ES-101 Environmental Studies PDF

ENVIRONMENTAL STUDIES ES-101 Suresh Gyan Vihar University Mahal, Jagatpura, Jaipur-302025 Published by: S. B. Prakashan Pvt. Ltd. WZ-6, Lajwanti Garden, New Delhi: 110046 Tel.: (011) 28520627 | Ph.: 9205476295 Email: [email protected] Web.: www.sbprakashan.com © S. B. Prakashan Pvt. Ltd. All rights reserved. No part of this book may be reproduced or copied in any form or by any means (graphic, electronic or mechanical, including photocopying, recording, taping, or information retrieval system) or reproduced on any disc, tape, perforated media or other information storage device, etc., without the written permission of the pub- lishers. Every effort has been made to avoid errors or omissions in the publication. In spite of this, some errors might have crept in. Any mistake, error or discrepancy noted may be brought to our notice and it shall be taken care of in the next edition. 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Printed at : INDEX CHAPTER 1 MULTIDISCIPLINARY NATURE OF ENVIRONMENT STUDIES 5 CHAPTER 2 NATURAL RESOURCES AND CHALLENGES 20 CHAPTER 3 ECOSYSTEMS, CONCEPTS, STRUCTURE, FUNCTIONS AND TYPES 54 CHAPTER 4 BIODIVERSITY AND ITS CONSERVATION 74 CHAPTER 5 ENVIRONMENTAL POLLUTION AND CONTROL MEASURES 89 CHAPTER 6 SOCIAL ISSUES, ENVIRONMENT, LAWS AND SUSTAINABILITY 141 CHAPTER 7 HUMAN POPULATION AND THE ENVIRONMENT 183 CHAPTER 1 MULTIDISCIPLINARY NATURE OF ENVIRONMENT STUDIES MEANING OF ENVIRONMENTAL STUDIES The word Environment came from the French Language which means the surroundings. The Environment is an interdisciplinary topic that includes the surroundings which cover the land, air, water, and their interrelationship and majorly their relationship with human beings and other organisms prevailing in the surroundings. Environment sciences not only deal in surroundings but it includes the processes in the land, water, and air which will even explain the pollutants that can harm and create pollution. When surrounding is not under control naturally then it can bring disasters. To manage these disasters, different committees, Acts, rules, and regulations are formed to maintain a clean, safe, and healthy ecosystem. Douglas and Holland defined that “The term Environment is used to describe, in aggregate, all the external forces, influences, and conditions, which affect the life, nature, behaviour and the growth, development, and maturity of living organisms” MULTIDISCIPLINARY NATURE OF ENVIRONMENT STUDIES Existence and behaviour of living and non-living components of environment require inputs from physical, social and geological science. Human behaviour and management of human societies are covered by social science, economics, psychology and political science. Regulations framed for environmental management and protection falls under jurisdiction of national legislation. Treaty reached regarding common problems faced by two or more countries comes under purview of international law and global governance. All the aspects of the environment and their respective disciplines of study are dealt with holistic approach. Environmental science is an interdisciplinary academic field that integrates physical, biological and information sciences (including ecology, biology, physics, chemistry, plant science, zoology, mineralogy, oceanography, limnology, soil science, 6 Environmental Studies NOTES geology and physical geography, and atmospheric science) to the study of the environment, and the solution of environmental problems. Environmental science emerged from the fields of natural history and medicine during the Enlightenment. Today it provides an integrated, quantitative, and interdisciplinary approach to the study of environmental systems. Environmental studies incorporate more of the social sciences for understanding human relationships, perceptions and policies towards the environment. Environmental engineering focuses on design and technology for improving environmental quality in every aspect. COMPONENTS OF ENVIRONMENT The “solid” portion of ” the earth, including water masses; the lithosphere plus the hydrosphere. Above the geosphere lies the atmosphere and at the interface between these two regions is found almost all of the biosphere or zone of life. The physical part of the earth is the lithosphere. The atmosphere is the blanket of air that surrounds the earth. A hydrosphere (from the Greek word hydro, “water” and sphaira “sphere”) in physical geography describes the combined mass of water found on, under, and over the surface of a planet. The term “biosphere” was coined by geologist Eduard Suess in 1875, which he defined as: “The place on the earth’s surface where life dwells.” GEOSPHERE The solid part of the earth consisting of the crust and outer mantle. The physical elements of the Earth’s surface crust, and interior. The term geosphere is often used to refer to the densest parts of Earth, which consist mostly of rock. The term originally applies to the lower nested geospheres identified with the states of terrestrial matter: solid (earth), liquid (water), gas (air), and plasma (fire). The nested geospheres then include the asthenosphere, atmosphere, lithosphere, hydrosphere, and the ionosphere or plasmasphere. The dense geosphere is also subdivided into the crust, mantle, and core. THE MULTI- DISCIPLINARY NATURE OF The outer core is unusual in that it is considered to be a liquid, yet it is a part ENVIRONMENTAL of Earth’s interior. STUDIES Environmental Studies 7 Geosphere refers to the solid parts of the Earth and is used along with the NOTES atmosphere, hydrosphere, and biosphere to describe the systems of the Earth, sometimes the term “lithosphere” is used instead of the geosphere, however, the lithosphere only refers to the uppermost layers of the solid Earth (oceanic and continental crustal rocks and uppermost mantle). The geosphere is considered that portion of the Earth system that includes the Earth’s interior, rocks and minerals, landforms, and the processes that shape the Earth’s surface. The Earth’s interior includes a thin, 5- to 70 km-thick layer of oceanic and continental crust overlying an additional 6,300 km of rock and metals. The crust varies in thickness and density, with oceanic crust consisting of a thin (around 5 km) layer of dense rock and continental crust consisting of less-dense, lighter-colored rock ranging between 30 and 70 km in thickness. Although the crust is comprised of many types of rocks and hundreds of minerals, these materials are assembled from a very small number of elements. A total of 98.7% of the crust (by weight) consists of just 8 elements, including oxygen (46.6%), silicon (27.72%), aluminum (8.13%), iron (5.00%), calcium (3.63%), sodium (2.83%), potassium (2.70%) and magnesium (2.09%). These elements form the building blocks of most of the inorganic materials we encounter in our daily lives such as glass (Si02), concrete (CaCO3), and steel. Oceanic crust is dominated by minerals consisting of silicon, oxygen, and magnesium and is thus called SIMA; the continental crust is made up of SIAL, in which silicon and aluminum dominate. The Earth’s interior is arranged somewhat like a layer cake, consisting of a series of layers that change in density, mineral composition, and thickness with depth. Directly below the crust is the mantle. It consists of two parts, an upper layer that is less dense and relatively brittle and a lower (much thicker) layer that is denser and plastic (it deforms without breaking). The crust and upper mantle combined form the brittle upper layers of the Earth’s interior called the lithosphere. The upper mantle is also called the asthenosphere. The mantle makes up the largest volume of the Earth’s interior. The region beneath the mantle is called the core, and consists of two parts, a liquid outer core that is around 2250 km thick and a solid inner core 1220 km thick. The core is primarily made up of iron, with a small amount of nickel. The liquid iron in the outer core is particularly important in that it is the primary source of the Earth’s magnetic field. Unlike a common magnet, though, the north and south ends of our “global magnet” are not exactly situated at Earth’s poles. Instead, the magnetic north pole is situated in northern Canada, and the magnetic south pole resides north of Antarctica and south of Australia. Another interesting feature of the magnetic poles is that their precise location moves over time. Every few million THE MULTI- years, even the polarity of the Earth’s magnetic field reverses (called a geomagnetic DISCIPLINARY reversal, where magnetic north and south “switch”). While scientists still do not NATURE OF fully understand why geomagnetic reversals occur, the presence of changing ENVIRONMENTAL STUDIES 8 Environmental Studies NOTES magnetic orientations preserved in rocks containing iron was a fundamental clue in unraveling the puzzle of Plate Tectonics. Almost all of our direct knowledge of the Earth’s interior is from the upper 10 km. Our knowledge of the remaining 6,300 km is based largely on indirect evidence from seismology, laboratory studies of igneous and metamorphic rocks, computer models, and meteorites. Hydrosphere It refers to all the water on Earth. It mainly consists of the oceans but includes all water surfaces in the world, including inland seas, rivers, and lakes. The outer layer of this hydrosphere is almost entirely ice, but current models predict that there is an ocean up to 100 km in depth underneath the ice. This ocean remains in a liquid form because of the tidal flexing of the moon in its orbit around Jupiter. The volume of Europa’s hydrosphere is 3 x 101S m3, 2.3 times that of Earth. Biosphere The biosphere is the global sum of all ecosystems, it can also be called the zone of life on Earth. From the broadest physiological point of view, the biosphere is the global ecological system integrating all living beings and their relationships, including their interaction with the elements of the lithosphere, hydrosphere, and atmosphere. The biosphere is postulated to have evolved, beginning through a process of biogenesis at least some 3.5 billion years ago. The actual thickness of the biosphere on earth is difficult to measure. Birds typically fly at altitudes of 650 to 1800 meters, and fish that live deep underwater can be found down to -8,372 meters in the Puerto Rico Trench. The THE MULTI- Indian government has established 15 Biosphere Reserves of India, (categories DISCIPLINARY roughly corresponding to HALM Category V Protected areas).