After reading this article you will learn about the impact of transport and power on environment.
Impact of Transport on Environment:
Transport especially road transport has a strong environmental impact and a variety of measures can be taken to reduce environmental damage by road transport. No doubt, transport is essential for economic and human development. The environmental effects of transport differ by mode. Non-motorized transport generally does not harm the environment.
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The environmental effect of rail transport comes from the use of coal and the use of diesel oil in diesel locomotives. Inland water way transport is fuel-efficient and has relatively little environmental impact. In oceans, major damages occur from tanker accidents. Shipping can pollute coastal waters. Aviation causes local air and noise pollution at ground level and gaseous emissions that can deplete the ozone layer.
The transport sector consumes a large part of the petroleum used in many countries. Air pollution caused by emissions from motorized vehicles is a serious environmental issue.
The main emissions from motorized road vehicles equipped with spark ignition gasoline engines include carbon monoxide (CO), oxides of nitrogen, unburned hydrocarbon in the exhaust, suspended particulate matter (SPM) and lead aerosols and certain other hydrocarbon emissions.
The most significant emissions from diesel – run vehicles include SPM, oxides of nitrogen, sulphur dioxide, carbon monoxide and hydrocarbons. Both diesel and gasoline – fuelled vehicles, particularly the two – stroke gasoline engines, used in two wheelers and three – wheelers emit CO2.
Hydrocarbon emissions from these vehicles are quite high because a significant part of the air – fuel mixture escapes un-burnt into the exhaust, so about 20-25% of the fuel used is lost in the way. Particulates from two stroke engines are also high.
Hydrocarbon emissions from one, two – stroke motorcycles may exceed those from three uncontrolled passenger cars, and particulate emissions can exceed those from a heavy duty diesel truck.
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This is a cause for serious concern in India where two-wheelers and three – wheelers now constitute nearly 80% of the registered vehicles many of these use two stroke engines are account for 45% of total gasoline consumption. Air pollution in urban areas is associated with higher incidence of respiratory ailments such as bronchitis and asthma, especially in children.
Recent technological advances have made it possible to reduce air pollution caused by vehicles. These advances relate to vehicular technology improvements, fuel options for controlling emissions, and alternative technologies.
For diesel – powered vehicles emissions can be greatly reduced through engine design changes, improved fuel injection systems, turbocharging, and charge air cooling. These changes also improve fuel economy significantly but increase engine costs. Use of low-sulphur fuel and an oxidation catalytic converter can reduce particulate matter and hydrocarbon emissions.
Gasoline and diesel can be substituted by cleaner burning fuels such as compressed natural gas, liquefied petroleum gas, methanol, ethanol, gasohol, and biodiesel. Hydrogen gas which can be generated by illuminating algae with sunlight is a clean burning fuel.
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Fuel cell technology coverts chemical energy into electricity and has potential application in cars. Electric cars have been made, that are less complex than gasoline vehicles, produce no emissions, and are clean. The limitations of these cars include the smaller running range and repeated battery – charging requirements. Hybrid vehicles (an electric vehicle) have been developed but are expensive.
Impact of Power on Environment:
Electricity constitutes one of the key infrastructural inputs for socio-economic development. Per capita electricity consumption in India has increased from a mere 15.6 kwh in 1950 to the current level of 360 kwh. Despite this per capita electricity consumption in the country is one-sixth the world average and one twentieth that in high counters. There are also huge inter-regional and inter-state disparities within the country.
With economic growth and social development bridging these disparities, coupled with the pressure of rising population, power consumption in the country will rise several folds in the form of water and air pollution, soil erosion, deforestation, loss of biological diversity, etc.
The three conventional forms of power are:
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(a) Thermal – Power:
Coal – based thermal power constitutes 62% of total power generation, accounting for almost 75% of total coal used in the country. Due to the high ash content of Indian coal, thermal power stations in India produce 7 to 8 times more as than those in European countries.
A TERI study estimated that emissions of SPM (suspended particulate matter), sulphur dioxide, and oxides of nitrogen from thermal power plants increased from 0.3 million tonnes in 1947 to 15 million tonnes in 1997, of which SPM claims the largest share (86%).
In addition to emissions, pollution from suspended solids and oil including grease present in the effluent and the discharge of water at high temperature from thermal power plants are environmental hazards.
Solid waste in the form of fly ash and the land area required for its disposal are other major concerns. For every megawatt of installed capacity, approximately 0.45 hectare of land is required for disposal of ash.
Of the 80-100 million tonnes of fly ash currently being generated, only about 10% is utilized in manufacturing bricks and cement. For the disposal of the rest, merely 28,000 hectares of land has already been converted into ash dumps.
This raises the threat of percolation of hazardous elements to ground water through ash ponds and greater incidence of pulmonary diseases in the vicinity of the dumps due to air-borne ash. Moreover currently fly ash is collected in slurry form, which requires 10 tonnes of water for every tonne of ash generated.
(b) Hydro Power:
Hydropower entails its own set of problems such as large-scale dislocation of people, submergence of valuable resources including forests, loss of estuaries and endangered species and adverse impacts in downstream hydrology. In India 14-22 million people have been displaced by dams.
Large river valley projects are alleged to have inundated about half a million hectares of forest between 1951 and 1976 alone. Critics also argue that the benefits a dam provides would be temporary since siltation can render the dam ineffective in a short period. The life of the Hirakud dam for instance has been reduced from as expected 110 years to paltry 35 years because of siltation.
(c) Nuclear Power:
The issue of nuclear energy is currently mixed in controversies. Nuclear power usually evokes fears of radioactive leakage and accidents. Other issues of concern include disposal of radioactive waste and decommissioning of power plants.
However, in the wake of rising concerns about global warming and the emission of greenhouse gases the nuclear option is being advocated by some as greener power. Electricity generation in large centralized installations, whether using fossil fuel or nuclear power have several environmental impacts.
The laws of thermodynamics make it inevitable that about 60% the heat energy generated is waste and unless it can be used as low- grade heat to warm buildings nearby it has to be released into the environment.
Waste heat may be discharged to the air, where it can affect local climate or to fresh or marine water with the ecological effects. It can also be used to boost plant production in horticulture or agriculture if warmed water is used for irrigation in winter.
Other impacts arise from electricity transmission is much more costly to place transmission through underground. In the 1970’s this was done mainly in areas of particularly outstanding landscape quality.
Hydropower schemes, usually being remote from the consumer, require especially long lines. The impact of such lines comes from their visual intrusion, but they also restrict agriculture on swatches of land 30-120 m wide and may cause some interference with nearby radio and television reception.
Hence economic growth does imply definitely the exploitation of natural resources. The rising population in India is posing great threat to the ecology and environment. Everybody tries to be leading a healthy life at the cost of the others. This frictional movement always exerting to use up the resources at their own end.
Before new economic reforms, the state has been functioning as an agent to take care of the proper relation between human beings and that of the natural resources on both ends. Now the situation is rapidly going to be changed with the “free for all” motives.
The need of the hour is to take extra care of free for all motives in the economy in terms of growth because distributive justice is possible, if only the universe remains in a balancing position.