Category: environmental Studies

Environmental Studies – Biodiversity Biodiversity, a shortened form of Biological diversity, refers to the existence of number of different species of plants and animals in an environment. The Convention on Biological Diversity (1992) of the United Nations gives a formal definition of biodiversity in its Article 2: “Biological diversity means the variability among living organisms from all sources including, inter alia, terrestrial, marine, and other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity within species, between species and of ecosystems.” Biodiversity is also defined as the existence of variability among living organisms on the earth, including the variability within and between species, and within and between ecosystems. Species Diversity Species diversity refers to the variety of different species of plants, animals, fungi, and organisms that are present in a region. It is estimated that there are above 30 million species on the earth. Species diversity is a part of diversity. Even within a small pond, we can notice a great variety of species. Species diversity differs from ecosystem to ecosystem. For example, in a tropical ecosystem more diversity is found than in temperate ecosystem. The most diverse group of species is invertebrates – animals without backbones. At present, conservation scientists have been able to identify and categorize about 1.8 million species on earth. Many new species are being identified. Areas that are rich in species diversity are called ‘hotspots’ of diversity. Genetic Diversity It is the variation in genes that exists within a species. Genetic diversity corresponds to the variety of genes contained in plants, animals, fungi, and micro-organisms. It occurs within a species as well as between species. For example, poodles, German shepherds and golden retrievers are all dogs, but they all are different in look, color, and abilities. Each human being is different from all others. This genetic variability is essential for a health breeding of a population of species. The diversity in wild species make the ‘gene pool’ from which crops and domestic animals have been developed over thousands of years. Ecosystem Diversity It is the diversity of ecosystems, natural communities, and habitats. In other words, ecosystem diversity refers to the variety of ways that species interact with each other and their environment. Tropical or temperate forests, grasslands, hot and cold deserts, wetlands, rivers, mountains, and coral reefs are instances of ecosystem diversity. Each ecosystem corresponds to a series of complex relationships between biotic (living) and abiotic (non-living) components. Value & Productive Use of Biodiversity The importance of biodiversity is second to none. It boosts the ecosystem of productivity where each species, irrespective of their size, have an important role to play. Greater diversity in species ensure natural sustainability for all life forms. Hence, there is a need to preserve the diversity in life on the earth. According to the UN sources at least 40 percent of the world’s economy and 80 percent of the needs of the poor are derived from biological resources. In addition, the richer the diversity of life, the greater the opportunity for medical discoveries, economic development, and adaptive response to such new challenges as climate change. Significance of Biodiversity Environmental services from species and smooth running cycles of ecosystems are necessary at global, regional, and local levels. Biodiversity is essential for maintaining the water cycles, production of oxygen, reduction in carbon dioxide, protecting the soil, etc. It is also essential for preserving ecological processes, such as soil formation, circulation of and cleansing of air and water, global life support, fixing and recycling of nutrients, maintaining hydrological balance within ecosystems, maintaining rivers and streams throughout the year, etc. Biodiversity has many values such as consumptive use value, productive use value, social values, ethical and moral values. A healthy biodiversity offers many valuable services as follows. The more a region is rich in terms of biodiversity, better is the regulation of the different cycles. For example, forests regulate the amount of carbon dioxide in the air by releasing oxygen as a by-product during photosynthesis, and control rainfall and soil erosion. Protects water resources from being depleted, contaminated, or polluted. Helps in soil formation and protection. Helps in nutrient storage and recycling. Helps check pollution. Contributes to climate stability. Helps an ecosystem in recovery from unpredictable events. Provides biological resources such as food, medicinal resources, and pharmaceutical drugs, wood products, ornamental plants, breeding stocks, etc. Provides recreation and tourism facilities. Helps in research, education, and monitoring. Preservation of biological resources is essential for the well-being and long-term survival of mankind. Productive Use Value of Biodiversity Productive Use Value refers to the commercial value of products that are commercially harvested for exchange in formal markets. Modern civilization is invariably a gift of biodiversity. The food we eat, the medicine we take in, the furniture we use, the industries, for example, are derivatives of biological diversity. The agricultural crops of the present day have originated from wild varieties. Biotechnologists use the wild plants for developing new, high-yielding, and pest or diseaseresistant varieties. Biodiversity is home to original stock from which new varieties are being developed. Similarly, all our domesticated animals came from their