Least Developed Countries (LDCs or Fourth World countries) are countries which according to the United Nations exhibit the lowest indicators of socioeconomic development, with the lowest Human Development Index ratings of all countries in the world. A country is classified as a Least Developed Country if it meets three criteria based on:
• low-income (three-year average GNI per capita of less than US $750, which must exceed $900 to leave the list)
• human resource weakness (based on indicators of nutrition, health, education and adult literacy) and
• economic vulnerability (based on instability of agricultural production, instability of exports of goods and services, economic importance of non-traditional activities, merchandise export concentration, and handicap of economic smallness, and the percentage of population displaced by natural disasters)
Countries may "graduate" out of the LDC classification when indicators exceed these criteria. The United Nations Office of the High Representative for the Least Developed Countries, Landlocked Developing Countries and Small Island Developing States coordinates UN support and provides advocacy services for Least Developed Countries.
The classification currently applies to around 49 countries (as of June 14, 2007).
In 2007, the United Nations graduated Cape Verde from the category of Least Developed Countries. This is only the second time it has happened to a country.[1] The first country to graduate from LDC status was Botswana in 1994. Samoa may become the third country to graduate in this manner , with a decision on this issue scheduled for 2008.
Major features of least developed countries are:
Least developed countries generally suffer conditions of extreme poverty, ongoing and widespread conflict (including civil war or ethnic clashes), extensive political corruption, and lack political and social stability. The form of government in such countries is often authoritarian in nature, and may comprise a dictatorship, warlordism, or a kleptocracy. AIDS is a major issue in a lot of these countries. The majority of LDCs are in Sub-Saharan Africa.
Note, however, that the above characteristics generally do not apply to LDCs located in Oceania. Kiribati, Samoa, Tuvalu and Vanuatu are politically stable democracies, and lack any form of civil or ethnic strife. Nor are they strongly affected by AIDS. Although they have small economies, often dependent on monocultures, the population generally does not suffer from extreme poverty, thanks to an enduring subsistence sector in the economy. The Solomon Islands is the only Oceanian LDC currently affected by political instability and ethnic tension. In 2006, the United Nations recommended that Samoa be upgraded from LDC status to that of Developing Country. The Samoan government disagreed, and asked for a review of the recommendation. Samoa retains LDC status, pending a decision scheduled for 2008.
During the last United Nations review in 2003, the UN defined LDCs as countries meeting three criteria, one of which was a three-year average estimate of gross national income (GNI) per capita of less than US $750. Countries with populations over 75 million are excluded.
Wednesday, December 5, 2007
Monday, December 3, 2007
With respect to Water Pollution, Causes and Effects of Pathogenic Organisms
Causes:
These pathogenic organisms are naturally present in water sources. Also these get contaminated in water due human activities such as disposal of kitchen waste, human and animal excrete near or in the water sources.
Effects:
The majority of waterborne diseases arise as a result of the contamination of water used for drinking with human or animal faeces. The pathogens contained in the faeces of a diseased human or animal are distributed within the water body and may be ingested by others, either directly by drinking or by consuming crops irrigated or washed with the same water. In addition to sewage, pathogens that infect humans have been identified in livestock, fowl, wildlife pets and even fish in contaminated water. This highlights the range of mobility that exists for enteric pathogens and explains the level of concern over faecal pollution.
These pathogenic organisms are naturally present in water sources. Also these get contaminated in water due human activities such as disposal of kitchen waste, human and animal excrete near or in the water sources.
Effects:
The majority of waterborne diseases arise as a result of the contamination of water used for drinking with human or animal faeces. The pathogens contained in the faeces of a diseased human or animal are distributed within the water body and may be ingested by others, either directly by drinking or by consuming crops irrigated or washed with the same water. In addition to sewage, pathogens that infect humans have been identified in livestock, fowl, wildlife pets and even fish in contaminated water. This highlights the range of mobility that exists for enteric pathogens and explains the level of concern over faecal pollution.
With respect to Water Pollution, Cause, Effects and Remedial Measures of Calcium
Causes:
Calcium is naturally present in water. It may dissolve from rocks such as limestone, marble, calcite, dolomite, gypsum, fluorite and apatite. Calcium is present in various construction materials, such as cement, brick lime and concrete. It is present in batteries, and is applied in plaster as calcium sulphate. Elementary calcium reacts with water. Calcium compounds are more or less water soluble.
Effects:
Calcium is largely responsible for water hardness, and may negatively influence toxicity of other compounds. Water hardness influences aquatic organisms concerning metal toxicity. When one takes up large amounts of calcium this may negatively influence human health. Metallic calcium corrodes the skin when it comes in contact with skin, eyes and mucous membranes.
Remedial Measures:
Removing calcium ions from water is carried out by water softeners. These are ion exchangers that usually contain Na+ ions, which are released and substituted by Ca2+ ions. Calcium compounds may be applied for wastewater treatment. Drinking water pH and hardness may be altered by means of calcium carbonate and calcium hydroxide.
Calcium is naturally present in water. It may dissolve from rocks such as limestone, marble, calcite, dolomite, gypsum, fluorite and apatite. Calcium is present in various construction materials, such as cement, brick lime and concrete. It is present in batteries, and is applied in plaster as calcium sulphate. Elementary calcium reacts with water. Calcium compounds are more or less water soluble.
Effects:
Calcium is largely responsible for water hardness, and may negatively influence toxicity of other compounds. Water hardness influences aquatic organisms concerning metal toxicity. When one takes up large amounts of calcium this may negatively influence human health. Metallic calcium corrodes the skin when it comes in contact with skin, eyes and mucous membranes.
Remedial Measures:
Removing calcium ions from water is carried out by water softeners. These are ion exchangers that usually contain Na+ ions, which are released and substituted by Ca2+ ions. Calcium compounds may be applied for wastewater treatment. Drinking water pH and hardness may be altered by means of calcium carbonate and calcium hydroxide.
With respect to Water Pollution, Cause and Effects of Fluoride
Cause:
The primary sources of fluoride emissions are the industries that manufacture it or use it in production. Some of the industries that use it in production are aluminum industry, oil drilling and refining, the chemical and plastics industries, agricultural and pesticide chemical manufacturers, dye manufacturers, manufacturers of metal parts.
