Global Warming: Its Causes And Effects

Global warming is a potential environmental problem. It can be defined as a steady increase in the global mean temperature which may result in the imbalance of environmental conditions. We know that the vital source of energy in the cosmos is the sun. The sunlight consists of light of different wavelengths such as Ultraviolet rays, visible rays and Infrared rays. Among those different rays, the Infrared radiations are responsible for the heating effect of sunlight. Due to that heating effect, life is possible on the earth. The sunlight manages the optimum temperature in the earth’s atmosphere so that life processes and other physical and chemical activities may continue effectively. However, the entire sunlight is not reached to the earth. Actually, when sunlight reaches the earth’s atmosphere, it is either reflected or absorbed by the clouds, earth’s surface and atmospheric gases. Only 50% of incoming solar radiations or sunlight reach the earth and warm it up for survival of living organisms.

Air which is the mixture of various gases contains some gases such as carbon dioxide, CFCs, ozone, methane, water vapour and nitrous oxide that allow solar radiations to pass through them but they absorb as well as partially reflect back the infrared radiations. Those gases are called Green House Gases (GHGs). GHGs are responsible for keeping the earth warm because they can retain the heat of the sunlight within their molecules. When these molecules of gases absorb heat from sunlight beyond their limit, they emit the heating rays like a red hot piece of iron and increase the temperature of the surroundings. Recently, their concentration has started rising and has resulted in increasing the mean global temperature. This increase in the temperature is termed as the global warming. During the past century, the temperature of the earth has increased by 0.6 °C. It is estimated that the average global temperature may increase by 1.4-5.8 °C by the year 2100. The gradual increase in the temperature of the environment can damage the entire living systems operating on the earth. Clearly, it is the GHGs which are chiefly responsible for the global warming. Hence, it would be better to check the increasing concentration of GHGs in order to sustain life and life processes on the earth.

There are several natural and man-made factors which are responsible for the global warming. Volcanic eruptions and forest fire are some of the important natural causes. But anthropogenic activities like deforestation, rapid urbanisation and industrialisation are more accountable for its intensification to a great extent. At present human population is budding rapidly. It has resulted in increased consumption of fossil fuels like coal and house hold fuels like firewood etc. We are now witnessing the faster technological changes and revolution in agriculture and transport sectors. No doubt, all over the world developments are taking places at the cost of environment. All these, along with several other human activities have been giving out substantial quantity of GHGs and the world is being left for facing the challenges of global warming.

Although one of the important GHGs i.e. Carbon dioxide gas is a comparatively insignificant non-pollutant gas in the atmosphere, its higher concentration is of grim environmental apprehension. As it is the most common GHG, its elimination or alteration is of prime importance. Nature has a mechanism for conversion of carbon dioxide gas into oxygen. Plants play the role of natural transducers here. They utilize carbon dioxides during the process of photosynthesis to make their own food and release oxygen gases as by-products. In this way, they keep up the delicate balance of carbon dioxide in ecosystems. But, deforestation due to the human needs results in the irregular rainfall, frequent floods, soil erosion, ground water reduction and increased drought condition. It also reduces the very utilization of carbon dioxide and augments its amount in the earth’s atmosphere. The more carbon dioxide means the more absorption of sunlight and the more chance of causing global warming.

Unfortunately, several anthropogenic activities are not eco-friendly and they pave the ways for consequences of global warming. Rise in global temperatures causes many climatic changes but most drastic change will be the increase in sea-level. A rise in sea levels is possible because of melting of ice from the poles due to the global warming. Melting even a fraction of the volume of polar ice can result in flooding of many low lying areas around the earth. The rise in global temperatures has already resulted in cracks in the Antarctic ice shelf.

Global warming is, therefore, of great concern and should be taken seriously. Every sphere of life is significantly affected from it. On the one hand, it has shifted the pattern of crop-yields and biodiversity at various levels around the world. On the other hand, it has badly damaged the quality and quantity of freshwater. It also causes natural disasters and climatic changes including storms, hurricanes, earthquakes, floods, droughts and exceptionally warm summers. The summer of 1998 predicted to be the warmest in the century.

