Hopes of a breakthrough at the 12-day climate summit in Copenhagen were boosted late yesterday after the US government announced it would start to regulate six greenhouse gases, including carbon dioxide, as dangerous pollutants.
Head of the US Environmental Protection Agency Lisa Jackson said her agency is now authorised to make reasonable efforts to reduce air pollution.
She said: 'It means that we arrive at the climate talks in Copenhagen with a clear demonstration of our commitment to facing this global challenge.'
The declaration means US President Barack Obama can now bypass Congress to order cuts in emissions.
The US is the world's second largest emitter of greenhouse gases behind China.
'It will only help to persuade delegates and observers from other countries that the US is seriously using all the tools it has,' David Doniger, policy director of the National Resources Defense Council's climate centre, said.
While the US announcement provided welcome momentum on the first day of the talks, delegates said the next few days would see different countries lay out their positions.
'It's going to be an exercise in clearing the undergrowth over the next three or four days,' a senior delegate from a developed country told AFP.
Towards the end of the week, former Danish climate minister Connie Hedegaard, chairing the December 7-18 conference of 194 nations, will carry out a 'stock-taking' of positions.
Ms Hedegaard will then put together a draft blueprint for the conference's outcome, which will be put to environment ministers, meeting early next week, and then to more than 110 heads of state and government attending the climax.
The leaders include US President Barack Obama, Premier Wen Jiabao of China, Indian Prime Minister Manmohan Singh, Prime Minister Yukio Hatoyama of Japan, Brazil's President Luiz Inacio Lula da Silva and the heads of the 27 countries of the EU.
The official was upbeat about progress on many peripheral issues, but said the core question of emissions controls would be a matter for the summit.
The talks, under the banner of the UN Framework Convention on Climate Change (UNFCCC), are a landmark.
They are the boldest attempt in a 17-year odyssey to turn back the threat of climate change through global political consensus.
If all goes well, the conference will yield an outline agreement that sets down pledges by major emitters of greenhouse gases for curbing their pollution.
It will also set down the principles of long-term financing, possibly worth hundreds of billions of dollars, to help wean poor countries off high-carbon technology and beef up their defences against climate change.
Two years of talks have taken place in the run-up to Copenhagen and further negotiations would be needed over the next year to flesh out the agreement.
Once agreed and ratified, the accord would take effect from 2013.
To show good faith, rich countries are under pressure to kick in €10bn a year in fast-track funding over the three years from 2010 to 2012.
Role of UN compiling reports
Two of Ireland's leading scientists have strongly disagreed over the role of the United Nations in compiling reports on climate change.
Professor Ray Bates of UCD has said the process would be more rigorously scientific if the International Council for Science undertook the job.
However, Professor John Sweeney of NUI Maynooth, has said the UN's Intergovernmental Panel on Climate Change is the most successful partnership between government and science in history.
Professors Bates and Sweeney are highly regarded academics who both strongly believe that human activity is causing climate change.
However, recently leaked emails from East Anglia University suggest that some climate scientists tried to suppress reports they did not like.
Prof Bates, UCD's Adjunct Professor of Meteorology, says the email is extremely damaging to the reputation of the UN's IPCC.
He said there was a case for making the science of climate change more objective by removing it from the control of the UN and giving it to the International Council for Science.
However, John Sweeney, Professor of Geography at NUI Maynooth and an IPCC editor, said the UN climate body had led to spectacular progress over two decades.
He argued that national academies often had committee members who were not representative of cutting-edge research or public servants legally barred from taking independent stances.