Other possible emitters of fluoride are metal cleaning operations, glass and enamel manufacturing and glazing, toothpaste, and fluoride enhanced water. It readily mixes with the water.
Effects:
Fluorides are everywhere throughout the environment, but at very low levels that are not believed to be harmful. Small amounts of sodium fluoride help prevent tooth decay, but high levels may harm your health. In children whose teeth are forming, excessive fluoride levels may cause dental fluorosis with visible changes in the teeth. In adults, high fluoride over a long time may lead to skeletal fluorosis with denser bones, joint pain, and limited joint movement. This is rare. High levels of fluorine or hydrogen fluoride gas can cause muscle spasms, harm the lungs and heart and cause death. At low levels they can irritate the eyes, skin and lungs.
The primary sources of fluoride emissions are the industries that manufacture it or use it in production. Some of the industries that use it in production are aluminum industry, oil drilling and refining, the chemical and plastics industries, agricultural and pesticide chemical manufacturers, dye manufacturers, manufacturers of metal parts.
Other possible emitters of fluoride are metal cleaning operations, glass and enamel manufacturing and glazing, toothpaste, and fluoride enhanced water. It readily mixes with the water.
Effects:
Fluorides are everywhere throughout the environment, but at very low levels that are not believed to be harmful. Small amounts of sodium fluoride help prevent tooth decay, but high levels may harm your health. In children whose teeth are forming, excessive fluoride levels may cause dental fluorosis with visible changes in the teeth. In adults, high fluoride over a long time may lead to skeletal fluorosis with denser bones, joint pain, and limited joint movement. This is rare. High levels of fluorine or hydrogen fluoride gas can cause muscle spasms, harm the lungs and heart and cause death. At low levels they can irritate the eyes, skin and lungs.
With respect to Water Pollution, Cause, Effects and Remedial Measures of Arsenic
Cause:
Arsenic ends up in the environment through industrial production of copper, lead and zinc, and through insecticide applications on farmland. Additionally, it is an ingredient of wood preservatives. Arsenic can be found naturally in certain soils. When arsenic comes in contact with groundwater it may end up in water, as well.
Effects:
Arsenic is a metalloid, which basically means that it has the properties of both metal and non-metal. As a compound, arsenic may be toxic. That is why it is commonly applied in rat poison. A long-term uptake of large quantities of drinking water that contains arsenic may cause skin conditions and certain cancers, such as skin cancer and lung cancer.
Remedial Measures:
Arsenic can be removed from water in various ways. Examples of water purification techniques that may be applied are iron and aluminum coagulation, activated alumina adsorption, ion exchange and membrane filtration.
Arsenic ends up in the environment through industrial production of copper, lead and zinc, and through insecticide applications on farmland. Additionally, it is an ingredient of wood preservatives. Arsenic can be found naturally in certain soils. When arsenic comes in contact with groundwater it may end up in water, as well.
Effects:
Arsenic is a metalloid, which basically means that it has the properties of both metal and non-metal. As a compound, arsenic may be toxic. That is why it is commonly applied in rat poison. A long-term uptake of large quantities of drinking water that contains arsenic may cause skin conditions and certain cancers, such as skin cancer and lung cancer.
Remedial Measures:
Arsenic can be removed from water in various ways. Examples of water purification techniques that may be applied are iron and aluminum coagulation, activated alumina adsorption, ion exchange and membrane filtration.
Technology brings changes in society including culture and tradition
Technology is the most contributing factor for the overall development of the whole world. It has always been concerned about modifications making things better. Technology has brought changes to our daily life style from art, music, clothing, eating habits to the way of celebrating festivals. People now use every kind of comfort they wish such as furniture, cloths, entertainment such as T.V, telephone; computer etc. Orthodox in traditional thinking has been replaced by wider outlooks. After the improvement in information technology and transport facility, people can feel and see the culture and traditions of another community far away from them and thus cultural and traditional activities of one place is easily transferred to other place. Also with the advent of newer technologies like more modern and sophisticated music instruments, the tradition ways of playing music and traditional instruments are all most becoming extinct. Similarly availability of modern world’s cooking appliances like microwave ovens, mixer grinders electric stoves are bringing about great changes in cooking styles and the type of food. Technology also played great role in changing women status in the society because women are now getting more job opportunities. It has also reduced superstitious beliefs and has relaxed the rigidity in caste and religion systems.
Transformation of Industrial Age to Information Age
Since the early the 18th century till this day, industrial age has ruled almost every parts of the modern world. It was during the World War II, people felt the need of transformation from industrial age to the information age. The year 1956/57 is marked as the beginning of the globalization of the information evolution. The society structure was changed into brain oriented. During that time America was paving path for a new society, where most of them were working with information rather than producing goods. During the same period Russian launched the Sputnik, which successfully introduced the era of global satellite communications. Hence these two years are taken as the key years of the programming of information age. A largest computer hardware manufacturer, Intel was formed by 1968. The economic growth was remarkable during the period 1948 to 1973. People’s interest in computer was increasing day by day from sixties of 20th century. The information age is still continuing. During this age the majority of service workers are actually engaged with the creation, processing and distribution of information as programmers, teachers, engineers, system analysts, accountants, lawyers, stock brokers, insurance people, scientists etc rather than with the production of goods as in industrial age. Today information system is involved in almost each and every tactical jobs be it in the field of communication, production or business.
Noise Pollution
Noise Pollution
Types
Transport noise
• Rail Traffic
• Road Traffic
• Air traffic
Occupational noise
• All industries
Neighborhoods noise
• Loud speakers
Noise has become a part of our environment. with the progress in industrial growth, the level of noise has been increasing continuously. In the 19th century the development of steam engine, petrol engine and technological machineries in industries resulted in increasingly noisy environment. In the 20th century this has been furthered accelerated by introduction of diesel engine, turbo prop, and jet engine, hi tech machineries, construction side machineries and increased road traffic. Noise is considered to be one of the dimensions of pollution which leads to degradation of environment and also possess health and communication hazards. They are measured in different units giving varying scale and magnitude. The common scientific acoustic unit is decibel (dB)
Impact
Permanent hear loss
Physical and psychological impact
Types
Transport noise
• Rail Traffic
• Road Traffic
• Air traffic
Occupational noise
• All industries
Neighborhoods noise
• Loud speakers
Noise has become a part of our environment. with the progress in industrial growth, the level of noise has been increasing continuously. In the 19th century the development of steam engine, petrol engine and technological machineries in industries resulted in increasingly noisy environment. In the 20th century this has been furthered accelerated by introduction of diesel engine, turbo prop, and jet engine, hi tech machineries, construction side machineries and increased road traffic. Noise is considered to be one of the dimensions of pollution which leads to degradation of environment and also possess health and communication hazards. They are measured in different units giving varying scale and magnitude. The common scientific acoustic unit is decibel (dB)
Impact
Permanent hear loss
Physical and psychological impact
Indoor Air Pollution
Indoor Air Quality (IAQ) deals with the content of interior air that could affect health and comfort of building occupants.
