IT IS an annual ritual: nearly 200 nations sit down at the end of each year for two weeks of glacially paced negotiations to stop global warming. Meanwhile, leading scientific and economic bodies warn that time is fast running out to cut greenhouse gas emissions.
Starting on Monday it is the turn of oil-dominated Qatar to host the latest major United Nations climate summit.
The agenda will include moves to extend the world's only climate change treaty, the Kyoto Protocol, the first stage of which is due to expire at the end of 2012.
Nations will also try to set a timeline to negotiate a new climate deal by 2015. If successful, it will, for the first time, include emissions targets for both rich and poor countries to take effect in 2020.
Old tensions are again emerging. In a pre-meeting statement, the powerful BASIC bloc of major developing countries - Brazil, South Africa, India and China - said a 2015 deal must be based on the principle that rich and developing nations have different degrees of responsibility to cut emissions.
But some wealthy nations, the US in particular, say the 2015 agreement must end that divide and recognise the extraordinary growth in emissions from China and India.
Australia has joined the European Union and a handful of other small developed nations in indicating it will sign-up for Kyoto 2, with some conditions, as a bridge to a deal covering all countries. Other rich countries such as the US, Japan, and Canada are refusing.
Climate Change Minister Greg Combet - who is not attending the talks - said Australia hopes the summit will establish a process for negotiating an agreement. That includes closing down old negotiating tracks separating developed and developing countries.
''We need to overcome that separation and have a single negotiating process … to get to an agreed outcome where all major emitters are in,'' he said.
Observers are also watching how Australia registers its target of cutting emissions to 5 per cent below 2000 levels by 2020 under Kyoto 2.