The International Panel on Climate Changes (IPCC) predicts a shift in the current agricultural production pattern away from the current production areas to the northern latitudes. Changes in ground water availability, increased occurrence of climate extremes and crop diseases are also predicated. Europe and America have already witnessed these changes considerably. If this process of global warming persists, the continued existence of different floras and fauna including humans will be very distressing. The impact of the global warming process will be felt several sectors such as agriculture, fisheries, forestry and industries etc. This would ultimately affect the economies of any country. The damages caused due to the global warming are equivalent to that of nuclear wars as both have massive irreversible outcomes.

According to the report submitted to the United Nations Environmental Programme (UNEP) in February 2007, greenhouse gases are responsible for cold days, hotter nights, killer heat waves, floods and devastation and droughts. Global warming can alter some of the vital activities of living organisms such as metabolism, behaviours, reproduction and embryonic development. It will eventually lead to the death. Health experts expect a rise in climate related diseases such as heat strokes and spreading of vector borne diseases such as malaria into areas so far unaffected. Others have warned about the outcomes of increased water shortages and increasing pollution.

Global warming forms warm air and it will result in the cooling of upper atmosphere. Ultimately, It will disrupt radio-communications and further warm the troposphere. In other words, it will have effects on the range of species, food production, damage to property, ecosystems loss, primary sector damages, low output in agriculture, defects in fishery and forestry, quality and quantity of water, different means of transports, tourism industries, pollutions, migration of organisms and risk of disasters. It will not be exaggeration to say that Global warming is a real problem and this is the right time to act against.

Man and Environment

Man and environment are interdependent and interrelated. Environment means the conditions that have an effect on the behavior and development of somebody or something. It has two fundamental components i.e. the physical component and the biological component. The physical part of environment comprise of light, temperature, humidity, wind, rainfall, land, water and air or atmospheric gases. Actually it includes the non-living physio-chemical factors of environment. The other component of environment is biological factors which include plants, animals and micro-organisms. In other words, the environment is considered as the physical and biological conditions in which all things exist. It is the basis of survival. It directs the continued existence, growth, development and reproduction of the humans.

Humans and their environment can be considered as a closed system since a cyclic exchange of materials such as Oxygen, Carbon, Nitrogen, Minerals and water between them takes place. In fact, everything that we use is obtained from the environment. We are delimited by our environment from which we derive our requirements. It will not be an exaggeration to say that man obliges environment for his endurance as it supplies energy and resources for him. We depend on it for crucial requisites and hence, we interact with different components or factors of the environment. It affects the distribution, structure, behavior and inter-relationship of man. All basic needs are directly derived from the environment.Water that constitutes the part of physical elements of environment is essential for life. Not only humans but other organisms also have to face different problems of water insufficiency or objectionable loads as floods. A proper regulation of water cycle is required for the proper functioning of life. Soil that provides water, minerals and fossil fuels to man is also another important part of the environment. No doubt, we have been affecting the environment from the very beginning as nomads to the present day civilized forms. The environment satisfies human wants. Are water, air, sunshine, land, soil, forests, wildlife, fishes, minerals and power resources etc. not useful to us? The environment is our sacred and priceless legacy.

With the development of human civilization environment has been dominated by humans. We face several environmental problems today because we ignore our environment for our greed and needs. As soon as we get up in the morning, we start to consume our various environmental resources and add pollutants to it. Our daily activities such as bathing, washing, cooking food, using automobiles etc. gradually harm our environment. It is also true that we cannot stop utilizing those resources but it should also be kept in mind that we care for cleanness and protection of our environment. The limited use of resources is not harmful or worthless. It is the time to think on it. The environment is capable of purifying itself to a certain extent. But the pressure has increase on it. Many anthropogenic activities including urbanization, industrialization and development activities have adverse effects on it. The smoke from vehicles and factories has degraded the quality of air. We, all, are facing the environmental pollutions. We cut down mercilessly several trees which resulted in the loss of biodiversity. Now the rainfall is not regular. Some regions are facing the problem of droughts and some other of floods. The excess use of chemical fertilizers altered the composition, quality and water holding capacity of soil. The protection and conservation of the environment is related to our own protection. It is the moral duty of all humans to take care of the health of our environment. We must manage to retain the purity of air, water and fertility of soil. We must encourage the environmental protection and conservation plans.