Indoor air pollution poses many challenges to the health professional.
The individual presenting with environmentally associated symptoms is apt to have been exposed to airborne substances originating not outdoors, but indoors. Studies from the United States and Europe show that persons in industrialized nations spend more than 90 percent of their time indoors1. For infants, the elderly, persons with chronic diseases, and most urban residents of any age, the proportion is probably higher. In addition, the concentrations of many pollutants indoors exceed those outdoors. The locations of highest concern are those involving prolonged, continuing exposure - that is, the home, school, and workplace.
The lung is the most common site of injury by airborne pollutants. Acute effects, however, may also include non-respiratory signs and symptoms, which may depend upon toxicological characteristics of the substances and host-related factors.
Cooking and heating with solid fuels on open fires or traditional stoves results in high levels of indoor air pollution. Indoor smoke contains a range of health-damaging pollutants, such as small particles and carbon monoxide
Indoor air pollution poses many challenges to the health professional.
The individual presenting with environmentally associated symptoms is apt to have been exposed to airborne substances originating not outdoors, but indoors. Studies from the United States and Europe show that persons in industrialized nations spend more than 90 percent of their time indoors1. For infants, the elderly, persons with chronic diseases, and most urban residents of any age, the proportion is probably higher. In addition, the concentrations of many pollutants indoors exceed those outdoors. The locations of highest concern are those involving prolonged, continuing exposure - that is, the home, school, and workplace.
The lung is the most common site of injury by airborne pollutants. Acute effects, however, may also include non-respiratory signs and symptoms, which may depend upon toxicological characteristics of the substances and host-related factors.
Cooking and heating with solid fuels on open fires or traditional stoves results in high levels of indoor air pollution. Indoor smoke contains a range of health-damaging pollutants, such as small particles and carbon monoxide
With respect to Water Pollution, Cause and Effects of Nitrate
Cause:
Nitrate (NO3) comes into water supplies through the nitrogen cycle rather than via dissolved minerals. It is one of the major ions in natural waters. Most nitrate that occurs in drinking water is the result of contamination of ground water supplies by septic systems, feed lots, and agricultural fertilizers. Nitrate is reduced to nitrite in the body. The US EPA's MCL for nitrate is 10 mg/l.
Effects:
Nitrates cause methemoglobenemia in infants, a potentially lethal form of anemia that is also called blue baby syndrome.
Nitrate (NO3) comes into water supplies through the nitrogen cycle rather than via dissolved minerals. It is one of the major ions in natural waters. Most nitrate that occurs in drinking water is the result of contamination of ground water supplies by septic systems, feed lots, and agricultural fertilizers. Nitrate is reduced to nitrite in the body. The US EPA's MCL for nitrate is 10 mg/l.
Effects:
Nitrates cause methemoglobenemia in infants, a potentially lethal form of anemia that is also called blue baby syndrome.
With respect to Water Pollution, Cause, Effects and Mitigation measures of Iron
Cause:
Iron can exist in water in one of two forms or both. Treatment depends on the form of iron present. Waters containing "ferrous iron" are clear and colorless when drawn. Exposure to air converts ferrous iron into the the insoluble, reddish brown "ferric iron".
Effects:
Iron in water imparts a disagreeable metallic taste. It combines with the tannin in tea, coffee, and alcoholic beverages to produce an unpleasant gray to black appearance. It causes red stains in toilets, plumbing fixtures, tableware and laundry. As little as 0.3 ppm of iron can cause these problems.
Mitigation Measures:
FERROUS IRON - A water softener can remove up to 5 ppm of ferrous iron depending upon size and the type of softener. Very large water softeners can remove up to 10 ppm of iron.
FERRIC IRON - If the water contains considerable ferric iron as evidenced by a reddish brown color, use a sediment filter ahead of the water softener. The sediment filter will remove a portion of the insoluble ferric iron and the water softener the soluble ferrous iron.
Iron can exist in water in one of two forms or both. Treatment depends on the form of iron present. Waters containing "ferrous iron" are clear and colorless when drawn. Exposure to air converts ferrous iron into the the insoluble, reddish brown "ferric iron".
Effects:
Iron in water imparts a disagreeable metallic taste. It combines with the tannin in tea, coffee, and alcoholic beverages to produce an unpleasant gray to black appearance. It causes red stains in toilets, plumbing fixtures, tableware and laundry. As little as 0.3 ppm of iron can cause these problems.
Mitigation Measures:
FERROUS IRON - A water softener can remove up to 5 ppm of ferrous iron depending upon size and the type of softener. Very large water softeners can remove up to 10 ppm of iron.
FERRIC IRON - If the water contains considerable ferric iron as evidenced by a reddish brown color, use a sediment filter ahead of the water softener. The sediment filter will remove a portion of the insoluble ferric iron and the water softener the soluble ferrous iron.
With respect to Water Pollution, Cause, Effects and Mitigation measures of Oxygen
Causes:
Although oxygen concentrations fluctuate under natural conditions, severe oxygen depletion usually results from human activities. Introducing large quantities of biodegradable organic materials, plant, fish, or animal matter, into surface waters can rapidly consume available oxygen. Leaves, lawn clippings, sewage, manure, milk solids, and other food processing wastes are examples of oxygen-depleting organic materials that enter our surface waters. Oxygen depletion can also result from chemical reactions that do not involve bacteria. Other factors, such as temperature and salinity (saltiness), influence the amount of oxygen dissolved in water.
