23 Environmental Degradation: Policies and Programmes
Nupur Mahajan and Gautam Kshatriya
Contents:
Environment: An overview
Environmental degradation: Definition
Causes of environmental degradation
- Environmental pollution
- Causes of pollution
- Types of pollution
- Sources of pollution
Air pollution
Water Pollution
Soil Pollution
Radioactive Pollution
- Global Warming
- Ozone Layer Depletion
- Pollutants
Classification of pollutants
Impact of environmental degradation on human life
Environmental policies and programmes
Summary
Learning objectives:
- To define environment and environmental degradation
- To know about the causes of environmental degradation
- To understand the causes, types and sources of pollution and classification of pollutants.
- To get an insight of the impact of environmental degradation on human life
- To list some of the policies and programmes on environment conservation in India and across the world
Environment: An overview
Environment can be defined in various different ways based on the context in which environment is being talked about. Environment is the sum of all social, economical, biological, physical or chemical factors which constitute the surroundings of man, who is considered as the creator and moulder of his environment. It also refers to the sum total of conditions which surround the man at a given point of space and time. Environment is considered as the representative of physical components of the earth wherein man is the most important factor influencing his environment.
Everything that surrounds or affects an organism during its life time is collectively known as its environment which comprises both living (biotic) and nonliving (abiotic) components. All organisms (from virus to man) are obligatorily dependent on the environment for food, energy, water, oxygen, shelter and for other needs. Therefore, environment is also defined as the sum total of living, non-living components; influences and events, surrounding an organism.
The relationship and interaction between organism and environment are highly complex. No organism can live alone without interacting with other organisms. So each organism has other organisms as a part of its environment. Each and everything with which we interact or which we need for our sustenance forms our environment. The environment is not static. Both biotic and abiotic factors are in a flux and keep changing continuously.
Components of environment
Environment consists of three important components:
- Abiotic or non-living components
- Biotic or living components
- Energy components
Abiotic components are the inorganic and nonliving parts of the world. The abiotic part consists of soil, water and air components. It also involves a large number of molecules like oxygen, nitrogen etc. and physical processes including volcanoes, earthquakes, floods, forest fires, climates, and weather conditions. Abiotic factors are the most important determinants of where and how well an organism exists in its environment. Although these factors interact with each other, one single factor can limit the range of an organism. Thus, the abiotic components can be sub-divided broadly into three categories:
- Lithosphere (Solid earth)
- Hydrosphere (Water components)
- Atmosphere (Gaseous envelope)
Biotic components include living organisms comprising plants, animals and microbes and are classified according to their functional attributes into producers and consumers.
- Primary producers – Autotrophs or self nourishing
Primary producers are basically green plants (and certain bacteria and algae). They synthesize carbohydrate from simple inorganic raw materials like carbon dioxide and water in the presence of sunlight by the process of photosynthesis for themselves, and supply indirectly to other non producers. In terrestrial ecosystem, producers are basically herbaceous and woody plants, while in aquatic ecosystem producers are various species of microscopic algae.
- Consumers – Heterotrophs or phagotrophs
Consumers are incapable of producing their own food (photosynthesis). They depend on organic food derived from plants, animals or both. Consumers can be divided into two broad groups namely micro and macro consumers.
Macro consumers feed on plants or animals or both and are categorized on the basis of their food sources. Herbivores are primary consumers which feed mainly on plants e.g. cow, rabbit. Secondary consumers feed on primary consumers e.g. wolves. Carnivores which feed on secondary consumers are called tertiary consumers e.g. lions which can eat wolves. Omnivores are organisms which consume both plants and animals e.g. man.
Micro consumers or saprotrophs (decomposers or osmotrophs) are bacteria and fungi which obtain energy and nutrients by decomposing dead organic substances (detritus) of plant and animal origin. The products of decomposition such as inorganic nutrients which are released in the ecosystem are reused by producers and thus recycled. Earthworm and certain soil organisms (such as nematodes, and arthropods) are detritus feeders and help in the decomposition of organic matter and are called detrivores.
The energy component includes solar energy, geochemical energy, thermo-electrical energy, hydro-electrical energy, nuclear atomic energy, etc. Energy due to radiation and other sources also plays an important role to maintain real life of organisms.
Environmental degradation: definition
The interaction between environment and human beings has been thoroughly studied and the environmental risks have been known to have significantly impacted human health, where people are directly or indirectly exposed to harmful agents by disturbing the life-sustaining ecosystems (Tyagi et al, 2014). Environmental degradation is a phenomenon of deterioration of the environment through depletion of natural resources (air, water and soil), the destruction of ecosystems and the extinction of wildlife. Environmental degradation may be defined as any change or disturbance to the environment which is considered to be to be deleterious or undesirable. Environmental degradation is listed as one of the Ten Threats which have been officially cautioned by the High Level Threat Panel of the United Nations. The United Nations International Strategy for Disaster Reduction (UNISDR) has defined environmental degradation as “The reduction of the capacity of the environment to meet social and ecological objectives, and needs”. Human disturbances to the environment are the primary cause of environmental degradation. The extent of the environmental impact varies with the cause, habitat, and the type of flora and fauna which inhabit it. Human beings and their activities are a key source of environmental degradation.
Causes of environmental degradation
The I=PAT definition anticipated that environmental degradation or impact (I) is caused by the collective effect of a large human population which is increasing at a startling pace (P), constantly rising economic growth or per capita affluence (A), and the increasing use of resource depleting and degrading technology (T).
