera under 47 families corresponding to about 30% of the world’s recorded flora.
  • India has 26 recognised endemism centres that are home to nearly a third of all the flowering plants identified and described to date in the country.
  • India has two major realms called the Palaeretic and the Indo-Malayan and three biomes i.e. tropical humid forests, tropical deciduous forests and the warm deserts/semi-deserts.
  • Indiahas tenbiogeographic regions.
  • India is one of the 12 centres of origin of cultivated plants.

(b) Distinguish between Biota of the Pelagic and Benthic zones of the Oceans with examples.

Ans – The marine habitat is distinguishable into two different zones:(1) Benthic zone – which forms the basin or floor of the ocean, regardless of depth; (2) Pelagic zone – which represents the free water zone, filling the basin.

Life in the sea is not particularly abundant, though the diversity of organisms is high.Almost everymajor group of animals and every major group of algae occur somewhere in the oceans, with the exception of vascular plants and insects. On the basis of depth-wise differences in life forms, the expanse of marine ecosystems has been divided into littoral, neritic, pelagic and benthic zones.

Biota of Pelagic Zone: Pelagic region constitutes 90 per cent of the total ocean surface and is less rich in species and numbers of organisms than the two regions discussed before.

Themost abundant pelagicphytoplanktons arestill the dinoflagellatesand diatoms which are the chief photosynthetic feeders, others are carnivores. Sea cucumbers and sea urchins crawl on the floor eating detritus and bacteria and serve as food for the carnivorous brittle stars and crabs.

Biota of Benthic Zone : It forms the floor of the ocean. Organisms here are hetrotrophic Rooted animals are sea lilies, sea fan, sponges etc. Snails and clams remain embedded in mud while starfish, sea cucumbers and sea urchins move on its surface.

(c) Differentiate between the surface and ground water. Describe the factors responsible for degradation of water.

Ans – Water which falls in the form of precipitation moves down into soil and through rocks and gets accumulated as ground water. The layer of rock through which it percolates down is known as aquifer and water can be utilised by digging out wells. Ground water can be found in two layers of the soil. The zone of aeration, where gaps in the soil are filled both with air and water.

The surface water includes the streams, ponds, lakes, human-made reservoirs and canals, and freshwater wetlands.As part of water cycle the surface water bodies are considered renewable resources though they are dependent on other parts of water cycle.

Degradation of Water Sources

The depletion of water resources and their contamination making them unfit as a source of water for human consumption. It is a major problem today. Most of our water bodies like rivers, lakes, oceans, estuaries and ground water bodies arefacing severe pollution due tointensive agriculture, urbanisation, industrialisation and deforestation. Siltation of rivers and lakes due to soil erosion progressively reduces their water holding capacity resulting in ravaging floods year after year.Today we are faced with the paradoxical situation of lack of safedrinking waterin above-average rainfall areas and regions having abundant water bodies.

Discharge of sewage and industrial effluents into water bodies not only pollute water but often lead to an increase in the growth of aquatic plants and algal blooms in water bodies, ultimately causing them to disappear. This may also cause the decay and destruction of various organisms in water, e.g., fish.

(d) Write a short note on global carbon cycle with the help of diagram.

Ans – Some carbon however enters a long term cycle referred to as ‘‘Global Carbon cycle’’ in which carbon accumulates in the form of organic matter in the peaty layers of bogs and moorlands or as insoluble carbonates (for example the insoluble calcium carbonate ((CaCO3) of various sea shells) in bottom sediments of aquatic systems. This sedimentary carbon eventually turns into sedimentary rocks such as lime stone and dolomite. In deep oceans such carbon can remain buried for millions of years till geological movement may lift these rocks above sea level. These rocks may be exposed to erosion, releasing their carbon dioxide, carbonates and bicarbonates into streams and rivers. Hard water has usually flowed through lime stone at some point, picking up carbonates which they accumulate as ‘fur’ in kettles when the water is boiled. Fossil fuels such as coal, petroleum and natural gas are also part of the carbon cycle which may release their carbon compounds after several years. These fossil fuels are organic compounds that were buried before they could be decomposed and were subsequently transformed by time and geological processes into solid or liquid hydrocarbon fuels. When fossil fuels are burned the carbon stored in them is released back into the atmosphere as CO2(2.10 b). The current global cycle shows an increased concentration of CO2 in the atmosphere. The resulting climate change phenomenon is at the forefront of the environmental problems faced by the world at present.

