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UNIT 5 SOCIAL ISSUES AND ENVIRONMENT Q1) State causes and effects of floods.A1) Floods occur when land that is usually dry is submerged by large amounts of water. Sudden submergence or inundation of land area with water is called a flood.
The occurrence of floods can be due to both natural and human causes. Anthropogenic causes of floods include: Clearing of forests: Lack of vegetation cover to hold the soil together on slopes causes erosion and deposition in river beds making them shallow, flooding occurs when these rivers overflow. Also, bare slopes increase surface runoff and the volume of water flowing into the rivers. Urban development: The clearing of land for the development of residential, commercial, and industrial complexes has rapidly increased built-up areas. These concrete pavements and roads prevent infiltration of rainwater into the ground coupled with lack of vegetation cover to intercept the rainwater results in increased runoff flowing into the rivers resulting in flooding. Improper farming and other land-use practices: The combination of the absence of forest cover on one hand, and inappropriate farming and land-use practices on the other have aggravated the flood devastation. There are hardly any forests left in the catchment area of the rivers. It is a well-known fact that forest areas are characterized by high infiltration capacity. Enhanced greenhouse effect: Various human activities resulting in the increased greenhouse effect and causing global warming are leading to various climate changes such as higher rainfall in a short duration, melting of more ice, etc. All these have led to increased incidences of floods. Natural causes of floods:1. Excessive rainfall: Floods occur when rainwater is unable to seep into the ground quickly enough or rivers overflow their banks because river channels cannot contain excess water. It is common in tropical areas. 2. Storm Surges: It occurs when strong winds raise the waves in the ocean to exceptionally high levels, causing them to crash into the coast and flood the land. It is common in coastal areas with low-lying relief.3. Melting Snow: Melting of snow in spring releases a large amount of water into the rivers, causing them to overflow their banks. It is common in places with a cool temperate climate.4. Global Atmospheric processes: Abnormal weather phenomenon such as El Nino (warming of surface ocean waters at South-eastern part of Pacific Ocean). 5. Earthquakes: Earthquakes can bring about landslides or trigger tsunamis. When landslides occur, loosened soil, rocks, mud debris, etc. may be deposited in rivers causing overflowing of these rivers. Tsunamis triggered by strong undersea earthquakes can flood and devastate coastal settlements. Impact of floods: 1. Loss of life: Floods mostly strike people unprepared, leading to loss of lives in drowning. Along with livestock and other life forms. The impact is higher in flood plain areas that are densely populated.2. Damage to infrastructure and property: Flood causes huge losses to homes, roads, power supply, and other infrastructure.3. Spread of Diseases: After flood water recedes, shallow stagnant water may cover areas over a considerable period. This may result in an outbreak of water-borne diseases. Moreover, homeless flood victims are housed in temporary shelters that are mostly overcrowded and with poor sanitation conditions which may turn the situation worse.4. Loss of natural habitat: Trees, vegetation, and other natural habitats may get destroyed leading to loss of biodiversity. Q2) Describe an Earthquake with effects and mitigation methods.A2) An earthquake (also known as a quake, tremor, or temblor) is the shaking of the surface of the Earth, with the sudden release of energy in the form of seismic waves on the surface of the earth. The point inside the crust where the pressure is released is called the focus. The point on the Earth's surface above the focus is called the epicentre. When an earthquake occurs beneath the sea it causes a tsunami. The study of earthquakes is called seismology and the instrument used to measure seismic waves is called a seismometer or seismograph. The magnitude of an earthquake is measured by the Richter scale and intensity by Mercalli scale.
