Climate change: What's fact, what's speculation?
That's the burning question for intergovernmental panel members
VALENCIA (SPAIN) - WHAT do we know for sure about climate change, and what do we only think we know?
This question is set to be discussed by scientists and policymakers from 145 governments at a week-long conference that opened here yesterday and which will release the last of four UN reports this year on global warming.
The document by the Intergovernmental Panel on Climate Change (IPCC), co-winner of this year's Nobel Peace Prize, sums up the scientific consensus on global warming.
It covers how rapidly the Earth is warming, the impact and the effects already observed, as well as what steps can be taken to keep the planet from overheating beyond control.
A summary about 25 pages long will be negotiated line by line this week, then adopted by consensus.
The report, to be issued on Saturday by UN Secretary-General Ban Ki Moon, will provide the factual underpinning for a crucial meeting next month in Indonesia, which will begin work on a new global strategy to curb greenhouse gas emissions.
The Kyoto Protocol, which had assigned binding reduction targets to 36 countries in its first phase, expires in 2012.
This week's report will be the first to include a brief chapter on 'robust findings and key uncertainties', in which the authors pick out what they believe are the most relevant certainties and doubts about climate change.
Among the uncertainties cited in an early draft are: the lack of data from key areas of the world, conflicting studies on the effects of cloud cover and carbon soaked up by oceans, and projections on how planners in developing countries will factor climate change into their decisions.
The IPCC is already under criticism for the selectivity and language of the policy summaries, which have been softened on several points because of objections by countries such as the United States, China and Saudi Arabia.
The World Wildlife Fund for Nature, one of several environmental groups invited to observe the process, yesterday accused some governments of 'politically inspired trimming' of facts during negotiations.
This diluted the urgency to make deep cuts in emissions of carbon dioxide and other greenhouse gases, they said.
Mr Yvo de Boer, the United Nations' top climate official, said that getting governments to sign off on the summaries is a critical element of the IPCC's value.
'Because those reports are adopted by governments, there is no government that can now stand up and say, 'I don't accept what's in the IPCC report.' That means that you have a common scientific base,' he said in an interview on Friday.
At yesterday's conference opening, he said that political failure to tackle global warming would be 'criminally irresponsible'.
He said: 'Climate change will hit hardest the poorest and most vulnerable countries. Its overall effect, however, will be felt by everyone and will in some cases threaten people's very survival.
'Failing to recognise the urgency of this message and act on it would be nothing less than criminally irresponsible.'