The UN's top body on climate change on Friday released a report approved by delegates from 120 nations, laying out how the world could avoid the worst impacts of global warming with minimal economic damage.

As the Intergovernmental Panel on Climate Change meeting began in Bangkok on Monday, delegates warned that it was fanciful to believe all the players had the interests of the planet at the top of their agenda.

They said nations would inevitably fight to protect their own economic and political interests, and as the meeting got underway, reports crept out from behind the closed doors that some delegations were indeed playing politics.

But after all the battles, wrangling and interventions, most agreed that science had triumphed, with politics sometimes even playing a helping hand.

"You could argue that some of the delegates that are most critical and difficult towards the text are the most important to the text," said Michael Williams, spokesman for the UN's Environment Programme.

"By challenging and nitpicking and asking questions, that just increases the chances of us getting a better text rather than just being polite about it."

The United States, usually fingered as a key culprit in protecting economic interests over climate change concerns, escaped largely unscathed from the conference, with most delegates pleasantly surprised by its performance.

"I was relieved to see the Americans behaving, that makes such a difference," said Stephan Singer, of the conservation group WWF.

Gavin Edwards from Greenpeace also said the United States delegation had kept a low profile, but "they burst into life when it came to nuclear power."

Throughout the week, news emerged from various camps that India, China and Brazil were pushing their positions with vigour, trying to get rich countries to recognise their historical burden for global warming.

Shouldering most of the blame for trying to stick a political oar in the proceedings was China, who were said to be trying to play up the costs of taking immediate action to battle global warming.

Michael Mueller, a German environment ministry official who attended the talks, accused China of impeding progress towards cutting greenhouse gases, and said its delegates had been "masters of deception and the art of interpretation."

But even the green groups eventually gave China a pat on the back.