Causes of earthquake: According to the theory of plate tectonics, Earth is composed of many individual plates that move and interact, constantly changing and reshaping Earth's outer layer. Plates do not always move smoothly against each other and sometimes get stuck. This builds up pressure. When this pressure is eventually released, an earthquake tends to occur. Volcanoes and earthquakes both result from the movement of tectonic plates. Volcanoes, tides can also trigger seismicity. Underground nuclear testing and dams can also cause seismic waves.Effects: 1) Soil Liquefaction: Due to earthquakes granular material (such as sand) temporarily loses its strength and transforms from a solid to a liquid (Soil liquefaction). This causes rigid structures, like buildings and bridges, to tilt or sink into the liquefied deposits.2) Landslides and avalanches: Earthquakes can produce slope instability leading to landslides and avalanches.3) Tsunamis: When earthquakes occur undersea it causes a tsunami. Most destructive tsunamis are caused by earthquakes of magnitude 7.5 or more.4) Floods: These are secondary effects of earthquakes, as they may occur if dams are damaged.5) Fires: Earthquakes can cause fires by damaging electrical power or gas lines.6) Destabilization: It destabilizes the ecological and social structure of a nation. Essential services also got disrupted.7) Loss of life and property: An earthquake may cause injury and loss of life, general property damage, and collapse or destabilization of buildings. The aftermath may bring disease, lack of necessities, mental consequences such as panic attacks and depression to survivors, etc. Management and mitigation methods:Earthquakes cannot be stopped or predicted accurately but certain management techniques could be followed to minimize their effect:1) Construction of buildings that can tolerate earthquakes. This can be done by: a) By keeping weak spots in the building to absorb vibrations.b) To keep pads or floats beneath buildings. c) Wooden house to be preferred in an earthquake-prone area. 2) Soil testing should be done so that the stability of the building is assured. 3) Seismic retrofitting is the modification of existing structures to make them more resistant to seismic activity, ground motion, or soil failure due to earthquakes.4) Preparedness and safe building construction can reduce the extent of damage and loss.5) Establishment of GPS station in the earthquake-prone region to assess future crustal movements.Q3) Explain Landslides.A3) A landslide/landslip is primarily a combination of several geological processes that include earth movements like extensive slope failure, rocks falling, and debris flow under the action of gravity. Landslides occur when gravitational and other types of shear stresses within a slope exceed the shear strength (resistance to shearing) of the materials that form the slope.
Causes Extensive Rainfall: Prolonged and heavy intensity rainfall triggers landslide. If rain duration and pore pressure are high, moderate rainfall can also trigger a landslide. A universal landslide survey held in 2003 revealed that 90% of the landslides that occurred were activated by heavy rainfall.Melting of Snow: In several cold mountain places, during snowmelt, the water produced infiltrates into the earth. These increases pore water pressures, causing the initiation of the landslide process.Rivers: Rivers can damage the slopes, particularly during the floods triggering a landslide. Seismic Shaking and volcanic eruption: They cause slope failure triggering a landslide.Deforestation: Roots of plants hold soil particles firmly thereby avoiding soil erosion. But the removal of vegetation makes rocks prone to landslides.Geology: Type of rock or soil such as coarse particles have low cohesive strength making it vulnerable to a landslide. Developmental activities: Excavation for minerals, tunnels, etc. and road construction can, too, trigger landslide.Effects: Landslides block streams with debris and stones, leading to overflowing. It disrupts vehicular movement, damages vegetation, roads, communication networks, and buildings. It also results in accidents. Overall, it acts as a risk to life. Ex. A massive landslide in 2017 in Himachal Pradesh has killed at least 46 people and injured several others.Management and mitigation methods: 1) Afforestation: It consolidates the slope thus checking slope instability. Degraded areas should be afforested and existing patches should be preserved.2) Wired stone blocks: Stone ridge is strapped with wire mesh to protect against landslides.3) Retaining wall: Construction of concrete retaining walls to prevent slippage from a slope.4) Landslide hazard zonation mapping: Zonation mapping will help in preventing settlements in the hazard-prone area and also developing and continuously updating the inventory of landslide incidences affecting a country.5) Surface drainage: Draining of surface and subsurface rivers to allow smooth flow of water. 6) Landslide Warning Techniques: Sensors have been developed which are used for landslide warning and detection Early warning systems can disseminate information to masses on time, thereby saving many lives. 7) Managing of catchment: Excess water in catchment areas should be stored to reduce the effect of flash floods, this will also recharge the groundwater level in areas prone to landslide in India.8) Public awareness: An aware and vigilant community can reduce the impact of impending landslides.Q4) Explain water conservation, watershed management and rain water harvesting.A4)
Water Conservation: Conserving water has become a prime environmental concern. Clean water is becoming increasingly scarce globally. With deforestation surface runoff increases and the subsoil water table drops as water has no time to seep slowly into the ground once vegetation is cleared. As many areas depend on wells, it has become necessary to go on making deeper and deeper wells. This adds to the cost and further depletes underground stores of water. This could take years to recharge even if the present rate of extraction is reduced which seems hardly possible in most situations. As deforestation and desertification spread due to extensive changes in land use the once perennial rivers are becoming increasingly seasonal. In many areas, the small streams run dry soon after the monsoon as the water table drops further and further below the surface. To this is added serious problems caused by the rapid surface flow of water during the rains, which leads to extensive floods with loss of life and property. When we waste water, we do not realize that it is affecting the lives of all of us in so many different ways. Water has to be equitably and fairly distributed so that household use, agriculture, and industry all get a share of the water. Its overuse and misuse due to various activities that wastewater has led to a serious shortage of potable drinking water. Thus, water conservation is linked closely with overall human well-being.
