What are green house gases?
       Gases, such as Carbon dioxide (CO2), Methane (CH4), Nitrous  
oxide (N2O), Fluorinated gases, that trap heat in the atmosphere are  
called Greenhouse gases,  These gases allow sunlight to enter the  
atmosphere freely. When sunlight strikes the Earth’s surface, some  
of it is reflected back towards the space as infrared radiation (heat).  
Greenhouse gases absorb this infrared radiation and trap the heat  
in the atmosphere.
        We produce larger amounts of carbon dioxide than any other  
greenhouse gas, and it's responsible for most of the warming.  
Carbon dioxide (54.7%) is the most important greenhouse gas  
emitted by humans, but several other gases contribute to climate  
change, too, such as Methane (30%), nitrous oxide (4.9%),  
Fluorinated gas (0.6%) and other gases (9.8%).