Quote:BANGKOK - U.N. talks on ways to fight climate change are on track to approve a blueprint for governments on Friday, but major differences are still being thrashed out, delegates say.

Arguments about the costs of curbing emission of greenhouse gases and stabilizing levels of the gases in the atmosphere are among the more contentious issues and talks could go down to the final minutes at the meeting in Bangkok, they said.

Two delegates who spoke to Reuters on condition of anonymity were confident a document would be agreed by Friday.

"There's no mood here to cause anything destructive," one said after talks dragged on until the early hours of Thursday. Another long day of talks was expected.

"Some countries are being difficult and we don't know how difficult until we come to the final moment," he said.

Robert MacFadden of the U.S. delegation said there were many complex issues being debated at the talks, not just one.

Scientists and government officials from more than 100 countries have been meeting since Monday to discuss the report by the U.N. Intergovernmental Panel on Climate Change (IPCC), which draws on the work of 2,500 scientists.

The report is the third to be released this year. The previous two painted a grim future of human-induced global warming causing more hunger, droughts, heatwaves and rising seas.

A draft of the latest report estimates that stabilizing greenhouse gas emissions will cost between 0.2 percent and 3.0 percent of world gross domestic product by 2030, depending on the stiffness of curbs on rising emissions.

For example, by 2030, the costs of letting greenhouse gas concentrations rise to 650 ppmv (parts per million volume) of carbon dioxide-equivalent are 0.2 percent of global gross domestic product, it says.

The lowest level of 445 ppmv would be the most costly and arguably impossible to achieve given the rapid increase in greenhouse gas emissions from burning fossil fuels, agriculture and mining.

Current concentrations are now at about 430 ppmv of CO2-equivalent and rising sharply.

EU-CHINA RIFT

One of the main issues in Bangkok, the delegates said, was a rift between Europe and China.

The European Union, which has already set a target of cutting greenhouse gas emissions by at least 20 percent by 2020, says curbing emissions will not cost that much.

But China objects to any language that suggests a cap on emissions or stabilization levels that could leave it vulnerable to demands in future climate talks to slow its rapid economic growth or spend vast sums on cleaner technology.

"Basically, what is happening is that the Europeans want to say it costs nothing and lots of other people want to emphasize the notion that it costs something. It's about as simple as that," one of the delegates said.

The other delegate said no particular stabilization target had been set in the talks. But the European Union says a 2 degree Celsius rise is a threshold for "dangerous" changes to the climate system, implying a fairly minimal rise in greenhouse gas concentrations.

"The EU wants a long way below 550 ppm. China is somehow wanting to exclude information about the low scenarios and others are too," the delegate said.

Global environment group WWF said on Thursday China should not be labeled a villain and Chinese delegates had been raising useful issues during the meeting.

"They have the renewable portfolio standard that the U.S. is currently lacking. They have car fuel-efficiency standards that are amongst the strictest in the world," said Hans Verolme, director of the WWF's Global Climate Change Programme.

A news report has just mentioned that the main critics of this report are China and the USA. No surprise that those two don`t like it is there?