A final attempt to iron out differences between industrialized and developing nations on a climate deal ahead of next month's summit to replace a carbon emissions pact will begin today in Barcelona, Spain. But an insider predicted that negotiators at the five-day meet are on a "mission impossible".

Differences also remain over the cost of transfer of technology. Statistics show that since 2008, the developed world has transferred no more than $100 million in technological aid to poor countries so far. However, the cost of adaptation to climate change in developing countries will be in the order of $75-100 billion per year from 2010 to 2050, according to a World Bank study's preliminary findings.

"China has recently acted faster than Western countries and has shown more willingness than them to transfer green technologies to other developing countries," Lot S. Felizco, climate change delegation member of the Philippines, told China Daily in an exclusive interview last week. "We can see China's commitment and actions on transferring technologies to the developing countries, but we didn't see big action from industrialized economies."

Felizco urged developed countries to return to track and accelerate negotiations in Barcelona. "If they (developed countries) fail to live up to their promises, it means they don't take UN treaties seriously. They will lose trust among the developing countries, which is dangerous," he said.

With less than six weeks to go until Copenhagen, Denmark's Prime Minister Lars Loekke Rasmussen invited US President Barack Obama and other heads of state to the conference to make it a success.

Speaking to BBC's Newsnight, Rasmussen said: "Without the presence of heads of state and governments we can't close a deal which can come into immediate effect and can be implemented immediately... It is a direct call to President Obama. But not only to him. This isn't just a question about the American position. I feel strong willingness from many leaders, and I have spoken to many in the last couple of weeks, that what we need now is to bring those bilateral talks into one meeting room."

Agencies contributed to this story