Delegates at UN climate talks in Qatar have agreed to extend the Kyoto Protocol until 2020, avoiding a major new setback.
The deal, agreed by nearly 200 nations, keeps the protocol alive as the only legally binding plan for combating global warming.
However, it only covers developed nations whose share of world greenhouse gas emissions is less than 15%.
The US - a major polluter - has never ratified the original 1997 protocol.
The agreement had been due to expire later this year.
The 12-day meeting in Qatar's capital Doha had also focused on a plan to adopt a wider treaty in 2015 that would apply to all countries and eventually replace the Kyoto Protocol.