During the British period, many dams were built across the country to supply water, especially, to growing urban areas. Post-independence, India’s policy on water changed towards building large dams for expanding agriculture to support the green revolution. While this reduced the need to import food material and removed starvation in the country, the country began to see the effects of serious water shortages and problems related to its distribution. The newer forms of irrigated agriculture such as sugarcane and other water-hungry cash crops required enormous quantities of water. Finally, however, such irrigated areas become waterlogged and unproductive. As excess water evaporates rapidly from the surface of heavily irrigated croplands, it pulls up subsoil water along with salts to the surface of the soil. This leads to salinization by which the land becomes unproductive. Reducing the high salinity levels in the soil is extremely expensive and frequently impossible.
With all these ill-effects of the poorly conceived management of water at the national and local level, there is a need to consider a new water policy for the country. Saving water in agriculture: Drip irrigation supplies water to plants near its roots through a system of tubes, thus saving water. Small percolation tanks and rainwater harvesting can provide water for agriculture and domestic use. Rainwater collected from rooftops can be stored or used to effectively recharge subsoil aquifers. Saving water in urban settings: Urban people waste large amounts of water. Leaking taps and pipes are a major source of loss of water. Canals and pipes carrying water from dams to the consumer lead to nearly 50% loss during transfer. Reducing the demand for water by saving it is more appropriate than trying to meet growing demands. Rainwater Harvesting As our world faces serious water shortages, every drop of water we can use efficiently becomes of great value. One method is to manage rainwater in such a way that it is used at the source. If as much water as possible is collected and stored this can be used after the rainy season is over. In many parts of the world especially in very dry areas, this has been traditionally practiced. However, the stored water has to be kept pollution-free and clean so that it can be used as drinking water. Stored water can grow algae and zooplankton (microscopic animals). This can be pathogenic and cause infections. Thus, keeping the water uncontaminated is of great importance.Current technologies of rainwater harvesting require that all roof and terrace water pass down into a covered tank where it can be stored for use after the monsoon. This is most advantageous in arid areas where clean water is very scarce. However, there are practical difficulties such as constructing large storage tanks which are expensive. Another way of using rooftop rainwater harvesting is to collect it so that it percolates into the ground to recharge wells instead of flowing over the ground into rivers. Thus, by recharging groundwater harvested from rooftops, the water table rises and the surrounding wells retain water throughout the year. Watershed Management: Rivers originate in streams that flow down mountains and hill slopes. A group of small streams flows down hillsides to meet larger streams in the valley which forms the tributaries of major rivers. The management of a single unit of land with its water drainage system is called watershed management. It is a technique that has several components. This includes soil and water management and developing vegetative cover. The natural drainage pattern of a watershed unit if managed appropriately can bring about local prosperity by a year-round abundance of water that improves the quality of human life in the area.As it provides water throughout the year, this improves health in the community, as clean water becomes available. Watershed management enhances the growth of crops and even makes it possible to grow more than one crop in a year in dry areas. Watershed management begins by taking control over a degraded site through local participation. People must appreciate the need to improve the availability of water both in quantity and quality for their area. Once this is adequately demonstrated, the community begins to understand the project, people begin to work together in the activities that lead to good watershed management.The first technical step is to take appropriate soil conservation measures. This is done by constructing a series of long trenches and mounds along the contours of the hill to hold the rainwater and allow it to percolate into the ground. This ensures that underground stores of water are fully recharged. This is enhanced by allowing grasses and shrubs to grow and by planting trees (mainly local species) that hold the soil and prevents it from being washed away in the monsoon. Local grass cover can however only increase if free grazing of domestic animals is prevented by stall feeding.The next measure is to make ‘Nala’ plugs in the streams so that the water is held in the stream and does not rush down the hillside. In selected sites, several small check dams are built which together hold back larger amounts of water. All these measures constitute sound watershed management. It improves the water table and keeps the streams and Nalas