Effects:
Such depletion of Oxygen from water sources is harmful for all including human, aquatic as well as terrestrial animals. Aquatic animals breathe using oxygen of water. It may cause the death of aquatic life and cause severe health hazards to human beings.
Mitigation Measures:
Efforts should be made for managing waste disposal
Although oxygen concentrations fluctuate under natural conditions, severe oxygen depletion usually results from human activities. Introducing large quantities of biodegradable organic materials, plant, fish, or animal matter, into surface waters can rapidly consume available oxygen. Leaves, lawn clippings, sewage, manure, milk solids, and other food processing wastes are examples of oxygen-depleting organic materials that enter our surface waters. Oxygen depletion can also result from chemical reactions that do not involve bacteria. Other factors, such as temperature and salinity (saltiness), influence the amount of oxygen dissolved in water.
Effects:
Such depletion of Oxygen from water sources is harmful for all including human, aquatic as well as terrestrial animals. Aquatic animals breathe using oxygen of water. It may cause the death of aquatic life and cause severe health hazards to human beings.
Mitigation Measures:
Efforts should be made for managing waste disposal
With respect to Water Pollution, Cause, Effects and Mitigation measures of Pesticides
Causes:
Pesticides used in agriculture get mixed in water sources and act as pollutant. In addition to use of pesticides in agriculture, silvi culture also makes extensive use of pesticides. In some countries, pesticides are even used for the control of forest pests, especially insects, is considered by the industry to be essential. Insecticides are often sprayed by aircraft over very large areas.
Effects:
Pesticides cause various fatal health hazards and degrade the quality of water. Degradation of water quality by pesticide runoff has two principal human health impacts. The first is the consumption of fish and shellfish that are contaminated by pesticides. The second is the direct consumption of pesticide-contaminated water.
Mitigation Measures:
Bans on certain active ingredients should be done. Revised pesticide registration criteria should be made. Training and licensing of individuals that apply pesticides should be done. Reduction of dose and improved scheduling of pesticide application to more effectively meet crop needs and to reduce preventative spraying should be done.
Pesticides used in agriculture get mixed in water sources and act as pollutant. In addition to use of pesticides in agriculture, silvi culture also makes extensive use of pesticides. In some countries, pesticides are even used for the control of forest pests, especially insects, is considered by the industry to be essential. Insecticides are often sprayed by aircraft over very large areas.
Effects:
Pesticides cause various fatal health hazards and degrade the quality of water. Degradation of water quality by pesticide runoff has two principal human health impacts. The first is the consumption of fish and shellfish that are contaminated by pesticides. The second is the direct consumption of pesticide-contaminated water.
Mitigation Measures:
Bans on certain active ingredients should be done. Revised pesticide registration criteria should be made. Training and licensing of individuals that apply pesticides should be done. Reduction of dose and improved scheduling of pesticide application to more effectively meet crop needs and to reduce preventative spraying should be done.
Green house gases and Global warming
Different types of short-wave radiations from space turns to the ling wave radiations after striking earth's surface. Although most part of such long wave radiations goes back to the space, some portion of it may get trapped inside the earth's atmosphere. Gases like water vapor, carbon dioxide, methane provides the trap which after continuous alternative absorption and reflection of those radiations conserves heat as glass in a green house does. It is for this reason such gases are known as greenhouse gases. The major greenhouse gases existing naturally are water vapor followed by carbon dioxide, methane and nitrous oxide. Human made chemicals that act as greenhouse gases include chlorofluorocarbon, hydrochloroflurocarbon and hydroflurocarbon.
Global warming refers to the increase in the average temperature of the Earth's near-surface air and oceans in recent decades and its projected continuation. As the concentration of greenhouse gases in atmosphere increases, more heat energy remains trapped below. When the concentration of those gases exceeds a certain limit , the earth's temperature is pushed towards continual warming thus resulting in the global warming. The predicted effects of global warming on the environment and for human life are numerous and varied. Rising sea levels, glacier retreat, and altered patterns of agriculture are cited as direct consequences, but predictions for secondary and regional effects include extreme weather events, an expansion of tropical diseases, and drastic economic impacts. Among these impacts, those requiring special attention are as follows:-
1) Weather
According to the scientists, the warmed world will be more humid. Since water vapor is a green house gas its increased presence will add to the insulating effect in the earth's surface. Greater humidity will increase rainfall and storms are expected to be more frequent and intense. De to continuous warming regions that receives light winter snows may receive no snow at all in future.
2) Sea Levels
Warming will melt glacier ice raising the sea level. Sea level world wide rose 10-25 cm during 20th century. Sea level rise will complicate many lives near costal areas. Erosion of cliffs and bleaches will increase.
2) Agriculture
Although the warmed earth will produce as much food as it used to but the change in weather of different places directly affects the agricultural systems. Types of plants and crops that used to be grown in a certain place may now grow well in some other parts. Analyzing the new places for different plants and vegetation is a vague job.
3) Animals and Plants
Due to global warming, animals will tend to migrate toward the poles and plants will shift their ranges seeking new habitats to grow. Both animals and plants will find difficult to escape from the consequences of global warming finally struggling for their existence.
4) Human Health
Global warming has a very negative impact on human health. Diseases now found in the tropics will widen their range. Epidemics of diseases like malaria, cholera, dengue fever, encephalitis are seen to spread more easily in hotter days than in winter season.
Efforts to reduce global warming
Various national and international programs for the control the adverse effects of global warming and the global warming itself have been conducted.. People are being made conscious about the impacts of greenhouse gases and their contribution to the global warming. Some of the efforts at international level for the control of global warming are as follows.
In the Earth Summit conducted in 1992 in Rio de Janeiro, 150 countries pledged to confront the problems of greenhouse gases and agreed to meet again to translate these good intentions into a good treaty.
In 1997 in Japan 160 countries drafted an agreement known as Kyoto Protocol. This treaty call for 38 industrialized countries that now release the maximum quantity of green house gases and to cut their emissions to level 5 percent below than that in 1990. More recently, European and Asian nations renewed their commitment to solve the problem as discussed in Kyoto Protocol.. On September 11, 2006 European and Asian leaders met in Helsinki, Finland, at their bi-yearly Asia-Europe Summit (ASEM) to discuss what to do about stemming greenhouse gas (GHG) emissions after the Kyoto Protocol on Climate Change expires in 2012. While stopping short of setting new targets beyond the Kyoto agreement, the leaders did agree to keep reducing GHG emissions after the Kyoto Protocol expires.
