Which of the following is not a greenhouse gas ?

Methane Carbon dioxide Nitrous oxide Nitrogen

Nitrogen

The correct answer is Option (4) – Nitrogen The main greenhouse gases whose concentrations are rising are carbon dioxide, methane, nitrous oxide, hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs) and ozone in the lower atmosphere. Nitrogen is not a greenhouse gas .