flowing throughout the year. Q5) Describe the need for Environmental ethics.A5) Environmental ethics deals with issues related to the rights of individuals that are fundamental to life and well-being. This concerns not only the needs of each person today but also those who will come after us. It also deals with the rights of other living creatures that inhabit our earth. Resource consumption patterns and the need for their equitable utilization: Environmental ethics deals with issues that are related to how we utilize and distribute resources. The just distribution of resources has global, national, and local concerns that we need to address. There are rich and poor nations. There are rich and poor communities in every country. And there are rich and poor families. In this era of modern economic development, the disparity between the haves and have-nots is widening. Our human environments in the urban, rural, and wilderness sectors, use natural resources that shift from the wilderness (forests, grasslands, wetlands, etc.) to the rural sector, and from there to the urban sector. Wealth also shifts in the same direction. This unequal distribution of wealth and access to land and its resources is a serious environmental concern. An equitable sharing of resources forms the basis of sustainable development for urban, rural, and wilderness dwelling communities. As the political power base is in the urban centers, this itself leads to inequalities and a subsequent loss of sustainability in resource management in the rural and even more so for forest-dwelling peopleA report emphasizing India’s environmental problems that were caused by the excessive consumption patterns of the rich that left the poor poorer was published in1985. It brought forth a set of 8 propositions that are of great relevance to the ethical issues that are related to environmental concerns. These include: 1. Environmental destruction is largely caused by the consumption of the rich. 2. The worst sufferers of environmental destruction are the poor. 3. Even where nature is being ‘recreated’, as in afforestation, it is being transformed away from the needs of the poor and towards those of the rich. 4. Even among the poor, the worst sufferers are the marginalized cultures and occupations, and most of all, women. 5. There cannot be proper economic and social development without a holistic understanding of society and nature. 6. If we care for the poor, we cannot allow the Gross Nature Product to be destroyed any further. Conserving and recreating nature has become our highest priority. 7. Gross Nature Product will be enhanced only if we can arrest and reverse the growing alienation between the people and the common property resources. In this, we will have to learn a lot from our traditional cultures. 8. It is inadequate to talk only of sustainable rural development, as the World Conservation Strategy does. We cannot save the rural environment or rural people dependent on it unless we can bring about sustainable urban development.Most sections of society do not feel the direct effects of degradation of the environment till it is too late. Those who suffer most are the poor, especially rural women, and tribal people who are dependent on forests. Traditional fishermen who are dependent on streams and rivers, and coastal people who fish and catch crustacea, are seriously affected by the degradation of aquatic ecosystems. Fuelwood gatherers from different types of forests and pastoralists who are dependent on common grazing lands suffer when their resources are depleted. Several marginalized sectors of society are most affected by deforestation, or the loss of grassland tracts, or the deterioration of perennial water sources. All these effects can be linked to unsustainable increasing pressures on land and natural resourcesWith the rapidly changing rural scenario, the development that is thrust on unsuspecting rural communities needs to be addressed through locale-specific environment awareness programs designed specifically for rural school children and adults. This must also use their local traditional knowledge systems as a base on which modern concepts can be built, rather than by fostering concepts that are completely alien to their knowledge systems.Equity – Disparity in the Northern and Southern countries Environmental ethics are concerned with, who owns resources and how they are distributed. This can be looked upon at different levels. At the global level, it deals with the great North-South divide between the rich industrialized nations of North America and Europe, as against the needs of developing countries of the South such as in South and Southeast Asia and South America. People living in economically advanced nations use greater amounts of resources and energy per individual and also waste more resources. This is at the cost of poor people who are resource dependant and live-in developing nations.The economically advanced West has exploited their natural resources to such an extent that they have exhausted them nearly everywhere. They now buy their resources from resource-rich but economically deprived nations at a low cost. This depletes the developing nations of natural resources on which their poor depend for their livelihood. Changing this unfair economic practice to a more just and fair