GLOBAL WARMING (GREEN HOUSE EFFECT)

GLOBAL WARMING (GREEN HOUSE EFFECT)

INTRODUCTION

Actually the grin house effect is natural assurance that maintains earth’s average temperature at approximately 60 degree Fahrenheit. The green house effect is necessary phenomenon that keeps all earth’s heat from escaping to the outer atmosphere. Without natural green house effect it is certain that we would all be lost. Temperature on earth would be much lower than they are now, and the existence of life on the planet would not be possible. The global average temperature would drop precipitously 33 degrees from its current 15degree to –18degree-celcius.the earth would become an ice planet.

The earth’s atmosphere, a thin blanket of gases, protects the planet from the harshest of the sun’s ultraviolet radiation .the atmosphere, by trapping the earth'’ warmth, keep rivers and oceans from freezing.

However, too many greenhouse gases in earth’s atmosphere could increase the green house effect. This could result in an increase in mean global temperature as well as changes in precipitation patterns.

GREEN HOUSE EFFECT

The term green house effect was first coined by J.fourier in 1827. The effect is also called as “atmospheric effect”, “global warming” or “carbondioxide problem”.

In cold countries green houses are built. The transparent wall and roof of green house are such that these allow the visible sunlight to enter and prevent the long wave- infrared radiation’s to go out. Subsequently the walls and roof re-emit absorbed radiations into the house. Such green houses are built for plants in cold countries.

Thus a green house is that body which allows a short wavelength solar radiation to come in but not allowed the longwave outgoing terrestrial infrared radiation to escape.

In similar way, the earth’s atmosphere bottles up the energy of the sun, and is said to act like a “green house”, where co2 acts like glass windows. Co2 and water vapor in the atmosphere transmits short wavelength solar radiation but reflect the longer wavelength heat radiation from the warmed surface of the earth. Co2 molecules are transparent to sunlight but not to the heat radiation. So they trap and re-enforce the solar heat stimulating an effect, which is popularly known as green house effect.
The green house effect may be therefore defined as “the progressive warming up of earth surface due to blanketing effect of manmade co2 in the atmosphere”.

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