ENVIRONMENTAL CONSEQUENCES OF USING FOSSIL FUELS Fossil fuels are used in large quantities in industries, railways and power plants. Thermal power plants release several tons of polluting gases, ash and unburnt carbon particles everyday into the atmosphere. Power plantsRailwaysIndustries Sources of Energy Environmental Consequences

The products of combustion of coal and hydrocarbon fuels are given below: Sources of Energy Environmental Consequences

Effects of Carbon dioxide — The Greenhouse Effect All fossil fuels on burning produce carbon dioxide gas. The presence of carbon dioxide in our atmosphere is essential for plant life. But, an increase in the concentration of carbon dioxide in the atmosphere leads to an increase in the temperature on the earth. Solar radiations consist of ultraviolet, visible and infrared radiation. Ozone in the upper atmosphere absorbs most of the harmful ultraviolet radiation. The visible and infrared radiation pass through this layer and reach the earth surface. When earth gets heated up, it starts radiating infrared radiation of longer wavelength. Sources of Energy Environmental Consequences

Carbon dioxide is heavier than air. So, it stays near to the earth at lower heights in the atmosphere. This layer of carbon dioxide does not allow the long wavelength infrared radiation to pass through it. As a result, the infrared radiation reflected from the warm earth gets trapped in the lower part of earth’s atmosphere and raises the temperature of the earth’s atmosphere. What are the effects of carbon dioxide — The Greenhouse Effect Sources of Energy Environmental Consequences

Consequences of the Greenhouse Effect Increase in the concentration of carbon dioxide in the air, raises the temperature of the earth’s atmosphere. This change in the earth’s temperature would (i)cause changes in the pattern of crop cultivation. (ii) adversely affect the monsoon rains. (iii)cause excessive melting of polar ice thereby raising the level of water in seas and oceans. This would cause flooding and submerging of many low-lying areas. Sources of Energy Environmental Consequences

Effects of the oxides of sulphur and nitrogen Coal contains a small amount of sulphur. When coal is burnt, it produces sulphur dioxide (SO 2 ) and sulphur trioxide (SO 3 ). Nitrogen present in petroleum-based fuels gets oxidised to give NO and NO 2. Sulphur oxides are also produced as waste gases during the fractional distillation of petroleum. These oxides of nitrogen and sulphur cause respiratory problems. These gases enter into the atmosphere, and then with water (present as moisture in the air) give H 2 SO4 and HNO 3. Sources of Energy Environmental Consequences

These acids are washed down to the earth by rain water. The rain water containing dissolved oxides of nitrogen and sulphur is called acid rain. Acid rain is highly acidic and corrosive. Some of the harmful effects of acid rain are, Effects of the oxides of sulphur and nitrogen (i)Acid rain promotes corrosion of metallic structures. (ii) Acid rain reacts with limestone and marble of the historical monuments. Due to such reactions, marble gets corroded and loses its shine. Sources of Energy Environmental Consequences

(iii) Acid rain also affects plants and aquatic (marine) life, i.e., it destroys plants, fish etc. (iv) Acid rain leads to loss of soil fertility. Effects of the oxides of sulphur and nitrogen Sources of Energy Environmental Consequences

Effects of carbon monoxide (CO) Carbon monoxide is the most dangerous of the air pollutants. Carbon monoxide when inhaled, combines with haemoglobin in the blood to form carboxy hemoglobin. It is due to this reason, that it is not advisable to sleep in a closed room with a coal-fired fire-place (Angithi) inside, on a cold wintry night. Carboxy hemoglobin cannot carry oxygen. This causes a deficiency of oxygen in the tissues resulting in suffocation and even death. Sources of Energy Environmental Consequences

Effects of lead compounds Petrol/diesel used in automobiles contains tetraethyl lead, (C 2 H 5 ) 4 Pb.Tetraethyl lead acts as an anti-knocking agent. Anti-knocking agent such as, tetraethyl lead is added to petrol/diesel to make its combustion smoother. During combustion, tetraethyl lead decomposes to produce lead compounds, which are poisonous. Thus, poisonous lead compounds are present in the exhaust of automobiles. These lead compounds pollute the air, get absorbed in plants and then enter our bodies through food chains. Sources of Energy Environmental Consequences