wild-living ancestral species. With the help of scientific breeding techniques, animals giving better yield of milk, meat, etc. are being developed. The animal products used by modern society come from the advances made in the fields of poultry farming, pisciculture, silviculture, dairy farming, etc. Fossil fuels, considered to be pivotal in modern society, such as coal, petroleum, and natural gas are gifts of biodiversity from the geological past. Most of the pharmaceutical drugs and medicines used in the present time are extracted from different plants. Biodiversity provides rich storehouse for industrialists and entrepreneurs to develop new products. It provides agricultural scientists and biotechnologists with ample scope for developing new and better crops. New crop varieties are being developed using the genetic material found in wild relatives of crop plants though biotechnology. The need of the hour is the preservation of biodiversity for industrial, economic, and above all,

Functions of Ecosystem The functional attributes of the ecosystem keep the components running together. Ecosystem functions are natural processes or exchange of energy that take place in various plant and animal communities of different biomes of the world. For instance, green leaves prepare food and roots absorb nutrients from the soil, herbivores feed on the leaves and the roots and in turn serve as food for the carnivores. Decomposers execute the functions of breaking down complex organic materials into simple inorganic products, which are used by the producers. Fundamentally, ecosystem functions are exchange of energy and nutrients in the food chain. These exchanges sustain plant and animal life on the planet as well as the decomposition of organic matter and the production of biomass. All these functions of the ecosystem take place through delicately balanced and controlled processes. Food Chain The order of living organisms in a community in which one organism consumes other and is itself consumed by another organism to transfer energy is called a food chain. Food chain is also defined as “a chain of organisms, existing in any natural community, through which energy is transferred”. Every living being irrespective of their size and habitat, from the tiniest algae to giant blue whales, need food to survive. Food chain is structured differently for different species in different ecosystems. Each food chain is the vital pathway for energy and nutrients to follow through the ecosystem. Food chains were first introduced by the African-Arab scientist and philosopher Al-Jahiz in the 9th century and later popularized in a book published in 1927 by Charles Elton. A food chain starts with a producer such as plants. Producers form the basis of the food chains. Then there are consumers of many orders. Consumers are organisms that eat other organisms. All organisms in a food chain, except the first organism, are consumers. Plants are called producers because they produce their own food through photosynthesis. Animals are called consumers because they depend on plants or other animals for food to get energy they need. In a certain food chain, each organism gets energy from the one at the level below. In a food chain, there is reliable energy transfer through each stage. All the energy at one stage of the chain is not absorbed by the organism at the next stage. Trophic Levels in a Food Chain Trophic levels are different stages of feeding position in a food chain such as primary producers and consumers of different types. Organisms in a food chain are categorized under different groups called trophic levels. They are as follows. Producers (First Trophic Level) − Producers otherwise called autotrophs prepare their food by themselves. They form the first level of every food chain. Plants and one-celled organisms, some types of bacteria, algae, etc. come under the category of Autotrophs. Virtually, almost all autotrophs use a process called photosynthesis to prepare food. Consumers − At the second trophic level, there are consumers who depend upon others for food. Primary Consumers (Second Trophic Level) − Primary consumers eat the producers. They are called herbivores. Deer, turtle, and many types of birds are herbivores. Secondary Consumers (Third Trophic Level) − Secondary consumers based at the third trophic level eat plants and herbivores. They are both carnivores (meateaters) and omnivores (animals that eat both animals and plants). In a desert ecosystem, a secondary consumer may be a snake that eats a mouse. Secondary consumers may eat animals bigger than they are. Some lions, for example, kill and eat buffalo. The buffalo weighs twice as much as the lions do. Tertiary Consumers (Fourth Trophic Level) − Tertiary consumers are animals eating other carnivores. The secretary bird in Africa and the King Cobra specialize in killing and eating snakes but all snakes are carnivores. The leopard seal eats mostly other carnivores – mainly other seals, squids, and penguins, all of which are carnivores. Decomposers − Decomposers which don’t always appear in the pictorial presentation of the food chain, play an important part in completing the food chain. These organisms break down dead organic material and wastes. Fungi and bacteria are the key decomposers in many ecosystems; they use the chemical energy in dead matter and wastes to fuel their metabolic processes. Other decomposers are detritivores—detritus eaters or debris eaters. Understanding the food chain helps us know the feeding interrelationship and interaction between an organism and the ecosystem. It also enables us to know the mechanism of energy flow in an ecosystem. Food Web The word ‘web’ means network. Food web