COPENHAGEN, Denmark — Barack Obama called it an "unprecedented" and "meaningful" agreement.
But the U.S. president flew out of Copenhagen leaving anger and confusion in his wake as environmental campaigners condemned a summit failure and developing nations threatened to block approval of the deal Obama negotiated.
"Industrialized nations have decided that damage to developing countries is acceptable, said Sudan's Lumumba Stanislaus Di-Aping, who has been speaking for a group of 77 developing nations at the talks. "This is not the end of the game. There is no deal."
Opposition from the likes of Sudan forced the summit into the small hours of the morning Saturday even after Obama left declaring qualified success after he negotiated a compromise with the leaders of China, India, Brazil and South Africa after a day of dramatic diplomatic maneuvering.
Despite the objections, officials said they expected the deal to go through, after the European Union reluctantly backed it even though it fell short of the EU's orginal hopes for a binding agreement committing other major economies to significant emissions cuts.
"This is not a perfect agreement, it will not solve the climate threat," admitted Swedish Prime Minister Fredrik Reinfeldt, speaking for the 27-nation bloc. "It's a start that needs to be developed near the start of next year."
Obama too acknowledged that the deal was a beginning rather than an end to efforts to limit global warming.
“We have come a long way, but we have much further to go,” he said, adding that turning the Copenhagen declaration into a legally binding treaty, "is going to be very hard, and it’s going to take some time.”
However he said the deal was a major step. "For the first time in history all major economies have come together to accept their responsibility to take action to confront the threat of climate change," Obama said.
Environmental campaigners however erupted with anger, claiming the summit billed as the best last chance to head off the catastrophic impact of global warming had been wasted. Demonstrators outside the conference center carried placards with the words "climate shame" written across a photo of Obama.
“The city of Copenhagen is a climate crime scene tonight, with the guilty men and women fleeing to the airport," said Greenpeace Executive Director Kumi Naidoo.
"World leaders had a once-in-a-generation chance to change the world for good, to avert catastrophic climate change. In the end they produced a poor deal full of loopholes big enough to fly Air Force One through," he added as Obama and other leaders left the summit ahead of a final debate on the deal.
Under the text, rich nations agree to set themselves targets for reducing greenhouse gas emissions by Feb. 1, 2010. Poorer nations should set and monitor their own "nationally appropriate" emissions reductions, reporting the results every two years.
A long-term target to cut overall greenhouse gas emissions by 50 percent of 1990 levels by 2020, and for developed nations to reduce theirs by 80 percent by the same period, was dropped, as was a target date to turn the declaration into a legally binding text. The leaders agreed that average global temperature rises should be held below 2 degrees Celsius but they could not formulate a roadmap for reaching that goal.
"Copenhagen has been an abject failure," said Nnimmo Bassy, chair of the campaign group Friends of the Earth. "We are disgusted by the failure of rich countries to commit to the emissions reductions they know are needed, especially the U.S."
The campaigners say the deal will likely mean that the 2-degree target will be exceeded. Many African and small island nations had said from the beginning that 2 degrees was too high anyway and lobbied for a limit of 1.5 degrees Celsius.
Even nations that went along with the deal acknowledged its shortfalls.
"Nobody's happy with it," said Sergio Serra, Brazil's special ambassador for climate issues. "It is a partial failure."
After hours of deadlock, Obama announced a breakthrough after he huddled with the leaders of Brazil, India, China and South Africa. He then persuaded European Union nations to go along with the deal, even if they were unhappy at its lack of ambition. French officials said the choice was either to accept the deal or walk away from Copenhagen with no agreement and bad blood between leading world powers.
"This accord is better than no accord," said European Commission President Jose Manuel Barroso. "I will not hide my disappointment ... . The text agreed today falls far short of our ambitions."
The rich world did offer $30 billion to help poor, vulnerable nations cope with climate change over 2010-2012, funding that should rise to $100 billion a year by 2020. But even that was denounced as insufficient by Sudan's Di-Aping.
"Industrialized nations have decide that damage to developing countries is acceptable," he told reporters. "They do not accept that developing nations have fundamental rights."
Editor's note: This story has been updated to account for news developments.