4. How does forest support ecological system and moderate global climate? Explain with suitable examples in about 250 words.

Ans – Forest performs certain function like moderation of global climate, supporting natural ecological systems and processes.

  1. Moderation of global climate: Forests stabilise global climate in a significant manner by influencing natural cycles such as hydrological and carbon cycles. You might have read about these cycles when you were in school. As you know, spatial as well as temporal patterns of rainfall are greatly influenced by forest. How much of water is retained in the soil, and how much flows away, sometime causing floods, also depends on tree cover. Similarly forest can also influence the atmospheric carbon dioxide level. Tree biomass holds carbon dioxide in a fixed state. Therefore, forest acts as a major source of carbon sink i.e. ability to absorb carbon dioxide from the atmosphere.In other words, a carbon sink is a natural or artificial reservoir that accumulates and stores some carbon-containing chemical compound for an indefinite period. When wood is burnt CO2is released in the atmosphere. This has a direct impact on the extent of greenhouse effect and global warming. In other words, more forests lead to greater removal of atmospheric carbon dioxide during photosynthesis resulting reduction of the greenhouse gases in the atmosphere. Therefore, large-scale afforestation has been adopted as a measure to reduce greenhouse effect.
  • Protection of biodiversity: Forests are the greatest repository of biodiversityonthe landastheyprovide idealconditionsforthe survival andgrowthof living organisms. Thenumber of speciesper unitarea is much greater in a forest than in any other terrestrial ecosystem. For example, thetropical rainforestcoverslessthan 7%of theearth’sland surface but accounts for more than 50% of all known species. About 62% of all known plants are found in these rainforests. That is why therehasbeenagrowingcampaignforsavingtherainforestinAmazon and Nile basin. The growing awareness about the importance and necessity to conserve biodiversity is helping human being to realise the significance of forest.
  • Supporting natural ecological systems and processes: As mentioned earlier forests perform certain activities which are crucial for supporting ecological systems and processes directly. Some of these functions and processes are as follows:
  • Forests check the soil erosion by preventing the action of winds and water thereby preserves the fertile top soil.
  •  It prevents landslides and reduces the intensity of cyclones and floods.
  • By preventing soil erosion, forests reduce silting of water bodies including reservoirs.
  • Forest improves air quality by absorbing toxic gases and particulate matter.
  • It protect watersheds and ensure perennial supplies of fresh water

5. “India has tremendous potential in non-conventional sources of energy.” Elucidate the statement with suitable examples and arguments in about 250 words.

Ans – The demand for energy doubles every 14 years and is taken as one of the indicators of development of a country. India, with 16% of the world’s population consumes roughly 3% of the total energy produced in the world, in comparison of USA which has 6.25% of the world’s population and utilizes 30% of the energy produced.Despite continuous increase in energy use, per capita consumption in India is still very low compared with other countries. Even today, about 80% of our population continues to depend on fuel wood, dung and agricultural wastes. We know that non-renewable sources of energy such as fossil fuels, coal and petroleum, are not going to last for long. Forests are also being depleted at the alarming rate due to indiscriminate felling of trees. It has become, therefore, necessary to think of alternative, nonconventional sources of energy. Energy needs in India are met by harnessing two categories of energy sources as shown below.

India has tremendous potential in non-conventional sources of energy. Our diverse geographical settings help in promotion of non-conventional energy sources of energy namely solar, wind and tidal. Looking at the future potential in generating solar energy, the International Solar Alliance was established in the year 2015. Major initiatives were taken by India for the establishment of this alliance. This would help us in developing clean and green energy that would address the problems emerging due to the use of conventional sources of energy like coal, petroleum and radio-active minerals.

But, today our major energy sources are coal, fossil fuel, natural gas, hydropower and atomic energy. These sources of energy are known as conventional sources of energy.


