Climate envoys from around the world opened talks Saturday in Panama in a bid to help break the deadlock on key sticking points ahead of a closely watched year-end conference in Durban, South Africa. The major obstacle is the fate of the landmark Kyoto Protocol, which requires wealthy countries to cut carbon emissions blamed for climate change. Its obligations run out at the end of 2012 with no new treaty in sight. Officials do not expect any firm announcements during the week of UN-led talks in Panama but hope to lay the groundwork for the Durban conference, which opens November 28 and is seen as a last chance to take action on Kyoto. The European Union, the main champion of the Kyoto Protocol, has proposed a new round of commitments under the treaty. Emerging economies such as China -- which is now the largest emitter and has no obligations under Kyoto -- welcome the idea. But no other major economy that would be affected by a Kyoto extension has endorsed the European Union view, with Canada, Japan and Russia all adamantly opposed. Australia and Norway have submitted a joint plan that would set a 2015 deadline for a new climate treaty that involves both developed and developing nations. To avoid any gap in action -- a key fear of environmentalists -- the Australian-Norwegian proposal would ask all nations to chart out climate actions for the coming years, which would gradually become more ambitious until they fold into a post-Kyoto treaty. Scientists backed by the nited Nations have warned that carbon emissions must peak by 2015, fearing that otherwise damage from climate change will become irreversible with rising floods, droughts and other extreme weather. The United States, the world's second largest emitter, was the only nation to reject the Kyoto Protocol, with former president George W. Bush saying it was unfair to developed countries. While technically not part of Kyoto discussions, the United States has stood firm that it would only accept an agreement that includes all countries. "We could consider it only if it's genuinely binding with respect to all the major players, whether developed or developing, including China and others," Todd Stern, the top US climate negotiator, said before the talks. President Barack Obama is facing strong opposition on climate change from the rival Republican Party, many of whose members dispute science that human activity is causing rising temperatures.