what is greenhouse gas ?how it causes

The radiation from the sun enter the Earth’s atmosphere but are unable to escape. This increases the temperature of the Earth. This is called the greenhouse effect. The gases in the atmosphere which are responsible for this effect are termed as green house gases. This includes carbon dioxide, carbon monoxide, methane and water vapors. These gases absorb the heat energy of sun and trap it so that it can not escape in the outer space. Hence, they keep earth warm. 

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