6. Explain the following terms in about 50 words: 

(a) Ecofeminism

Ans – Ecofeminism is radically a new vision. It is rooted in women’s biological, procreative and maternal role. Ecofeminism finds instant rapport with Eastern concepts of ‘Mother Nature’.According to some experts on the subject, ‘The capitalist, patriarchal World system’ is founded upon and sustains itself through three ‘colonisations’ – of women, of foreign people and their lands and of nature. The ecology of nature is linked to the biologyof women’s bodies, and the exploitation of nature to the exploitation of women’s wombs. It is anti modern science and economic growth, as both are characteristic of a violent male ethos. It envisions a work of subsistence life style, in harmony with nature and pervaded by ‘feminist principle’. For the greater good of both man and woman, ecofeminism seeks to forge a ‘new sexual and reproductive ecology’.

(b) Agenda 21

Ans – Agenda 21 is a non-binding action plan of the United Nations with regard to sustainable development. It is a product of the Earth Summit (UN Conference on Environment and Development) held in Rio de Janeiro, Brazil, in 1992. It is an action agenda for the UN, other multilateral organizations, and individual governments around the world that can be executed at local, national, and global levels.

The “21” in Agenda 21 refers to the original target of the 21st century where they were hoping to achieve their development goals by then. It has been affirmed and had a few modifications at subsequent UN conferences. Since it found 2000 was an overly optimistic date, its new timeline is targeting 2030. Its aim is to achieve global sustainable development. One major objective of the Agenda 21 initiative is that every local government should draw its own local Agenda 21. Since 2015, Sustainable Development Goals are included in the newer Agenda 2030.

(c) Global Warming

Ans – The increase in the concentration of CO2 and other greenhouse gases leads to an enhanced greenhouse effect. This is casing an increase in the global temperature which is known as global warming. Studies suggest that temperature has already increased by 0.3°C – 0.6°C since 1860 and the last two decades of the twentieth century were the warmest particularly the year 1998. From 1850 onwards, the decade 2000-2010 had been the warmest one particularly the two years 2005 and 2010 were the warmest years.

This global warming would change global climate patterns and cause a rise in sea levels. It is estimated that the sea-level may rise by 0.5 m to about 1m.

(d) Hazardous Wastes

Ans – Hazardous wastes are chemical by-products of an industry, a factory or a chemical plant. They may result from household activities or even from a hospital or a research laboratory.Armed conflicts, where nuclear or chemical weapons are used, also release enormous amounts of hazardous wastes. A chemical produced by any of the above sources which may endanger human health, pollute the environment or carryhidden risk to life if managed or disposed off improperly is called ‘hazardous’.

7. Answer the following questions in about 150 words. 

(a) How does Landfilling act as an important method of waste disposal? Explain. (b) What is Acid rain? Describe its effect.

Ans – The disposal of hazardous waste by landfilling is an important method of disposal in many countries. Landfilling means under ground storing of harmful substances. This involves hauling the refuse to an area allocated for this purpose. In India, such areas range from unsanitary open dumps to properly operated sanitary landfills. Open dumps are a poor method of waste disposal because they cause environmental problems. For example, they can ruin the appearance of ah area and provide a home for rats and other rodents who spread disease. If garbage is exposed, it rots and smells foul. Most dumps allow some burning, which fills the surroundings with smoke. In addition, rain water can drain through refuse and carry harmful substances to streams.

Properlyoperated sanitarylandfills cause little damage to the environment. The area to be filled with waste must be lined with a nonporous substance such as clay, or high density polyethylene (HDPE)-plastic membrane to prevent the wastes from leaking to the surrounding areas. The wastes are packed and dumped at the site and covered with earth each day. The cover of earth prevents insects and rodents from getting into refuse. Operators of these sites forbid burning. In time, sanitary landfill sites become filled up, many communities then cover the site for a final time and use the area for recreationalpurpose.

A typical landfill site consists of an artificial double liner at the bottom and a cover at the top. The cross section of a conceptual design of a double lined hazardous landfill is shown in Fig.

Outline of a typical landfill site.

(b) What is Acid rain? Describe its effect

Ans – The wet deposition in the form of acid rain or acid snow contain nitric acid and sulphuric acid which are formed by the reaction of oxides of nitrogen and oxides of sulphur, respectively, with water.

