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.

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 UN panel that last year shared the Nobel Peace Prize with former President Al Gore.

President George W. Bush pulled the US 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.