The Copenhagen Accord sets emission limits but isn't legally binding. It's vague on details and has infuriated smaller nations and environmentalists. The U.N. chief calls it 'an essential beginning.'

An international climate summit officially ended here today with an agreement among the world's largest economies to take steps to curb greenhouse gas emissions, no formal consensus from the 193 nations present, and major questions over what comes next in the global negotiating process.

Conference attendees merely acknowledged -- and did not vote to adopt -- the so-called Copenhagen Accord, which stemmed from an eleventh-hour deal cut Friday evening between President Obama and leaders of four fast-growing nations.

Obama had hailed the deal as an "unprecedented breakthrough" in climate talks, but it was denounced by critics as too weak to avert the harshest effects of global warming.

At the end of the summit there was no formal enrollment of countries that supported the accord, though officials involved with the talks said about 30 nations had helped draft it.

The United Nations said in a press release that the agreement was backed "by a majority of countries, including amongst them the biggest and the richest, and the smallest and most vulnerable."

Conference leaders here gave the accord a wary blessing, even as they warned of its faults.

"We have sealed the deal," said U.N. Secretary-General Ban Ki-moon. "This accord cannot be everything that everyone hoped for, but it is an essential beginning,"

Yvo de Boer, the U.N.'s top climate official, said nations "must be honest about what we have got" after two weeks of negotiations that appeared on the brink of collapse Friday night.

"The world walks away from Copenhagen with a deal," he said. "But clearly ambitions to reduce emissions must be raised significantly" to meet the deal's goal of limiting warming to 2 degrees Celsius above pre-industrial levels.

The conference ended after an all-night negotiating marathon that featured surreal twists of rhetoric, including a representative from the genocide-racked nation of Sudan comparing the Copenhagen Accord to the Holocaust - a move that appeared to galvanize smaller nations to speak up for the agreement.

In its wake, world leaders are left with huge questions about where they go next in the process of negotiating a follow-up treaty to the 1997 Kyoto Protocol. They're also left to argue over just how meaningful the Copenhagen Accord will prove to be.

The agreement is not legally binding. But it would set the first emission limits for emerging powers India and China, along with new reduction targets for the United States, which never adopted the Kyoto commitments. It also would provide for an aid fund, to reach $100 billion a year by 2020, to help poor nations adapt to a changing climate and employ low-emission fuels.

A provision for international scrutiny of developing nations' emission pledges could prove crucial to Obama's hopes of passing an emission-reducing climate bill this spring in the Senate.

Still, the agreement was vague on key details, including basic components of the aid fund. It would give nations until February to sign on with specific emission commitments, and it would offer no firm deadline to turn what is essentially a framework document into a binding treaty; nations agreed only to revisit the stringency of emissions reduction targets in 2015, and the U.N. noted that future bargaining sessions are scheduled in Germany and Mexico next year.

Even Obama acknowledged that the agreement's reduction targets, to the chagrin of environmental groups, fell well short of what scientists project is necessary to stabilize warming at sub-catastrophic levels.

"This progress did not come easily, and we know that this progress alone is not enough," Obama said in a late-evening news conference announcing the deal.

"We've come a long way, but we have much further to go."

The failure to produce tougher emission cuts, greater financial assistance and a set deadline for follow-up disappointed many environmental activists and infuriated leaders of poor, climate-vulnerable nations like Nicaragua and Cuba, which appeared unlikely to endorse the agreement.

A final plenary session began debating the agreement early today. The goal was to reach enough consensus that the president of the conference, Danish Prime Minister Lars Lokke Rasmussen, could declare the document outlining the agreement approved. But that goal was thrown into question as a string of developing nations began to protest what they called an inadequate and nonbinding text.

Oxfam International, which works on climate and poverty issues around the world, called it a "historic cop-out" on its website. A protest group that has rallied in Copenhagen throughout the summit called it "toothless." Kassie Siegel, director of the Climate Law Institute at the Center for Biological Diversity in Tucson, said, "If this is the best we can do, it is not nearly good enough."

A delegate from the low-lying South Pacific island nation of Tuvalu -- which was the focus of disruptions during the first days of the summit and hoped to force stronger actions to reduce emissions from rich nations -- told fellow diplomats early this morning that his nation "cannot accept this document."

Hopes that Copenhagen would be the site of a legally binding treaty evaporated long ago. It appeared unlikely this morning that any framework agreement would meet even reduced expectations and emerge from the summit as a product meeting the approval of all 193 members.

Instead, it seemed the deal, which rescued the negotiations from the brink of collapse, would garner support of the largest and fastest-growing emitters, which account for most greenhouse gas pollution.

After two weeks of grinding negotiations and a slow-going morning Friday, several of those countries reached a breakthrough in the evening. Obama had arrived in town early, exhorted the summit to act instead of talk and dived into negotiations.

By the afternoon, he was frustrated with Chinese officials, who sent low-level ministers to multinational bargaining sessions. The Americans had clashed with the Chinese throughout the conference on the issue of transparency in enforcing emission limits.

Obama asked aides to arrange a second meeting of the day with Chinese Premier Wen Jiabao, with whom he had a comfortable relationship. At the appointed meeting time, an administration official said, the president found Wen in a room that surprisingly also included the leaders of Brazil, India and South Africa, some of whom the United States had believed to be headed for the airport in defeat.

Together, the leaders found compromise on key issues, chiefly a system to subject developing nations to scrutiny of their pledges to limit emissions as a share of their economies. Under the system, nations would self-report their emission progress every two years, and other countries could ask to examine the data.

In the U.S., several Rust Belt senators, who are considered swing votes on the climate bill, have pushed for such a system to protect U.S. manufacturers from unfair competition from developing nations with no real emission limits -- and thus lower energy costs.

The chief Chinese climate negotiator said the meeting "had a positive result, everyone should be happy.

"After negotiations, both sides have managed to preserve their bottom line. For the Chinese, this was our sovereignty and our national interest," the negotiator said.

Obama did not indicate what he gave up to win China's support on the transparency measure.

"We tried to be modest in what we thought we could accomplish," he said, emphasizing that the U.S. was seeking to avoid the mistake in Kyoto of committing to a treaty the Senate would not ratify.

The president cast Friday's deal as a steppingstone to a new, official climate treaty down the road, and he directly addressed critics who faulted the deal for not being legally binding, suggesting that treaty enforcement mattered less than momentum.

"Instead of setting up a bunch of goals that end up just being words on a page and are not met," he said, it is better to act now.

"Everybody is taking as aggressive a set of actions as they can -- that there is a sense of mutual obligation and information sharing so that people can see who's serious and who's not, that we strive for more binding agreements over time, and that we just keep moving forward."

jtankersley@latimes.com