When fossil fuels such as coal or oil containing sulphur impurities are burnt, then oxides of sulphur i.e. sulphur dioxide (SO2) and sulphur trioxide (SO3) are produced. Similarly, when any organic matter with high nitrogen content is burnt, oxides of nitrogen (NOx) i.e. nitric oxide (NO) and nitrogen dioxide (NO2) are produced. The oxides of nitrogen also originate from forest fires, electric power plants and motor vehicles.

Effects of Acid Rain

The pH value of acid rain water is around 4. There are many damaging effects of such acidic water. These are discussed below:

  • Effect on Crops and Plants: The acid rain has detrimental effects on crops and forests. The acid rain can dissolve important minerals and nutrient present in the soil. Soil bacteria and fungi that playimportant role in nutrient cycling and nitrogen fixation are also affected. Thus, soil fertility is reduced and plant growth is affected.
  • Effect on water Bodies and Aquatic Life: Water bodies like lakes, rivers and ponds are also affected by the acid rain. The accumulation of acid in them over a period of time lowers the pH and affects the aquatic plants and animals. Manyaquatic plants and different types of fish have different tolerance levels for such conditions and hence, cannot survive.
  • Effect on Human Health: The gases responsible for the acid rain and the acids present in acid rain can affect human health especially the lungs and the respiratory system. The dry depositions from air can cause heart and lung problems such as asthma and bronchitis.
  • Effect on Materials: Acid rain also damages bridges, buildings, statues and monuments. It can cause corrosion of metals and paints. Many historic monuments are under careful watch now. One such monument in India is Taj Mahal inAgra.The colour ofTaj Mahal has already beenaffected. Buildings made of marble and limestones (CaCO3) are affected by acid rain.

(c) Describe issues emerges in enforcement of national environment legislations.

Ans- Following are the  issues emerges in enforcement of national environment legislations

  • After an analysis of all enactments and provisions at national level, It is to be noted that nature of most of the existing environmental legislations are essentially punitive not preventive. Only once the chemicals or substances are discharged into the air or water or soil does the act apply. The preventive measures have hardlyever evoked or worked and the concerned agencies have moved into action only after the harm has been done.
  • More serious problem in the implementation of environmental legislation is overlapping powers of authorities involved in supervising the safety mechanism and devices of companies, and in granting or refusing No Objection Certificate (NOC). Thus though the water and air pollution board may refuse to grant NOC, the Municipality may grant a license to an industrial unit based on which it may start its manufacturing activity.
  • In some cases statutes of environmental legislations do not lay down any guidelines on the nature of the authority and their specific rights and the obligations. For example, Delhi State Government in 2009 has banned the manufacture and use of coloured plastic, without formulating the rule to prosecute defaulters. Because of this 2009 ban did not do too well.Again Delhi State Government amended this bill 2011 and imposed a blanket ban on use, storage, sale and manufacture of plastic bags in the city. This total ban again failed to make any difference in the city largelydue to poor implementation and absence of strong rules.
  • Acommon feature with environmental legislation in India is that they exclude peoples’ participation intheir implementation. The enterprises, which make profits at the expense of the environment, are always well represented and their interests well protected but not those of the common person who suffer the consequences of pollution and degradation.
  • Sometime enforcement of legislation is difficult due to shortage of funds. Take for example the case of rivers pollution in India. It is well known that the major source of pollution of rivers is domestic sewage, which municipalities nonchalantly dump in the nearest rivers. The colossal cleaning up operation of rivers will be an exercise in futility if it is not accompanied by a massive effort to prevent the municipalities from dumping their wastes in the river. Everyone knows that the technology for treating municipal wastes exists. But many and most of the municipalities cannot afford it its cost .
  • Public opposition also makes the implementation of environmental legislation difficult.As we have seen the difficulty in implementation of the Supreme Court ruling regarding mandatory use of CNG for all public transport vehicles in Delhi. Delhi Government has taken lot of time in implementing this order. Similarly public did not support the order of Supreme Court regarding ban on diesel public vehicles that were more than 10 years old and also complete ban on the registration of diesel vehicles in NCR region.

(d) What is environmental ethics? Why do we need a set of ethics for the environment? Explain.

