Around 150 countries have agreed to limit the use of hydrofluorocarbon (HFC) greenhouse gases in a bid to protect the Earth's climate.
Used in refrigeration and air conditioning, HFCs play a growing role in driving up global temperatures.
Under the deal, developed nations commit to reducing their use of the chemicals sooner than poorer countries.
US Secretary of State John Kerry told delegates in Rwanda on Friday that HFCs were "disastrous for our climate".
The chemicals' molecules can trap heat from the Sun thousands of times times more effectively than carbon dioxide, a better-known driver of climate change.
Delegates worked through the night in the Rwandan capital, Kigali, to reach an agreement that would suit both developed and developing countries.
The use of air conditioning has been rising in emerging economies, pushing a 10-15% rise in the amount of HFCs being released into the atmosphere.