way of managing trade would require new thinking on the part of people who live in the super-rich countries. Urban-rural equity issues The common property of rural communities has increasingly been used to supply the needs of the urban sector. The land itself that was once held as a common property resource of villages is being taken over by the urban and industrial sectors as it expands. The rural sector not only supplies food but also a part of the energy needs (mainly fuelwood) to most towns and cities in India, at a pittance. As a result, the commons of the rural sector are being depleted of their resources. Thus while the cities get richer, the rural sector, especially the landless, gets poorer. The urban rich must appreciate where their resources are derived from and be willing to pay a fair price for using them. The need for Gender Equity All over India, especially in the rural sector, women work on whole longer hours than men. The life of a woman is enmeshed in an inextricable cycle of poverty. In attempting to eke out a living from their environment, they must constantly collect fuelwood for their homes and sell it to nearby urban areas. They laboriously collect fodder for their cattle. They have to trudge several kilometres to reach a reasonably clean water source. And finally, must cook meals in a smoky unhealthy atmosphere on crop waste or other inefficient sources of energy. All this can take 10 to 12 hours a day of very hard work, every day of the year. There is thus the question of who should control the environmental resources of a rural community. Unfortunately, it is the men who play a decisive role in managing the village commons and its resources whereas it should be the local women whose lives are deeply linked with the utilization and conservation patterns of natural resources, who should be decision-makers at the local level. Unfortunately, women have not been given an equal opportunity to develop and better their lot. This begins with the lack of attention given to girls whose education is always given less attention than the boys in the family. The great divide between women and men is most apparent in communities that live near forests and have by tradition made the woman play a greater role than men in the collection of natural resources. Women fetch water, collect fuelwood, fruit, medicinal products, etc. day in and day out, while the men work only sporadically in the fields. This disparity in the lives of women and men has also led to lower access to education and health care for girl children. This has deep implications for the rate of utilization of natural resources and their conservation. Rural women who are intimately connected to resources appreciate the value of conserving natural resources more deeply than men. Thus, several environmental movements such as Chipko have been more strongly supported by local women folk rather than men.Preserving resources for future generations: Can we use up all the resources of the world, leaving nothing for our future generations? This ethical issue must be considered when we use resources unsustainably. If we overuse and misuse resources and energy from fossil fuels, our future generations would find survival much more difficult. A critical concern is to preserve species and natural undisturbed ecosystems that are linked with bio resources, which must be protected for the use of future generations. Our generation does not own the world’s resources to do whatever we please with them. Just as our ancestors have left resources for us, we must leave them behind for our future generations. These unborn people have a right to these resources. We only hold the world as trustees so that future generations can also survive.Our current development strategies have led to environmental resources being overused and misused by our present generation, without a thought for the needs of future unborn generations. We need to appreciate that the next generation and those that will come later also have a right to the earth’s natural resources. As they are not here today to exercise their rights, it is our generation’s responsibility to appreciate the needs of future generations. We have no right to destroy their claim to the use of the earth’s resources just because of the accident of being born before them. Development strategies have not looked at the sustainable levels at which we can use resources so that the rights of future generations are protected. The rights of animals: Cruelty to an animal is no different ethically from cruelty to another human being. Every plant and animal has a right to life as a part of our earth’s community of living things. While nature by itself has natural prey-predator relationships, left to itself, nature maintains a balance in each ecosystem. While evolution has developed a system whereby species become extinct and new ones evolve to fill the world’s ecosystems with new plant and animal species, it is man alone that has been responsible for the recent rapid decline in the number of species on earth. Much more important man is now reducing the abundance levels of so many species that soon we will in all probability create a major extinction spasm on earth that will seriously endanger the existence of mankind. Thus, endangering the existence of wild plants and animals and bringing