The Kyoto Protocol on cutting greenhouse gas emissions will not stop climate change, a leading think tank has warned.
The report from the Institute for Public Policy Research (IPPR) in the UK, which has close links to the government, comes as some experts cite Britain's heat wave as further evidence of global warming.
Some experts see the heat wave as an omen of global warming
Even if the Kyoto agreement is fully implemented, greenhouse gas emissions worldwide will still increase by 70%, says the IPPR.
The think tank wants a new approach instead of the "horse trading" over emissions allowed under the treaty, which the government stresses is the only agreement in place.
Deciding safe level
The US and Australia have opted out of the protocol but will join those nations who have signed in Milan in December for talks on climate change.
Tony Grayling, associate director of the IPPR, said: "Kyoto will not stop climate change.
"The next international climate change negotiations must agree on a safe level of emissions in the long term and fair shares between nations.
"In practice, this should mean contraction of global emissions and convergence towards equal per capita emissions rights.
"This approach also has a better chance of bringing America, Australia and the developing nations on board."
Only show in town?
Mr Grayling urged the government to come clean about its acceptance of advice from the Royal Commission on Environmental Pollution.
The commission in 2000 said the UK needed to cut its carbon dioxide emissions by 60% by 2050.
Mr Grayling added: "Future international climate change policy should be based on sound science and social justice, not the horse trading that characterised the negotiations for the Kyoto Protocol."
A spokesman for the Department for Environment, Food and Rural Affairs said: "Kyoto remains the only internationally agreed method which will deliver reductions in greenhouse gas emissions.
"There may well on paper be other systems which would also deliver reductions, but the fact is that those systems remain on paper."
UK officials hope Russia will soon be able to ratify the Kyoto Protocol, which only comes into force after that ratification.
Professor John Whitelegg, Professor of Sustainable Development at the University of York, said the Green Party had always argued the protocol would achieve nothing without meaningful targets.
Professor Whitelegg, who is tipped to take up a leading role in the Green Party, said: "Blair and Prescott have boasted about 'leading the world' in terms of Kyoto.
"But all they'd done was agree to a treaty aimed at 5% carbon dioxide reductions by 2012, with slightly higher but still completely inadequate targets for the UK.
"Since then they've acknowledged that stopping climate change means achieving 60% carbon dioxide reductions globally by 2050, but in typical New Labour style they've called this an 'aspiration'."
He added: "New Labour has completely failed to grasp that 60% global reductions means a 90% reduction in high-polluting countries like the UK."
Earlier this week Australia's top government scientist echoed the view that the Kyoto Protocol would not stop climate change.
Graeme Pearman, chief scientist at the Australian CSIRO research body, said: "Slowing the rate of emissions of carbon dioxide into the atmosphere will not stop the increase of its concentration and thus climate change.
"We can show that reductions of 70% or more in current global emissions are necessary in order to stabilise concentrations. This is an enormous challenge."