Overpopulation, pollution (air, water, soil, radioactive, etc.), deforestation, global warming, unsustainable agricultural and fishing practices, overconsumption, mal-distribution of wealth, the rise of the corporation, the Third World debt crisis, and militarization and wars are major causes of environmental degradation. Mining has been one of the most destructive development activity in which the environment suffers at the price of economic development of a nation. Scientific mining operations along with ecological restoration and revival of mined wastelands and cautious a use of geological resources, by searching for environment friendly substitutes and options must offer astounding revelation to the impact of mining on human bionetwork. Modern urbanization, industrialization, over-population growth, deforestation etc are also the main causes of environmental depletion. These have led to environment changes that have become harmful to all living beings.
Environmental pollution
The word pollution has derived from latin word pollutionem which means to dirty or defile. Like environment, pollution can also be defined in several ways depending upon the context. Pollution is an unfavourable alteration of our environment largely caused due to human activities. Deviation from natural composition of a part of the environment having adverse effects on life is also defined as pollution. It is an undesirable change in the physical, chemical or biological characteristics of air, land and water having harmful effects on humans, flora, fauna and the cultural assets. Lastly, pollution means the addition of undesirable foreign material like inorganic, organic, biological or radiological or any physical change occurring in nature which may harm or affect living organisms directly or indirectly, immediately or after a long time.
Environmental pollution refers to the degradation of quality and quantity of natural resources. It is the result of urban-industrial technological revolution and speedy exploitation of every bit of natural resources. The term environment, as far as pollution is concerned, includes air, water, soil, noise, buildings, landscapes, oceans, lakes, rivers, parks, vehicles and many other things. Thus, pollution is generally defined as “The addition of the constituents to water, air or land, which adversely alter the natural quality of the environment.” In some cases, pollution may involve removal, rather than the addition of the constituents from the environment.
Causes of pollution
Modern ecologists, point out that there are various factors, such as human population explosion, rapid industrialization, deforestation, unplanned urbanization, scientific and technological advancement, etc. which are mainly responsible for the pollution crisis on earth. It is well evident, that United States, with its vast infrastructure of industries is one of the leading polluters of the world. The worst pollution occurs in countries where there have been the greatest scientific and technological advances.
Rapid population growth, combined with modern technology has caused a serious environmental crisis. This is because of the fact that in well developed countries, citizens consume more food; use more fertilizers and pesticides, fuel, minerals, automobiles and other manufactured products of all kinds. Almost all of these products are manufactured in one or other kinds of industries. These industries are responsible for adding pollutants in our environment and hence cause pollution.
Everything today is polluted by pollutants. The rivers, seas and lakes are polluted by wastes coming from various industries, the air by toxic effluents from thermal power plants and exhausts of automobiles and the land or soil by chemicals, fertilizers, pesticides, acidic rains and insecticides, etc.
The most important and common pollutants of well developed and developing countries are deposited matter (such as soot, smoke, tar, dust and frit), gases (such as carbon monoxide, carbon dioxide, nitrogen oxides, sulphur dioxide, fluorine, chlorine, ozone, ammonia, etc.), chemical compounds (such as aldehydes, detergents, hydrogen fluorides, arsines, phosgene, etc.), toxic metals (such as cadmium, mercury, lead, zinc, iron, etc.), economic poisons (such as herbicides, pesticides, fungicides, insecticides, rodenticides, etc.), fertilizers (such as NPK fertilizers), sewage (such as human waste), radioactive substances (such as argon-41, cobalt-60, caesium-137, iodine-131, krypton-85, strontium-90, tritium and plutonium-239), noise and heat.
Types of pollution
Pollutants need not be material substances. Noise and even electromagnetic waves can be classified as pollutants too. However, today man is the principal source of pollution, because there is no way for nature to decompose many man-made materials and return their elements to the cycle of nature. These substances will just remain and will cause whatever harmful effects they can, until they are somehow dispersed or diluted so that their action is no longer harmful.
Thus pollution may be categorized as natural (which originates from natural processes such as forest fires, natural organic and inorganic decays, volcanic eruptions, earthquake, etc.) or artificial which originates due to activities of man.
However, it is better to classify pollution either according to the environment (air, water, soil, noise, radiation, thermal, etc.) in which it occurs or according to the pollutants by which pollution is caused.
Classification according to environment
When different spheres of the environment are affected by pollution, they are categorised as
- Air pollution
- Water pollution
- Soil or land pollution
Classification according to the pollutant
The pollution caused by pollutants may be of a number of types. For examples:
- Radioactive pollution
- Sewage pollution
- Pesticide or biocide pollution
- Noise pollution
- Thermal pollution
- Marine pollution
- Chemical and industrial pollution
- Oceanic pollution
- Biological pollution
- Pollution caused by soaps and detergents
- Acid rain pollution
- Pollution by oil spills
Sources of pollution
Major sources of air pollution
The natural sources of air pollution are volcanic eruptions releasing poisonous gases (such as sulphur dioxides, hydrogen sulphide and carbon monoxide, etc.), forest fires, natural organic and inorganic decays or vegetative decays, marshy gases, blowing of sand and dust, extra terrestrial bodies, cosmic dust, pollen grains of flowers, soil debris, comets and fungal spores. All these are produced naturally and released in the air, making it foul and injurious to health. Green plants through evapotranspiration release huge amount of carbon dioxide. Forest fires and reactions between natural gas emissions also constitute a source of air pollution.
Man made sources such as increase in population, deforestation, burning of fossil fuels and fires, emissions from vehicles, rapid industrialization, agricultural activities and wars, are the major causes of air pollution.
The rapid explosion of population is of the most important factor for air pollution. If this rate remains the same then the population would be doubled after every 35 years. The increase in population creates several serious problems including the worsening of the condition of the environment. An increase in population also contributes to loss in forest cover and loss in wildlife species.
