GREEN HOUSE EFFECT AND GLOBAL WARMING:  

The term ―Greenhouse effect has been derived from a phenomenon that occurs in greenhouse.

In a greenhouse the glass panel lets the light in, but does not allow heat to escape. Therefore the greenhouse warms up, very much like inside a car that has been parked in the sun for a few hours. 

The greenhouse effect is a naturally occurring phenomenon that is responsible for heating of Earth‘s surface and atmosphere.

Without greenhouse effect the average temperature at surface of earth would have been a chilly -18° C rather than the present average of 15°C. 

Clouds and gases reflect about one-fourth of the incoming solar radiation and absorb some of it but half of incoming solar radiation falls on Earth‘s surface heating it, while a small portion is reflected back. 

Earth‘s surface re-emits heat in the form of infrared radiation but some part of this does not escape into space because of atmospheric gases (e.g. carbon dioxide, methane etc).

The molecule of these gases radiate heat energy and a major part of which again comes to Earth‘s surface, thus heating it up once again. 

Carbon dioxide and methane – are commonly called as greenhouse gases because they are responsible for greenhouse effect.

Increase in the level of greenhouse gases has led to considerable heating of Earth leading to global warming orenhanced green house effect. 

During the past century, the temperature of Earth has increased by 0.6 °C.