Ans – The term “Environmental Ethics” we refer to it as a discipline that studies the moral relationship of human beings, and also the value and moral status of the environment and its non-human contents.

We need a new set of ethics for the environment.These includes three factors –

  1. New effects on nature: As our modern technological civilisation affects nature greatly, we must examine the ethical consequences of these new technological actions.
  • New knowledge about nature: Modern science demonstrates as to how we have changed and are in the process of changing our environment in ways not previously understood, thus raising new ethical issues. For example, until the past decade, few people believed that human’s activities could be changing the global environment. Now, scientists however, believe that burning fossil fuels and clearing forests have increased the amount of carbon dioxide in the atmosphere, and that this causes changes in our climate. Hence the emphasis is on a global perspective.
  • Expanding moral concerns: Some people argue that animals, trees, and even rocks have normal and legal rights. These expanded concerns lead to a need for a new ethic.

For most of human history, ethics has concentrated on “human rights”, the rights of individuals, of families and ethnic groups. However ethics now include the rights of animals, plants and the environment beyond the human rights to rule and use them.

8. “Habitat destruction is recognised as most significant threat to global biodiversity?” Elucidate the statement in present context with suitable examples in about 250 words. 

Ans – Habitat destruction is recognised today as the most significant threat to global biodiversity and bears responsibility for much of the species loss worldwide. This includes:

  • felling of forests for land use (e.g. clear felling for development, agriculture), large scale logging and small scale patchwork agriculture. Shifting cultivation alone is believed to be responsible for 70% of deforestation inAfrica, 50% of deforestation inAsia, and 35% of forest loss in theAmerica.
  • destruction of mangrove sites for aquaculture
  • mining and destruction of corals
  • conversion of wetlands for land uses
  • over-extraction of timber and fuel wood
  • human-induced burning of habitats(e.g. forest firing for shifting cultivation and firing grasslands to improve fodder for cattle)
  • damming of rivers
  •  siltation and sedimentation of freshwater bodies
  • pollution also disturbs the natural habitat considerably. Industrial wastes cause severe impact, particularly on the aquatic habitats. For example, during the 1950s and 1960s, insecticides particularly chlorinated hydrocarbons (such as DDT), reduced the population levels of several birds such as the bald eagle and brown pelican.

In many countries there are very few pristine areas left that have not been modified in some way by humans. When habitats are not completely destroyed, they are fragmented into smaller patches, creating islands of habitats in a sea of development. Fragmentation exposes species to more light, wind and temperature effects than are natural, thus affecting the species survival as food and water sources are lost and few mates remain. In fragmented landscapes many species soon become isolated from others of their own kind resulting in inbreeding, loss of genetic diversity and local extinction.

More than three quarters of the species that are in danger of extinction today are due to the destruction of their forest habitats.Alarge number of these species are from the tropics, where human population growth has been most explosive and habitats have been destroyed most rapidly. Tropical rain forests cover a mere 7 per cent of the earth’s surface, yet they house about three quarters of the total species. Today these forests are being destroyed at an alarming rate.

9. Differentiate between the primary and secondary pollutants. Explain how these pollutants are harmful for humans and environment in about 250 words. 

Ans – Primary Pollutants: These pollutants are emitted directly into the air as a result of natural or human activity (Fig. 9.2). Examples include sulphurdioxide, nitrogenoxides, carbondioxide, carbon monoxide, hydrocarbons and particulates released from fuel burning.

Secondary Pollutants: Secondary pollutants are produced as a result of chemical reactions between primary pollutants and normal atmospheric compounds under the influence of electromagnetic radiations from the sun (Fig.9.2). For example, the primary pollutant sulphur dioxide (SO2) reacts with oxygen (O2) in the atmosphere to form sulphur trioxide (SO3), a secondary pollutant.

Major air pollutants, their sources and effects on humans and environment.