- which protect NATURE OF larger areas of natural habitat (than a National Park or Animal Sanctuary) and ENVIRONMENTAL often include one or more National Parks and/or preserves, along buffer zones that STUDIES Environmental Studies 9 are open to some economic uses, Protection is granted not only to the flora and NOTES fauna of the protected region, but also to the human communities who inhabit these regions, and their ways of life. The Biosphere in Education The biosphere is a core concept within Biology and Ecology, where it serves as the highest level of biological organization, which begins with parts of cells and proceed to populations, species, ecoregions, biomes, and finally, the biosphere. Global patterns of biodiversity within the biosphere are described using biomes. In earth science, the biosphere represents the role of living organisms and their remains in controlling and interacting with the other spheres in the global biogeochemical cycles and energy budgets. The biosphere plays a central role in the biogeochemical processing of carbon, nitrogen, phosphorus, sulfur, and other elements. As a result, biogeochemical processes such as photosynthesis and nitrogen fixation are critical to understanding the chemistry and physics of earth systems as a whole. The physical properties of the biosphere in terms of its surface reflectance (albedo) and exchange of heat and moisture with the atmosphere are also critical for understanding the global circulation of heat and moisture and therefore climate. Alterations in both the physics (albedo, heat exchange) and chemistry (carbon dioxide, methane, etc.) of earth systems by the biosphere are fundamental in understanding anthropogenic global warming. The Future of the Biosphere The Biosphere “experiments”, which were conducted in the early 1990s in Arizona using private funding, enclosed a complex array of plants and animals together with humans in a sealed greenhouse complex that included a large “ocean”. Within a short lime, this “experimental biosphere” demonstrated how little we understand biosphere I (the biosphere of our planet): the project failed to replicate the basic biogeochemical functions that support life on Earth. Without resorting to drastic chemical interventions to inject oxygen and reduce toxic levels of carbon dioxide, it was impossible to support human life in the complex. Moreover, many keystone species such as pollinators died off within a short time. Many now see this as a good analogy for the current changes in atmospheric composition we are causing by rapidly burning off the fossil carbon captured by plants over millions of years, and by our conversion of forests to croplands. By releasing carbon stored by the biosphere over geologic time back to the atmosphere at unprecedented rates, humans are causing rapid global warming, and this warming is further altering global biogeochemical cycles and patterns of biodiversity across the biosphere. Anthropogenic climate change together with land-use change and other anthropogenic alterations of the biosphere and other spheres have now reached THE MULTI- DISCIPLINARY such a high level that some earth scientists are now calling for the recognition that NATURE OF we have now entered a new, human-dominated, geologic era: The Anthropocene. ENVIRONMENTAL STUDIES 10 Environmental Studies NOTES We need a greater understanding of how to better manage our only biosphere for the long-term benefit of ourselves and all other organisms. Hydrosphere The hydrosphere is composed of all of the water on or near the earth. This includes the oceans, rivers, lakes, and even the moisture in the air. Ninety-seven percent of the earth’s water is in the oceans. The remaining three percent is freshwater; three- quarters of the freshwater is solid and exists in ice sheets Biosphere The biosphere is composed of all living organisms. Plants, animals, and one- celled organisms are all part of the biosphere. Most of the planet’s life is found from three meters below the ground to thirty meters above it and in the lop 200 meters of the oceans and seas. SCOPE AND IMPORTANCE OF ENVIRONMENTAL STUDIES The main source of environmental destruction in the world is the demand for natural resources generated by the consumption of the rich (whether they are rich nations or rich individuals and groups within nations). Environmental movements of various countries have emerged due to the different reasons. This is basically due to the prevailing environmental quality of the locality. The environmental movements in the north are basically on the issue of quality of life. Whereas the environmental movements in the south arise due to some other reasons, such due to conflict for controlling natural resources. The scope of Environmental Science is as follows: Academics: Nowadays, it’s mandatory to teach environmental science at every level and to make every child aware of the environment and to teach such subjects, teachers with specialized knowledge on these subjects are being appointed. Industries: Many industries are using high technology which can impact our environment. On the other hand, the service sector industry is taking initiatives to use Green marketing, green banking, green media techniques to save our environment. Research and Development: Many experts are researching ecology and biodiversity. With the support of the researcher, we can save our environment to some extent. Some researchers have even working in Governmental jobs to procure our environment. NGOs: They are playing an important role to create awareness among the public by presenting different plays and conducting different programs with the support THE MULTI- DISCIPLINARY of national and international agencies. These agencies support NGOs financially. NATURE OF Consultancies: Environmental Acts also have processes and procedures to ENVIRONMENTAL STUDIES accomplish to utilize the natural resources for any particular reason. To fulfill those Environmental Studies 11 procedures some expertise, knowledged person or Consultants need to be their NOTES guide Environment Impact Assessment is also being done in different industries, and to guide them, expert knowledge is always helpful. Green Advocacy: Environment also has legal aspects. Many lawyers are making their career in environmental advocacy. There are many Environmental Acts and Public Interest Litigation that empowers human beings to fight against anti- environmental issues. IMPORTANCE OF ENVIRONMENT Needs Global Attention: Any environmental issue is not a domestic issue to discuss instead it impacts the international level like the ozone layer. It will not only harm the Indian environment but the global environment. Managing Natural Resources: It is also important to procure the natural resources available in our country. The exploitation of natural resources can bring disastrous effects on our country. Many researchers are continuously working on the procuring and effective utilization of resources. Everyone must conserve our ecology and biodiversity. Growth of the Country: Growth and Development of any country impact the environment of that country. Technology and Urbanization have majorly impacted the environment negatively. Cleanliness and hygiene play an important role to play in the growth and development of any area. Control Pollution: With the increase in population on the land, they need all the necessities for their growth and development, due to which they are cutting down the trees, using electronic and electric gadgets which are impacting directly or indirectly the environment and create pollution. Sustainable Development: It is required to utilize the environmental resources in a way so that the upcoming generations can also utilize the same resources for their betterment. Even we can say that we need to sustain the natural resources for our future generation. Proper Planning and Development: Developing countries need proper planning to maintain ecology in the world. They should not exploit the natural resources for the development of their countries. It can affect sustainable development. Environmental education: To Educate today’s generation about environmental safety, the UN is also taking different initiatives like conducting conferences with UN countries. It is mandatory to aware the population about the pros and cons of utilizing the environmental resources extensively. HISTORY OF ENVIRONMENTALISM THE MULTI- In the early 1800s, In Europe, the concept of environmentalism came into picture DISCIPLINARY NATURE OF through an another ideology Romanticism. As the name suggests, Romanticism was ENVIRONMENTAL not a movement which focus on love but on emotions. This movement Romanticism STUDIES 12 Environmental Studies NOTES emphasises on love for nature, its motto was - people to appreciate the woods for their beauty, which challenged the scientific view which many people had towards nature at that period of time. And in Late1800s, the environmental movement had strongly emphasised in Britain as a response to the Industrial Revolution. As there were no environmental regulations which can stop this movement, the productions of the Industrial Revolution polluted air and water and expanded out into beautiful farmland. Quickly, the dark side of the Industrial revolution, factories with people calling for wild spaces to be protected. Early conservation groups, like ‘the Society for the Protection of Birds (1889)’ and ‘the National Trust for Places of Historic Interest or Natural Beauty (1894),’ began popping up all over England. The environmental movement took shape in North America when John Muir, a great environmentalist, convinced the U.S. congress to create the Yosemite National Park to preserve the beautiful valley. Many other conservation efforts began to take place across the continent with people trying to protect the dwindling American bison population. And in 1916, President Woodrow Wilson founded the National Park Service, which deeply supported the growing environmental movement. In the early 20th century, environmental laws and government agencies began to pop up all over the world but especially in Nazi Germany! Several of the high ranking Nazis were environmentalists and wanted to protect the German forests. The environmental movement continued to grow in the 1950s, 60s, and 70s with many influential books being published, such as ‘A Sand County Almanac (1949)’ and ‘Silent Spring (1962).’ Silent Spring, written by American biologist Rachel Carson, is especially influential as it exposed the harmful and dangerous effects of the pesticide DDT. The book played very important role for the environmental movement that leads to the creation of the Environmental Protection Agency in 1970 and DDT was banned in 1972. The 1970s were greatly important for the green movement with many groups, like Greenpeace, forming in the 1970s. The first Earth Day and the UN’s first environmental conference also happened in the 70s. Into the 1980s, a growing awareness on global warming brought the environmental movement even more into the mainstream. Unfortunately, the environmental movement’s strength has declined somewhat since the late 2000s after it hit a high with the anger following the great recession. ECOLOGY The term Ecology or Oeaologic (Greek) was coined by the German biologist ‘ErnstHaecken’ Ecology is derived from two words Oikos + Logos Oikos means household; logos means knowledge (Study). Ecology refers to the study of the organism in their natural habitat. Ecology.is concerned with the study of the organism in various habitats such as islands, oceans, THE MULTI- freshwater, and air. DISCIPLINARY NATURE OF “The study of the structure and function of nature is known as ecology” As per, ENVIRONMENTAL Odum STUDIES Environmental Studies 13 “It is a scientific study of the distribution and abundance of living organism and NOTES their interaction among organism and between organisms and their environment” Amdrewartha Ecology proceeds at three levels (i) The individual organism; (ii) The population; (iii) The community; LEVEL OF ECOLOGICAL ORGANIZATION Individuals Population: Group of individual organisms of the same species living within an area. Community: As an assembly of the population living in a prescribed area that has characteristic besides individual and population components Ecosystem: The community of organisms and populations interacting with one another and with the chemical and physical factors of their environment constitute an ecosystem. Biosphere: The part of the earth including water, and land within which life occurs and in which biotic process alter or transform, Living organism and their non-living environment are inseparably interrelated and interact with each other Any area of nature that includes living organisms and non-living substances interacting to produce and exchange material between them is an ecological system or ecosystem. The term ecosystem was used by British Ecologist AG Tansley. According to him, the ecosystem consists of a biotic community and it’s an abiotic component that is interrelated and interacts with each other. An ecosystem is the basic fundamental unit of ecology which includes both the organisms and the non-living environment each influencing the properties of the other and each is necessary for the maintenance of life- Odum. NEED FOR ENVIRONMENTAL AWARENESS Since our environment is getting degraded due to human activities, we need to do something about it to sustain the quality. We often feel that government should take proper measuring steps. But all of us are equally responsible to protect our environment. Hence public awareness needs to be created. Both print media and electronic media can strongly influence public opinion. Politicians should respond positively to a strong publicly supported activity. NGOs can take active role in creating awareness from grass root levels to the top-most policy decision makers. Environment is an integration of both living and non-living organisms. Water, air, soil, minerals, wild life, grass lands, forests, oceans, agriculture are all life THE MULTI- supporting systems. Since these natural resources are limited, and human activities DISCIPLINARY are the causative factors for environmental degradation, each one of us need to feel NATURE OF responsible to protect the environment. ENVIRONMENTAL STUDIES 14 Environmental Studies NOTES The activities help in creating awareness among public are: Join a group to study nature such as WWF-I or BNHS or any other organization Read newspaper articles and periodicals like Down to earth, WWF-I newsletter, BNHS, Hornbill, Sanctuary magazine. Discuss environmental issues with friends and relatives. Join local movements that support activities like saving trees in your locality, reducing use of plastics, going for nature treks, practicing 3 Rs i.e. reduce, reuse, & recycle. Practice and promote good civic sense and hygiene such as enforcing no spitting or tobacco chewing, no throwing garbage on the road and no urinating in public places. Take part in events organized on World Environment Day, Wildlife week etc. Visit a National park or sanctuary or spend time in whatever natural habitat you have near your home. World Environment Day: June 5th ENVIRONMENTAL EDUCATION Environmental education is a process that allows individuals to explore environmental issues, engage in problem solving, and take action to improve the environment. As a result, individuals develop a deeper understanding of environmental issues and have the skills to make informed and responsible decisions. The components of environmental education are: Awareness and sensitivity to the environment and environmental challenges Knowledge and understanding of the environment and environmental challenges Attitudes of concern for the environment and motivation to improve or maintain environmental quality Skills to identify and help resolve environmental challenges Participation in activities that lead to the resolution of environmental challenges Environmental education does not advocate a particular viewpoint or course of THE MULTI- action. Rather, environmental education teaches individuals how to weigh various DISCIPLINARY sides of an issue through critical thinking and it enhances their own problem-solving NATURE OF ENVIRONMENTAL and decision-making skills. STUDIES Environmental Studies 15 IMPORTANCE OF ENVIRONMENTAL EDUCATION NOTES Environmental study is based upon a comprehensive view of various environmental systems. It aims to make the citizens competent to do scientific work and to find out practical solutions to current environmental problems. The citizens acquire the ability to analyze the environmental parameters like the aquatic, terrestrial and atmospheric systems and their interactions with the biosphere and astrosphere. IMPORTANCE World population is increasing at an alarming rate especially in developing countries. The natural resources endowment in the earth is limited. The methods and techniques of exploiting natural resources are advanced. The resources are over-exploited and there is no foresight of leaving the resources to the future generations. The unplanned exploitation of natural resources leads to pollution of all types and at all levels. The pollution and degraded environment seriously affect the health of all living things on earth, including man. The people should take a combined responsibility for the deteriorating environment and begin to take appropriate actions to save the earth. Education and training are needed to save the biodiversity and species extinction. The urban area, coupled with industries, is major sources of pollution. The number and area extinct under protected area should be increased so that the wild life is protected at least in these sites. The study enables the people to understand the complexities of the environment and need for the people to adapt appropriate activities and pursue sustainable development, which are harmonious with the environment. The study motivates students to get involved in community action, and to participate in various environment and management projects. It is a high time to reorient educational systems and curricula towards these needs. Environmental education takes a multidisciplinary approach to the study of THE MULTI- human interactions with the natural environment. DISCIPLINARY NATURE OF Environmental study is a key instrument for bringing about the changes ENVIRONMENTAL STUDIES 16 Environmental Studies NOTES in the knowledge, values, behaviours and lifestyles required to achieve sustainability and stability within and among countries NEED FOR ENVIRONMENTAL EDUCATION The need to protect the environment hence the rationales for environmental education arise as a result of the following: Environment is the basis of all life and therefore deserves proper care and management. If the environment is threatened on a continuous basis, numerous problems which would constitute a danger to human existence could arise. The environment is part of our cultural heritage which should be handed down to prosperity. Some resources of the environment are not easily replaceable and should be managed on a sustainable basis, to prevent the extinction of certain components of the environment such as plants and animals. There is need to enhance the sanity and aesthetic quality of our environment in order to promote healthy living. The environment is part of nature and needs to be preserved for its own sake. MULTIPLE CHOICE QUESTIONS: 1. Which of the following element is present in the large percentage in the biosphere? a. Carbon b. Hydrogen c. Nitrogen d. Oxygen 2. Which of them is fittest for survival of humans? a. Lithosphere b. Hydrosphere c. Atmosphere d. Biosphere 3. World environment day is celebrated on: THE MULTI- a. September 5 DISCIPLINARY b. July 5 NATURE OF ENVIRONMENTAL c. June 5 STUDIES d. May 5 Environmental Studies 17 4. 