The conventional sources of energy are wood, coal and fossil fuels etc. about 97% of the energy we use in our homes and factories is generated by coal, oil and natural gas, which are called fossil fuels. Coal consists of the remains of land plants, while oil and gas were formed from the remains of tiny plants and animals that lived in lakes and seas. Oil and gas are more important fuels than coal, because they are easier to extract and by weight, they give out more heat. Burning of these sources is responsible for air pollution.
The automobile exhausts are responsible for more than 75% of total air pollution. The automobiles such as cars, scooters, motors, taxies, trucks, etc. release huge amounts of poisonous gases such as carbon monoxide (about 77%), nitrogen oxides (about 8%) and hydrocarbons (about 14%), in addition to leaded gas and particulate lead etc. as a result of incomplete combustion of petrol and diesel which react with oxides of nitrogen in presence of sunlight to form photochemical smog in the atmosphere. This smog is very toxic in nature.
A large number of industries such as chemical industries, paper and pulp mills, cotton mills, metallurgical plants and smelters, petroleum refineries, mining, and synthetic rubber industries are responsible for about 20% of air pollution. The common pollutants of these industries are various types of inorganic and organic gases and materials in the smoke they produce. The most common pollutants are CO2, CO, SO2, H2S, NO, NO2, etc. in addition, the smoke coming out from their chimneys also contains all particles of dust, carbon, metals, other solids, liquids and even radioactive materials which get mixed in the smoke and pollute the air. All such gases and suspended particles in them are injurious to human health.
Different types of biocides such as pesticides, insecticides, herbicides, etc. which are used in agricultural practices, also cause air pollution because some amount of these poisonous substances is carried away by wind to different places, during their spray over crops, thus make the air foul for human health and other animals.
The air pollution is also caused by various types of sophisticated explosives used in wars. Radioactive rays coming out from atomic reactors or nuclear explosions pollute the air extensively and bring sufferings to mankind to a very large extent. The atomic bomb explosions on Hiroshima and Nagasaki during the World War II, and recent Gulf War are well known to us.
Sources of Water pollution
Water, the most abundant and wonderful natural resources, is extremely essential for survival of all living organisms. But today clean water has become a precious commodity and its quality is threatened by numerous sources of pollution which are as follows:
Sewage and Domestic Wastes
Sewage is commonly a cloudy dilute aqueous solution containing mineral and organic matter. About 75% of water pollution is caused by sewage, domestic wastes and food processing plants. It also includes human excreta, soap, detergent, metals, glass, garden waste and sewage sludge from cess pools etc. if domestic waste or sewage is not properly handled after it is produced or if the effluent received at the end of sewage treatment plant is not of adequate standard, there is chance of water being polluted. The indiscriminate method of handling the domestic sewage may also cause pollution of underground sources of water such as wells. If sewage or partially treated sewage is directly discharged into water bodies such as river, the water of such rivers is polluted or contaminated.
Municipal waste is the principal contributor of water pollution. Domestic sewage contains trace quantities of toxic metals such as Cu, Cr, Zn, Mn, Pb, Ni. Sewage contains decomposable organic matter and exerts an oxygen demand on the receiving waters. Organic matter generally includes fatty acids, ester, amino acids, amides, amino sugars and proteinaceous amines. Most municipal sewages receive no treatment before they are discharged in water. Sewage treatment deposits the suspended material, called sludge at the bottom, while the liquid waste consists of ions like Ca2+, Mg2+, Na+, K+, Cl-, NO2-, SO42-, PO43-, NH4+ and HCO3- in dissolved condition.
Industrial Effluents
Industrial effluents discharged into water bodies contain toxic chemicals, hazardous compounds, phenols, aldehydes, ketones, amines, cyanides, metallic wastes, plasticizers, toxic acids, corrosive alkalis, oils, greases, dyes, biocides, suspended solids, non-biodegradable matter, radioactive wastes and thermal pollutants from numerous industries. The principal type of industries which contribute to water pollution of rivers in India are chemicals and pharmaceuticals, coal washeries, soaps and detergents, pulp and paper, sugar, distilleries, dyeing, tanneries, steel mills, fertilizers, etc. these effluents when discharged through sewage system poison the biological purification mechanism of sewage treatment and pose several pollution problems.
The toxicity of various pollutants to aquatic environments is variable but all of them contaminate on the bottom of water systems where they poison or smoother the aquatic organisms. Most of the industrial effluents are insusceptible to degradation. Toxic metals are extremely lethal for living beings. Sulphuric acid waste from coal mines is a chronic pollutant which enhances hardness of water and corrodes concrete, etc. it has also drastically affected the living biota.
Agricultural Discharges
Plant nutrients, pesticides, insecticides, herbicides, fertilizers, farm wastes, manure slurry, sediments, drainage from silage, plants and animal’s debris, soil erosion containing mostly the inorganic materials are reported to cause heavy pollution to water sources. In modern agricultural practices NPK fertilizers containing nitrate and phosphate are added to the soil. Some of these are washed off through rain fall, irrigation and drainage into water bodies, where they severely disturb the aquatic ecosystem. The excessive use of plant nutrients leads to the disruption of nitrogen and phosphorous balance in water affecting plant growth. Organic wastes increase the biochemical oxygen demand (BOD) of receiving water.
Some pesticides are not only non-biodegradable but are slightly soluble in water. Consequently when they are sprayed on cropland, they adhere to the soil for long periods. During rainfall they tend to be carried as suspended particles into water systems. It is deemed that pollutants affecting underground aquifers are more serious that it would be in surface water systems due to impossibility of treatment of polluted water. Over pumping in coastal areas is considered to be responsible for water pollution.
Fertilizers
Modern agiculture rely heavily on artificial fertilixers, incliding several biocides. Although these chemicals enhance vegetation but they disrupt the entire natural aquatic ecosystem. They actually pollute the water. However, it is not only the increasing use of fertilizers but also escalated production which poses adverse effects on water and living biota.