Oxides of Carbon (COx )  – Carbon dioxide (CO2)  – Carbon monoxide (CO)Combustion of coal, oil and other fuels for energy production, manufacturing and transport; biomass burningCO2 has a major role in green-house effect, produces weak carbonic acid adding to acid rains; CO affects human health by binding to haemoglobin, which may result in asphyxia.
Oxides of Sulphur (SOx)  – Sulphur dioxide (SO2)  – Sulphur trioxide (SO3) – Sulphate (SO4)Combustion of sulphur containing fuel e.g. coal, petroleum extraction and refining; paper manufacturing; municipal incineration; ore smelting for metal extractionSO2 can cause severe damage to human and other animal lungs and is important precursor to acid rain; adverse effects include corrosion of paints, metals and injury or death to animals and plants.
Oxides of Nitrogen (NOx) – Nitrogen oxide(NO) – Nitrogen dioxide (NO2) – Nitrous oxide (N2O) – Nitrate(NO3)Burning of fuels; biomass burning; byproduct in the manufacture of fertilizersForm the secondary pollutants: peroxy acetyl nitrate (PAN) and nitric acid (HNO3); suppression of plant growth and tissue damage; cause irritation to eyes.
Hydrocarbons (HCs) also called Volatile Organic Compounds (VOCs) – Methane(CH4) – Butane (C4H10) – Ethylene(C2H4) – Benzene (C6H6) – Benzo pyrine (C20H12)  – Propane (C3H8)Evaporation from gasoline tanks, carburators; burning of fuels, biomass; municipal landfills; microbial activity of sewage; industrial process involving solventsCan have carcinogenic effect on humans; higher concentrations are toxic to plants and animals; can convert into harmful compounds through complex chemical changes that occur in atmosphere; some are more reactive with sunlight and produce photochemical smog
Other organic compounds] – Chlorofluorocarbons (CFCs), – Formaldehyde (CH2O) – Methylene chloride (CH2Cl2) – Trichloroethylene (C2H Cl3) – Vinyl chloride (C2H3Cl) – Carbon tetrachloride (CCl4)  – Ethylene Oxide(C2H4O)Aerosol sprays; foam and plastics for making disposable fast food containers; refrigerationCFCs cause reduction in stratospheric ozone thus allowing greater penetration of ultraviolet light at earth’s surface; intensified UV radiations cause skin cancer and can have lethal effects on various life forms
Metals and other inorganic compounds – Lead (Pb),Mercury(Hg) – Hydrogen sulphide(H2S) – Hydrogen fluoride(HFOil wells and refineries; transport vehicles; municipal landfills; fertilizer, ceramic, paper, chemical and paint industries; pesticides; fungicides; aluminium production; coal gasificationCause respiratory problems, toxicity and even death to humans and other animals; damage to crops; prove to be carcinogenic
Liquid droplets – Sulphuric acid (H2SO4) – Nitric acid (HNO3) – Oil – Pesticides e.g. DDT and malathionAgricultural pesticides; fumigation; oil refineries; reactions of pollutants in the atmosphereContribute to acid rains; corrosion; damage to various life forms
Suspended particulate matter (SPM-solid particles) – Dust, soil, sulphate salts, heavy metal salts, fine particles of carbon (soot), silica, asbestos, liquid sprays, mist etc.Fuel combustion; building constructions; mining; thermal power stations; stone crushing; industrial processes; forest fires; refuse incinerationHave chronic effects on respiratory system; deposition on the surface of green leaves thus interfering with absorption of CO2 and release of O2; blocking of sunlight; particles size that range from 0.1 to 10 mm, cause lung damage
Photochemical oxidants – Ozone (O3), peroxy acyl nitrates (PANs), – Formaldehyde (CH2O) – Acetaldehyde (C2H4O) – Hydrogen peroxide (H2O2) – Hydroxyl radical (HO)Photochemical reactions in the atmosphere that involve sunlight, oxides of nitrogen and hydrocarbonsProduce haze; irritation to eyes, nose and throat ;respiratory problems; blocking of sunlight

10. Critically analyse a case of people’s movement in India against environmental degradation in about 300 words. 

Ans – Though legislations and regulations are the foundations of most environmental protection policies, the global nature of resources and pollution make international legislations and conventions essential. Public interest Litigations and People’s Movement have also played very important role in environmental protection. Few cases of PIL and people’s movement in India against environmental degradation.