them close to the brink of extinction is not only unfair to a species but also to the future generation of people who may find them of great use. Quite apart from the use of these species, there is a strong ethical basis for the rights of animals and plants to exist on earth. Every individual, human or animal, that is living has feelings and emotions. Cruelty to animals is a crime that must be regarded seriously and action must be taken against offenders. Animals have a right to a dignified existence, and their life, well-being, and liberty must be respected. While dominating the animal world due to his superior intelligence, man cannot remain unfeeling to the right to life and well-being of other species. There is a growing awareness of animal rights in our country and cruelty to animals is being increasingly regarded as a criminal offense. Q6) Describe Climate change in brief.A6) The average temperature in many regions has been increasing in recent decades. The global average surface temperature has increased by 0.6° + 0.2° C over the last century. Many countries have experienced increases in rainfall, particularly in the countries situated in the mid to high latitudes. In some regions, such as parts of Asia and Africa, the frequency and intensity of droughts have been observed to increase in recent decades. All these are signs that the earth is sick. Its climate is changing, making it more difficult for mankind to survive. The earth is losing its ability to balance itself due to the imbalances created by human activities. Projections of future climate change are derived from a series of experiments made by computer-based global climate models. These are worked out on estimates of aspects such as future population growth and energy use. Climatologists of the Intergovernmental Panel on Climate Change (IPCC) have reviewed the results of several experiments to estimate changes in climate in this century. These studies have shown that soon, the global mean surface temperature will rise by 1.4° to 5.8°C. Warming will be greatest over land areas, and at high latitudes. The projected rate of warming is greater than has occurred in the last 10,000 years. The frequency of weather extremes is likely to increase leading to floods or drought. Human societies will be seriously affected by extremes of climate such as droughts and floods. A changing climate would bring about changes in the frequency and/or intensity of these extremes. This is a major concern for human health. To a large extent, public health depends on safe drinking water, sufficient food, secure shelter, and good social conditions. All these factors are affected by climate change. Freshwater supplies may be seriously affected, reducing the availability of clean water for drinking and washing during drought as well as floods. Water can be contaminated and sewage systems may be damaged. The risk of spread of infectious diseases such as diarrhoeal diseases will increase. Food production will be seriously reduced in vulnerable regions directly and also indirectly through an increase in pests and plant or animal diseases. The local reduction in food production would lead to starvation and malnutrition with long-term health consequences, especially for children. Food and water shortages may lead to conflicts in vulnerable regions, with serious implications for public health. Climate change-related impacts on human health could lead to the displacement of a large number of people, creating environmental refugees and lead to further health issues. Climate changes may affect the distribution of vector species (ex. mosquitoes) which in turn will increase the spread of diseases, such as malaria and filariasis, to new areas that lack a strong public health infrastructure. Strategies aimed at reducing potential health impacts of anticipated climate changes should include monitoring of infectious diseases and disease vectors to detect early changes in the incidence of diseases and the geographical distribution of vectors; environmental management measures to reduce risk; disaster preparedness for floods or droughts; and their health-related consequences. It will be necessary to create early warning systems and education for epidemic preparedness. Improved water and air pollution control will become increasingly essential for human health. Public education will have to be directed at changes in personal behavior. Training of researchers and health professionals must become an essential part of the world becoming more responsible towards the expected outcome of Global Climate Change (GCC). Q7) What is Global Warming?A7) About 75% of the solar energy reaching the Earth is absorbed on the earth’s surface which increases its temperature. The rest of the heat radiates back to the atmosphere. Some of the heat is trapped by greenhouse gases, mostly carbon dioxide. As carbon dioxide is released by various human activities, it is rapidly increasing. This is causing global warming. The average surface temperature is about 15°C. This is about 33°C higher than it would be in the absence of the greenhouse effect. Without such gases, most of the Earth’s surface would be frozen with a mean air temperature of -18°C. Human activities during the last few decades of industrialization and population growth have polluted the atmosphere to the extent that it has begun to seriously affect the climate. Carbon dioxide in the atmosphere has increased by 31% since pre-industrial times, causing more heat to be trapped in the lower atmosphere. There is evidence to show that carbon levels are still increasing. Many countries have signed a convention to reduce greenhouse gases under the United Nations Convention on Climate Change. Current international agreements are however not still effective to prevent the significant changes in climate and a rise in sea levels. Q8) What are effects of Acid rain?A8) Acid rain is known to cause widespread environmental damage. 