Detergents
Household detergents contain several pollutants which severely affect water bodies. They contain surface active agents and contribute to phosphates of sodium, sodium silictaes, spdium sulphate, amides and several other builders in water. Present day sewage contains appreciable quantities of sunthetic detergents.
Toxic Metals toxic metals are added in aquatic system from industrial process, domestic sewage discharge, street dust, land run off and fossil fuel burning. Traces of heavy metals such as Mercury (Hg), Cadmium (Cd), Lead (Pb), Arsenic (As), Cobalt (Co), Manganese (Mn), Iron (Fe) and Chromium (Cr) have been indentified as deleterious to aquatic ecosystem and human health. Waste containing high concentration of toxic metals either separately or in combination are exteremely toxic to all organisms.
The mojor sources of lead poisoning have been steel and paint industries. About 80% of lead retained in the body enters the bone affecting the metabolic activities. Cd is toxic to living organisms even in low concentration of <1 mg Cd per litre. Toxicity of chromium (Cr3+) to aquatic forms varies differently. Copper is also acutely harmful to hfish and its adverse effects depend on the hardness of water. These metals are cumulative poisons and affect dangerously all the aquatic flora.
Siltation
Siltation is the most widespread and damaging pollutat especially in hill streams. These soil partcles create high turbidities in water and may hinder the free movemnet of aquatic organisms, growth of fishes and their productivity.
Thermal Pollutants
These pollutants include the waste chiefly from atomic, nuclear and thermal power plants. The discharge of unutilized heat is highest in the thermal power plats which adversely affect the aquatic environment. Municipal sewage also contributes to thermal pollution. Domestic sewage normally have a higher temperature than the receiving eater. When sewage is discharged into water stremas, not only the stream tempreature rises to a measurebale extent but there are other effects also. The thermal pollution of water creates two major problems.
The activity of biological life is more at higher temperature and hence as temoerature of water rises, there is more demand for dissolved oxygen.
As the temperature of water rises, the amount of dissolved oxygen in water decreases. Hence at higher temperature, less amount of dissolved oxygen will be present in water and it may be fatal for aquatic life.
Radioactive Materials in Water
Radioactive pollutants enter into water streams from various sources such as nuclear power plants, nuclear reactors, nuclear test, nuclear installations, operations of power, processing fission and fusion products etc.
Sources of soil pollution
Disposal of industrial waste is the major problem responsible for soil pollution. These industrial pollutants are mainly discharged from pulp and paper mills, chemical industries, oil refineries, sugar factories, tanneries, textiles, steel, distilleries, fertilizers, pesticide industries, coal and mineral mining industries, metal processing industries, drugs, glass, cement, petroleum and engineering industries etc. Industrial sludge are even more dangerous than industrial solid wastes to dispose of tidily. The composition of industrial sludge vary enormously, the common boiler scale, for example, consists of calcium carbonate and flue gas sludge. These wastes also consist of calcium salts and several toxic volatile elements such as arsenic, selenium, mercury, lead and cadmium, which pose detrimental effects on the environment.
Urban wastes comprise both commercial and domestic wastes consisting of dried sludge of sewage. All the urban solid wastes are commonly referred to as ‘refuse’. Solid wastes and refuse, particularly in urban areas contribute to soil pollution. This refuse contains garbage and rubbish materials like plastics, glasses, metallic cans, fibres, paper, rubbles, street sweepings, fuel residues, leaves, containers, abandoned vehicles and other discarded manufactured products.
Radioactive substances resulting from explosions of nuclear devices, atmospheric fallout from nuclear dust and radioactive wastes (produced by nuclear testing laboratories and industries) penetrate the soil and accumulate there creating land pollution.
Now-a-days agricultural practices rely heavily on artificial fertilizers, pesticides, fumigants. Fertilizers generally contain one or more of the plant nutrients i.e. nitrogen, phosphorous and potassium. Critical pollution problems arise mainly from their excessive application rates. Although the fertilizers are used to fortify the soil, yet they also contaminate the soil with their impurities, when the fertilizers are contaminated with other synthetic organic pollutants, the water presents in the soil may also get polluted. Among pesticides the most important are the chlorinated hydrocarbons e.g., D.D.T, B.H.C., aldrin, endrin, dieldrin, lindane, chlordane, heptachlor and endosulphan. Organo-phosphates include-malathion, parathion, ethion, fenthion, trithion, dursban, dimethoate, phosdrin and metasystox etc. the remnants of these pesticides may get absorbed by soil particles which may contaminate root crops grown in soils.
Soil conditioners, fumigants and chemical agents used in agricultural and irrigation practices also pollute the soil. These chemical agents are reported to cause alterations in both agricultural and horticultural soil areas. They contain several toxic metals like lead, arsenic, cadmium, mercury and cobalt etc. which when applied to a land will accumulate on the soil permanently thereby introducing these chemical components into growing crops.
Increasing population of cows, cattle, pigs and poultries have resulted in considerable soil pollution. Buildings in which grazing animals are housed can be cleaned using water but the manure is also washed out and deposited as wet slurry on the land. This slurry deposited on soil may seep into ground water and pollute it. When these farm wastes are dumped into heaps, they may become a good breeding ground for insects and nuisance may arise.
A number of industries including textiles, pesticides, paints, dyes, soaps and synthetic detergents, tanneries, drugs, batteries, cement, asbestos, rubber, petroleum, paper and pulp, sugar, steel, glass, electroplating and metal industries pour their hazardous effluents in soil and water creating disastrous effects on living organisms.
