LIMA - UN members on Sunday adopted a format for national pledges to cut greenhouse gases, the heart of a planned pact to defeat climate change.
At a marathon conference in the Peruvian capital of Lima, they also approved a broad blueprint for negotiations leading up to the historic deal, due to be sealed in Paris in December 2015.
"The document is approved," declared Environment Minister Manuel Pulgar-Vidal of Peru as exhausted delegates cheered and clapped.
The agreement - dubbed the Lima Call for Climate Action - sets down the foundations for what is envisioned as the most ambitious agreement in environmental history.
Sealed in Paris in 2015 and taking effect by 2020, it would for the first time bind all the nations of the world into a single arena for curbing heat-trapping carbon gases that drive dangerous climate change.
Its aim is to limit global warming to no more than two degrees Celsius (3.6 degrees Fahrenheit) over pre-industrial levels, averting what could be potentially catastrophic damage to Earth's climate system by the turn of the century.
But the Lima deal came at the cost of a major compromise to bridge a rift between rich and poor countries that campaigners said could crimp the effectiveness of the Paris outcome.