can be defined as ‘a network of interconnected food chains so as to form a number of feeding relationships amongst different organism of a biotic community. A food chain cannot stand isolated in an ecosystem. The same food resource may be a part of more than one chain. This is possible when the resource is at the lower tropic level. A food web comprises all the food chains in a single ecosystem. It is essential to know that each living thing in an ecosystem is a part of multiple food chains. A single food chain is the single possible path that energy and nutrients may make while passing through the ecosystem. All the interconnected and overlapping food chains in an ecosystem make up a food web. Food webs are significant tools in understanding that plants are the foundation of all ecosystem and food chains, sustaining life by providing nourishment and oxygen needed for survival and reproduction. The food web provides stability to the ecosystem. The tertiary consumers are eaten by quaternary consumers. For example, a hawk that eats owls. Each food chain ends with a top predator and animal with no natural enemies (such as an alligator, hawk, or polar bear). Learning working make money

Environmental Studies – Water Resources Water is a vital elixir for all living beings. Although it is a renewable resource, scarcity of quality water is felt in many parts of the world. We need water to grow food, keep clean, generate electricity, control fire, and last but not the least, we need it to stay alive. World Ocean water covers about 75 percent of the surface of the earth. Therefore, the earth is called the water planet. Ocean water is saline and not fit for human consumption. Fresh water is just about 2.7 percent of the total water. Global warming and perpetuating water pollution have made a considerable part of available freshwater unfit for human consumption. As a result, water is very scarce. Steps need to be taken to conserve water. Water is renewable, but its overuse and pollution make it unfit for use. Sewage, industrial use, chemicals, etc. pollute water with nitrates, metals, and pesticides. Use of Water Resources Water resources are used for agricultural, industrial, domestic, recreational, and environmental activities. Majority of the uses require fresh water. However, about 97 percent of water found on the earth is salt water and only three percent is fresh water. A little over two-thirds of the available fresh water is frozen in glaciers and polar ice caps. The remaining freshwater is found mainly as groundwater and a negligible portion of it is present on the ground or in the air. Following is a brief account of how water is used in different sectors. Agricultural Use Agriculture accounts for 69 percent of all water consumption basically in agricultural economies like India. Agriculture, therefore, is the largest consumer of the Earth’s available freshwater. By 2050, the global water demand of agriculture is estimated to increase by a further 19% due to irrigational needs. Expanding irrigation needs are likely to put undue pressure on water storage. It is still inconclusive whether further expansion of irrigation, as well as additional water withdrawals from rivers and groundwater, will be possible in future. Industrial Use Water is the lifeblood of the industry. It is used as a raw material coolant, a solvent, a transport agent, and as a source of energy. Manufacturing industries account for a considerable share in the total industrial water consumption. Besides, paper and allied products, chemicals and primary metals are major industrial users of water. Worldwide, the industry accounts for 19 percent of total consumption. In industrialized countries, however, industries use more than half of the water available for human use. Domestic Use It includes drinking, cleaning, personal hygiene, garden care, cooking, washing of clothes, dishes, vehicles, etc. Since the end of World War II there has been a trend of people moving out of the countryside to the ever-expanding cities. This trend has important implications on our water resources. Government and communities have had to start building large water-supply systems to deliver water to new populations and industries. Of all water consumption in the world, domestic use accounts for about 12 percent. Use for Hydropower Generation Electricity produced from water is hydropower. Hydropower is the leading renewable source of electricity in the world. It accounts for about 16 percent of total electricity generation globally. There are many opportunities for hydropower development throughout the world. Today, the leading hydropower generating countries are China, the US, Brazil, Canada, India, and Russia. Use for Navigation and Recreation Navigable waterways are defined as watercourses that have been or may be used for transport of interstate or foreign commerce. Agricultural and commercial goods are moved on water on a large scale in a number of regions in the world. Water is also used for recreational purposes such as boating, swimming, and sporting activities. These uses affect the quality of water and pollute it. Highest priority should be given to public health and drinking water quality while permitting such activities in reservoirs, lakes, and rivers. Overutilization of Surface and Ground Water Water scarcity has become a burning global issue. The UN has held several conventions on water in recent decades. Continuous overutilization of surface and ground water has led to virtual water scarcity in the world today. The depleting sources for high growth in human population over the centuries and increased man-induced water pollution across the world have created unforeseen water scarcity around