(AP) -- A historic U.N. climate conference ended Saturday with only a nonbinding "Copenhagen Accord" to show for two weeks of debate and frustration. It was a deal short on concrete steps against global warming, but signaling a new start for rich-poor cooperation on climate change.
The agreement brokered by President Barack Obama with China and others in fast-paced hours of diplomacy on Friday sets up the first significant program of climate aid to poorer nations. But although it urges deeper cuts in emissions of carbon dioxide and other gases blamed for global warming, it does nothing to demand them. That will now be subject to continuing talks next year.
As delegates wrapped up an exhausting overnight negotiating marathon Saturday afternoon, to end the 193-nation conference, U.N. climate chief Yvo de Boer assessed the results for reporters.
It's "an impressive accord," he said of the three-page document. "But it's not an accord that is legally binding, not an accord that pins down industrialized countries to targets."
A legally binding international agreement - a treaty - requiring further emissions cuts by richer nations was the goal in Bali, Indonesia, in 2007 when the annual U.N. conference set a two-year timetable leading to Copenhagen.
A new pact would succeed the first phase of the 1997 Kyoto Protocol, whose relatively modest emissions cuts by 37 nations expire in 2012. It was hoped a new regime would encompass the U.S., which rejected Kyoto.
But the hopes for Copenhagen faded as 2009 wore on and the first U.S. legislation to cap carbon emissions worked its way only slowly through Congress. Without a U.S. commitment, others were wary of submitting to a new legally binding deal.
Big polluters, nonetheless, submitted plans for reductions ahead of the U.N. talks.
The European Union has committed to cutting emissions by 20 percent by 2020, compared with 1990 levels; Japan to 25 percent, if others take similar steps, and the U.S. provisionally to a weak 3 to 4 percent.
For the first time, China also offered to rein in its greenhouse gas output, pledging to reduce its "carbon intensity" - that is, its use of fossil fuels per unit of economic output - by 40 to 45 percent. India, Brazil and South Africa followed suit with their own voluntary targets.
But scientists say that's too small a rollback in gases from fossil-fuel burning, emissions that have increased an average of 2 to 3 percent a year in the past decade.
Some U.S. experts are predicting a big enough rise in temperatures to lead to serious damage from coastal flooding, droughts, species die-offs and other impacts of climate change.
The U.N. climate summit this past week in the snowy Danish capital brought more than 110 leaders. The Copenhagen Accord emerged principally from Obama's meeting with Chinese Premier Wen Jiabao and the leaders of India, Brazil and South Africa.
The compromise document indicated richer and poorer nations are ready for closer cooperation on climate. Its key elements, with no legal obligation, were:
-Nations agreed to cooperate in reducing emissions, "with a view" to scientists' warnings to keep temperatures from rising more than 2 degrees Celsius (3.6 degrees F) above preindustrial levels.
-Developing nations will report every two years on their voluntary actions to reduce emissions. Those reports would be subject to "international consultations and analysis" - a concession to the U.S. by China, which had seen this as an intrusion on its sovereignty.
-Richer nations will finance a $10 billion-a-year, three-year program to fund poorer nations' projects to deal with drought and other climate-change impacts, and to develop clean energy.
-They also set a "goal" of mobilizing $100 billion-a-year by 2020 for the same adaptation and mitigation purposes.
In a U.S. concession to China and other developing nations, text was dropped from the declaration that would have set a goal of reducing global emissions by 50 percent by 2050. Developing nations thought that would hamper efforts to raise their people from poverty.
In a news conference here Friday, Obama deflected criticism that Copenhagen had failed to achieve a strong agreement. If the world waited to reach a binding deal, "then we wouldn't make any progress," he said, warning that could produce "such frustration and cynicism that rather than taking one step forward, we ended up taking two steps back."
Environmentalists and a handful of developing countries were unconvinced.
"The deal is a triumph of spin over substance. It recognizes the need to keep warming below 2 degrees but does not commit to do so. It kicks back the big decisions on emissions cuts," said Jeremy Hobbs of Oxfam International, a group that works with developing countries.
The full U.N. conference, in its long overnight session that finally ended Saturday, approved by consensus a compromise decision to "take note" of the accord, instead of formally approving it.
"We have a deal in Copenhagen," said a visibly relieved U.N. Secretary-General Ban Ki-moon, who has made climate change his No. 1 priority. He said "this is just the beginning" of a process to craft a binding pact on emissions.
The next deadline for a treaty will be the 2010 U.N. climate conference in Mexico City.
EDITOR'S NOTE - Associated Press writers John Heilprin, Seth Borenstein, Michael Casey, Arthur Max and Karl Ritter contributed to this report
Explore further: Why some fish can't go with the flow