RENEWABLE & NON-RENEWABLE RESOURCES

RENEWABLE &NON-RENEWABLE RESOURCES

There are two types of energy sources:

1.      Non-renewable resources: These are minerals that have been formed in the lithosphere over millions of years and constitute a closed system. These non-renewable resources, once used, remain on earth in a different form and, unless recycled, become waste material. Non-renewable resources include fossil fuels such as oil and coal, which if extracted at the present rate, will soon be totally used up. The end products of fossil fuels are in the form of heat and mechanical energy and chemical compounds, which cannot be reconstituted as a resource. In other words, Resources that exist in a fixed quantity in the earth’s crust are called non–renewable resources. These resources lack the ability of recycling and replacement.

E.g.: minerals, fossil fuels etc.

2.      Renewable resources: Though water and biological living resources are considered renewable. They are in fact renewable only within certain limits. They are linked to natural cycles such as the water cycle.  In other words, these resources have the capacity to reappear themselves by quick recycling within a reasonable span of time.

E.g.: forests, and wildlife.

 

 

FOREST RESOURCES

Forest plays an important role in the economy and development of a country. They are useful to man and other organisms directly and indirectly in many ways. Forests are one of the most important natural resources on this earth predominantly composed of trees, shrubs, woody vegetation etc… Approximately 1/3rd of the earth’s total land area is covered by forests.

Functions of forests: 

Forests have three types of functions

1. Productive functions: This includes the production of timber, bamboo & a variety of compounds such as resins, alkaloids (the poisonous substances in plants), oil and pharmaceuticals.

2. Protective functions: It includes conservation of soil and water, prevention of drought, protection against wind, cold, radiation, noise, odours etc…

3. Regulative functions: This includes absorption, storage and release of gases like CO2 & O2. Droughts & particularly CO2 is regulated by forests. The regulative functions of forests improve atmospheric & temperature conditions.

 

Uses of forests:

 

1.      Wood and timber are the major products of forests. Wood is used as fuel in industries and houses. Timber is used in the manufacture of plywood, carts, furniture etc.

2.      They give food items like fruits, nuts, honey, spices etc.

3.      Leaves and grass are used as food for animals.

4.      They provide many drugs, oils, gums resins, pulp for paper etc.

5.      They are useful in balancing of O₂ and CO₂ in the atmosphere.

6.      They protect people from floods and droughts.

 

Over-exploitation of forests:

Overexploiting of forests due t increasing population, urbanization, industrialization, increasing cultivation, mining etc. the over-exploitation of forests causes the following changes.

1.      The forest resources are reduced

2.      The plantation is reduced which increases CO2 in the atmosphere. It leads to global warming or the greenhouse effect.

3.      Some of the naturally useful wild animals and small creatures may be disappeared.

4.      The rainfall may be reduced.

Deforestation:

Deforestation is defined as the removal of trees in forests. The removal of trees leads to adverse effects as it leaves soil exposed & results in soil erosion, rapid water run-off, and loss of wildlife. Forest ecosystems are extremely good & hold a good quantity of water. About 80% of the original forests on the earth have already been cleared. Only 20% of forest area (63 million hectares) is seen based on satellite data as per National Forest Policy.

Disadvantages of deforestation:

1. A variety of food products such as coffee, tea, spices, nuts, fruits etc will be reduced.

2. Various living beings may come down resulting in an imbalance of the forest ecosystem.

3. Soil erosion increases to a great extent.

4. Rainfall decreases to a great extent.

5. Climatic conditions are changed.

6. Wildlife is diminished.

7. Historical values are lost.

 

MINERAL RESOURCES

Minerals are naturally occurring inorganic, crystalline; solids having a definite chemical composition with a certain physical property or a substance that is naturally present in the earth and is not formed from animal or vegetable matter Mineral resources can be classified under three main types. They are metallic, non-metallic and atomic minerals.

1.      Metallic minerals include native elements such as gold and silver; hematite and magnetite (iron); Cuprite ( copper); Literate (aluminium)

2.      non-metallic minerals include sand ( quartz ), garnet ; steatite (talc); muscovite ( mica )

3.      Atomic minerals include Pitchblende (Uranium, Thorium).

Uses of mineral resources:

Mineral resources are non-renewable and the mineral /ore is extracted by the process of mining. Minerals are used in a large number of ways for domestic, industrial, commercial sectors etc…

1.      Generation of energy by using coal (lignite/anthracite); uranium, gold, silver, platinum, and diamond are used in jewellery.

2.      Copper, aluminium etc are used as cables for the transmission of power.

3.      Some of the minerals are used in ayurveda as medicine.

4.       Gold is reputed to strengthen the heart muscle and increase energy and stamina.

5.       Silver is a very important healing substance due to its cooling and antiseptic properties

 

 

  ENERGY RESOURCES

The term energy means the capacity to do work. Energy can neither be created nor destroyed but transformed from one form to other. Energy is present in a number of forms such as mechanical, thermal, chemical, biological energy etc. Energy is one of the important requirements that a country needs for its economic growth. At the same time, energy production has an impact on the environment due to pollution and finally affects the quality of life of people. The energy is used for the following purposes:

a)     Cooking, heating and lighting

b)     Transporting people and goods by means of vehicles.

c)     Manufacturing consumer goods and equipment

d)     Conversion of fuels into other forms of energy for various use..

For Example:

a)     Burning coal to produce electrical energy or mechanical energy

b)     Chemical to electrical by dry cell batteries

c)      Using water in dams to produce electricity through mechanical energy

There are two types of energy sources namely:

(1) Renewable energy sources and (2) Non – renewable energy sources.

The important renewable energy resources are described below:

1.      Solar energy: The energy which is derived from the sun is known as solar energy. It can be used for direct heating or the sun’s heat is converted into electricity. Photo voltaic cells convert direct solar energy into electricity. A number of solar equipment have been developed to utilize sun rays to heat water, cook food, pump water and run certain machines that are used for street lighting, railway signals etc. But the major problem with solar energy is that during cloudy weather it is available in less quantity than on sunny days.

2.      Geothermal energy: Geothermal energy is found within rock formations. Inside the earth, the temperature raises with depth. The temperature in the earth’s crust is around 4000oC. Geysers (natural spring that emits hot water) and hot springs are examples of geothermal energy where the steam and hot water come to the surface, in areas where the steam is tapped by drilling. The obtained steam is then used to generate power. Air pollution results in the case of geothermal energy where gases like H2S, NH3, and CO2 are present in the steam coming out of the geothermal sources. The overall efficiency of power production is low (15%) as compared to fossil fuels (40%).