the globe. As a result, there has been continuous overutilization of the existing water sources due to mammoth growth in world population. Groundwater is the major source of water in many parts of the world. However, there has been continuous depletion of this source due to its overexploitation by rising human population and the rapid rise in industrialization and urbanization in modern times. Consequences of Overutilization Water scarcity now becomes an important topic in international diplomacy. From village to the United Nations, water scarcity is a widely-discussed topic in decision making. Nearly three billion people in the world suffer from water scarcity. International, intrastate and regional rivalries on water are not new to world. The ongoing Jordan River conflict, Nile River conflict, and Aral Sea conflict are cases in point. The intra-state issues such as Cauvery Water dispute in South India, 2000 Cochabamba protests in Bolivia is still a simmering cauldron causing periodic tension at the national and regional levels. According to World Health Organization (WHO) sources, a combination of rising global population, economic growth and climate change means that by 2050 five billion (52%) of the world’s projected 9.7 billion people will live in areas where fresh water supply is under pressure. Researchers expect about 1 billion more people to be living in areas where water demand exceeds surface-water supply. Climate Change Scientists, environmentalists, and biologists worldwide are now alarmed that climate change can have an impact on the drainage pattern and hydrological cycle on the earth thereby severely affecting the surface and groundwater availability. Climate change is believed to rise the global temperature at an increasing pace. Temperature increase affects the hydrological cycle by directly increasing evaporation of available surface water and

Threats to Biodiversity Biodiversity is a paramount factor for the survival of the living world in general and mankind in particular. The fewer species (animals and plants) we have, the fewer people we will have on the earth. During the last few decades, loss of biodiversity is on the rise. Following are the major causes of threat to biodiversity. Habitat Loss Today, major loss to biodiversity in the world has been done by man. Man has begun to overuse or misuse most of these natural ecosystems. Due to mindless and unsustainable resource use, once productive forest and grasslands have been turned into deserts, and wastelands have increased all over the world. Rapid industrialization, urbanization, and growth in population have resulted in massive deforestation and consequential habitat loss around the world. For instance, mangroves have been cleared for fuel-wood and prawn farming, which has led to a decrease in the habitat essential for breeding of marine fish. Forests all over the world, in particular tropical rainforests such as the Amazon, are under unforeseen threat largely from conversion to other land-uses. Scientists have estimated that human activities are likely to eliminate approximately10 million species by the year 2050. It is also estimated that at the present rate of extinction about 25 percent of the world’s species will undergo extinction fairly rapidly. Rich biodiversities such as tropical forests, wetlands, and coral reefs world over will constitute the major part of this extinction. Poaching of Wildlife Poaching of wildlife for trade and commercial activities has been on the rise for the last many decades. It has been a significant cause of the extinction of hundreds of species and the endangerment of many more, such as whales and many African large mammal, Asian tigers, etc. Most extinction over the past several hundred years is mainly due to overharvesting for food, fashion, and profit. Illicit trade in wildlife in current times is driving many species of wild animals and plants to extinction. Elephants are poached for ivory; tigers and leopards for their skin; pangolins for meat and scales; and rare timber is targeted for hardwood furniture. The global illegal wildlife trade is estimated to be between $7 billion and $23 billion in illicit revenue annually. It is now considered the most lucrative global crime after drugs, humans, and arms. In 2015, the United Nations General Assembly unanimously adopted a resolution for tackling illicit trafficking in wildlife. The Sustainable Development Goals has laid down specific targets to combat poaching and trafficking of protected species. Man-Wildlife Conflict Man-wildlife conflict refers to the interaction between wild animals and people and the consequential negative impact on both of them. Human population growth and the resultant destruction of wildlife habitat for human habitation and economic prosperity create reduction of resources or life to some people and wild animals. World Wide Fund for Nature (WWF) defines this conflict as “any interaction between humans and wildlife that results in a negative impact on human social, economic, or cultural life, on the conservation of wildlife population, or on the environment.” Although man-wildlife conflict is as old as human civilization, in modern times the degree of conflict has been on the rise due to high rise in human population in the past several centuries. Since human populations expand into wild animal habitats, natural wildlife territory is displaced. Reduction in the availability of natural prey/food sources leads to wild animals seeking alternate sources. Alternately, new resources created by humans draw wildlife resulting in conflict. Competition for food resources also occurs when humans attempt to harvest natural resources such as fish and grassland pasture. There are many consequences of man versus wildlife conflicts. The major consequences are − Destruction of wildlife habitat Injury and loss of life of both humans and wildlife Crop damage and livestock depredation Damage to human property Decrease in wildlife population and reduction in geographic ranges Trophic cascades Apart from the above, there are other causes of threat to biodiversity. Factors such as climate change, invasion of non-native species also add to biodiversity losses in some or the other. Learning working make money

