Though the accords were limited, it was the first time in three years the 193-nation conference adopted any climate action, restoring faith in the unwieldy U.N. process after the letdown a year ago at a much-anticipated summit in Copenhagen.
After debating into the early hours, the conference overrode a lone objection by Bolivia, which argued the plan did not do enough to do enough combat climate change.
The Cancun Agreements created institutions for delivering technology and funding to poorer countries, though they did not say where the funding would come from.
COP 16 Climate Change Conference, Cancun
In urging industrial countries to move faster on emissions cuts, it "recognized" the goal recommended by scientists to reduce greenhouse gas emissions from industrial countries by 25 to 40 per cent from 1990 levels within the next 10 years. Current pledges amount to about 16 percent.
Mexican President Felipe Calderon, in a 4 a.m. speech, declared the conference "a thoroughgoing success," after two separate agreements were passed. The agreements shattered "the inertia of mistrust" that had settled over the frustrated efforts for a broad climate treaty, he said.
One of the agreements renewed a framework for cutting greenhouse gas emissions but set no new targets for industrial countries. The second created a financial and technical support system for developing countries facing grave threats from global warming.
Foreign Secretary Patricia Espinosa, the conference president, gaveled the deal through early Saturday over the objections of Bolivia's delegate, who said it was so weak it would endanger the planet.
Decisions at the U.N. climate talks are typically made by consensus, but Espinosa said consensus doesn't "mean that one country has the right to veto" decisions supported by everyone else.
The accord establishes a multibillion dollar annual Green Climate Fund to help developing countries cope with climate change, though it doesn't say how the fund's money is to be raised. Last year in Copenhagen governments agreed to mobilize $100 billion a year for developing countries, starting in 2020, much of which will be handled by the fund.
The agreements also set rules for internationally funded forest conservation, and provides for climate-friendly technology to expanding economies.
Espinosa won repeated standing ovations from a packed conference hall for her deft handling of bickering countries and for drafting an acceptable deal that fully satisfied no one.
Environmentalists cautiously welcomed the deal.
It "wasn't enough to save the climate," said Alden Meyer of the Washington-based Union of Concerned Scientists. "But it did restore the credibility of the United Nations as a forum where progress can be made."
The Cancun deal finessed disputes between industrial and developing countries on future emissions cuts and incorporates voluntary reduction pledges attached to the Copenhagen Accord that emerged from last year's climate summit in the Danish capital.
It struck a skillful compromise between the U.S. and China, which had been at loggerheads throughout the two week conclave on methods for monitoring and verifying actions to curtail greenhouse gases.
"What we have now is a text that, while not perfect, is certainly a good basis for moving forward," said chief U.S. negotiator Todd Stern. His Chinese counterpart, Xie Zhenhua, sounded a similar note and added, "The negotiations in the future will continue to be difficult."
The accord "goes beyond what we expected when we came here," said Wendel Trio of the Greenpeace environmental group.
Underscoring what's at stake in the long-running climate talks, NASA reported that the January-November 2010 global temperatures were the warmest in the 131-year record. Its data indicated the year would likely end as the warmest on record, or tied with 2005 as the warmest.
The U.N.'s top climate science body has said such swift and deep reductions are required to keep temperatures from rising more than 2 degrees Celsius (3.8 F) above preindustrial levels, which could trigger catastrophic climate impacts.
Solon protested that the weak pledges of the Copenhagen Accord condemned the Earth to temperature increases of up to 4 degrees Celsius (7.2 F), which was tantamount to "ecocide" that could cost millions of lives.
He also complained that the text was being railroaded over his protests in violation of the U.N.'s consensus rules.
In the 1992 U.N. climate treaty, the world's nations promised to do their best to rein in carbon dioxide and other heat-trapping gases emitted by industry, transportation and agriculture. In the two decades since, the annual conferences' only big advance came in 1997 in Kyoto, Japan, when parties agreed on modest mandatory reductions by richer nations.
But the U.S., alone in the industrial world, rejected the Kyoto Protocol, complaining it would hurt its economy and that such emerging economies as China and India should have taken on emissions obligations.
Since then China has replaced the U.S. as the world's biggest emitter, but it has resisted calls that it assume legally binding commitments - not to lower its emissions, but to restrain their growth.
Here at Cancun such issues came to a head, as Japan and Russia fought pressure to acknowledge in a final decision that they will commit to a second period of emissions reductions under Kyoto, whose current targets expire in 2012.
The Japanese complained that with the rise of China, India, Brazil and others, the 37 Kyoto industrial nations now account for only 27 percent of global greenhouse emissions. They want a new, legally binding pact obligating the U.S., China and other major emitters.