Which of the following fluorinated gases was added as the seventh greenhouse gas by the United Nations Framework Convention on Climate Change?

Nitrogen trifluoride was added as the seventh greenhouse gas under the Doha Amendment to the Kyoto framework.

Hydrofluorocarbons were already among the original six controlled gases, used widely as refrigerants.

Perfluorocarbons too featured in the original basket, released mainly from aluminium smelting and electronics.

Sulphur hexafluoride was likewise one of the earlier six, an extremely potent gas used in electrical insulation.

The first basket held carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons and sulphur hexafluoride.

Nitrogen trifluoride, used in flat-screen and solar-cell manufacture, has a global warming potential thousands of times that of carbon dioxide.