Environmental Studies – Useful Resources The following resources contain additional information on Environmental Studies. Please use them to get more in-depth knowledge on this. Useful Links on Environmental Studies − Wikipedia Reference for Environmental Studies Useful Books on Environmental Studies To enlist your site on this page, please drop an email to [email protected] Learning working make money

Environmental Studies – Quick Guide Environmental Studies – Environment The word ‘environment’ is derived from the old French word ‘environer’ – which means to ‘surround, enclose, and encircle’. Environment refers to an aggregate of conditions or surroundings in which living beings such as humans, animals, and plants live or survive and non-living things exist. All living beings including man and their environment are mutually reactive, affecting each other in a number of ways. It is generally equated with nature wherein physical components of the planet earth such as earth, air, water, etc. support and affect life in the biosphere. Environment represents the physical components of the earth, wherein man is an important factor affecting the environment. Environment comprises interacting systems of physical, biological, and cultural elements, which are interlinked individually as well as collectively in various ways. Constituents of Environment Physical elements constitute space, landforms, water-bodies, climate, soils, rocks, and minerals. These elements determine the variable character of human habitat, and also its opportunities and limitations. Biological elements include plants, animals, micro-organisms, and man. Cultural elements include economic, social and political conditions which are largely man-made features. Types of Environment Since environment is a combination of physical and biological factors, it contains both living or biotic and non-living or abiotic components. On the basis of this basic structure, environment can be divided into physical or abiotic and living or biotic environment. Physical or Abiotic Environment Physical environment is made up of the following states – solid, liquid, and gas. These three elements signify lithosphere, hydrosphere, and atmosphere respectively. On the basis of spatial distribution, smaller units are termed as coastal environment, plateau environment, mountain environment, lake environment, river environment, maritime environment, etc. Living or Biotic Environment Biotic environment consists of plants (flora) and animals (fauna) including human beings as a significant factor. Thus, biotic environment can be of two types such as floral environment and faunal environment. Apart from the above, there are social, cultural, and psychological environment. Social and Cultural Environment This type of environment includes the varied aspects of socio-cultural interactions along with its outcomes such as beliefs, attitudes, stereotypes etc. The tangible and intangible aspects of environment are included in it. Psychological Environment Psychological environment deals with the perception and experiences related to any environmental setting. Some environment may be stimulating and exciting for us, while others may be dull and boring. Psychological environment is more often used in the organizational context. Man-Environment Relationship Man and environment relationship is as old as the evolution of mankind. Since the evolution of man, the physical elements of the planet earth, such as terrain, soil, water, climate, flora and fauna formed man’s environment. During that time man was a typically a ‘physical man’ because of his limited wants, requirements, and total dependence on nature. With the growth in social and economic activities, advancement in technologies, man expanded his own environment through design and skill to have provisions for improved and better food, shelter, access, and comfort or luxuries. Man’s ability to survive in a variety of ecosystem and his unique ability to adapt to a great variety of external conditions make man-environment relationship quite a fascinating area of study. The environment in which man survives and to which he adapts himself and which he influences include physical, socio-cultural, and biological aspects. Man and environment has never been static and a great many factors are responsible for the shifts in man environment relationship. Approaches to Man-Environment Relationship The man and environment relationship can be studied under the following approaches. Determinism − Friedrich Ratzel, the German geographer, was responsible for the development of the concepts of determinism, which was further expanded by Ellsworth Huntington. This approach is based on the concept of ‘nature controls man’ or ‘earth made man’. According to this approach, man is largely influenced by nature. In fact, the determinism states that man is subordinate to natural environment because all aspects of human life such as physical (health and well-being), social, economic, political, ethical, aesthetic, etc. not only depend on but are dominantly controlled by the physical environment. World famous biologist, Charles Darwin, in 1859 laid the foundation