Man lives in nature and depends on the resources of nature. The progress of mankind depends upon the exploitation of different natural resources. The utilization of soil, water, coal, electricity, oil, gas and nuclear energy is very important for the development of a nation. These resources have changed the living standards of man. India contains the world's largest resource of coal and third and fourth largest resource of manganese and iron.
The world is facing an ecological crisis and is degrading her natural resources day by day, due to over exploitation. India is no exception.
Food, shelter and clothing are the primary requirements of man. Early human society has used natural resources, relatively in much less quantity to cover its wants.
The word 'resource' means a source of supply or support that is generally held in reserve. The natural resources are the components of lithosphere, hydrosphere and atmosphere. They include energy, air, water, soil, minerals, plant and animals. For man resources are those materials and sources of energy which are needed for survival and comforts.
The nature of resources varies from society to society.
Natural resources are classified in different ways. i.e. on the basis of chemical composition, availability and distribution.
A. Natural resources are of three types on the basis of their chemical composition
B. Natural resources are of two types depending upon their availability and abundance.
They are not likely to be exhausted by man's use. They are air, clay, sand, tidal energy etc. Although the air is available in exhaustible quantity, it can be degraded, if its pollution is not checked.
They are likely to be exhausted by human use. They are further of two types-renewable and non-renewable.
a. Renewable Resources
They have inherent capacity to reappear or replenish themselves by quick recycling, reproduction and replacement within a reasonable time. Soil and living organisms are the main renewable resources.
b. Non- Renewable Resources
They lack the ability for recycling and replacement. The substances with a very long recycling time are also regarded as non-renewable resource e.g. fossil fuels like coal, petroleum and natural gas and minerals.
It is important to note that underground water, forests and wild life are regarded renewable resources but become non-renewable, if they are not used properly.
Source: Ecologically man is only a part of energy flow in nature. Man requires energy for his daily needs. The major energy sources are fuel wood, fossil fuels such as coal, petroleum and natural gas. Apart from these, the other direct energy resources are sunlight, hydroelectric and wind power, tidal, geothermal and nuclear energy.
Energy Requirement: During early stages of human civilization, the daily per capita need for energy was just 2,000-4,000 kilo calories. During the agricultural stage, the muscular energy of domestic animals was used for work. The per capita energy consumption gradually increased. In nineteenth century, during the industrial stage of human civilization, the use of fossil fuel started and the per capita energy requirement increased to 70,000 kilo calories per day.
Today we need energy for agriculture, industry, transport, communication, comfort and defence. The per head energy consumption varies from country to country
Depletion of fossil fuels
Today the world's energy resources have reached critical stage. Most of the world's human population uses fossil fuels (coal, petroleum and natural gas). The fossil fuel resources are being rapidly depleted. As a result these resources may last only another few centuries. The dwindling stocks of fuels has led to the search of alternate sources of energy.
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