Taj Trapezium Zone

Problem of pollution has now become so severe that it is not only affecting human health and livestock but it is also damaging buildings and monuments. Over the past four decades, the fate of the India’s most emblematic monument, the Taj Mahal, has repeatedly come into the spotlight because of the ill effect of the pollution caused by the iron foundries, Mathura refinery, glass factories of Firozabad and brick kiln in the Taj Trapezium Zone (TTZ). This is the area around Taj spreading over 10,400 On repeated occasions, sulphur dioxide emissions from industries in this area reached levels ten times above the prescribed standard level. Combined with oxygen and moisture, sulphur dioxide converts to highly corrosive acid, sulphuric acid.

Blaming pollution and regulatory negligence of Taj’s decay, Mahesh Chandra Mehta, a prominent environmental lawyer, filed a case before the Supreme Court of India in 1984. Mehta pleaded with the court to order the various industries to take anti-pollution measures or to close. He also stressed that pollution was affecting the health of the workers and people living in Agra. Because of Mehta’s efforts, in 1996, the Supreme Court finally ruled that the industries in the area were actively contributing to air pollution and ordered major industries units to install pollution control devices. “Not even one per cent chance can be taken when human life apart- the preservation of a prestigious monument like the Taj is involved,” stated the court order. The court ordered 292 coal-based industries to switch to natural gas or else to relocate outside the protected zone by April 30, 1997. Because of the opposition from industries and workers court order was not enforced completely. The Supreme Court struck again in 1997 ordering the closure of 53 iron foundries and 107 other factories in Agra that had not cleaned up their act. The Supreme Court later also banned cars and parking within 500 meters of the Taj’s boundary walls. Experts agree that some of these measures have helped to improve air around the Taj.

Chipko Movement

From the last 19th century the Himalayan forests, have been subject to rapid exploitation (Fig. 13.7). This large-scale destruction has led to severe ecological problems. Rapid soil erosion, growing frequency of floods, reduction in the availability of fire wood and fodder, landslides and disappearance of water table, caused concern among people. In upper Alkananda Valley. People also resented the conversion of natural forests into monoculture plantations.

To check environmental degradation in this region, voluntary organizations like the Gangotri Gram Swarajaya Sangh (GGSS) in Uttarakashi and Dasholi Gram Swarajaya Mandal (DGSM) in Gopeshwar started Chipko Movement in the 1970s. Environmentalists like Chandi Prasad Bhatt and Sunderlal Bhauguna ledthe Chipko Movement in Garhwal Himalayas.

Chipko means to hug the tree. Volunteers in their attempt to stop commercial felling threatened to hug the trees if the saws came near them. Their activities popularised the movement through folk songs, street plays and widespread campaign. Its slogan was “What do the forest bear? Soil, water and pure air, Soil, water and pure air are the basis of life”.

As a result of this struggle, the Government replaced the contractor system and formed Uttar Pradesh Forest Department Corporation (UDFDC) and the forest related activities were encouraged through local cooperatives. In 1981, as a response to Sunderlal Bahuguna’s indefinite fast, the Government constituted an eight member expert committee to prepare a comprehensive report on the Himalayan forest policy.The government later put a fifteen-year moratorium on commercial tree fellings in the Uttrakhand Himalayas.

Silent Valley Movement

This movement is regarded as one of the most important ecological movements in India. Silent valley is the narrow valley of the Kunthi River in the state of Kerala in the south west of India at high elevation (Fig. 13.8). Its 8950 hectares of rain forest is rich with valuable plants and animals. In 1973, the state government of Kerala decided to build a dam across the gorge in order to generate hydro electricity. It would have drowned valuable forest and threatened the loss of wild life. Even the government’s ecological task force expressed its dissatisfaction over the loss of forest and wild life.

By 1979, students, voluntary organization like Kerala Sastra Sahitya Parishad (KSSP), science forums, teachers, progressive citizens and journalists began to work against the project. In 1979, Save Silent Valley Committee emerged. This hue and cry among all circles led the government headed by the then Prime Minister Mrs. Indira Gandhi, to set up a high-level technical committee chaired by Prof. M.G.K. Menon and accepted its recommendation that the project should not be proceeded with and that the Valley should be preserved as a precious biosphere reserve.

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