5th June is observed as NOTES a. World forest day b. World environment day c. World wildlife day d. World population day 5. 21st March is observed as: a. World forest day b. World environment day c. World wildlife day d. World population day 6. The term “Environment” means a. Sum total of all conditions that the life and development of all organisms on earth b. A beautiful earth c. Earth and water d. A combination of plants and animals 7. Elements of environment are a. Nitrogen, Carbon dioxide, Oxygen b. Nitrogen, Oxygen, Ozone c. Carbon dioxide, Oxygen, Ozone d. Lithosphere, Atmosphere, Hydrosphere and Biosphere 8. The term Environment is derived from an old French word “enviro” means a. Outside b. Surroundings c. Inside d. Biotic community 9. Hydrosphere includes a. Animals b. Soil c. Plants d. Water bodies THE MULTI- 10. The important component of environment is DISCIPLINARY a. Biosphere NATURE OF ENVIRONMENTAL b. Lithosphere STUDIES 18 Environmental Studies NOTES c. Atmosphere d. all of the above 11. The organisms which feed on dead organisms and excreta of living organisms are known a. Decomposers b. Consumers c. Producers d. Carnivores 12. Biotic environment includes a. producers b. Consumers c. decomposers d. all the above 13. Abiotic environment does not include a. Air b. Water c. Soil d. Plants 14. Energy flow in ecosystem is given by: a. Haeckel b. Odum c. Tansely d. Ramdeo Mishra 15. The 99% of the Earth’s atmosphere consists of a. Oxygen b. Nitrogen c. Oxygen and Nitrogen d. Nitrogen and Water 16. By volume, Earth’s atmosphere (or air) contains about _____% of Nitrogen and _____% of Oxygen. a. 78, 21 THE MULTI- b. 21, 78 DISCIPLINARY NATURE OF c. 70, 25 ENVIRONMENTAL STUDIES d. 25, 70 Environmental Studies 19 17. Most stable ecosystem is NOTES a. Forest b. Desert c. Ocean d. Mountain 18. Zone consisting air, water and soil is known as a. Hydrosphere b. Atmosphere c. Lithosphere d. Biosphere 19. Word oikos means __________ and logos means _______ a. Houses and study b. Study and houses c. Only houses d. Study of people 20. Ecology deals with the study of: a. Living beings b. Living and non-living components c. Reciprocal relationship between living and non-living components d. Environment EXERCISE 1. Define Environment. What are the components of the environment? 2. What is the scope of Environmental Studies? 3. Highlight the importance of Environment Science. 4. Is there any scope of Environment Science in future? If Yes, Explain how. 5. Explain the concept of Ecosystem with its components. 6. Why a healthy environment is needed? 7. Describe the energy flow in an ecosystem. 8. Explain the concept of Community ecology. sssss THE MULTI- DISCIPLINARY NATURE OF ENVIRONMENTAL STUDIES CHAPTER 2 NATURAL RESOURCES AND CHALLENGES DEFINITION OF RESOURCES Substances that are required for survival comforts and prosperity. They are obtained directly from the environment resources can be materials, products, or waste that has potential value and can be used to process new useful products. Any of the factors of production are used as inputs in the production process. A supply of environmental benefits, like water, or sunlight, Substances that support life and fulfill human needs, including air, land, water, minerals, fossil fuels, forests, and sunlight. The natural resources are of two kinds: Renewable resources are in exhaustive and can be regenerated within a given periodic. Forests, wildlife, wind energy, biomass. energy, tidal energy, hydropower, etc. Solar energy is also a renewable form of energy as it is an inexhaustible source of energy. Non-renewable resources that cannot be regenerated e.g. Fossil fuels like coal, petroleum, minerals, etc. Once we exhaust these reserves, the same cannot be replenished. Even our renewable resources can become non-renewable if we exploit them to such an extent that their rate of consumption exceeds their rate of regeneration. For example, if a species is exploited so much that its population size-declines below the- threshold level-then it is not able to sustain itself and gradually the. species become endangered or extinct. It is very important to protect and conserve our natural resources and use them in an a-judicious manner so that we don’t exhaust them. It does not mean that we should stop using most of the natural resources. Rather, we should use the resources in such a way that we always save enough of them for our Environmental Studies 21 future generations. In this unit we shall discuss the major natural resources: NOTES Forest resources Water resources Mineral resources Food resources Energy resources Land resources FOREST RESOURCES Forests are one of the most important natural resources on this earth. Covering the earth like a green blanket these forests not only produce innumerable material goods but also provide several environmental services that are essential for life. About 1 /3rd of the world’s land area is forested which includes closed as well as open forests. Former USSR accounts for about a 5th of the world’s forests, Brazil for about raJ7th and Canada and USA each for 6-7%. But it is a matter of concern that almost everywhere the cover of the natural forests has declined over the years. The greatest occurred in tropical Asia where one-third of the forest resources have. USES OF FORESTS Commercial uses: Forests provide us a large number of commercial goods which include timber, firewood, pulpwood, food items, gum, resins, non-edible oils, rubber, fibers, lac, bamboo canes, fodder, medicine, drugs, and many more items, the total worth of which is estimated to be more than $300 billion per year. Half of the timber cut each year is used as fuel for heating and cooking. One- third of the wood harvest is used for building materials like lumber, plywood and hardwood, particleboard, and chipboard. One-sixth of the wood harvest is converted into pulp and used for the paper industry. Many forest lands are used for mining, agriculture, grazing, and recreation, and the development of dams. Ecological uses: While a typical -tree produces commercial goods worth about $ 590 it provides environmental services worth nearly S 196, 250— ”The ecological services provided by our forests may be summed up as follows: Production of oxygen: The trees produce oxygen by photosynthesis which is so vital for life on this earth. They are rightly the earth’s lungs. Reducing global warming: The main greenhouse gas carbon dioxide (CO2) is absorbed by the forests as a raw material -for photosynthesis. Thus, the forest canopy acts as a sink for CO2 thereby reducing the problem of global warming caused by greenhouse gas CO2. NAGTURAL RESOURCES AND CHALLENGES 22 Environmental Studies NOTES Wildlife habitat: Forests are the homes of millions, of wild animals and plants. About 7 million” species are found in the tropical forests along. Regulation of hydrological cycle: Forested watersheds act like giant sponges, absorbing the rainfall, slowing down the runoff, and slowly releasing the water for recharge of springs. About 50-80 %of the moisture in the air in tropical forests comes from their transpiration which helps in bringing rains. Soil Conservation: Forests bind the soil particles tightly in their roots and prevent soil erosion. They also act as the wind- Pollution moderators: Forests can absorb many toxic gases, and can help in keeping the air pure”. They have also been reported to absorb noise and thus help in preventing air and noise pollution. OVER EXPLOITATION OF FORESTS Since time immemorial, humans have depended heavily on forests for food, medicine, shelter, wood, and fuel. With a growing civilization, the demands for raw material like timber, pulp, minerals, fuelwood, etc. shot up resulting in large scale logging, mining, road-building and clearing of forests. Our forests contribute substantially to the national economy. The international timber trade alone is worth over the US $ 40 billion per year. Excessive use of fuelwood and charcoal, expansion of urban, agricultural and industrial areas and overgrazing have together led to over- exploitation of our forests leading to their rapid degradation. WATER RESOURCES Water is an indispensable natural resource on this earth on which all life depends. About 97% of the earth’s surface is covered by water and most of the animals and plants have 60-65% water in their body. Water is characterized by certain unique features that make it a marvelous resource: It exists as a liquid over a wide range of temperatures i.e. from 0° to 100°C. It has the highest specific heat, due to which it warms up and cools down very slowly without causing shocks of temperature jerks to the aquatic life. It has a high latent heat of vaporization Hence; it takes a huge amount of Energy for getting vaporized. That’s why it produces a cooling effect as it evaporates. It is an excellent solvent for several nutrients. Thus, it can serve as a very good carrier of nutrients, including oxygen, which is essential for life. But it can also easily dissolve various pollutants and become a carrier of pathogenic microorganisms, (v) Due to high surface tension and cohesion it can easily NAGTURAL RESOURCES AND rise through great heights through the trunk even in the tallest of the trees CHALLENGES like Sequoia. Environmental Studies 23 It has an anomalous expansion behaviour i.e. as it freezes, it expands instead NOTES of contracting and thus becomes lighter. It is because of this property that even in extreme cold, the lakes freeze only on the surface. Being lighter the ice keeps floating, whereas the bottom waters remain at a higher temperature and therefore, can sustain aquatic organisms even in extreme cold. The water we use keeps on cycling