The major 6 greenhouse gases are as listed below: (Kyoto Protocol)

Carbon dioxide (CO ₂ ),

Methane (CH ₄ ),

Nitrous oxide (N ₂ O),

Hydrofluorocarbons

Perfluorocarbons

Sulphur Hexafluoride (SF6)

(Out of these, first three are of primary concern as they are closely associated to human activities)

Hello

well answering to your questions

the 6 main green house gases are

1.carbon di oxide

2.Methane

3.Nitrous oxide

4.HFC(hydroflurocarbons)

5.Perflurocarbon

6.Sulphur Hexaflouride

out of which 3 are caused by Human activities

HFC is the most common green house gas

Thanks And Regards