Greenhouse effect (GHE)

Greenhouse effect (GHE)

Radiation from the sun always tries to passes through the earth. This wave length is usually shorter. This shortwave radiation when strikes the inner earth surface of green house, converts into heat long – wave radiation. This long wave radiation is again reflected back into atmosphere from the inside surfaces but it cannot go out as the atmosphere restricts the long wave going to out and traps the heat. This trapped heat (which should have happened without glass) contributes to warming of earth and provides energy for growth of plants. Therefore, this effect is known as greenhouse effect.

The presence of CO₂ in earth atmosphere gives it the warmth essential for the substance of life. This happens because CO₂ has peculiar optical properties. CO₂ absorbs a good part of this long wave radiation, thus warming the globe. This is important life sustained that poses a threat to the human life in the coming decades.

CO₂ is the chief and also CH₄, NO₂ and certain CFCs have similar effects. Collectively these gases are responsible for greenhouse effect, threatening an average increase in earth temperature by 1.5 to 5°C by the middle of this century which will seriously affect sea level, agriculture and forestry. From the ground, earth atmosphere is nearly invisible and easy to take for granted. From space, it is perceived more readily as a thin blanket of glasses, shielding the earth from sun’s UV – radiation and trapping the sun’s warmth to keep Earth Rivers and oceans from freezing. The greenhouse gases emitted into the atmospheric functions significantly, degrading the UV-shielding of O₃– layer and intensifying the heat trapping properties of the atmosphere as a whole.

Factors affecting Greenhouse effect:

Carbon is the stuff that biological molecules are made of. In the oceans, it serves as the basic ingredients of shells and other body parts of marine organisms, which eventually die and sink to the bottom and form sedimentary rock. Through an intricate feedback system, the earth has contrived to keep the amount of carbon in the air, in the sea on the land relatively constant.

If the atmospheric levels of carbon increase, resulting greenhouse effect causes the earth to retain more heat, which leads to more evaporation of water from oceans and thus more rains. Rain drops absorb carbon from the air and erode carbon – laden rock; eventually the excess carbon is washed into the sea, where it is absorbed into seashells and returned to ocean bottom as sedimentary rocks.

If the amount of carbon in the atmosphere decreases, the process is reversed. There is less evaporation and less rainfall, carbon in rock at the ocean’s bottom eventually works its way back into the atmospheric through volcanoes and deep-sea vents.

The cycle operates over millions of years; however human disturbances such as the burning of fossils fuels and deforestation have outpaced this natural process, resulting in atmospheric carbon.

Steps taken to control greenhouse effect:

The greenhouse effect is overwhelming in scope and will specially impact on using departments dealing with energy. In accordance with this, some of the steps have been taken by many countries which are as follows:

1.     Increased usage of Natural gases instead of fuels which highly emit CO₂.

2.     Finding source and using more hydro-power.

3.     Use of alternative energy.

4.     Increasing the usage of nuclear power.

5.     Using efficient equipment that controls CO₂.

6.     Eliminating the usage of CFC from refrigeration industry and finding the alternate refrigerant.

7.     Increasing forestation and stopping deforestation.

8.     Implementing methodology of tax charges respect to carbon emission by industries.