While the economic impact of tackling climate change has been the biggest sticking point, other issues such as whether to ramp up use of carbon-clean nuclear power have also caused fierce debate.
 
The final instalment in the three-part United Nations initiative on how to fight global warming will be unveiled on Friday.
 
The first two reports looked into the evidence and potential impact of global warming, while the third and final paper will focus on what action governments need to take to minimise its effects.
 
One delegate attending the Bangkok gathering described the cost issue as "the big 100,000-pound gorilla in the room".
 
"The cost is the underlying threat for some and the underlying opportunity for others," the source told the AFP news agency.
 
Amendments
 
Scientists say up to 30 per cent of the world's
species face extinction [GALLO/GETTY]
China has disagreed with estimates contained in a draft of the report, saying it will cost more and be harder to reduce greenhouse gas emissions than is detailed in the document.
 
It has sought more than 10 amendments to a draft of the report.
 
Carbon dioxide in the atmosphere is measured in parts per million (ppm), with current levels close to 400 ppm, although the figure is rapidly increasing.
 
If the world wants to stabilise carbon dioxide in the atmosphere at 640 ppm by 2030, it would cost 0.2 per cent of the average global gross domestic product (GDP), according to an early draft of the report.
 
The higher the targeted reduction, the higher the cost, said the draft.
 
Warning
 

"The costs for ambitious emissions reduction are very low compared to the dangers caused by climate change"

Stephan Singer,
WWF

But environmental groups have warned that even at a lower level, global  warming could cause droughts, floods and other disasters, while at 640 ppm the impacts could be catastrophic.
 
One European delegate accused China of trying to water down every single statement relating to the cost of fighting climate change.
 
"They want the evidence as low as possible on what we know about cost... China is trying to minimise the impact of the comments," the scientist told AFP.
 
While delegates battle it out, environmental groups have stressed that besides the economic impact, nations should also consider the potential devastation that climate change brings.
 
Stephan Singer, European head of climate and energy policy at environmental group WWF, said: "The costs for ambitious emissions reduction are very low compared to the dangers caused by climate change if they take no action."