Gases responsible for greenhouse effect are :
CO2,CH4,N2O,H2O(g) CFCs and O3.
Carbon dioxide molecules trap heat as they are transparent to sunlight but not to the heat radiations. Carbon dioxide is, thus, the major contributor to global warming. Methane is produced naturally when vegetation is burnt, digested or rotted in the absence of oxygen. Large amounts of methane are released in paddy fields, coal mines from rotting garbage dumps and fossil fuels.
Chlorofluorocarbons (CFCs) are man-made industrial chemicals used in air conditioning, etc. CFCs are also damaging the ozone layer. These gases together are responsible for greenhouse effect.