Sources of radioactive pollution
Natural sources of radiation include solar rays, environmental radiation, radionuclides in Earth’s crust and internal radiation. Solar rays coming from the sun keep a steady drizzle of gamma rays, cosmic rays and heavy particles. Solar storms vastly intensify these showers, but the earth’s atmosphere shields us from most celestial radiations.
Radio-isotopes of naturally occurring radio elements release enormous amount of radiations in the form of alpha, beta and gamma particles. Radioactive elements occurring mainly in lithosphere comprise uranium, thorium, radium, isotopes of potassium and carbon (C-14). These radiations mix and interact with natural particulate materials in the atmosphere enhancing the extent of radio pollution.
Radioactive minerals such as uranium (U-238), thorium (Th-232) and potassium (K-40) are widely distributed in the earth’s crust give rise to the phenomenon referred to as “terrestrial radioactivity”. The concentration of these radioisotopes in the soil determines the intensity of nuclear radiations at any particular place.
Generally radiations originate within our bodies, particularly during the decay of potassium in our muscles. Besides potassium, radioactive elements such as uranium, thorium, strontium and carbon (C-14) exist in minute quantities in human body.
Global Warming
Global warming means the rise in the mean global temperature to a level which affects the life-forms on the earth surface. The factors responsible for this warming may be both natural and man-made. Warming of the globe due to natural factors is not an unusual phenomenon.
The earth is kept warm due to what is known as the “green house effect”. Without it, the earth would be a frozen waste-land. The short wavelengths or ultraviolet radiation coming from the Sun penetrates the atmosphere and is absorbed by the earth. This absorbed energy is also radiated back to space at infrared wavelengths. The earth atmosphere contains gases which trap some of the outgoing radiation and thereby warm the earth. These gases are known as “Green House Gases”. Water vapour, carbon dioxide, methane, ozone, nitrous oxide and CFCs are prominent examples. To maintain the global energy balances, both the atmosphere and the surface will warm until the outgoing energy equals the incoming energy.
The increase in the quantity of the greenhouse gases in the atmosphere can reinforce the greenhouse effect and lead to global warming. CFCs and nitrous oxide are many time more potent than the same quantity of carbon-dioxide or methane. However carbon-dioxide is the largest contributor to the global warming as it holds the largest share among the green house gases in the atmosphere. CFCs are totally man-made greenhouse gases which are controlled under Montreal Protocol. The largest sources of methane in the atmosphere are natural wetlands, rice paddies and livestock. Natural gas production, bio-mass burning, termites, landfills and coal mining also releases methane. Nitrous oxides are released by the oceans and soils but human activities such as bio-mass burning and the use of fertilizers play a major role in it. According to the IPCC report, which takes into account the global warming potential of different gases, it is estimated that 72% of global warming is contributed by carbon-dioxide, 18% by methane and 5% due to nitrous oxide. The contribution of CFCs to overall global warming related to carbon-dioxide is low. The warming effect of CFCs is cancelled out by the global cooling due to their destruction of stratoscopic ozone.
The earth has warmed by about one degree Fahrenheit in the last century and the warming has accelerated in the last two decades. This accelerated warming is the result of the emission of heat-trapping waste industrial gases like CO2 and if the emissions are not reduced the surface will warm by about 3.5 degrees over the next century.
According to World Resources Institute between 1992 and 1997, the global carbon-dioxide emission increased by 38%. USA is the largest emitter of CO2, but two developing countries- China and India-are also among the ten largest polluters, although they are among the least polluters on the per capita basis. The OECD countries accounts for 45% of the total global CO2 emission and the European Union alone contributes 13% of the total.
On the per capita basis the US remains the biggest polluter (19.1 tons per capita), while China is third lowest and emits the least amount of carbon dioxide (0.8 tons per capita).
Drought and water scarcity is the third major climate change impact which significantly leads to climate-related migration. Droughts, desertification, and water scarcity are likely to rise because of global warming. About one-third of the current world population is going to be affected by increase in these phenomena. Droughts are expected to cause displacement of millions of people around the world which will further affect food insecurity and human livelihoods. The rise in sea levels is likely to extend areas of salinization of groundwater and estuaries, indicating towards in a decrease in the availability of freshwater for humans consumption and ecosystems in coastal areas. Furthermore, altering precipitation patterns has been generating pressures on the accessibility of clean water supplies.
In order to tackle these problem three approaches can be adopted:
Prevention: It means slow or half the rate of increase in atmospheric concentrations of greenhouse gases. This would involve reductions in the use of fossil fuels, switching between fossil fuels with different carbon contents, removal of carbon dioxide from power plant smokestacks, switching from fossil fuel combustion to biomass combustion, reforestation, etc.
Mitigation: this would involve release of particulates into the atmosphere, of gases that offset the effects if the greenhouse gases, promoting cloud formation, steering tropical storms away from populated areas.
Adaptation: this would involve stopping new development in low-lying coastal areas, changing agricultural practices, using different plants and animal varieties, undertaking research in new plants and animal varieties.
Ozone layer depletion
The sun emits radiation over a broad range of wavelengths, to which human eye responds in the region from approximately 400nm to 700nm.
The maximum concentration of ozone (about 0.5 ppm) occurs between the altutide of 20 to 35 km and the layer at this level is called ozone layer, the presence of ozone is an essential necessity for life on Earth. Stratospheric ozone layer absorbs dangerous UV rays of Sun and thus protects the Earth’s surface from these high energy radiations. Over the last few decades O3 layer is thinning out because of man-made pollutants which catalyse the dissociation of O3 at a very fast rate. Major pollutants responsible for depletion of ozone are chlorofluorocarbons (CFCs), nitrogen oxides hydrocarbons and oxides of chlorine and bromine.
Increased UV radiation would retard photosynthesis in plants. Moreover, it would increase earth’s mean temperature which has disastrous consequence of flooding or submerging many low-lying islands. Recently it has been found that UV radiation degrades polymers used in paints and building materials.