Each component of environment is essential whether it is living or non-living. Knowledge regarding the importance of environment should be made the part of school text books. A constant interaction between man and his environment goes on to produce more from the latter and to conserve it longer. Environment is not only complex and dynamic but also mutually reactive. It is not only environment but man also is in danger. Forests check pollution to a great extent. According to Ashoka the king’s duty is not to protect only citizens of the country and to punish the wrong doers. A king’s duty is also to preserve human animal life and forest tree. It was only Ashoka who had ordered that animals should not be killed for food and sports. What does it indicate? We should grow up with a sense of kinship with nature. Biotic components and abiotic factors are components essential for our development.

The seriousness of the problem of environmental degradation is evident from the fact that the Indian constitution has placed the protection of the environment in the class of fundamental duties of the citizens. June 5 of every year is celebrated throughout the world as Environment Day to make people think and act to protect and develop the environment. As our own very existence depends on it, we should keep the environment pure, clean and safe. We should set up many environment clubs, seminars and symposiums with a view to protecting and developing human environment. Clearly, our problems are anthropogenic; therefore, they can be solved by man. Man’s reason and spirit have often solved the seemingly unsolvable problems, and we believe they can do it again. We should not forget that the environment is older than man from the angle of their origin and growth. Man is the last species evolved on the earth. However both grow in close association with each other. It is right that man exists because the environment exists. The struggle of man as regards his existence and survival has been very formidable and the man has to fight tooth and nail in order to come out victorious. The environment has ever supported the man in this respect. But at times there is conflict between both of them. Thus for man environment is the supreme factor to influence his survival. Hence, the two cannot be estranged.

Air Pollution

The World Health Organization defines air pollution or atmospheric pollution as the presence of materials in the air in such concentration which are harmful to man and his environment. Air pollution is one of the most hazardous and common class of environmental pollution. It has an unfavorable effect on all living things. It brings about untimely fatality for flora and fauna. In recent years, the problem of air pollution has become very severe. It rises due to the hunger for riches and ignorance of human. A sign of development seems to be the increasing number of vehicles on Indian roads. But, the key cause of air pollution in the urban India is automobiles which inefficiently burn petroleum and release 80% of air pollutants. On the other hand, deforestation is on an unprecedented scale which has created a greater pressure on the quality of air. The large scale production by industrialization has also resulted in air pollution. Concentration of industries in one area is another major cause of it. One should remember that air pollutants even in small concentration are extremely destructive to life and assets. The combustion of fossil fuels like natural gas, petroleum and coal as well as wood in industries or automobiles or aircrafts or railways or thermal power plants, agricultural burning and domestic uses etc has caused the air pollution. Metallurgical processing creates mineral dust and fumes containing poisonous or toxic substances like fluorides, sulphides, lead, chromium, nickel, beryllium, arsenic, vanadium, cadmium, zinc, mercury etc. As a result, generations to come are likely to suffer from a number of incurable diseases. Its very extreme can even threaten the existence of human races. Chemical industries like asbestos, cosmetics, welding etc, cotton and textiles industry, wheat flour mills, stone crushing and gem grinding industry add to air pollution. It is estimated that 52% of air pollution is caused by carbon dioxide, 18% by sulphur dioxide, 12% by hydrocarbons and 10% by particulates consisting of soot, fly ash, dusts of various types, fur, hair, spores and pollen grains etc, 6% by nitrogen dioxides and 2% by the remaining. Some natural things and process may also cause air pollution to some extent. The natural air pollutants include pollens, spores, marsh gases, volcanic gases and synthesis of harmful chemicals by electric storms, lightning and solar flares.

Generally, air pollutants not only impair oxygen transport that results in giddiness, asphyxia, decreased vision and cardiovascular malfunction but also cause the damages of building, sculptures and painted surfaces etc. A study conducted by the World Bank in 1995 revealed that 40,000 Indians die prematurely due to the polluted air in cities. Yet another study made by the Environmental Protection Agency shows that every year nearly 40,000 children in India are affected by respiratory disorders caused by the growth of carbon dioxide in the atmosphere. Modern environmental biologists feel that the increase in air pollution may cause the reduction in the amount of sunlight energy reaching to the earth’s surface which lowers solar radiation at the earth’s surface and produce a cooling effect on world climates. It could ultimately prompt another ice age. The other scientists believe that the air pollution causes what is called the Green House Effect. It results in the heating of the earth’s surface. It is fueling global warming which has serious consequence for life on this planet. Recently certain ecologists have tried to correlate air pollution with serious and prolonged droughts, heavier rains and floods and more serious hurricanes and tornadoes. The reported threat to the Taj Mahal of Agra from nearby refinery of Maharastra is due to the presence of sulfur dioxides in air. If the air continues to be polluted in this way in urban India, humans will face greater and greater health hazards. Air will not remain breathable and health will suffer.

