Nations seek deal to phase out HFCs; could cut temperatures

U.S. Secretary of State John Kerry, center-left, prepares for a bilateral meeting with the Chinese delegation, on the sidelines of the 28th Meeting of the Parties to the Montreal Protocol on Substances that Deplete the Ozone Layer, in Kigali, Rwanda, Friday, Oct. 14, 2016. Nations strove Friday for a deal to phase out hydrofluorocarbons from air conditioners and refrigerators as part of efforts to fight climate change. (AP Photo) (The Associated Press)

Secretary of State John Kerry, centre-right, shakes hands with India's Minister of Environment, Forest and Climate Change Shri Anil Madhav Dave, center-left, at the start of a bilateral meeting on the sidelines of the 28th Meeting of the Parties to the Montreal Protocol on Substances that Deplete the Ozone Layer, in Kigali, Rwanda Friday, Oct. 14, 2016. Many nations are meeting Friday for a deal to phase out hydrofluorocarbons from air conditioners and refrigerators as part of efforts to fight climate change. (AP Photo) (The Associated Press)

Secretary of State John Kerry, center-left at podium, delivers a speech to the 28th Meeting of the Parties to the Montreal Protocol on Substances that Deplete the Ozone Layer, in Kigali, Rwanda Friday, Oct. 14, 2016. Nations strove Friday for a deal to phase out hydrofluorocarbons from air conditioners and refrigerators as part of efforts to fight climate change. (AP Photo) (The Associated Press)

Nations are striving for a deal to start phasing out hydrofluorocarbons from air conditioners and refrigerators to help fight climate change.

They could seal an agreement Friday.

At issue are greenhouse gases far more powerful than carbon dioxide. HFCs, as they're known, were introduced in the 1980s as an answer to ozone-depleting gases. But their danger has grown as air conditioner and refrigerator sales have soared in emerging economies like China and India.

Scientists say eliminating HFCs could put a half-degree Celsius dent in global warming by the end of the century.

Major economies are still debating how fast to phase out HFCs. The U.S. and Western countries want quick action. Nations such as India don't want to face reductions until after 2030, perhaps.