endlessly through the environment, which we call the Hydrological Cycle. We have enormous resources of water on the earth amounting to about 1404 million Km3. The water from various moist surfaces evaporates and falls again on the earth in the form of rain or snow and passes through living organisms and ultimately returns to the oceans. Every year about the 1.4-inch-thick layer of water evaporates from the oceans, more than 90% of which returns to the oceans through the hydrological cycle. Solar energy drives the water cycle by evaporating it from various water bodies, which subsequently return through rainfall or snow. Plants play a very important role by absorbing the groundwater from the soil and releasing it into the atmosphere by the process of transpiration. The global distribution of water resources is quite uneven depending upon several geographic factors. Tropical rain forest areas receive maximum rainfall while the major world deserts occur in zones of dry, descending air (20-40° N and S) and receive very little rainfall. WATER USE AND OVER-EXPLOITATION Due to its unique properties water is of multiple uses for all living organisms. Water is essential for life. Most of the life processes take place in the water contained in the body. Uptake of nutrients, their distribution in the body, regulation of temperature, and removal of wastes are all mediated through the water. Human beings depend on water for almost every developmental activity; Water is used for drinking, irrigation, and transportation, washing, and waste disposal for industries and used as a coolant for thermal power plants. Water shapes the earth’s surface and regulates our climate. Water use by humans is of two types: water withdrawal: taking water from groundwater or surface water resource and water consumption: the water which is taken up but not returned for reuse. Gteba41yr”o” only about 60 percent of the water withdrawn is consumed due to loss through evaporation. With the increasing human population and rapid development, the world water withdrawal demands have increased in many folds and a large proportion of the water withdrawn is polluted due to anthropogenic activities. On a global average, 70 percent of the water withdrawn is used for agriculture. In India, we use93% of the water in the agricultural sector while in a country like Kuwait, which is water- NAGTURAL RESOURCES AND poor, only 4% is used for watering the crops. About 25% of the water on the global CHALLENGES 24 Environmental Studies NOTES average is used in industry, which again varies from a high of 70% in European countries to as low as 5% in less developed countries. Per capita use of water shows wide variations. In the USA, an average family of 4 consumes more than 1000 M3 of water per year, which is many times more than that in most developing countries. WATER: A PRECIOUS NATURAL RESOURCE Although water is very abundant on this earth, yet it is very precious. Out of the total water reserves of the world, about 97% is salty water (marine) and only 3% is freshwater. Even this small fraction of freshwater is not available to us as most of it is locked up in polar ice caps and just 0.003% is readily available to us in the form of groundwater and surface water. Overuse of groundwater for drinking, irrigation, and domestic purposes has resulted in rapid depletion of groundwater in various regions leading to the lowering of water tables and drying of wells. Pollution of many of the groundwater aquifers has made many of these wells unfit for consumption. Rivers and streams have long been used for discharging the wastes. Most of the civilizations have grown and flourished on the banks of rivers, but unfortunately, growth, in turn, has been responsible for the pollution of the rivers. As per the United Nations estimates (2002), at least 101 billion people do not even have access to safe drinking water and 2.4 billion do not have adequate sanitation facilities. Increasing population and expanding development would further increase the demands for wastes. It is estimated that by 2024, two-thirds of the world population would be suffering from acute water shortage. Groundwater About 9.86% of the total freshwater resources are in the form of groundwater and it is about 35-50 times that of surface water supplies. Till some time, back groundwater was considered to be very pure. However, of late, even groundwater aquifers are contaminated by leachates from sanitary landfills, etc. A layer of sediment or rock that is highly permeable and contains water is called an aquifer. Layers of sand and gravel are good aquifers while clay and crystalline rocks (like granite) are not since they have low permeability. Aquifers may be of two types: Unconfined aquifers are overlaid by permeable earth materials and they are recharged by water seeping down from above in the form of rainfall and snowmelt. Confined aquifers are sandwiched between two impermeable layers of rock or sediments and are recharged only in those areas where the aquifer intersects the land surface. Sometimes the recharged area is hundreds of kilometers away from the location of the well. Groundwater is not static, it moves, though at a very slow rate NAGTURAL of about a meter or so in a year. RESOURCES AND CHALLENGES Environmental Studies 25 EFFECTS OF GROUNDWATER USAGE NOTES Subsidence: When groundwater withdrawal is more than its recharge rate, the sediments in the aquifer get compacted, a phenomenon known as ground subsidence. Huge economic losses may occur due to this phenomenon because it results in the sinking of the overlying land surface. The common problems associated with it include structural damage in buildings, fracture in pipes, reversing the flow of sewers and canals, and tidal flooding. Lowering of water table: Mining of groundwater is done extensively in arid and semi-arid regions for irrigating crop fields. However, it is not advisable to do excessive mining as it would cause a sharp decline in future agricultural production, due to the lowering of the water table. Waterlogging: When excessive irrigation is done with brackish water raises the water table gradually leading to water-logging and salinity problems. SURFACE WATER The water coming through precipitation (rainfall, snow) when does not percolate down into the ground or does not return to the atmosphere as evaporation or transpiration loss, assumes the form of streams, lakes, ponds, wetlands or artificial reservoirs known as surface water. The surface water is largely used for irrigation, industrial use, public water supply, navigation, etc. A country’s economy is largely dependent on rivers. WATER-RICH VS. WATER POOR COUNTRIES The top ten water-rich countries are Iceland, Surinam, Guyana, Papua New Guinea Gabon, Solomon Islands, Canada, Norway, Panama, and Brazil lying in the far north and have low evaporation losses. The water poof countries include Kuwait, Egypt, United Arab Emirates, Malta, Jordan, Saudi Arabia, Singapore, Maldivian, Israel, and Oman, lying in the desert belt at about 15° to 25° Latitude and some of them like Malta and Singapore are densely populated areas resulting in a low per capita water. FLOODS In some countries like India and Bangladesh, rainfall does not occur throughout the year, rather, 90% of it is concentrated into a few months (June-September). Heavy rainfall often causes floods in the low-lying coastal areas. Prolonged downpours can also cause the over-flowing of $ lakes and rivers resulting in floods. Deforestation, overgrazing, mining, rapid industrialization, global warming, etc. have also contributed largely to a sharp rise in the incidence of floods, which otherwise is a natural disaster. NAGTURAL RESOURCES AND CHALLENGES 26 Environmental Studies NOTES Floods have been regular features of some parts of India and Bangladesh causing huge economic loss as well as the loss of life. People of Bangladesh are accustomed to moderate flooding during monsoon and they utilize the flood water for raising paddy. But, severe floods like that in 1970, 1988, and 1991 resulting from excessive Himalayan runoff and storms, had very disastrous consequences causing massive deaths and damages. In 1970, about one million people were drowned while 1,40,000 people died in 1991. Networking of rivers is being proposed at are national level to deal with the problems of floods. DROUGHTS There are about 80 countries in the world, lying in the arid and semi-arid regions that experience frequent spells of droughts, very often extending up to year-long duration. When annual rainfall is below normal and less than evaporation, drought conditions are created. Ironically, these drought-hit areas are often having a high population growth which leads to poor land use and makes the situation worse. Anthropogenic causes: Drought is a meteorological phenomenon, but due to several anthropogenic causes like over-grazing, deforestation, mining, etc. there is spreading of the deserts tending to convert more areas to drought-affected areas. In the last twenty years, India has experienced more and more desertification, thereby increasing the vulnerability of larger parts of the country to droughts. Erroneous and intensive cropping patterns and increased exploitation of scarce water resources through well or canal irrigation to get high productivity ha^ converted drought-prone areas into desertified ones. In Maharashtra, there has been no recovery from drought for the last 30 years due to over-exploitation of water by sugarcane crop which has high water demands. Remedial measures: Indigenous knowledge in control of drought and desertification can be very useful for dealing with the problem. Carefully selected mixed cropping helps optimize production and minimize the risks of crop failures. Social Forestry and Wasteland development can prove quite effective to fight the problem, but it should be based on a proper understanding of ecological requirements and natural process, otherwise, it may even boom rang. The Kolar district of Karnataka is one of the leaders in