| By Richard Black Environment correspondent, BBC News website |
Negotiations on a major UN climate report due to be released on Friday in Bangkok appear set to go to the wire. 
The third part of this year's assessment from the Intergovernmental Panel on Climate Change looks at ways to curb emissions and economic factors.
Delegates said an all-night sitting was possible, as session chairs tried to resolve outstanding issues.
Areas of dispute include language regarding the Kyoto protocol, the costs of cutting emissions and nuclear power.
China has repeatedly tried to tone down some elements of the draft text prepared for the start of the week-long discussions, delegates said.
It has been keen to remove references to scenarios which it fears could affect its short-term economic growth.
Nevertheless, observers suggested the outstanding issues could be resolved by the time the final text is due to be published, at 1300 Bangkok time Friday (0700GMT). 
There isn't the investment going into renewable technologies and energy efficiency that's sufficient for them to meet the potential they have 
"It is a painstaking process; the content of the report is detailed, and we expect negotiations to go through the night," said Catherine Pearce, international climate campaigner with Friends of the Earth UK, who is in Bangkok.
"Certainly one direction seems to be that there isn't the investment going into renewable technologies and energy efficiency that's sufficient for them to meet the potential they have to tackle this problem," she told the BBC News website.
The IPCC has already this year produced the two other elements of this global assessment report - its fourth since 1990 - dealing respectively with the science of climate change and on the potential impacts.
Stable futures
The draft report assesses the likely costs to the global economy of stabilising greenhouse gases at various concentrations in the atmosphere.
Aiming for a total greenhouse gas concentration equivalent to 650 parts per million (ppm) of carbon dioxide would reduce global GDP by about 0.2%, it says, whereas a more ambitious target of 550ppm would cost about 0.6% of global GDP. 
The current atmospheric concentration is about 425ppm, and many climate scientists now argue that only agreeing to keep below about 450ppm can prevent major climatic consequences.
The IPCC draft says keeping concentrations at this level could cost up to 3% of GDP.
"I can tell you that the probability for achieving 450ppm in anything approaching the world as it now is is almost impossible," commented Professor Stephen Schneider from Stanford University in California, who helped draft the IPCC's first report this year on the science of climate change.
"But a temperature rise over 2-3C leads to potential mass extinctions, serious problems with coasts, mountain glaciers disappearing, melting ice sheets... and one has to talk about stabilisation at 450-550ppm range to have a better than 20-30% chance of preventing that."
The IPCC does not make policy recommendations, but even so China, with some other delegations, has sought to play down references to the lower stabilisation levels.
Other "difficult" areas have concerned the report's conclusions on the potential of nuclear power, and on the Kyoto protocol, with major developing countries anxious to avoid any hint that they might be required to hit emissions targets in the future.