Japan GHG Reduction Fund (JGRF) is a carbon fund (scale of about 140 million dollars) that was established in December 2004 by 33 Japanese participating firms. With the funds invested by partners, JGRF implements projects to reduce greenhouse gas emissions in developing countries, etc., and the amount of CO2 emissions reduced by the projects (CO2 credits) is distributed to the partners.
Global warming refers to the increase in the average temperature of the Earth's near-surface air and oceans in recent decades and its projected continuation. As the concentration of greenhouse gases in atmosphere increases, more heat energy remains trapped below. When the concentration of those gases exceeds a certain limit , the earth's temperature is pushed towards continual warming thus resulting in the global warming. The predicted effects of global warming on the environment and for human life are numerous and varied. Rising sea levels, glacier retreat, and altered patterns of agriculture are cited as direct consequences, but predictions for secondary and regional effects include extreme weather events, an expansion of tropical diseases, and drastic economic impacts. Among these impacts, those requiring special attention are as follows:-
1) Weather
According to the scientists, the warmed world will be more humid. Since water vapor is a green house gas its increased presence will add to the insulating effect in the earth's surface. Greater humidity will increase rainfall and storms are expected to be more frequent and intense. De to continuous warming regions that receives light winter snows may receive no snow at all in future.
2) Sea Levels
Warming will melt glacier ice raising the sea level. Sea level world wide rose 10-25 cm during 20th century. Sea level rise will complicate many lives near costal areas. Erosion of cliffs and bleaches will increase.
2) Agriculture
Although the warmed earth will produce as much food as it used to but the change in weather of different places directly affects the agricultural systems. Types of plants and crops that used to be grown in a certain place may now grow well in some other parts. Analyzing the new places for different plants and vegetation is a vague job.
3) Animals and Plants
Due to global warming, animals will tend to migrate toward the poles and plants will shift their ranges seeking new habitats to grow. Both animals and plants will find difficult to escape from the consequences of global warming finally struggling for their existence.
4) Human Health
Global warming has a very negative impact on human health. Diseases now found in the tropics will widen their range. Epidemics of diseases like malaria, cholera, dengue fever, encephalitis are seen to spread more easily in hotter days than in winter season.
Efforts to reduce global warming
Various national and international programs for the control the adverse effects of global warming and the global warming itself have been conducted.. People are being made conscious about the impacts of greenhouse gases and their contribution to the global warming. Some of the efforts at international level for the control of global warming are as follows.
In the Earth Summit conducted in 1992 in Rio de Janeiro, 150 countries pledged to confront the problems of greenhouse gases and agreed to meet again to translate these good intentions into a good treaty.
In 1997 in Japan 160 countries drafted an agreement known as Kyoto Protocol. This treaty call for 38 industrialized countries that now release the maximum quantity of green house gases and to cut their emissions to level 5 percent below than that in 1990. More recently, European and Asian nations renewed their commitment to solve the problem as discussed in Kyoto Protocol.. On September 11, 2006 European and Asian leaders met in Helsinki, Finland, at their bi-yearly Asia-Europe Summit (ASEM) to discuss what to do about stemming greenhouse gas (GHG) emissions after the Kyoto Protocol on Climate Change expires in 2012. While stopping short of setting new targets beyond the Kyoto agreement, the leaders did agree to keep reducing GHG emissions after the Kyoto Protocol expires.
Japan GHG Reduction Fund (JGRF) is a carbon fund (scale of about 140 million dollars) that was established in December 2004 by 33 Japanese participating firms. With the funds invested by partners, JGRF implements projects to reduce greenhouse gas emissions in developing countries, etc., and the amount of CO2 emissions reduced by the projects (CO2 credits) is distributed to the partners.
Intellectual revival of Europe in 13th, 14th and 15th century.
Middle Ages, the period in the history of Europe that lasted from about AD 350 to about 1450.By the end of the Middle Ages, many modern European states had taken shape. The term middle ages was invented by people during the Renaissance, a period of cultural and literary change in the 13, 14 and 15th centuries. During the Renaissance, people thought that their own age and the time of ancient Greece and Rome were advanced, sophisticated, enlightened and civilized. The adjective medieval comes from the Latin words for this term, medium (middle) and aevum (age).
The word medieval is often used today to mean barbaric, ignorant, and backward. It is true that some aspects of the middle Ages horrify many people today the ideas of heretics being burned at the stake, mercenary armies on the rampage, and plagues for which there are no cures are not pleasant ones.
Although the period is often portrayed negatively, the middle ages were a time when the precursor and herald of many important modern institutions were created. Medieval universities are the direct ancestors of modern ones. The liberal arts of the middle ages remain the core of the arts and sciences programs of today’s college. The English Parliament that met in London yesterday can trace its origins to the days of Henry III.
Similarly, modern cities grew out of medieval ones. Although ancient cities had existed before the middle Ages, they had been centers of political and religious life, not centers of commerce. Medieval cities, in contrast, were primarily commercial. They were supported by trade, exchange, production, consumption, and moneymaking. Many of the sorts of businesses that exist today, such as banks and corporations, can map out their ancestry to the middle ages.
Even nationalism began in the middle ages, as was demonstrated by the hundred years’ war and Joan of Arc. The age was the period in which different groups Romans, Franks, and Visigoths intermingle, fought, worked together and changed. Medieval social, economic, and artistic transformation both reflected and provoked creative responses and accommodations. The history of the middle ages (13, 14 and 15th century) is a story of ceaseless borrowing, adaptation and change with the aggrandizement in various pre-requisite of development.
The word medieval is often used today to mean barbaric, ignorant, and backward. It is true that some aspects of the middle Ages horrify many people today the ideas of heretics being burned at the stake, mercenary armies on the rampage, and plagues for which there are no cures are not pleasant ones.
Although the period is often portrayed negatively, the middle ages were a time when the precursor and herald of many important modern institutions were created. Medieval universities are the direct ancestors of modern ones. The liberal arts of the middle ages remain the core of the arts and sciences programs of today’s college. The English Parliament that met in London yesterday can trace its origins to the days of Henry III.