Chronic diseases like bronchitis, lung cancer and emphysema are caused by air pollution. It is estimated that mortality from lung cancer could be lowered 25% by a 50% reduction in air pollution. Due to air pollution the incidence of respiratory disease in Delhi is about 12 times the national average. Air pollutants also cause a number of other diseases including eye irritation, dizziness, headaches, nasal irritation, coughing and shortness of breath, sore throat, chest pains, increased cold and allergies etc. They also produce offensive odors and give general discomfort anxiety or suffering to people. There are several abiotic and biotic factors that can affect the response of plants to an air pollutant exposure dose. It causes soiling of clothing and curtains.

As air pollution is not visible to the naked eye, it cannot be handled or removed by individual efforts. It requires awareness among all the people to check the air pollution. At first, there should be balanced and planned industrializations in India. Urbanization should be well planned. Pollutants should be destroyed by the use of suitable scientific technique like incineration. A comprehensive programme of tree plantation should be taken in hand. Deforestation should be prohibited. Besides, an intensive research is essential to solve it. Certain other protective measures should also be adopted for effective control of this menace. There should be sustained efforts to find alternatives like solar powered vehicles and appliances to reduce our dependence upon oil engines to run vehicles and generator sets.

To measure and control the magnitude of air pollution in various industrial hubs of India, National Environmental Engineering Research Institute (NEERI) has set Air Monitoring Stations in Mumbai, Kolkata, Delhi, Madras, Hyderabad, Kanpur, Jaipur, Ahmedabad and Nagpur. Delhi is getting special attention on account of its high pollution level. The WHO has classified this city among the ten most polluted cities in the worked. In India, air pollution control legislation envisages the formation of Air Pollution Boards at the central and state levels with powers to issue and revoke licenses to polluting industries, enforce emission standards and frame rules and regulations for the control of air pollution. However, there is a need of legislation to deal with fumes of Petrochemical Units, ash, carbon particles and unpalatable smell and even noises from industrial units. In order to collect information about the nature, sources and extent of air pollution, a national Air Quality Monitoring Programme is conducted by the Central Pollution Control Board (CPCB) with the objectives of identification of areas in need of restoration of air quality and their prioritization, identification of nature and extent of pollution control need and assessment of the effectiveness of pollution control programme.. As vehicular emissions are major pollutants of ambient air quality, vehicular pollution is sought to be controlled.

Government of India’s new auto fuel Policy has laid out a road map to cut down vehicular pollution in urban India. The goal of this policy is to reduce sulphur and aromatics contents in petrol and diesel to 50ppm and 35% respectively. The Bharat stage II (equivalent to Euro II norms) will be applicable to all the automobiles throughout the country from April 1, 2005. Cities like Delhi, Mumbai, Chennai, Bangalore, Hyderabad, Ahmedabad, Pune, Surat and Kanpur. Agra will have to meet EuroII emission norms from April 1, 2005 and Euro IV emission norm from April 1 2020.

Air pollution may be controlled and reduced if industrial plants should be advised to use high chimneys for escape of smokes fumes or heated air. If the pollutants are part of the fuel, we can consider using fuels with lower pollutant content, removing the pollutant from the fuel and during the combustion process. The use of Compressed Natural Gas (CNG) has reduced air pollution to a great extent because CNG burns more efficiently than petrol or diesel. It is cheaper as well as very little of it is left unburnt. It, also, cannot be siphoned off by thieves or adulterated like petrol or diesel. Public awareness regarding air pollution, potential of sewage and many other solid wastes will certainly help in reducing air pollution in town and cities. It should be made mandatory for municipalities to carry out the proper treatment of sewage and other wastes. Many plant species have been evaluated for their scavenging potential against air pollutants. It has been suggested that the efforts should be made for green belt development since it serves as a sink for air pollutants. To remove the particulate matter in the air, it should be filtered before releasing it into the air. Plantation should be done on a large scale. Trees use carbon dioxide and release oxygen and depollute the air. Control equipments likes gravity settling tanks or porous filters and electrostatic precipitators should be installed in factories to minimize the air pollution