Social Forestry with World Bank Aid, but all its 11 talukas suffer from drought. It is because the tree used for plantation here was Eucalyptus which is now known to lower the water table because of its very high transpiration rate. NATIONAL AND INTERNATIONAL CONFLICTS OVER WATER The indispensability of water and its unequal distribution has often led to inter- state or international disputes. Issues related to the sharing of river water have been NAGTURAL RESOURCES AND largely affecting our farmers and also shaking our governments. Some major water CHALLENGES conflicts are discussed here. Environmental Studies 27 Water conflict in the Middle East: Three river basins, namely the Jordan, NOTES the Tigris-Euphrates, and the Nile are the shared water resources for Middle East countries. Ethiopia controls the headwaters of 80% of Nile’s flow arid plans to increase it. Sudan too is trying to divert more water. This would badly affect Egypt, which is a desert, except for a thin strip of irrigated cropland along the river Nile and its delta. The population of Egypt is likely to double in the next 20 years, thereby increasing its water crisis. Likewise, there is a fierce battle for water among Jordan, Syria, and Israel for the Jordan River water share. Turkey has abundant water and plans to build 22 dams on Tigris-Euphrates for Hydroelectric power generation. But it would drastically reduce the flow of water to Syria and Iraq, lying downstream. Turkey dreams to become the region’s water Superpower. It plans to transport and sell water to starved Saudi Arabia, Kuwait, Syria, Israel, and Jordan. Probably, the next war in the Middle East would be fought over water and not oil. The Indus Water Treaty: The Indus, one of the mightiest rivers is dying a slow death due to dams and barrages that have been built higher up on the river. The Sukkur barrage (1932), Ghulam Mohamad Barrage at Kotri (1958), and Tarbela and Chasma Dams on Jhelum, a tributary of Indus have resulted in a severe shrinking of the Indus delta. In I960, the Indus water treaty was established vide which Indus, the Jhelum, and the Chenab were allocated to Pakistan, and the Satluj, the Ravi, and the Beas were allocated to India. Being the riparian state, India has a pre-emptive right to construct barrages across all these rivers in Indian territory. However, the treaty requires that the three rivers allocated to Pakistan may be used for non- consumptive purposes by India i.e. without changing its flow and quality. With improving political relations between the two countries, it is desirable to work out techno-economic details and go for integrated development of the river basin sustainably. The Cauvery water dispute: Out of India’s 18 major rivers 17 are shared between different states. In all these cases, there are intense conflicts over these resources which hardly seem to resolve. The Cauvery river water is a bone of contention between Tamil Nadu and Karnataka and the fighting is almost a hundred years old. Tamil Nadu, occupying the downstream region of the river wants water-use regulated in the upstream Whereas, the upstream state Karnataka refuses to do so am claims its primacy over the river as an upstream user. The river water is almost fully utilized and both the states have increasing demands for agriculture and industry. The consumption is more in Tamil Nadu Chan Karnataka where the catchment NAGTURAL are^ is rockier. On June 2,1990, the Cauvery Water Dispute Tribunal was RESOURCES AND set up which through an interim award directed Karnataka to ensure that CHALLENGES 28 Environmental Studies NOTES 205 TMCF of water was made available in Tamil Nadu’s Mettur dam every year where the settlement was reached. In 1991-92 due to good monsoon, there was no dispute due to good stock of water in Mettur, but in 1995, the situation turned into a crisis due to delayed rains and an Expert Committee was set up to look into the matter which found that there was a complex cropping pattern in Cauvery basin. Sambrapaddy in winter, Kurvaipaddy in summer, and some cash crops demanded intensive water, thus aggravating the water crisis. Proper selection of crop varieties, optimum use of water, better rationing, rational sharing patterns, and pricing of water is suggested as some measures to solve the problem. The Satluj-Yamuna Link (SYL) canal dispute: The issue of sharing the Ravi-Beas waters and the SYL issue between Punjab and Haryana is being discussed time and again and the case is in the Supreme Court. The Eradi Tribunal (1985) based on the allocation of water based on the time-inflow data of 20 years (1960-80), according to which 17.17 MAP (million-acre feet) water was available. However, now it is argued by Punjab that in the last 17 years there has been a consistent decline reducing the quantity to 14.34 MAP. The Supreme Court on January 15,2002, directed Punjab to complete and commission the SYL within a year, failing which the Center was told to complete it. However, two years have passed, but neither the SYL has been completed nor the conflict over sharing of Ravi- Beas water is resolved. The conflict is that Punjab being the riparian state for Jhelum, Ravi and Satluj stakes its claim, Haryana has faced ‘acute’ shortage of water after it became a state in 1966 and has been trying to help it out by signing an MOU (Memorandum of understanding) with UP, Rajasthan, and Delhi for allocation of Yamuna waters. The Yamuna basin covers the state of Haryana while the Indus basin covers Punjab. The conflict revolving around the sharing of river water needs to be tackled with greater understanding and objectivity. MINERAL RESOURCES Minerals are naturally occurring, inorganic, crystalline solids having a definite chemical composition and characteristic physical properties. There are thousands of minerals occurring in different parts of the world. However, most of the rocks, we see every day are just composed of a few common minerals like quartz, feldspar, biotite, dolomite, calcite, laterite, etc. These minerals, in turn, are composed of some elements like silicon, oxygen, iron, magnesium, calcium, aluminium, etc. USES AND EXPLOITATION NAGTURAL RESOURCES AND Minerals find use in a large number of ways in everyday use in domestic, CHALLENGES Environmental Studies 29 agricultural, industrial and commercial sectors and thus form a very important part NOTES of any nation’s economy. The main uses of minerals are as follows: Development of industrial plants and machinery. Generation of energy e.g. coal, lignite, uranium. Construction, housing, settlements. Defense equipment’s-weapons, armaments. Transportation means. Communication- telephone wires, cables, electronic devices. Medicinal system- particularly in Ayurvedic System. Formation of alloys for various purposes (e.g. phosphorite). Agriculture-as fertilizers, seed dressings, and fungicides (e.g. zineb containing zinc, Maneb-containing Manganese, etc.). Jewelry - e.g. Gold, silver, platinum, diamond. Based on their properties, minerals are basically of two types; Nonmetallic minerals e.g. graphite, diamond, quartz, feldspar. Metallic minerals e.g. Bauxite, laterite, hematite, etc. The use of metals by human beings has been so extensive since the very beginning of human civilization that two of the major epochs of human history are named after them as Bronze Age and Iron Age. The reserves of metals and the technical know-how to extract them have been the key elements in determining the economy and political power of nations. Out of the various metals, the one used in maximum quantity is Iron and steel (740 million metric tons annually foil owed by manganese, copper, chromium, aluminium, and Nickel. The CIS countries (The Commonwealth of Independent States i.e 12 republics of former USSR), the United States of America, Canada, South Africa, and Australia are having the major world reserves of most of the metallic minerals. Due to huge mineral and energy resources, the USA became the richest and the most powerful nation in the world in even less than 200 years. Japan too needs a mention here, as there are virtually no metal reserves, coal, oil and timber resources in Japan and it is dependent on other countries for its resources. But it has developed energy-efficient technologies to upgrade these resources to high quality finished products to sustain its economy. Minerals are sometimes classified as Critical and Strategic. Critical minerals are essential for the economy of a nation e.g. iron, aluminum, copper, gold, etc. Strategic minerals are those required for the defense of a country e.g. Manganese, NAGTURAL cobalt, platinum, chromium, etc. RESOURCES AND CHALLENGES 30 Environmental Studies NOTES SOME MAJOR MINERALS OF INDIA Energy generating minerals Coal and lignite: West Bengal, Jharkhand, Orissa, M.P., A.P. Uranium (Pitchblende or Uranite ore): Jharkhand, Andhra Pradesh (Nellore, Nalgonda), Meghalaya, Rajasthan (Ajmer). Other commercially used minerals Aluminum (Bauxite ore): Jharkhand, West Bengal, Maharashtra, M.P., Tamil Nadu. Iron (hematite and magnetite ore): Jharkhand, Orissa, M.P., A.P., Tamil Nadu, Karnataka, Maharashtra, and Goa. Copper (Copper Pyrites): Rajasthan (Khetri), Bihar, Jharkhand, Karnataka, M.P., West Bengal, Andhra Pradesh, and Uttaranchal. ENVIRONMENTAL IMPACTS OF MINERAL EXTRACTION AND USE The issue related to the limits of the mineral resources in our earth’s crust or the ocean is not so significant. More important environmental from the impacts of extraction and processing of these minerals during mining, smelting, etc. Indian Scenario: India is the producer of 84 minerals the annual value of which is about Rs. 50,000 crores. At least six major mines need mention here which are known for causing severe problems: Jaduguda Uranium Mine, Jharkhand—exposing local people to radioactive hazards. Jharia coal mines, Jharkhand—underground fire leading to land subsidence and forced displacement of people. Sukinda chromite mines, Orissa—seeping of hexavalent chromium into river posing a serious health hazard, Cr6+ being highly toxic and carcinogenic. Kudremukh iron ore mine, Karnataka—causing riverpollution and a threat to biodiversity, East coast Bauxite mine, Orissa—Land encroachment and the issue of rehabilitation unsettled. North-Eastern Coal Fields, Assam—Very high Sulphur contamination of groundwater. IMPACTS OF MINING Mining is done to extract minerals (or fossil fuels) from deep deposits in soil by NAGTURAL using mining or from shallow “deposits by surface mining. The former method is RESOURCES AND CHALLENGES more destructive, dangerous, and expensive including risks of occupational hazards and accidents. Environmental Studies 31 Surface mining can make use of any of the following three types: NOTES Open-pit mining in which machines dig holes and remove the ores (e.g. copper, iron, gravel, limestone, sandstone, marble, granite). Dredging in which chained buckets and draglines are used which scrap up the minerals from under-water mineral deposits. Strip mining which the ore is stripped off by using bulldozers, power shovels, and stripping wheels (e.g. phosphate rocks). The environmental damage caused by mining activities are as follows: De-vegetation and defacing of landscape: The topsoil as well as the vegetation are removed from the mining area to get access to the deposit. While large-scale deforestation or de-vegetation leads to several ecological losses as already discussed in the previous section, the landscape also gets badly affected. The huge quantities of debris and tailings along with big scars and disruptions spoil the aesthetic value of the region and make it prone to soil erosion. Subsidence of land: This is mainly associated with underground mining. Subsidence of mining areas often results in tilting of buildings, cracks in houses, buckling of roads, bending of rail tracks, and leaking of gas from cracked pipelines leading to serious disasters. Ground-water contamination: Mining disturbs the natural hydrological processes and also pollutes the groundwater. Sulphur, usually present as an impurity in many ores is known to get converted into sulphuric acid through microbial action, thereby making the water acidic. Some heavy metals also get leached into the groundwater and contaminate it posing health hazards. Surface water pollution: The acid mine drainage often causes the nearby streams and lakes. The acidic water is detrimental to many forms of aquatic life. Sometimes radioactive substances like uranium also contaminate the water bodies through mine wastes and kill aquatic animals. Heavy metal pollution of water bodies near the mining areas is a common feature creating health hazards. Air pollution: To separate and purify the metal from other impurities in the ore, smelting is done which emits enormous quantities of air pollutants damaging the vegetation nearby and has serious environmental health impacts. The suspended particulate matter (SPM), SOx, soot, arsenic particles, cadmium, lead, etc. shoot up in the atmosphere near the smelters and the public suffers from several health problems. Occupational Health Hazards: Most of the miners suffer from various respiratory and skin diseases due to constant exposure to the suspended NAGTURAL particulate matter and toxic substances. Miners working in different types RESOURCES AND CHALLENGES of mines suffer from asbestosis, silicosis stack lung disease, etc 32 Environmental Studies NOTES Remedial measures: Safety of mine workers is usually not a priority subject of industry, Statistical data show that, on average, there are 30 non-fatal but disabling accidents per ton of mineral produced and one death per 2.5 tons of mineral produced. To minimize the adverse impacts of mining it is desirable to adopt eco-friendly mining technology. The low-grade ores can be better utilized by using the microbial- le aching technique. The bacterium Thiobadllusferroxidans has been successfully and economically used for extracting gold embedded in iron sulphide ore. The ores are inoculated with the desired strains of bacteria, which remove the impurities (like Sulphur) and leave the pure mineral. This biological method is helpful for Economic as well as environmental point of view. Restoration of mined areas by re-vegetating them with appropriate plant species, stabilization of the mined lands, the gradual restoration of flora, prevention of toxic drainage discharge, and conforming to the standards of air emissions are essential for minimizing environmental impacts of mining. ENERGY RESOURCES Energy consumption of a nation is usually considered as an index of its development. This is because almost all the developmental activities are directly or indirectly dependent upon energy. We find wide disparities in per capita energy use between the developed and the developing nations. The first form of energy technology probably was the fire, which produced heat and the early man used it for cooking and heating purposes. Wind and hydropower have also been in use for the last 10,000 years. The invention of steam engines replaced the burning of wood with coal and coal was later replaced to a great extent by oil. In the 1970s due to the Iranian revolution and Arab oil embargo, the prices of oil shot up. This ultimately led to the exploration and use of several alternative sources of energy. GROWING ENERGY NEEDS Development in different sectors relies largely upon energy. Agriculture, industry, raining, transportation, lighting, cooling, and heating in buildings all need energy. With the demands of a growing population, the world is facing a further energy deficit. The fossil fuels like coal, oil, and natural gas which at present are supplying 95% of the commercial energy of the world’s resources and are not going to last for many more years. Our lifestyle is changing very fast and from a simple way of life, we are shifting to a luxurious lifestyle. If you just look at the number of electric gadgets in your homes and the number of private cars and scooters in your locality you will realize that in the last few years, they have multiplied many folds and all of them consume energy. NAGTURAL RESOURCES AND Developed countries like the U.S.A. and Canada constitute about 5% of the CHALLENGES world’s population but consume one-fourth of global energy resources. An average Environmental Studies 33 person there consumes 300 GJ (Giga Joules, equal to 60 barrels of oils) per year. NOTES By contrast, an average man in a poor country like Bhutan, Nepal, or Ethiopia consumes less than 1 GJ in a year. So a person in a rich country consumes almost as much energy in a single day as one person does in a whole year in a poor country. This clearly shows that our lifestyle and standard of living are closely related to energy needs. U.S.A., Norway, Switzerland, etc. with high GNP show high energy use while India, China, etc. have low GNP and low energy use. Bahrain and Quatar are oil-rich state (UAE) and hence their energy consumption and GNP are more, although their development is not that high. RENEWABLE ENERGY RESOURCES Solar energy: Sun is the ultimate source of energy, directly or indirectly for all other forms of energy. The nuclear fusion reactions occurring inside the sun release enormous quantities of energy in the form of heat and light. The solar energy received by the near-earth space is approximately 1.4kilojoules/second/m2 known as solar constant. Traditionally, we have been using solar energy for drying clothes and food-grains, preservation of eatables, and obtaining salt from sea-water. Now we have several techniques for harnessing solar energy. Some important solar energy harvesting devices are discussed here. Solar heat collectors: These can be passive or active. Passive solar heat collectors are natural materials like stones, bricks, etc., or material like glass which absorb heat during the day time and release it slowly at night. Active solar collectors pump a heat-absorbing medium (air or water) through a small collector which is normally placed on the top of the building. Solar cells: They are also known as photovoltaic cells or PV cells. Solar cells are made of thin wafers of semiconductor materials like silicon and gallium. When solar radiations fall on them, a potential difference is produced which causes the flow of electrons and produces electricity. Silicon can be obtained from silica or sand, which is abundantly available and inexpensive. By using gallium arsenide, cadmium sulphide, or boron, the efficiency of the PV cells can be improved. The potential difference produced by a single PV cell of 4 cm2 size is about 0.4-0.5 volts and produces a current of 60 milliamperes. A group of solar cells joined together in a definite pattern form a solar panel that can harness a large amount of solar energy and can produce electricity enough to run street-light, irrigation water pump, etc. Solar cells are widely used in calculators, electronic watches, street lighting, traffic signals, water pumps, etc. They are also used in artificial satellites for electricity generation. Solar cells are used for running radio and television also. They are more in use in remote areas where conventional electricity NAGTURAL supply is a problem. RESOURCES AND CHALLENGES 34 Environmental Studies NOTES Solar cooker: Solar cookers make use of solar heat by reflecting the solar radiation using a mirror directly onto a glass sheet that covers the black insulated box within which the raw food is kept. A new design of solar cooker is now available which involves a spherical reflector (concave or parabolic reflector) instead of a plane mirror that has more heating effect and hence greater efficiency. The food cooked in solar cookers is more nutritious due to slow heating. However, it has the limitation that it cannot be used at night or on cloudy days. Moreover, the direction of the cooker has to be adjusted according to the direction of the sun rays. Solar water heater: It consists of an insulated box painted black from inside and having a glass lid to receive and store solar heat. Inside the box, it has a black painted