A UN-ordered review has said that the global panel on climate change needed to 'fundamentally reform' how it operates after embarrassing errors in a landmark report dented its credibility.
The five-month probe recommended an overhaul of the position of Rajendra Pachauri, chair of the Intergovernmental Panel on Climate Change (IPCC).
The UN ordered the review by the InterAcademy Council, which groups 15 leading science academies, after a political uproar over its landmark 2007 study that critics called the 'Climategate' scandal.
The study found that the IPCC has been 'successful overall' but called for changes in its leadership structure, stricter guidelines on source material and a check on conflicts of interests.
The IPCC released a 938-page study in 2007 pointing to evidence that climate change was already hurting the planet, building momentum for global action to limit carbon emissions that mostly come from burning coal, gas and oil.
But in the run-up to a highly anticipated climate summit in Copenhagen in 2009, the IPCC was rocked by a scandal involving leaked emails which critics say showed that they skewed data.
'I think the errors made did dent the credibility of the process - there's no question about it,' said Harold Shapiro, a former president of Princeton University who led the review.
One part of the report said that Himalayan glaciers which provide water to one billion people in Asia could be lost by 2035 - an assessment later traced to a magazine article.
The IPCC has admitted that the Himalayan glacier reference was wrong, but says its core conclusions about climate change are sound.
In Brussels, European Climate Action Commissioner Connie Hedegaard said that 'after all the fights' the main findings of the 2007 report are 'still unchallenged'.
'The bottom line, and this report says it, is that overall the IPCC has done a very good job, but there were some minor errors and they were corrected,' she told AFP.
The review said the glacier reference showed that the IPCC - driven by a 'confirmation bias' to prove ideas - did not pay close enough attention to dissenting viewpoints, which should be presented more openly in studies.
'There were a number of reviewers who pointed out that this didn't seem quite right to them and that just was not followed through,' Mr Shapiro said.
Scientist criticised
The UN review said that guidelines on source material for the IPCC were 'too vague' and called for specific language - and enforcement - on what types of literature are unacceptable.
Mr Pachauri, an Indian scientist primarily employed by the TERI think-tank, has come under criticism, with some arguing that he had a vested interest by business dealings with carbon trading companies.
The review recommended creating a more permanent and professional position of IPCC chair, changing the current part-time arrangement.
It also said that the chair tenure - two terms of six years each - was too long.
'Formal qualifications for the chair and all other bureau members need to be developed, as should a rigorous conflict-of-interest policy to be applied to senior IPCC leadership' and authors, the review said.
Mr Pachauri said after the report that he would let member-states decide his future.
Mr Shapiro said that the study was making a 'recommendation for the process as a whole' and was not criticising Mr Pachauri.
'It was not motivated by or in any way connected to Dr Pachauri or any other leader in IPCC,' he said.
The IPCC's study, known formally as the Fourth Assessment Report, helped earn it a Nobel Peace Prize which it co-shared with former US vice-president turned environmental activist Al Gore.
But momentum for a post-Kyoto treaty on climate change has since dwindled. Critics have seized on the scandal to challenge the scientific basis behind climate change.
Environmental group Greenpeace welcomed the review and pointed to severe weather this year - including Pakistan's massive floods and Russia's worst-ever heatwave - as evidence of global warming.
'Despite the muckraking and crude attempts to undermine the findings of the IPCC, the scientific consensus is clear, climate change represents a serious threat to the future of the environment and humanity,' Greenpeace said.