Considering the monumental damages ozone depletion does, the world community is taking steps to control the ozone depletion, the Montreal Protocol, adopted in 1987 and strengthened in 1990, called for phasing out CFCs and other ozone depleting substances (ODS) by 2000, established rules governing international trade in ODS and their products, since the developing countries ask the financial and technological means to replace CFC and other ODS they were given a grace period of 10 years. That is, they were required to phases out CFC by 2010.
Classification of pollutants
Pollution is usually brought about by the addition of waste products of human activity to the environment. When the waste products are not efficiently assimilated, decomposed, or otherwise removed by the natural, biological and physical processes of the biosphere, adverse effects may result as the pollutants accumulate or get converted into more toxic substances. Thus the materials which cause pollution of environment are called pollutants. Pollutants can be classified in a number of ways. For example:
- On the basis of their forms they exist in the environment after their release. On this basis pollutants can be classified as primary and secondary pollutants.
Primary pollutants are those substances emitted directly from an identifiable source. These pollutants exist as such after being added or released into the environment. Sulphur dioxide, nitrogen oxide are some of the primary pollutants.
Secondary pollutants are the substances which derive from primary pollutants by chemical reactions. For example, primary pollutants such as hydrocarbons and nitrogen oxides, particularly in the environment, react in presence of sunlight to form a group of nitrous compounds like peroxyacetyl nitrate (PAN) as the secondary pollutant.
- From ecosystem point of view, the pollutants may be classified as biodegradable and non-biodegradable pollutants.
Biodegradable pollutants include domestic sewage, heat, etc. The domestic sewage can be readily decomposed by natural processes or by engineered systems (such as municipal sewage treatment plant) which enhance capacity of the nature to decompose and recycle. However, if these pollutants enter the environment in such large quantities that complete degradation of all cannot take pace, and then these become biodegradable pollutants and thus pollute the environment.
Non-biodegradable pollutants include aluminium, iron, mercury, phenolic compounds and DDT etc. which are usually not present in the environment, these either do not degrade or degrade only very slowly or partially and thereby pollute the environment, such pollutants are harmful even in low concentration. These pollutants not only accumulate, but are often biologically magnified as they move in biochemical cycles and along food chains.
Impact of pollutants on human life
Harmful effects of sewage and domestic waste
Sewage is an excellent medium for the growth of pathogenic bacteria, viruses and protozoa. Vibriocholerae found in sewage causes cholera. Salmonella typhosa causes typhoid, while shigella dysenteriae causes bacillary dysentery. Even after sewage treatment, the water contains pathogenic bacteria and the chances if pathogens mingling with river water are critically high.
Domestic sewage which is primarily composed of spent water containing faeces, soapy wastes, food material and paper makes the water extremely anaesthetic. The ova and larvae of many worms are parasitic to humans. They may pass out in urine and faecal matter thereby contaminating the receiving water. Several pathogenic micro-organisms introduced into the water course cause deleterious effects and chronic diseases in man and animals. Sewage containing oxidizable and fermentable matter causes depletion of dissolved oxygen in the receiving water bodies affecting the aquatic flora severely. Oxygen deficiency also leads to production of objectionable odours in water.
Presence of solid matter floating in suspension, colloidal and pseudo-colloidal dispersion sewage creates serious water problems. Suspended matter present in sewage has a tendency to blanket the stream thereby interfering with the spawning of fish and reduction of aquatic biota.
Harmful effects of industrial pollutants
Industrial effluents cause deleterious effects on living organisms and may bring about death or sub lethal pathology of kidneys, liver, lungs, brain and reproductive system. Effluents like methyl mercaptan and pentachlorophenol lower the photosynthetic rate of aquatic communities by hindering sunlight penetration into water column.
Disinfectants which are added in water to control algal growth and bacteria may persist in water bodies and may cause mortality of fish, planktons and diatoms. Mercury poisoning among aquatic organisms has resulted in crippling and often fatal diseases. Industrial effluents consisting of As, Pb and CN etc. cause cellular degeneration in brain which results in coma, stupor and numbness.
Effluents containing acids and alkalis make the water corrosive. Mineral constituents can be responsible for excessive hardness of water which then becomes unsuitable for domestic and industrial purposes.
Some of the wastes contain pathogenic bacteria. For instance the pathogen Anthrax bacilli are present in tannery wastes. Heated effluents discharged into water system may severely alter the aquatic ecosystem by increasing the temperature of the stream. Industrial discharges impart colour, foul odour and turbidity to the receiving waters. They undergo putrefaction to form objectionable tastes.
Effects of thermal pollution
The rise in temperature in aquatic system has a profound effect on organisms as well as on water quality. These detrimental effects are reduction in dissolved oxygen, increase in BOD, early hatching of fish eggs, and direct fish mortality due to failure in respiratory, nervous or essential cell processes, adverse effects on spawning and reproductive mechanism during spring season. It has also led to rapid multiplication of bacteria which in turn become the food of protozoans, undesirable changes in algal population, excessive eutrophication, acceleration in activities of pathogenic organisms which make the pathogen more virulent and fish less resistant. It is also a leading cause of migration in aquatic biota.
Effects of radioactive pollutants
The ill effects due to radioactive pollutants in water are numerous. For example,
- Serious skin cancer, carcinoma, melanoma, breast cancer, leukaemia, DNA breakage and cataracts are rapidly climbing the list of diseases in man.
- Polluted water containing radio-isotopes produce a set of syndromes characterised by nausea, vomiting, diarrhoea, anorexia, epilation, lethargy and general weakness which is known as radiation sickness.
- It destroys biological immune system.
