The United Nations began negotiations on a sweeping new pact in March after governments agreed last year to work out a treaty to succeed the Kyoto Protocol by the end of next year.

"If this momentum continues you will get an agreement that is not too full of compromises," said Rajendra Pachauri, head of the U.N. Intergovernmental Panel for Climate Change, during a seminar at the Asian Development Bank annual meeting in Madrid.

Without a deal to cap greenhouse gas emissions around 2015, then halve them by 2050, the world will face ever more droughts, heatwaves, floods and rising seas, according to the U.N. panel.

The United Nations hopes to go beyond Kyoto by getting all countries to agree to curbs on emissions of greenhouse gases that fuel global warming.

Only 37 rich nations were bound to cut emissions under Kyoto. The United States, one of the world's biggest polluters, refused to join the agreement.

The next talks, to be held in Germany in June, will address funding technology to mitigate climate change -- a key demand from developing countries who say rich countries should foot much of the bill.

Getting the private sector on board with a well regulated carbon emissions trading system is key to long-term financing, according to delegates at the ADB seminar.

"Investors need some certainty they will get some return," said Simon Brooks, vice president at the European Investment Bank.

PRESTIGE AND POLITICS

India's Pachauri said popular awareness of global warming had risen sharply over the last 12 months and put pressure on Washington and other governments for action.

He said he believed it would be very difficult for any country to remain outside a climate change pact.

"There's a question of national prestige involved," said Pachauri, head of the U.N. panel that last year shared the Nobel Peace Prize with former U.S. President Al Gore.

President George W. Bush pulled the United States out of Kyoto in 2001, saying the pact would hurt the economy and was unfair since it excluded big developing nations from committing to emissions cuts.

Key to a new agreement is Asia, notably China, said Odin Knudsen, a managing director for JP Morgan & Chase.

"China is making tremendous progress," said Knudsen, a specialist in climate change. "It's in China's interests and they want to be energy efficient."

In the last 3 decades Asia's energy consumption has grown 230 percent and the region has gone from producing one tenth of world greenhouse gas emissions, to a quarter, according to the Asian Development Bank.

The United Nations calculates global warming will cause a 30 percent decline in crop yields in central and south Asia by 2050 and decrease freshwater availability for over a billion people.

Faced with such threats, China is switching over to renewable energy sources which are expected to provide more than 30 percent of its power needs by 2050, according to the United Nations.