copper coil through which cold water is made to flow in, which gets heated and flows out into a storage tank. The hot water from the storage tank fitted on the rooftop is then supplied through pipes into buildings like hotels and hospitals. Solar furnace: Here thousands of small plane mirrors are arranged in concave reflectors, all of which collect the solar heat and produce as high a temperature as 3000°C. Solar power plant: Solar energy is harnessed on a large scale by using concave reflectors which cause boiling of water to produce steam. The steam turbine drives a generator to produce electricity. A solar power plant (50 K Watt capacity) has been installed at Gurgaon, Haryana. NON RENEWABLE ENERGY RESOURCES COAL Coal was formed 255-350 million years ago in the hot, damp regions of the earth during the carboniferous age. The ancient plants along the banks of rivers and swamps were buried after death into the soil and due to the heat and pressure gradually got converted into peat and coal over millions of years. There are mainly three types of coal, namely anthracite (hard coal), bituminous (Soft coal), and lignite (brown coal). Anthracite coal has a maximum carbon (90%) and calorific value (8700 kcal/kg.) Bituminous, lignite, and peat contain 80, 70, and 60% carbon, respectively. Coal is the most abundant fossil fuel in the world. At the present rate of usage, the coal reserves are likely to last for about 200 years and if its use increases by 2% per year, then it will last for another 65 years. India has about 5% of the world’s coal and Indian coal is not very good in terms of heat capacity. Major coalfields in India are Raniganj, Jharia, Bokaro, Singrauli, NAGTURAL and Godavari valley. The coal slates of India are Jharkhand, Orissa, West Bengal, RESOURCES AND CHALLENGES Madhya Pradesh, Andhra Pradesh, and Maharashtra. Anthracite coal occurs only in J & K. Environmental Studies 35 When coal is burnt it produces carbon dioxide, which is majorly a greenhouse NOTES gas responsible for causing enhanced global warming. Coal also contains impurities like sulphur and therefore as it burns the smoke contains-toxic gases like oxides of sulphur and nitrogen. PETROLEUM It is the lifeline of the global economy. There are ‘ 3 countries in the world having 67% of the petroleum reserve which together form the OPEC (Organization of petroleum exporting countries). About l/4th of the oil reserves are in Saudi Arabia. At the present rate of usage, the world’s crude oil reserves are estimated to get exhausted in just 40 years. Some optimists, however, believe that there are some yet undiscovered reserves. Even then the crude oil reserves will last for another 40 years or so. Crude petroleum is a complex mixture of alkane hydrocarbons. Hence it has to be purified and refined by the process of ’ fractional distillation, during which process different constituents separate at different temperatures. We get a large variety of products from this, namely, petroleum gas, kerosene, petrol, diesel, fuel oil, lubricating oil, paraffin wax, asphalt, plastic, etc. Petroleum is a cleaner fuel as compared to coal as it burns completely and leaves no residue. It is also easier to transport and use. That is the reason why petroleum is preferred amongst all fossil fuels. Liquefied petroleum gas (LPG): The main component of petroleum is butane, the other being propane and ethane. The petroleum gas is easily converted to liquid form under pressure as LPG. It is odorless, but the LPG in our domestic gas cylinders gives a foul smell. This is, in fact, due to ethyl mercaptan, a foul-smelling gas, added to LPG so that any leakage of LPG from the cylinder can be detected instantaneously. Oil fields in India are located at Digboi (Assam), Gujarat Plains, and Bombay High, offshore areas in deltaic coasts of Godavari, Krishna, Kaveri, and Mahanadi. NATURAL GAS It is mainly composed of methane (95%) with small amounts of propane and ethane. It is a fossil fuel. Natural gas deposits mostly accompany oil deposits because it has been formed by decomposing remains of dead animals and plants buried under the earth. Natural gas is the cleanest fossil fuel. It can be easily transported through pipelines. It has a high calorific value of about 50KJ/G and burns without any smoke. Currently, the number of natural gas deposits in the world are of the order of 80, 450 g nr3. Russia has maximum reserves (40%), followed by Iran (14%) and the USA (7%). Natural gas reserves are found in association with all the oil fields in India. Some new gas fields have been found in Tripura, Jaisalmer, the Off-shore area NAGTURAL of Mumbai, and the Krishna Godavari Delta. RESOURCES AND CHALLENGES 36 Environmental Studies NOTES Natural gas is used as a domestic and industrial fuel. It is used as a fuel in thermal power plants for generating electricity. It is used as a source of hydrogen gas in the fertilizer industry and as a source of carbon in the tyre industry. Compressed natural gas (CNG): It is being used as an alternative to petrol and diesel for the transport of vehicles. Delhi has switched over to CNG where buses and auto-rickshaws run on this new fuel. CNG use has neatly reduced vehicular pollution in the city. Synthetic natural gas (SNG): It is a mixture of carbon monoxide and hydrogen. It is a connecting link between fossil fuel and substituted natural gas. Low-grade coal is initially transformed into synthetic gas by gasification followed by catalytic conversion to methane. BIOGAS Biogas is a mixture of methane, carbon dioxide, hydrogen, and hydrogen sulphide, the major constituent being methane. Biogas is produced by anaerobic degradation of animal wastes (sometimes plant wastes) in the presence of water. Anaerobic degradation means the breakdown of organic matter by bacteria in the absence of oxygen. Biogas is a non-polluting, clean, and low-cost fuel that is very useful for rural areas where a lot of animal waste and agricultural waste are available. India has the largest cattle population in the world (240 million) and has tremendous potential for biogas production. From cattle dung alone, we can produce biogas of a magnitude of 22,500 Mm3 annually. A sixty cubic feet gobar gas plant can serve the needs of one average family. Biogas has the following main advantages: It is clean, non-polluting, and cheapest source. There is a direct supply of gas from the plant and there is no storage problem. The sludge left over is a rich fertilizer containing bacterial biomass with most of the nutrients preserved as such. Air-tight digestion/degradation of the animal wastes is safe as it eliminates health hazards which normally occur in case of direct use of dung due to direct exposure to faucal pathogens and parasites. Biogas plants used in our country are basically of two types: 1. Floating gas-holder type and 2. Fixed-dome type. Floating gas holder type biogas plant: This type has a well-shaped fester tank that is placed under the ground and made up of bricks. In the digester tank, over the dung slurry, an inverted steel drum floats to hold the biogas produced. The gas holder can move which is controlled by a pipe and the gas outlet is regulated by a valve. The digester tank has a partition wall and one side of it receives the dung-water mixture through an inlet pipe while the other side discharges the spent slurry through the outlet pipe. Sometimes NAGTURAL corrosion of steel gas-holder leads to leakage of biogas. The tank has to be RESOURCES AND CHALLENGES painted time and again for maintenance which increases the cost. Environmental Studies 37 Fixed dome type biogas plant: The structure is almost similar to that of the NOTES previous type. However, instead of a steel gas-holder, there is a dome-shaped roof made of cement and bricks. Instead of partitioning, here there is a single unit in the main digester but it has inlet and outlet chambers. The Ministry of Non-Conventional Energy Source (MNES) has been promoting the Biogas Program in India. Out of the various models, the important ones used in the rural set-up are the KVIC Model (Floating drum type), Jama Model (Fixed dome type), Deenbandhu Model (Fixed dome type), Pragati Model (floating drum type), Ganesh Model (KVIC type but made of bamboo and polythene sheet) and Ferro-cerpent digester Model (KVIC type with Ferro-cement digester), BIOMASS ENERGY Biomass is the organic matter produced by plants or animals which includes wood, crop residues, cattle dung, manure, sewage, agricultural wastes, etc. Biomass energy is of the following types: Energy Plantations: Solar energy is trapped by green plants through photosynthesis and converted into biomass energy. Fast growing trees like cottonwood, poplar, and Leucaena, non- oody herbaceous grasses, crop plants like sugarcane, sweet sorghum, and sugar beet, aquatic weeds like water hyacinth and sea-weeds and carbohydrate-rich potato, cereal, etc. are some of the important energy plantations. They may produce energy either by burning directly or by getting converted into burnable gas or may be converted into fuels by fermentation. Petro-crops: Certain latex-containing plants like Euphorbias and oil palms are rich in hydrocarbons and can yield an oil like sub stance under high temperature and pressure. This oily material may be burned in diesel engines directly or maybe refined to form gasoline. These plants are popularly known as petro-crops. Agricultural and Urban Waste biomass: Crop residues, bagasse (sugarcane residues), coconut shells, peanut hulls, cotton stalks, etc. are some of the common agricultural wastes which produce energy by burning. Animal dung, fishery and poultry waste, and even human refuse are examples of biomass energy. In Brazil, 30 % of electricity is obtained from burning bagasse. In rural India, animal dung cakes are burnt to produce heat. About 80 % of rural heat energy requirements are met by burning agricultural wastes, wood, and animal dung cakes. In rural areas, these forms of waste biomass are burne

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