The chief advisor to the UN on climate change has claimed that a US revolution could come about as a result of proposed carbon cuts.

The head of the Intergovernmental Panel on Climate Change (IPCC), Rajendra Pachauri, claimed that if Barack Obama commits to the carbon cuts campaigners and scientists say are needed, he could face a “revolution”.

In an interview with the Guardian, Pachauri said: "He [Obama] is not going to say by 2020; 'I'm going to reduce emissions by three per cent'. He'll have a revolution on his hands. He has to do it step by step."

Obama has said the US aims to reduce its carbon emissions to 1990 levels by 2020, a target almost within the 25-40 per cent recommendation made by the IPCC to avoid dangerous climate change.

Pachauri’s comments come as researchers at the Copenhagen conference said that IPCC estimates of environmental effects on the likely rise of sea level need to be revaluated.

Despite Europe’s pledge to cut emissions greenhouse gas emissions by 20-30 per cent on 1990 levels by 2020, the IPCC has warned polar ice cap melting in Greenland could drive sea levels to rise more than a metre by 2100.

The US president’s new chief climate negotiator, Todd Stern, has also said that a US target of 25-40 per cent cuts is “not possible.”

But this position could jeopardize a new Kyoto treaty, the first phase of which expires in 2012. Environmental campaigners have demanded a resolution must be agreed at the UN conference in Copenhagen this December.

Obama has announced long-term targets of an 80 per cent target on emissions by 2050, but critics say that short-term pledges will be of more value in convincing other developed countries such as China to sign the treaty.

Pachauri echoed these remarks, saying that the US needed stricter involvement in the short term, but questioned whether this would be on the agenda by this December.