Similarly, modern cities grew out of medieval ones. Although ancient cities had existed before the middle Ages, they had been centers of political and religious life, not centers of commerce. Medieval cities, in contrast, were primarily commercial. They were supported by trade, exchange, production, consumption, and moneymaking. Many of the sorts of businesses that exist today, such as banks and corporations, can map out their ancestry to the middle ages.
Even nationalism began in the middle ages, as was demonstrated by the hundred years’ war and Joan of Arc. The age was the period in which different groups Romans, Franks, and Visigoths intermingle, fought, worked together and changed. Medieval social, economic, and artistic transformation both reflected and provoked creative responses and accommodations. The history of the middle ages (13, 14 and 15th century) is a story of ceaseless borrowing, adaptation and change with the aggrandizement in various pre-requisite of development.
Effect of Technology on Price Control
The world of today is the technical dependent. The economy of the country is determined by the development of technology (in present context digitization) there. Directly as well as indirectly there is a great impact of technology on economics. Technology aids in the ease of work and production. It makes our work load a whole lot easier and speedy.
If it were not for technology, it might take us three times as long to do something that we could do in a third of the time. Technology has contributed in the rapid increment in the productive power of society. The better the technology more will be productions in different fields. This creates competition among producers and businessmen which helps to reduce price of the products. Technology has lent a hand to reduce the labor costs through the process of automation which reduces the price of the goods produced. For instance, this can be seen from the reduced cost of electronic goods, garments etc.
Not only in the reduction of cost of merchandise but also the tasks that used to take longer times and more funds is now shortened and abridged. Without technology and advancements, it would be much harder for the financial system to expand. Thus, technology has rallied round in monetary growth and therefore in scheming cost with each work being accomplished with ease, more rapidly and appropriately.
If it were not for technology, it might take us three times as long to do something that we could do in a third of the time. Technology has contributed in the rapid increment in the productive power of society. The better the technology more will be productions in different fields. This creates competition among producers and businessmen which helps to reduce price of the products. Technology has lent a hand to reduce the labor costs through the process of automation which reduces the price of the goods produced. For instance, this can be seen from the reduced cost of electronic goods, garments etc.
Not only in the reduction of cost of merchandise but also the tasks that used to take longer times and more funds is now shortened and abridged. Without technology and advancements, it would be much harder for the financial system to expand. Thus, technology has rallied round in monetary growth and therefore in scheming cost with each work being accomplished with ease, more rapidly and appropriately.
Eco-System
Ecosystem may be defined as a unit or system that includes the entire organism in a given area interacting with the physical environment so that a flow of energy leads to clearly define tropic structure, biotic diversity and material cycle.
It is the sum of communities and nonliving environment in area where interdependencies on each other exists. An ecosystem consists of various components and it can be recognized with different characteristics. The main characteristics of ecosystem are listed below:
1. The nature of ecosystem (ecosystem as several fundamental characteristics)
2. An ecosystem as structure: living and non living part.
3. An ecosystem as process: energy flow and chemical element cycling.
4. An ecosystem changes over time through a process called succession.
It is the sum of communities and nonliving environment in area where interdependencies on each other exists. An ecosystem consists of various components and it can be recognized with different characteristics. The main characteristics of ecosystem are listed below:
1. The nature of ecosystem (ecosystem as several fundamental characteristics)
2. An ecosystem as structure: living and non living part.
3. An ecosystem as process: energy flow and chemical element cycling.
4. An ecosystem changes over time through a process called succession.
Bio Gas
Biogas typically refers to a (biofuel) gas produced by the anaerobic digestion or fermentation of organic matter including manure, sewage sludge, municipal solid waste, biodegradable waste or any other biodegradable feedstock, under anaerobic conditions. Biogas is comprised primarily of methane and carbon dioxide.
Depending on where it is produced, biogas is also called:
• swamp gas
• marsh gas
• landfill gas
• digester gas
Biogas containing methane is a valuable by-product of anaerobic digestion which can be utilised in the production of renewable energy.Biogas can be used as a vehicle fuel or for generating electricity. It can also be burned directly for cooking, heating, lighting, process heat and absorption refrigeration.
Benefits of Biogas in Nepal
Bio gas can be use in place of Lp gas and other petrolium products.
It helps to utilize the waste materials.
Organic substances will be used for biogas .
Unimployment problem of nation will reduce.
Fertilizer of cattles and other animals as well as human will be utilized .
It may help in peoples income rate.
Government and nongovernment companies are helping us so it is cheaper to install and maintain.
Biogas and anaerobic digestion
Main article: anaerobic digestion
Biogas holder and flare
Biogas production by anaerobic digestion is popular for treating biodegradable waste because valuable fuel can be produced, while destroying disease-causing pathogens and reducing the volume of disposed waste products. It burns more cleanly than coal, and emits less carbon dioxide per unit of energy. The harvesting of biogas is an important part of waste management because methane is a greenhouse gas with a greater global warming potential than carbon dioxide. The carbon in biogas was generally recently extracted from the atmosphere by photosynthetic plants, so releasing it back into the atmosphere adds less total atmospheric carbon than burning fossil fuels.
Recently, developed countries have been making increasing use of biogas generated from both wastewater and landfill sites or produced by mechanical biological treatment systems for municipal waste. High energy prices and increases in subsidies for electricity from renewable sources (such as renewables obligation certificates) and drivers such as the EU Landfill Directive have led to much greater use of biogas sources
Landfill gas
Landfill gas is produced from organic waste disposed of in landfill. The waste is covered and compressed mechanically and by the pressure of higher levels. As conditions become anaerobic the organic waste is broken down and landfill gas is produced. This gas builds up and is slowly released into the atmosphere. This is hazardous for three key reasons:
• Risk of explosion
• Global warming through methane as a greenhouse gas
• Volatile organic compounds (VOCs) as precursor to photochemical smog
Biogas composition
The composition of biogas varies depending upon the origin of the anaerobic digestion process. Landfill gas typically has methane concentrations around 50%. Advanced waste treatment technologies can produce biogas with 55-75%CH4
Typical composition of biogas
Matter %
Methane, CH4 50-75
Carbon dioxide, CO2 25-50
Nitrogen, N2 0-10
Hydrogen, H2 0-1
Hydrogen sulphide, H2S 0-3
Oxygen, O2 0-2
*often 5 % of air is introduced for microbiological desulphurisation
Safety
The methane in biogas forms explosive mixtures in air. The lower explosive limit is 5% methane and the upper explosive limit is 15% methane.
