German Chancellor Angela Merkel urged world environment ministers "to find a basis of trust" before the next UN meet in Cancun, recalling the near-collapse of the Copenhagen climate summit.
"One thing that did not work well in Copenhagen is that a small circle met and the regional groups felt left out of the debate," she said as delegates from some 45 countries convened to breathe life into stalled climate talks.
"A preparatory job before Cancun will be to find a basis of trust for all countries that will be present in Cancun so that no one feels left out," Mrs Merkel told the assembled ministers and negotiators.
Many of the 194 nations in the UN Framework Convention on Climate Change have not backed the Copenhagen Accord, complaining that it was hammered out at the last minute behind closed doors by a handful of powerful economies led by China and the US.
The contested accord calls for reducing greenhouse gas emissions enough to keep global temperatures from rising more than 2C, but does not share out responsibility for reaching that goal.
Mrs Merkel pointed out that voluntary pledges currently registered in the accord put earth on track for a 3.5C or even a 4.0C jump by 2100, far above the widely held threshold for dangerous warming.
"There is no alternative to the UN process ... In the end all of this has to go into one UN process," she said.
The Copenhagen Accord called for $30 billion up to the end of 2012, to be scaled up to $100 billion annually by 2020.
"This atmosphere of trust is something we really need to make use of for the 'fast track' financing," he told the ministers on Sunday evening. "2010 is the year when we need to take action."
Just how hard that may be was laid bare in Bonn only weeks ago at the first meeting since Copenhagen of the UNFCCC, the main vehicle for global talks.