1. Acid rain dissolves and washes away nutrients in the soil which are needed by plants. It can also dissolve naturally occurring toxic substances like aluminum and mercury, freeing them to pollute water or poison plants. 2. Acid rain indirectly affects plants by removing nutrients from the soil in which they grow. It affects trees more directly by creating holes in the waxy coating of leaves, causing brown dead spots that affect the plant’s photosynthesis. Such trees are also more vulnerable to insect infestations, drought, and cold. Spruce and fir forests at higher elevations seem to be most at risk. Farm crops are less affected by acid rain than forests. 3. Acid rain that falls or flows as groundwater to reach rivers, lakes, and wetlands, causes the water in them to become acidic. This affects plant and animal life in aquatic ecosystems. 4. Acid rain also has far-reaching effects on wildlife. By adversely affecting one species, the entire food chain is disrupted, ultimately endangering the entire ecosystem. Different aquatic species can tolerate different levels of acidity. For instance, clams and mayflies have high mortality when the water has a pH of 6.0, while frogs can tolerate more acidic water, although, with the decline in the supply of mayflies, frog populations may also decline. Land animals that are dependent on aquatic organisms are also affected. 5. Acid rain and dry acid deposition damages buildings, automobiles, and other structures made of stone or metal. The acid corrodes the materials causing extensive damage and ruins historic buildings. For instance, the Parthenon in Greece and the Taj Mahal in India have been affected by acid rain.6. Although surface water polluted by acid rain does not directly harm people, the toxic substances leached from soil can pollute the water supply. Fish caught in these waters may be harmful for human consumption. Acid, along with other chemicals in the air, produces urban smog, which causes respiratory problems.Q9) Describe Ozone layer depletion.A9) Ozone is a highly poisonous gas with a strong odor. It is a form of oxygen that has three atoms in each molecule. It is considered a pollutant at ground level and constitutes a health hazard by causing respiratory ailments like asthma and bronchitis. It also causes harm to vegetation and leads to a deterioration of certain materials like plastic and rubber. Ozone in the upper atmosphere, however, is vital to all life as it protects the earth from the sun’s harmful ultraviolet radiation. The ozone layer in the upper atmosphere absorbs the sun’s ultraviolet radiation, preventing it from reaching the earth’s surface. This layer in the atmosphere protects life on earth from the dangerous UV radiation from the sun. In the 1970s, scientists discovered that chemicals called chlorofluorocarbons or CFCs, which were used as refrigerants and aerosol spray propellants, posed a threat to the ozone layer. The CFC molecules are virtually indestructible until they reach the stratosphere, where UV radiation breaks them down to release chlorine atoms. The chlorine atoms react with ozone molecules which break down into oxygen molecules, which do not absorb UV radiations. Since the early 1980s, scientists detected a thinning of the ozone layer in the atmosphere above Antarctica. This phenomenon is now being detected in other places as well including Australia. Although the use of CFCs has been reduced and now banned in most countries, other chemicals and industrial compounds such as bromine, halocarbons, and nitrous oxides from fertilizers may also attack the ozone layer. The destruction of the ozone layer is seen to cause increased cases of skin cancer and cataracts. It also causes damage to certain crops and plankton, thus affecting nature's food chains and food webs. This in turn causes an increase in carbon dioxide due to the decrease in vegetation. With the signing of the Montreal Protocol in 1987, a treaty for the protection of the ozone layer, the use of CFCs was to be banned by the year 2000. After 2000, the ozone layer is expected to recover slowly for about 50 years. Q10) What do you mean by Wasteland reclaimation?A10) Loss of vegetation cover leads to loss of soil through erosion, which ultimately creates wastelands. This is one of the pressing problems of the country. Loss of soil has already ruined a large amount of cultivable land in our country. If it remains unchecked, it will affect the remaining land. Unless we adequately safeguard our ‘good’ lands, we may eventually face a serious shortage of food grains, vegetables, fruit, fodder, and fuelwood. Hence, conservation of soil, protecting the existing cultivable land, and reclaiming the already depleted wastelands