Applications of renewable natural gas in Nepal
In this form the gas can be now used in any application that natural gas is used for. Such applications include distribution via the natural gas grid, electricity production, space heating, water heating and process heating. If compressed, it can replace compressed natural gas for use in vehicles, where it can fuel an internal combustion engine or fuel cells.
Cooking
Gober gas is a biogas generated out of cow dung. In Nepal, gober gas is generated at the countless number of micro plants (an estimated more than 2 million) attached to households. The gober gas plant is basically an airtight circular pit made of concrete with a pipe connection. The manure is directed to the pit (usually directed from the cattle shed). The pit is then filled with a required quantity of water (usually waste water). The gas pipe is connected to the kitchen fire place through control valves. The flammable methane gas generated out of this is practically odorless and smokeless. The residue left after the extraction of the gas is used as biofertiliser. Owing to its simplicity in implementation and use of cheap raw materials in the villages, it is often quoted as one of the most environmentally sound energy source for the rural needs.
Depending on where it is produced, biogas is also called:
• swamp gas
• marsh gas
• landfill gas
• digester gas
Biogas containing methane is a valuable by-product of anaerobic digestion which can be utilised in the production of renewable energy.Biogas can be used as a vehicle fuel or for generating electricity. It can also be burned directly for cooking, heating, lighting, process heat and absorption refrigeration.
Benefits of Biogas in Nepal
Bio gas can be use in place of Lp gas and other petrolium products.
It helps to utilize the waste materials.
Organic substances will be used for biogas .
Unimployment problem of nation will reduce.
Fertilizer of cattles and other animals as well as human will be utilized .
It may help in peoples income rate.
Government and nongovernment companies are helping us so it is cheaper to install and maintain.
Biogas and anaerobic digestion
Main article: anaerobic digestion
Biogas holder and flare
Biogas production by anaerobic digestion is popular for treating biodegradable waste because valuable fuel can be produced, while destroying disease-causing pathogens and reducing the volume of disposed waste products. It burns more cleanly than coal, and emits less carbon dioxide per unit of energy. The harvesting of biogas is an important part of waste management because methane is a greenhouse gas with a greater global warming potential than carbon dioxide. The carbon in biogas was generally recently extracted from the atmosphere by photosynthetic plants, so releasing it back into the atmosphere adds less total atmospheric carbon than burning fossil fuels.
Recently, developed countries have been making increasing use of biogas generated from both wastewater and landfill sites or produced by mechanical biological treatment systems for municipal waste. High energy prices and increases in subsidies for electricity from renewable sources (such as renewables obligation certificates) and drivers such as the EU Landfill Directive have led to much greater use of biogas sources
Landfill gas
Landfill gas is produced from organic waste disposed of in landfill. The waste is covered and compressed mechanically and by the pressure of higher levels. As conditions become anaerobic the organic waste is broken down and landfill gas is produced. This gas builds up and is slowly released into the atmosphere. This is hazardous for three key reasons:
• Risk of explosion
• Global warming through methane as a greenhouse gas
• Volatile organic compounds (VOCs) as precursor to photochemical smog
Biogas composition
The composition of biogas varies depending upon the origin of the anaerobic digestion process. Landfill gas typically has methane concentrations around 50%. Advanced waste treatment technologies can produce biogas with 55-75%CH4
Typical composition of biogas
Matter %
Methane, CH4 50-75
Carbon dioxide, CO2 25-50
Nitrogen, N2 0-10
Hydrogen, H2 0-1
Hydrogen sulphide, H2S 0-3
Oxygen, O2 0-2
*often 5 % of air is introduced for microbiological desulphurisation
Safety
The methane in biogas forms explosive mixtures in air. The lower explosive limit is 5% methane and the upper explosive limit is 15% methane.
Applications of renewable natural gas in Nepal
In this form the gas can be now used in any application that natural gas is used for. Such applications include distribution via the natural gas grid, electricity production, space heating, water heating and process heating. If compressed, it can replace compressed natural gas for use in vehicles, where it can fuel an internal combustion engine or fuel cells.
Cooking
Gober gas is a biogas generated out of cow dung. In Nepal, gober gas is generated at the countless number of micro plants (an estimated more than 2 million) attached to households. The gober gas plant is basically an airtight circular pit made of concrete with a pipe connection. The manure is directed to the pit (usually directed from the cattle shed). The pit is then filled with a required quantity of water (usually waste water). The gas pipe is connected to the kitchen fire place through control valves. The flammable methane gas generated out of this is practically odorless and smokeless. The residue left after the extraction of the gas is used as biofertiliser. Owing to its simplicity in implementation and use of cheap raw materials in the villages, it is often quoted as one of the most environmentally sound energy source for the rural needs.
Acid Rain
ACID RAIN
Definition
Acid rain is rain or any other form of precipitation which is unusually acidic. It has harmful effects on plants, aquatic animals and buildings. Acid rain is mostly caused by human emissions of sulfur and nitrogen compounds which react in the atmosphere to produce acids. In recent years, many governments have introduced laws to reduce these emissions.
The term "acid rain" is commonly used to mean the deposition of acidic components in rain, snow, fog, dew, or dry particles. The more accurate term is "acid precipitation." Distilled water, which contains no carbon dioxide, has a neutral pH of 7. Liquids with a pH less than 7 are acidic, and those with a pH greater than 7 are bases. "Clean" or unpolluted rain has a slightly acidic pH of about 5.0, because carbon dioxide and water in the air react together to form carbonic acid, a weak acid.
