Bali: Australia was praised at the start of UN-led climate change talks in Bali by agreeing to ratify the Kyoto Protocol, isolating the United States as the only developed nation outside the pact.

Soon after the pact was made, new Australian Prime Minister Kevin Rudd took the oath of office and signed documents to ratify, ending his country's long-held opposition to the global climate agreement.

Conference host and Indonesian Environment Minister Rachmat Witoelar said, "I think I can speak for all present here by expressing a sigh of relief."

Australia, the world's top coal exporter and among the world's highest per-capita greenhouse gas polluters, has been criticised for years for refusing the ratify Kyoto.