Nearly 200 nations have reached a deal to limit the use of greenhouse gases far more powerful than carbon dioxide in a major effort to fight climate change.
The talks on hydrofluorocarbons, or HFCs, were called the first test of global will since the historic Paris Agreement to cut carbon emissions was reached last year.
HFCs are described as the world's fastest-growing climate pollutant and are used in air conditioners and refrigerators.
The agreement caps and reduces the use of HFCs in a gradual process beginning by 2019, with action by developed countries including the United States, the world's second-worst polluter.
More than 100 developing countries, including China, the world's top carbon emitter, will start taking action by 2024, when HFC consumption levels should peak.
Developing nations secure extended deadline
A small group of countries including India, Pakistan and some Gulf states pushed for and secured a later start in 2028, saying their economies needed more time to grow.
That is three years earlier than India, the world's third-worst polluter, had first proposed.
"It's a very historic moment, and we are all very delighted that we have come to this point where we can reach a consensus and agree to most of the issues that were on the table," said India's chief delegate, Ajay Narayan Jha.
Environmental groups had hoped the deal could reduce global warming by 0.5 degrees Celsius by the end of this century.
This agreement gets about 90 per cent of the way there, said Durwood Zaelke, president of the Institute for Governance and Sustainable Development.
"[It's the] largest temperature reduction ever achieved by a single agreement," he said
HFCs were introduced in the 1980s as a substitute for ozone-depleting gases.
However their danger has grown as air conditioner and refrigerator sales have soared in emerging economies like China and India.
Major economies have debated how fast to phase out HFCs. The United States, whose delegation was led by Secretary of State John Kerry, and Western countries want quick action. Nations such as India want to give their industries more time to adjust.
Small island states and many African countries had pushed for quick action, saying they faced the biggest threat from climate change.