Climate change 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 accord, agreed upon 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 US Secretary of State John Kerry, who participated in the talks. "This will allow us to reduce global warming by half a degree Celsius."
Hydrochlorofluorocarbons (HFCs) have been used for years as a substitute for chlorofluorocarbons (CFCs), which were once found in aerosol spray cans as well as 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.
Negotiators meeting in Kigali agreed Saturday to an amendment to the Montreal Protocol that would also curb the use of HFCs, which have a limited impact on the ozone but are a major contributor to global warming.
"We've moved from Paris pledges to concrete action," said Durwood Zaelke, president of international research organization Institute for Governance and Sustainable Development.
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 new accord.
The majority of developing countries, including China, Brazil, South Africa and Argentina, committed to reduce HFC production and use by 2024.
India, Iran, Iraq and Pakistan meanwhile agreed to start reductions by 2028.
In Washington, US President Barack Obama welcomed the global agreement to fight "a rapidly growing threat to the health of our planet."
"It shows that we can take action to protect our planet in a way that helps all countries improve the lives and livelihoods of their citizens," he said in a statement.
The effort along with the implementation of the Paris agreement and a deal to limit aviation emissions "show that, while diplomacy is never easy, we can work together to leave our children a planet that is safer, more prosperous, more secure, and more free than the one that was left for us," he said.
The HFC amendment could be easily and cheaply implemented, said UN Environmental Programme executive director Erik Solheim, calling the accord "one of the lowest hanging fruits in the arsenal of climate change."
"The Kigali amendment is the most significant climate mitigation step the world has ever taken," said Rwanda's natural resources minister, Vincent Biruta.
Many countries had already been working to towards a reduction in HFCs, which experts say cause 100 to 1,000 times more damage than carbon dioxide.
The deal at the UN-hosted Meeting of the Parties to the Montreal Protocol in Rwanda builds upon steps taken by the international community at a conference in Dubai one year ago.