H2O (l) + CO2 (g) → H2CO3 (aq)
Carbonic acid then can ionize in water forming low concentrations of hydronium ions:
2H2O (l) + H2CO3 (aq) ⇌ CO32- (aq) + 2H3O+(aq)
The extra acidity in rain comes from the reaction of primary air pollutants, primarily sulfur oxides and nitrogen oxides, with water in the air to form strong acids (like sulfuric and nitric acid). The main sources of these pollutants are vehicles and industrial and power-generating plants
Emissions of chemicals leading to acidification
The most important gas which leads to acidification is sulfur dioxide. Emissions of nitrogen oxides which are oxidized to form nitric acid are of increasing importance due to stricter controls on emissions of sulfur containing compounds. 70 Tg(S) per year in the form of SO2 comes from fossil fuel combustion and industry, 2.8 Tg(S) from wildfires and 7-8 Tg(S) per year from volcanoes.
Natural Phenomena
The principal natural phenomena that contribute acid-producing gases to the atmosphere are emissions from volcanoes and those from biological processes that occur on the land, in wetlands, and in the oceans. The major biological source of sulfur containing compounds is dimethyl sulfide.The effects of acidic deposits have been detected in glacial ice thousands of years old in remote parts of the globe.
Human activity
The coal-fired Gavin power plant in Cheshire, OhioThe principal cause of acid rain is sulphuric and nitrogen compounds from human sources, such as electricity generation, factories and motor vehicles. Coal power plants are one of the most polluting. The gases can be carried hundreds of kilometres in the atmosphere before they are converted to acids and deposited. In the past, factories had short funnels to let out smoke, but this caused many problems; thus, factories now have longer smoke funnels. However, this causes pollutants to be carried farther, causing greater ecological damage.
Chemical processes
Gas phase chemistryIn the gas phase sulfur dioxide is oxidized by reaction with the hydroxyl radical via a intermolecular reaction:
SO2 + OH• → HOSO2•
which is followed by:
HOSO2• + O2 → HO2• + SO3
In the presence of water sulphur trioxide (SO3) is converted rapidly to sulphuric acid:
SO3(g) + H2O(l) → H2SO4(l)
Nitric acid is formed by the reaction of OH with Nitrogen dioxide:
NO2 + OH• → HNO3
Acid deposition
Processes involved in acid deposition (note that only SO2 and NOx play a significant role in acid rain).
Wet deposition
Wet deposition of acids occurs when any form of precipitation (rain, snow, etc) removes acids from the atmosphere and delivers it to the Earth's surface. This can result from the deposition of acids produced in the raindrops (see aqueous phase chemistry above) or by the precipitation removing the acids either in clouds or below clouds. Wet removal of both gases and aerosol are both of importance for wet deposition.
Dry deposition
Acid deposition also occurs via dry deposition in the absence of precipitation. This can be responsible for as much as 20 to 60% of total acid deposition. This occurs when particles and gases stick to the ground, plants or other surfaces.
Definition
Acid rain is rain or any other form of precipitation which is unusually acidic. It has harmful effects on plants, aquatic animals and buildings. Acid rain is mostly caused by human emissions of sulfur and nitrogen compounds which react in the atmosphere to produce acids. In recent years, many governments have introduced laws to reduce these emissions.
The term "acid rain" is commonly used to mean the deposition of acidic components in rain, snow, fog, dew, or dry particles. The more accurate term is "acid precipitation." Distilled water, which contains no carbon dioxide, has a neutral pH of 7. Liquids with a pH less than 7 are acidic, and those with a pH greater than 7 are bases. "Clean" or unpolluted rain has a slightly acidic pH of about 5.0, because carbon dioxide and water in the air react together to form carbonic acid, a weak acid.
H2O (l) + CO2 (g) → H2CO3 (aq)
Carbonic acid then can ionize in water forming low concentrations of hydronium ions:
2H2O (l) + H2CO3 (aq) ⇌ CO32- (aq) + 2H3O+(aq)
The extra acidity in rain comes from the reaction of primary air pollutants, primarily sulfur oxides and nitrogen oxides, with water in the air to form strong acids (like sulfuric and nitric acid). The main sources of these pollutants are vehicles and industrial and power-generating plants
Emissions of chemicals leading to acidification
The most important gas which leads to acidification is sulfur dioxide. Emissions of nitrogen oxides which are oxidized to form nitric acid are of increasing importance due to stricter controls on emissions of sulfur containing compounds. 70 Tg(S) per year in the form of SO2 comes from fossil fuel combustion and industry, 2.8 Tg(S) from wildfires and 7-8 Tg(S) per year from volcanoes.
Natural Phenomena
The principal natural phenomena that contribute acid-producing gases to the atmosphere are emissions from volcanoes and those from biological processes that occur on the land, in wetlands, and in the oceans. The major biological source of sulfur containing compounds is dimethyl sulfide.The effects of acidic deposits have been detected in glacial ice thousands of years old in remote parts of the globe.
Human activity
The coal-fired Gavin power plant in Cheshire, OhioThe principal cause of acid rain is sulphuric and nitrogen compounds from human sources, such as electricity generation, factories and motor vehicles. Coal power plants are one of the most polluting. The gases can be carried hundreds of kilometres in the atmosphere before they are converted to acids and deposited. In the past, factories had short funnels to let out smoke, but this caused many problems; thus, factories now have longer smoke funnels. However, this causes pollutants to be carried farther, causing greater ecological damage.
Chemical processes
Gas phase chemistryIn the gas phase sulfur dioxide is oxidized by reaction with the hydroxyl radical via a intermolecular reaction:
SO2 + OH• → HOSO2•
which is followed by:
HOSO2• + O2 → HO2• + SO3
In the presence of water sulphur trioxide (SO3) is converted rapidly to sulphuric acid:
SO3(g) + H2O(l) → H2SO4(l)
Nitric acid is formed by the reaction of OH with Nitrogen dioxide:
NO2 + OH• → HNO3
Acid deposition
Processes involved in acid deposition (note that only SO2 and NOx play a significant role in acid rain).
Wet deposition
Wet deposition of acids occurs when any form of precipitation (rain, snow, etc) removes acids from the atmosphere and delivers it to the Earth's surface. This can result from the deposition of acids produced in the raindrops (see aqueous phase chemistry above) or by the precipitation removing the acids either in clouds or below clouds. Wet removal of both gases and aerosol are both of importance for wet deposition.
Dry deposition
Acid deposition also occurs via dry deposition in the absence of precipitation. This can be responsible for as much as 20 to 60% of total acid deposition. This occurs when particles and gases stick to the ground, plants or other surfaces.
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