stone of the concept of environment influences on man and other organism. Possibilism − Lucien Febvre, the French historian, founded the concept of Possibilism. Possibilism approach in the study of man-environment relationship is an offshoot of the criticism of environmental determinism and the impact of science and technology on such a relationship. Possibilism indicates that the physical environment is passive and man is the active agent at liberty to choose between wide ranges of environmental possibilities. According to it, the pattern of human activity is the result of the initiative and mobility of man operating within the natural framework. Nowadays, the role of natural elements in conditioning, though not controlling human activities, is often lost sight of. Possibilists were largely aware of the limitations of freedom of man to dictate terms to environment. It was agreed upon by the possibilists that man lacks the abilities to fully tame the nature and is not always victorious over it. As result of the above, some geographers vouched for ‘cooperation with nature’ or ‘mutual interaction’ between man and environment. Ecological Approach − This approach is based upon the basic principle of ecology, which is the study of mutual interaction between organisms and physical environment on the one hand, and the interaction among the organism on the other in a given ecosystem. This approach describes man as an integral part of nature or environment. Man, being most skilled and intelligent, has a unique role to play in maintaining a natural environment as healthy and productive as it should be. This approach emphasizes on wise and restrained use of natural resources, application of appropriate environmental management programs, policies and strategies keeping in view certain basic principles of ecology so that already depleted natural resources are replenished, and health and productivity of the nature is restored. What is Environmental Studies? Environmental studies refer to an extensive

Environmental Studies – Mineral Resources Minerals are naturally occurring elements or compounds that have been formed through slow inorganic processes. Modern civilization is based on the use and exploitation of mineral resources. Minerals can be metallic and non-metallic. Minerals are not evenly distributed in the Earth. Some countries are rich in mineral deposits whereas others are devoid of it. Use of mineral resources is an integral part and one of the key premises of development worldwide. With rapid increase in population and a more rapid increase in society’s development needs, the requirements for minerals have grown and diversified manifold. Extraction of minerals is carried out through mining. Minerals are extracted from beneath the surface, processed, and used for different purposes. Mineral resources, however, are exhaustible and finite, which means excessive use may affect their availability in the future. Exploitation of Mineral Resources Exploitation of mineral refers to the use of mineral resources for economic growth. Exploitation of mineral resources at a mindless speed to meet the growing needs of modern civilization has resulted in many environmental problems. Although, the exploitation of minerals began at a slow pace during the industrial revolution in Western countries, during the 20th century, the exploitation of some minerals, especially the fossil fuels increased exponentially to meet the growing energy need. Today, about 80% of the world’s energy consumption is sustained by the extraction of fossil fuels, which consists of oil, coal, and gas. Consequences of Exploitation of Mineral Resources. Excessive exploitation of mineral resources has led to the following severe problems. Deforestation and desertification Extinction of species Rapid depletion of high grade minerals Forced migration Wastage of upper soil layer and vegetation Soil erosion and oil depletion Ozone depletion Greenhouse gas increase Environmental pollution Natural hazards, etc. Learning working make money

Environmental Studies – Ecosystem The interaction and interrelationship between the living community (plants, animals, and organisms) in relation to each other and the non-living community (soil, air, and water) is referred to as an ecosystem. Thus, an ecosystem is a structural and functional unit of biosphere. It is made up of living and non-living beings and their physical environment. In other words, a natural ecosystem is defined as a network of interactions among the organisms and between organisms and their environment. Nutrient cycles and energy flows keep these living and non-living components connected in an ecosystem. Ecosystem – Scope and Importance Ecosystem is a part of natural environment consisting of a community of living beings and the physical environment both constantly interchanging materials and energy between them. It is the sum total of the environment or a part of nature. The environment consists of four segments as follows − Atmosphere − The atmosphere refers to the protective blanket of gases, surrounding the earth. It sustains life on the earth. It saves the Earth from the hostile environment of the outer space. The atmosphere composed of nitrogen and oxygen in large quantity along with small percentage of other gases such as argon, carbon dioxide, and trace gases (the gases which makes up less than 1 percent by volume of the atmosphere. Hydrosphere − Hydrosphere comprises all water resources such as ocean, seas, lakes, rivers, reservoirs, icecaps, glaciers, and ground water. Lithosphere − It is the outer mantle of the solid earth. It contains minerals occurring in the earth’s crust and the soil. Biosphere − It constitutes the realm of living organisms and their interactions with the environment (atmosphere, hydrosphere, and lithosphere). The study of ecosystem or environmental studies has been seen to be multidisciplinary in nature, hence, it is considered to be a subject with great scope. It is no more confined only to the issues of sanitation and health; rather, it is now concerned with pollution control, biodiversity conservation, waste management and conservation of natural resources. Learning working make money

