THE HARD-FOUGHT deal at a global climate conference in South Africa keeps talks alive but doesn't address the core problem: The world's biggest carbon polluters aren't willing to cut emissions of greenhouse gases enough to stave off dangerous levels of global warming.

"We avoided a train wreck and we got some useful incremental decisions," said Alden Meyer, of the Washington-based Union of Concerned Scientists.

"The bad news is that we did very little here to affect the emissions curve which is accelerating, and the impacts of climate change which are climbing day by day."

The two-decade-long climate negotiations have been focused on preventing global temperatures from rising more than 2 degrees Fahrenheit above current levels by the end of this century.

Yesterday's deal agreed to in Durban, extends by five years the Kyoto Protocol, the 1997 agreement that has binding emissions targets for some industrial countries but not the world's biggest carbon polluters, China and the United States.