The Kyoto pact was due to expire this year, so failing to agree on an extension would have been a major setback for the talks. Despite objections from Russia, which opposed rules limiting its use of carbon credits, the accord was extended through 2020 to fill the gap until a wider global treaty is expected to take effect. However, the extension covers only about 15 percent of global emissions after Canada, Japan, New Zealand and Russia opted out.
The extension was adopted by a UN climate conference after hard-fought sessions. The decisions also include vague promises of financing to help poor countries cope with climate change and an affirmation of a previous decision to adopt a new global climate pact by 2015.
Though expectations were low for the Doha talks, many developing countries rejected the deal as insufficient to put the world on track to fight the rising temperatures that are shifting weather patterns, melting glaciers and raising sea levels.
The 2-decade-old UN climate talks have failed so far in their goal of reducing the carbon dioxide and other greenhouse gas emissions that a vast majority of scientists says are warming the planet.
The 1997 Kyoto Protocol, which controls the emissions of rich countries, is considered the main achievement of the negotiations, even though the United States rejected it for its lack of any binding commitments on China and other emerging economies.
U.S. climate envoy Todd Stern said the United States couldn't accept a provision in the Doha deal that said the talks should be "guided" by principles laid down in the UN's framework convention for climate change.
The goal of the UN talks is to keep temperatures from rising more than 3.6 degrees Fahrenheit, compared to preindustrial times. Temperatures have already risen about 1.4 degrees above that level, according to the UN's top climate body.