Poor nations say wealthy countries became rich using coal, oil and gas and that they must be allowed to burn fossil fuels to escape poverty. Rich nations say major developing economies, such as China, India and Brazil, must submit to emissions cuts if the world has any chance of halting dangerous climate change.

The stakes are high. Two U.N. reports this month said greenhouse gases had reached record levels in the atmosphere and a warming world would likely bring more floods, stronger cyclones and more intense droughts.

The Organisation for Economic Cooperation and Development (OECD) said global average temperatures could rise by 3-6 degrees Celsius by the end of the century if governments failed to contain emissions, bringing unprecedented destruction as glaciers melt and sea levels rise.

It said an 80 per cent rise in global energy demand was set to raise carbon dioxide (Co2) emissions by 70 percent by 2050 and transport emissions were expected to double, due in part to a surge in demand for cars in developing nations.

E.U. climate negotiator Artur Runge-Metzger told a news conference unless progress was made, "(People) will just lose confidence in this travelling circus. How high must the water get in these conference places before the negotiators start deciding?"

Flash flooding from heavy rain killed at least six people in Durban the night before the talks opened.

The Kyoto Protocol commits most developed nations to legally binding targets to cut greenhouse gas emissions.

The talks in Durban are the last chance to set another round of targets before the first stage of the protocol ends in 2012.

"It may seem impossible, but you can get it done," Christiana Figueres, executive secretary of the UN Framework Convention on Climate Change, told delegates.

Diplomats hope there will be some progress on funding to help developing countries most at risk from the effects of global warming, particularly in Africa and small island states.

Rich nations have committed to a goal of providing $100 billion a year in climate cash by 2020. But the United States and Saudi Arabia have objected to some aspects of the Green Climate Fund that will help manage it.