- It causes somatic and genetic disorders, gene mutations and blood abnormalities in higher animals including man.
Environmental policies and programmes
United Nations Conference on Environment and Development (UNCED)
It is also well-known as the Rio Summit, Rio Conference or Earth Summit which was held in Rio de Janeiro in the year 1992.
It addressed several issues, which also included the following:
- Development of task forces for systematic scrutinization and monitoring of production patterns specially that of toxic components including radioactive chemicals.
- To look for alternative sources of energy, this can possibly replace fossil fuels and help in reducing the impact of climate change.
- To popularize the idea of reliance on public transport system, so that there is reduction in vehicular emissions, health problems due to smog and decongestion in cities.
- To deal with the growing scarcity of water.
Convention on Biological Diversity (CBD)
CBD is recognised as the first legally binding convention. According to CBD, conservation of biodiversity is a common concern for humankind and it is a significant part of the development process. The agreement of CBD covers all the important aspects of ecosystem, its species and the genetic resources.
Convention on Biological Diversity has three major goals:
- The conservation of biodiversity
- Sustainable use of the components of biodiversity
- Equitable sharing of benefits and profits which generate from the commercial utilization of genetic resources.
The convention concedes that considerable investments are essential to conserve biological diversity. Furthermore, it suggests that conservation of biodiversity will bring important environmental, economic and social benefits in return.
Nagoya Protocol
The Nagoya Protocol on Access to Genetic Resources and the Fair and Equitable Sharing of Benefits Arising from their Utilization (ABS) to the Convention on Biological Diversity is a supplementary agreement to the Convention on Biological Diversity. It provides a transparent legal framework for the effective implementation of one of the three objectives of the CBD t is the “fair and equitable sharing of benefits arising from the utilization of genetic resources”, thereby contributing to the conservation and sustainable use of biodiversity.
The Nagoya Protocol addresses traditional knowledge associated with genetic resources with provisions on access, benefit-sharing and compliance. It also addresses genetic resources where indigenous and local communities have the established right to grant access to them. Contracting Parties are to take measures to ensure these communities’ prior informed consent, and fair and equitable benefit-sharing, keeping in mind community laws and procedures as well as customary use and exchange.
The Nagoya protocol will create greater legal certainty and transparency for both providers and users of genetic resources by:
- Establishing more predictable conditions for access of genetic resources.
- Helping to ensure benefit-sharing when genetic resources leave the contracting party providing the genetic resources.
By helping to ensure benefit-sharing, the Nagoya Protocol creates incentives to conserve and sustainably use genetic resources, and therefore enhances the contribution of biodiversity to development and human well-being.
Other major environmental international conventions have been:
Nature conservation
- United Nations Conference On Environment And Development (UNCED)
- Ramsar Convention on Wetlands
- Convention on International Trade in Endangered Species of Fauna and Flora (CITES)
- The Wildlife Trade Monitoring Network (TRAFFIC)
- Convention on the Conservation of Migratory Species (CMS)
- Coalition Against Wildlife Trafficking (CAWT)
- International Tropical Timber Organization (ITTC)
- United Nations Forum on Forests (UNFF)
- International Union for Conservation of Nature and Natural Resources (IUCN)
- Global Tiger Forum (GTF)
Hazardous material
- Stockholm Convention
- Basel Convention
- Rotterdam Convention
Land
- United Nations Convention to Combat Desertification (UNCCD)
Marine environment
- International Whaling Commission (IWC)
Atmosphere
- Vienna convention and Montreal Protocol
- United Nations Framework Convention on
- Climate Change (UNFCCC)
- Kyoto Protocol
Indian environmental acts
The environment policies of the Government of India include legislations related to environment. In the Directive Principles of State Policy, Article 48 says “the state shall endeavour to protect and improve the environment and to safeguard the forests and wildlife of the country”; Article 51-A states that “it shall be the duty of every citizen of India to protect and improve the natural environment including forests, lakes, rivers and wildlife and to have compassion for living creatures.”
India is among one of the many participant country of the Convention on Biological Diversity (CBD) treaty. Before the CBD, India had different laws for governing the environment. The Indian Wildlife Protection Act 1972 was made to protect the biodiversity. Later on, multiple amendments were made in this act. Similarly, conservation was the elementary principle of the National Forest Policy (1988). In addition to these policies, the government of India also passed the Environment (Protection) Act 1986 and Foreign Trade (Development and Regulation) Act 1992 for control of biodiversity.
Wildlife Protection Act (1972)
India is the first country in the world to have made provisions for the protection and conservation of environment in its constitution. On 5th June 1972, environment was first discussed as an item of international agenda in the United Nations’ Conference of Human Environment in Stockholm and thereafter 5th June is celebrated all over the world as World Environment Day.
Soon after the Stockholm Conference our country took substantive legislative steps for environmental protection. The Wildlife (Protection) Act was passed in 1972, followed by the Water (Prevention and Control of Pollution) Act 197 4, the Forest (Conservation) Act, 1980, Air (Prevention and Control of Pollution) Act, 1981 and subsequently the Environment (Protection) Act, 1986.
The Wildlife Protection Act, 1972 is a product of process which started long ago in 1887 for the protection of a few wild birds and after addition of wild animals in 1912 and specified plants in 1919 it covered almost all the Wildlife resources which need protection and management. An expert committee, constituted by the Indian Board of Wildlife considers amendments to the Act, as and when necessary.
With the amendment of the Act in 1991, powers of the State Governments have been withdrawn almost totally. Now the State Governments are not empowered to declare any wild animal, a vermin. Further by addition of provision, immunization of livestock within a radius of 5 km from a National Park or sanctuary has been made compulsory.
