The biggest climate talks in history opened yesterday with a stark UN warning about risks of rising seas and desertification and a prediction by hosts Denmark that a deal to combat climate change was "within reach".
Danish Prime Minister Lars Lokke Rasmussen told delegates from 190 nations that momentum was building for a deal and that 110 world leaders including US President Barack Obama would attend a summit at the end of the December 7-18 talks.
The presence of so many leaders meant "an opportunity the world cannot afford to miss", he said of the talks, aimed at agreeing a pact to replace the existing UN Kyoto Protocol that runs to 2012. "A deal is within our reach."
Politicians and scientists urged the meeting, attended by 15,000 delegates, to agree immediate action to curb greenhouse gases and come up with billions of dollars in aid and technology to help poorer countries limit their emissions.
Rajendra Pachauri, the head of the UN panel of climate scientists, said action was needed to avoid cyclones, heatwaves, floods, and possible loss of the Greenland ice sheet, which could mean a sea level rise of seven metres over centuries.
He said that even a widely accepted goal of limiting global warming to a maximum of two degrees Celsius over pre-industrial times could still bring an increase in sea levels that "could submerge several small island states and Bangladesh".
"The evidence is now overwhelming that the world would benefit greatly from early action, and that delay would only lead to costs in economic and human terms that would become progressively high," he said.
He defended the findings by his panel after leaked e-mails from a British university last month led sceptics to say that researchers had conspired to exaggerate the evidence. He said there were rigorous checks on all research.
"Hopefully it will only be a small blip in the history of this process," Jonathan Pershing, the head of the US delegation who used to be an author on Pachauri's panel, said of the scandal, dubbed "Climategate".
Many nations say that the United States is the key to a deal in Copenhagen. President Obama is aiming to cut US emissions by three per cent below 1990 levels by 2020 but legislation is stalled in the Senate.
The European Union said it may sharpen its carbon-cutting bid if the United States paid for more carbon cuts in poor nations, especially to curb deforestation.
Developing nations including small island states, which are most vulnerable to rising sea levels, demanded more action.
Alden Meyer, of the Union of Concerned Scientists, said Copenhagen was starting with two problems - a lack of US climate legislation and "issues of trust between north and south".
Developing states called for more action by the rich.
"So far we have not seen any real leadership" from rich nations, said Ibrahim Mirghani Ibrahim of Sudan, speaking on behalf of the Group of 77 and China.
Dessima Williams, of Grenada, speaking on behalf of small island states at risk from rising seas, said the group "will not accept a made-for-television solution... We are here to save ourselves from burning and from drowning."
Outside the conference centre, delegates walked past a slowly melting ice sculpture of a mermaid, modelled on the Danish fairy tale of The Little Mermaid, as a call for action.
The attendance of the leaders and pledges to curb emissions by all the top emitters - led by China, the United States, Russia and India - have raised hopes for an accord after sluggish progress in negotiations over the past two years.
World leaders did not attend when environment ministers agreed the Kyoto Protocol in 1997.
A Fijian climate campaigner broke down in tears in an appeal for the talks to save her island nation from rising seas. She then handed conference officials some Danish Lego blocks, meant to symbolise the foundations of an ambitious climate pact. In a major development, Washington took a step last night towards curbing US greenhouse gas emissions, aiding the first day of the biggest climate talks in history where 190 nations are seeking a deal to curb global warming.
The US Environmental Protection Agency ruled that greenhouse gases endanger human health, allowing it to regulate planet-warming gases without legislation from the Senate, where a Bill to cut US emissions by 2020 is stalled.
The ruling was welcomed at the opening day of talks in Copenhagen, where a record 15,000 participants are trying to work out the first new UN pact in 12 years to combat rising seas, desertification, floods and cyclones.
"This is very significant in the sense that if... the Senate fails to adopt legislation (on emissions), then the administration will have the authority to regulate," Yvo de Boer, head of the UN Climate Change Secretariat, told Reuters in Copenhagen.
The United States is the number two emitter behind China and is alone among industrialised nations outside the existing Kyoto Protocol that curbs emissions until 2012.
"This is great news and shows that the administration is committed to enforcing the Clean Air Act and addressing climate change," said Keya Chatterjee of the WWF environmental group.