The U.S., India and China all have specific proposals on the table for the first time, and world leaders are aiming for a deal that includes commitments on reducing emissions and financing for developing countries. They no longer expect to reach a legally binding agreement, as had long been the goal.
Obama is hoping to capitalize on steps by India and China and build a more meaningful political accord, the White House said.
The move means Obama will be at the summit on Dec. 18, considered a crucial period when more leaders will be in attendance, as opposed to his scheduled stop in Denmark on Wednesday on his way to receive the Nobel Peace Prize in Oslo.
It also means that Obama will be squeezing in a separate, 10th foreign trip before Christmas
- a record pace of travel for a first-year president - as a means to giving momentum to a deal aimed at combatting global warming.
Obama will now leave for Oslo late Wednesday, attend Nobel events Thursday and return to Washington on Friday.
The president had said that he would travel to the Copenhagen conference if his appearance would help clinch a deal. His decision to go early to the two-week meeting had been seen by many as a sign that an agreement was still a long shot.
The possibility of an agreement may be improving, however.
"There are still outstanding issues that must be negotiated for an agreement to be reached, but this decision reflects the president's commitment to doing all that he can to pursue a positive outcome," White House press secretary Robert Gibbs said in a statement. Gibbs said the U.S. will have negotiators involved throughout the Dec. 7-18 conference.
It is also possible that Obama could tack on another agenda item to his revamped, final trip of the year: the signing of a broad treaty with Russia to reduce both nations' nuclear arsenals. The White House had hoped that deal would be ready in time to coordinate it with his receiving the Nobel Peace Prize, but talks have not produced a final breakthrough.
On climate, India pledged Thursday to significantly slow the growth of its carbon emissions over the next decade. China announced its own targets for cutting carbon emissions last week, a day after Obama announced the U.S. goals.
None of the three countries - which are among the top five emitters of carbon dioxide in the world
- were subject to limits put in place by the 1997 Kyoto Protocol, the treaty that negotiations in Denmark seek to replace.