Negotiators from more than 170 nations agreed Saturday to begin limiting heat-trapping greenhouse gases known as HFCs, often used in air conditioners and refrigerators.
The legally binding agreement, reached in the Rwandan capital Kigali, was celebrated as the biggest environmental success since last year’s Paris climate deal, which aims to limit the global temperature rise to 2 degrees Celsius.
“It’s a huge step forward,” said U.S. Secretary of State John Kerry, who participated in the talks. “This will allow us to reduce global warming by half a degree Celsius.”
Hydrochlorofluorocarbons have been used for years as a substitute for chlorofluorocarbons, known as CFCs), which were once found in aerosol spray cans, insulation and packing materials.
CFCs were a primary cause of the hole in Earth’s ozone and were eventually banned under the 1987 Montreal Protocol.
The negotiators meeting in Kigali agreed to an amendment to the Montreal Protocol that would also curb the use of HFCs, which have a limited effect on the ozone but are a major contributor to global warming.
Developed countries pledged to make first HFC cuts by 2019 and provide additional money through the Montreal Protocol’s Multilateral Fund to help implement the agreement.
Most developing countries, including China, Brazil, South Africa and Argentina, committed to reduce HFC production and use by 2024.
India, Iran, Iraq and Pakistan agreed to start reductions by 2028.