"Greenhouse gas" means any of the following gases, either alone or in combination:
1. Carbon dioxide (CO2);
2. Hydrofluorocarbons;
3. Methane (CH4);
4. Nitrous oxide (N2O);
5. Perfluorocarbons; and
6. Sulphur hexafluoride (SF6).
(Added to NRS by 2007, 1906)