President Barack Obama is due to head to Copenhagen overnight to join the leaders of over 100 other nations for the final day of the U.N. Climate Change conference in the Danish capital.
The question remains what sort of compromise they can agree on to cut greenhouse gas emissions and to help the most affected and less developed nations of the world cope with global warming.
For the past two weeks thousands of delegates have been meeting in a conference center on the outskirts of Copenhagen. Their task was to come up with a global plan to deal with climate change.
But, agreement has been elusive. Many of the sessions were taken up with finger pointing and rhetoric of who's to blame for global warming, who suffers most, and who needs to do more.
Addressing the conference, Australian Prime Minister Kevin Rudd warned that, as he put it, no one has come here with "clean hands."
"The inescapable truth is that we, the developed world, carry the overwhelming historical responsibility for the accumulation of greenhouse gases in the atmosphere," Rudd said.
Prime Minister Rudd's message was that the developed world must set things right. But, he also admonished emerging economies to not continue to spew out greenhouse gases.
There have been major differences here at the conference between developed and developing nations and with major emerging economies.
U.S. Secretary of State Hillary Clinton announced a major funding initiative with a promise to contribute to a global fund of $100 billion annually to help poor nations deal with climate change. But, she said that could only happen if all major economies agree on emissions cuts and on proper monitoring of implementation. She made a clear reference to China, with whom the U.S. has been at odds over the issue.
But, Prime Minister Rudd reminded delegates that everyone has a stake.
"The truth is that unless we all act together because we are all in this together there will be limited prospects of development because the planet itself will no longer sustain development," Rudd said.
That was much the message from French President Nicolas Sarkozy, who admonished his fellow world leaders that failure is not an option.
He warned them they would all have to answer before global opinion and public opinion at home if they failed to act. Science has told us what must be done, he said, and we are the last generation to be able to do it.
In an impassioned speech, President Sarkozy said everyone would have to compromise. He appealed to world leaders to sit down and work out their differences and suggested a serious working meeting after Thursday's dinner to do just that.
Initial hopes had been the Copenhagen conference could come up with a successor to the 1997 Kyoto Protocol, which mandates emission cuts for most developed nations. Developing countries are adamant that they want Kyoto extended beyond its 2012 expiration date. Leaders here have indicated they are looking for a political framework agreement from Copenhagen, with another summit to be held in about six months to work out details and turn it into a legally binding accord.