KEVIN Rudd has launched a full frontal assault on global warming sceptics, lumping Opposition Leader Malcolm Turnbull in with a ''new league of world government conspiracy theorists'' he accuses of sabotaging progress on a climate treaty.
The attack came as senior politicians conceded a treaty to cut greenhouse gas emissions is not possible this year, and will be delayed at least six months.
Wealthy nations said the best hope for next month's Copenhagen climate summit was a ''politically binding'' agreement, setting out timelines and emissions targets for rich nations, as well as funding for poor nations to adapt to climate impacts.
The pessimism followed a week in which 50 African nations briefly walked out of UN climate talks in Barcelona, accusing the leaders of wealthy nations - including, by name, Mr Rudd - of not doing enough to cut emissions.
''I don't think we can get a legally binding agreement by Copenhagen - I think that we can get that within a year after Copenhagen," UN climate chief Yvo de Boer said.
Climate Change Minister Penny Wong said the minimum result for Copenhagen to be considered a success would be ''an effective political agreement''.
Yesterday the Prime Minister accused conservative politicians and media commentators of ''quite literally holding the world to ransom, provoking fear campaigns in every country they can''.
Speaking in Sydney, he said climate sceptics came in several guises: from those in outright denial - comparing them with cigarette companies that dismissed a link between smoking and lung cancer - to those who paid lip service to the scientific evidence but preached a wait-and-see response. ''It's time to remove any polite veneer from this debate,'' Mr Rudd said. ''The stakes are that high.''
''If Copenhagen does not deliver the outcome we so urgently need, no individual climate change sceptic will be responsible, but each of them will have played their part.''
He said Mr Turnbull's refusal to back the proposed emissions trading scheme was evidence of entrenched scepticism in conservative politics.
The speech came as negotiations continue over amendments to the emissions trading scheme. Senator Wong confirmed the Government would not accept all the Opposition's proposals due to updated Treasury costings revealing a massive shortfall in revenue from the scheme.
Mr Turnbull dismissed Mr Rudd's attack as an attempt to distract attention from the controversy over border protection policy. ''He ought to calm down and concentrate on the negotiations,'' Mr Turnbull said.
This week's UN climate meeting was the last before the Copenhagen conference. Observers believe a legal treaty may be possible at a second Copenhagen meeting in mid-2010 or at another UN summit in Mexico next December.
The US this week tried to push responsibility for the perceived failure of climate talks on to China. Its chief climate envoy, Todd Stern, said the US would not agree to emissions targets unless China made similar moves.
But a new analysis suggests developing countries are acting. Consultants Ecofys found major developing nations are on track to slow their emissions growth by more than 20 per cent by 2020.
This meets one of the Rudd Government's conditions for Australia to set a target of a 25 per cent cut in emissions by 2020. But the condition that Australia wants other rich nations to meet - that they agree to cut emissions by at least 25 per cent in total - has not been met.