Environmental Studies – Pollution and Control Environmental pollution or simply pollution refers to undesirable changes occurring in the physical, chemical, and biological composition of natural environment consisting of air, water, and soil. Pollution also means the presence of harmful pollutants in an environment that makes this environment unhealthy to live in. According to National Academy of Science, USA (1966), pollution is defined as, “An undesirable change in physical, chemical, and biological characteristics of water, air, and soil that may harmfully affect human, animal, and plant life, industrial progress, living conditions and cultural assets. Pollution is also viewed as ‘an unfavorable alteration’ in the sustaining and carrying capacity of the natural environment wholly or largely by the byproducts of human activities. Natural environment has an inbuilt capacity to replenish the losses or reduction in its constituents to restore it as sustainable and healthy as required. Ever expanding population and evolution of man into modern homo sapiens have led to rapid urbanization, industrialization and unprecedented rise in human habitations. All these human endeavors have, in turn, virtually perpetuated deforestation, loss of habitats for flora and fauna, depletion of natural resources at a large scale over the last couple of centuries, which have told upon the inherent resilience of the natural environment. As a result, natural environment continues to be undesirably polluted. Pollutants A pollutant is defined as any form of energy or matter or action that causes imbalance or disequilibrium in the required composition of natural objects such as air, water, etc. A pollutant creates damage by interfering directly or indirectly with the biogeochemical process of an organism. Pollutants may be − Natural Pollutants − Natural pollutants are caused by natural forces such as volcanic eruption and forest fire. Man-made Pollutants − These refer to the release of excess amount of gases or matter by human activities. For instance, increase in the number of automobiles adds excess carbon monoxide to the atmosphere causing harmful effect on vegetation and human health. Classification of Pollution Different types of pollution are classified based on the part of the environment which they affect or result caused by a particular pollution. Each type of pollution has its own distinctive cause and consequences. The major types of pollution are as follows. Air pollution Water pollution Noise pollution Soil or land pollution Learning working make money

Environmental Impact Assessment The effects of human activities related to the use of environmental resources on natural environment is called Environmental Impact. The assessment and evaluation of environmental effects of human activities are collectively called Environmental Impact Assessment (EIA). Environmental Impact Assessment is, therefore, a method of evaluating environmental consequences such as environmental changes which are likely to be caused by the proposed human activities related to land use changes, construction of dams, reservoirs, roads, rails, bridges, industrial locations, urban expansion, etc. and the possible adverse effects of these environmental changes. Environmental changes mean environmental degradation and pollution resulting into ecological imbalance and ecosystem disequilibrium. The environmental impact assessment process began with the enactment of the National Environmental Policy Act (NEPA) in the US in 1969. Objectives of Environmental Impact Assessment In view of the colossal damage to the environment, there is a felt need for assessing the environmental impacts of developmental activities. EIA is a tool to anticipate the possible damage to the environment caused by developmental projects and schemes, and propose mitigation measures and strategies. EIA exerts to declare a national policy to encourage productive and enjoyable harmony between man and environment. It promotes efforts to prevent or eliminate damage to the environment and the biosphere, and stimulate the health and welfare of man. It seeks to increase the understanding of ecological system and nature resources important to the nation and to provide for appropriate institutional structure to carry out the objectives. It provides a broad, integrated perspective of a region about to undergo or undergoing developments. EIA ascertains the cumulative impacts from the multiple development in the region. It establishes priorities for environmental protection. It also identifies the positive and negative aspects of any project as well as assesses the policy options and analyzes the impact on the environment therein. Projects that Require Environmental Clearance Manufacturing Industries Mining Thermal Power Plants River Valley Projects Infrastructure and Coastal Regulation Zone Nuclear Power Projects Steps in Environmental Impact Assessment Describe the present environment Describe the project, including purposes and needs Describe the effects of the project Describe the impact, both short term and long term Suggest and compare alternatives (projects) Suggest mitigating activities or remedial measures Learning working make money