The correct answer for this question is Air
Chlorofluorocarbons or CFCs (also known as ferons) are anthropogenic compounds, it is non-toxic, non-inflammable and non-carcinogenic. It can be found as coolant in various man made instruments like air conditioner, refrigerator.
Man made CFCs (present in air) are the main cause of stratospheric ozone depletation. However, the atmospheric impacts of CFCs are not limited to its role as an active ozone reducer. This anthropogenic compound is also a greenhouse gas, with a much higher potential to enhance the greenhouse effect than co2