Environment Protection Act, 1986
As compared to all other previous laws on environment protection, the Environment (Protection) Act, 1986 is a more effective and bold measure to fight the problem of pollution. The Act consists of and deals with more stringent penal provisions. The minimum penalty for contravention or violation of any provision of the law is an imprisonment for a term which may extend to five years or fine up to one lakh rupees, or both. The Act also provides for further penalty if the failure or contravention continues after the date of conviction. It is Rs. 5000/- per day. If the failure of contravention continues beyond the period of one year, then the offender is punished with imprisonment for a term which may extend to seven years.
The Act empowers the Central Government to take all appropriate measures to prevent and control pollution and to establish effective machinery for the purpose of protecting and improving the quality of the environment and protecting controlling and abating environmental pollution.
National Forest Policy (1988)
The principal aim of National Forest Policy, 1988 is to ensure environmental stability and maintenance of ecological balance including atmospheric equilibrium which are vital for sustenance of all life forms, human, animal and plant.
Objectives
- Maintenance of environmental stability through preservation and, where necessary, restoration of the ecological balance that has been adversely disturbed by serous depletion of the forests of the country.
- Conserving the natural heritage of the country by preserving the remaining natural forests with the vast variety of flora and fauna, which represent the remarkable biological diversity and genetic resources of the country.
- Checking soil erosion and denudation in the catchments areas of rivers, lakes, reservoirs in the “interest of soil and water conservation, for mitigating floods and droughts and for the retardation of siltation of reservoirs.
- Checking the extension of sand-dunes in the desert areas of Rajasthan and along the coastal tracts.
- Increasing substantially the forest/tree cover in the country through massive afforestation and social forestry programmes, especially on all denuded, degrade and unproductive lands.
- Meeting the requirements of fuel-wood, fodder, minor forest produce and small timber of the rural and tribal populations. Increasing the productivity of forests to meet essential national needs.
- Encouraging efficient utilisation of forest produce and maximising substitution of wood. Creating a massive people’s movement with the involvement of women, for achieving these objectives and to minimise pressure on existing forests.
The major achievements of National Forest Policy, 1988,
- Increase in the forest and tree cover.
- Involvement of local communities in the protection, conservation and management of forests through Joint Forest Management Programme.
- Meeting the requirement of fuel wood, fodder minor forest produce and small timber of the rural and tribal populations.
- Conservation of Biological Diversity and Genetic Resources of the country through ex-situ and in-situ conservation measures.
- Significant contribution in maintenance of environment and the ecological stability in the country.
National Green Tribunal (NGT)
The Preamble of the act provides for the establishment of a National Green Tribunal for the effective and expeditious disposal of cases relating to environmental protection and conservation of forests and other natural resources, including enforcement of any legal right relating to environment and giving relief and compensation for damages to persons and property and for matters connected therewith or incidental thereto (The National Green Tribunal Act, 2010).
With the establishment of the NGT, India has joined the distinguished league of countries that have a dedicated adjudicatory forum to address environmental disputes. India is third country in the world to full fledged green tribunal followed by New Zealand and Australia. The specialized architecture of the NGT will facilitate fast track resolution of environmental cases and provide a boost to the implementation of many sustainable development measures. NGT is mandated to dispose the cases within six months of their respective appeals.
The Ozone Depleting Substance Rules
The Ozone Depleting Substances (Regulation and Control) Rules, 2000 under the Environment (Protection) Act, in July 2000. These Rules set the deadlines for phasing out of various ODSs, besides regulating production, trade import and export of ODSs and the product containing ODS.
The Ozone Depleting Substances (Regulation and Control) Rule, 2000 were amended in 2001, 2003, 2004 and 2005 to facilitate implementation of ODS phase-out at enterprises in various sectors.
These Rules prohibited the use of CFCs in manufacturing various products beyond 1st January 2003 except in metered dose inhaler and for other medical purposes. Similarly, use of halons was prohibited after 1st January 2001 except for essential use. Other ODSs such as carbon tetrachloride and methylchloroform and CFC for metered dose inhalers could be used up to 1st January 2010.
Further, the use of methyl bromide was allowed up to 1st January 2015. Since HCFCs are used as interim substitute to replace CFC, there are allowed to be in use uptil 1st January 2040.
Summary
To summarize, it can be seen that based on the context in which the concept of environment and environmental degradation is being talked about; there can be numerous ways to define these concepts. The environment consists of living, non-living and the energy components, where the living component shows interplay with the other components to maintain a balance on the ecosystem. The disturbance in this equilibrium may lead to environment degradation. Overpopulation, pollution, deforestation, global warming, unsustainable agricultural and fishing practices, overconsumption and wars are major causes of environmental degradation. Pollution is one of the major forms of environmental degradation along with soil erosion, deforestation, global warming and degradation of ozone layer. Pollutants are present in varied forms in the environment and they can prove to be harmful to humans as well as other animals living on earth. International agencies as well as national governing bodies of many countries across the globe are making efforts to reduce environmental degradation by employing measures and encouraging citizens to adopt eco-friendly ways of living. These steps may be small but may prove to be very useful and fruitful in long run to save the earth from getting degraded.
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- Abiotic components are the inorganic and nonliving parts of the world. The abiotic part consists of soil, water and air components.
- Biotic components include living organisms comprising plants, animals and microbes
- Environment is the sum of all social, economical, biological, physical or chemical factors which constitute the surroundings of man, who is considered as the creator and moulder of his environment.
- Environmental degradation is a phenomenon of deterioration of the environment through depletion of natural resources (air, water and soil), the destruction of ecosystems and the extinction of wildlife.
- Environmental pollution refers to the degradation of quality and quantity of natural resources.
- Global warming means the rise in the mean global temperature to a level which affects the life-forms on the earth surface.
- Pollution is an unfavourable alteration of our environment largely caused due to human activites.
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