figures prominently among the priority tasks of planning for the future. Some of the wasteland reclamation programs have been unsuccessful because after some time the land reverts to its original poor condition due to mismanagement and unscientific ways in which the reclamation has been carried out. In choosing wasteland reclamation methods attention must be paid to the cost factor. This has to be taken into account before deciding on a particular method for the reclamation of wastelands. A proper study of environmental aspects and human impacts that are responsible for the development of wastelands have to be looked into. Wasteland can be classified into three forms: (1) Easily reclaimable, (2) Reclaimable with some difficulty, (3) Reclaimable with extreme difficulty. Easily reclaimable wastelands can be used for agricultural purposes. Those which can be reclaimed with some difficulty can be utilized for agro-forestry. Wastelands that are reclaimed with extreme difficulty can be used for forestry or to recreate natural ecosystems. Agriculture: Wasteland can be reclaimed for agriculture by reducing the salt content which can be done by leaching and flushing. Gypsum, urea, potash, and compost are added before planting crops in such areas. Agro-forestry: This involves putting land to multiple uses. Its main purpose is to have trees and crops inter-and /or underplanted to form an integrated system of biological production within a certain area. Thus, agroforestry implies the integration of trees with crops or livestock management simultaneously.Forestry: Attempts to grow trees in highly non-alkaline saline soils have been largely unsuccessful. Field experiments have shown that species like Eucalyptus, Prosopis, and Acacia Nilotica could not be grown in highly alkaline soil. Studies have shown that if tree seedlings are planted with a mixture of the original soil, Gypsum, and manure, better growth can be achieved. It is however important to use indigenous species of trees so that the program recreates the local ecosystem with all its species. Components of wasteland reclamation: The first major task is the identification of the problem at the micro-level. For this, it is necessary to have District, Village, and plot-level surveys of the wasteland. A profile of the maps indicating the detailed distribution and information on the wasteland is essential. With the help of local government institutions such as the village Panchayats, along with Block Development Officers, Revenue Department functionaries, a plan based on the community needs must be produced. This must be done through a participatory exercise that involves all the different stakeholders in the community. A think-tank of administrators, ecologists, and local NGOs must also be involved in the process. The next step is to identify the factors that are responsible for the formation of wastelands. Based on these factors the wasteland is classified into: marginally, partially, or severely deteriorated lands. Locale specific strategies for reclaiming the wasteland must be worked out. Government officials along with the local NGOs must assist the farmers by demonstrating improved methods of cultivation, arranging for loans for the small, marginal, and landless farmers and the people from the weaker sections of the society. Involving local women has proved to be of great value. Another essential component of the program is to organize publicity campaigns, integrated with training farmers and frontline Government and Forest Department staff on the various aspects of wasteland utilization. Q11) Explain Consumerism.A11) It is seen that today’s consumption patterns are depleting natural resources at a rapid rate and widening the inequalities in consumption in different societies. Consumerism causes wasteful use of energy and material far beyond that needed for everyday living at a comfortable level. Money is not the only way to measure the cost of an item that we use. When one adds up all the raw material and energy that goes into the manufacture of goods or the services provided by nature that one uses during a day’s activities, the toll on the environment is large. When this cost is multiplied over a lifespan, the amount is staggering. If one considered the overutilization in each family, city, or country, the impacts are incredibly high. Consumerism is related to the constant purchasing of new goods, with little attention to their true need, durability, product origin, or the environmental consequences of their manufacture and disposal. Consumerism is driven by huge sums spent on advertising designed to create both a desire to follow trends and a personal feeling of satisfaction based on acquisition. Materialism is one of the results of consumerism. Consumerism interferes with the sustainable use of resources in society by replacing the normal common-sense desire for an adequate supply of life’s necessities, with an insatiable quest for things that are purchased by larger and larger incomes to buy them. There is little regard for the true utility of what is bought. An intended consequence of this strategy which is promoted by those who profit from consumerism is to accelerate the discarding of the old, either because of lack of durability or a change in fashion.
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