Gas that trap heat in the atmosphere is termed as Greenhouse gases abbreviated as GHG. Some of the abundant GHG are carbon dioxide, methane, water vapor, nitrous oxide and ozone. Atmospheric greenhouse gases play a critical role in shaping global climate. These gases contribute to heating of earth’s surface which is known as greenhouse effect and hence responsible for global warming. The greenhouse gases naturally exist in the atmosphere and in recent times the amount of these gases has increased due to anthropocentric activities. The main sources of greenhouse gases due to human activity are

1.       Burning of fossil fuels resulting  in increase in concentration of carbon dioxide in the atmosphere

2.       Use of chlorofluorocarbons (CFCs) in refrigeration systems

3.       Agricultural activities, especially use of fertilizers