We have not been effective at telling the public, 'yes, we made a mistake', but that does not change the fact that the glaciers are melting Dr Rajendra Pachauri, IPCC chairman

The head of the Intergovernmental Panel on Climate Change (IPCC) has said the organisation needs to learn from recent criticisms and modernise its workings.

But despite making an error over Himalayan glacier melt in its landmark 2007 report, the panel's basic conclusions remain sound, he said.

Rajendra Pachauri was speaking at the opening session of a UN-commissioned review into the IPCC's workings.

The review is due to hear from some of the IPCC's critics in coming months.

Dr Pachauri admitted his organisation had been ill-prepared and ill-resourced to deal with the recent criticism it has received.

"We have to listen and learn all the time and evolve in a manner that meets the needs of society across the world," Dr Pachauri told the review panel.

While the IPCC admits to including an erroneous date by which Himalayan glaciers might disappear in its 2007 Fourth Assessment report, Dr Pachauri said: "We have not been effective at telling the public, 'yes, we made a mistake but that does not change the fact that the glaciers are melting'."

And he rebutted accusations made in some newspapers and websites that the IPCC's intentions have been other than honest.

"I'm afraid these allegations of corruption and malfeasance are completely misplaced and distorted," he told BBC News.

"But we have to make sure we do our best and live up to the expectations of the public and of governments, which are basically our masters."

Friends and foes

Back in February, the IPCC suggested setting up an independent review, feeling that its 20-year-old rules and working practices perhaps needed an overhaul, and also feeling it was perhaps ill-equipped to counter the heat of unprecedented political attention in the wake of "Himalayagate" and the release of emails stolen from the University of East Anglia's Climatic Research Unit.

We will try to put together some public sessions of those who are I would say 'thoughtful critics' - very very respectable and highly thought of scientists with criticisms of the organisation Professor Harold Shapiro, IPCC review chairman

Governments endorsed the idea; and in March, UN Secretary-General Ban Ki-moon commissioned the review from the InterAcademy Council, an international umbrella body for science academies such as the UK's Royal Society.

The council established a 12-strong review panel, chaired by US economist Professor Harold Shapiro, a former advisor to both Presidents George Bush and Bill Clinton.

"We're neither friend nor foe," he told BBC News.

"We're a neutral body; most of us have never participated in the IPCC, but all of us have been part of organisations where quality control is an issue; and we have experience in dealing with that, and we hope that experience can help the IPCC."

After Dr Pachauri's presentation, the panel heard from senior UN figures including Janos Pasztor, director of Mr Ban's climate change support team.

"Nothing that has been alleged in recent press reports or from hacked emails has altered the consensus on climate change," he said.

"However, as the IPCC embarks on its fifth assessment report, it's important that… the potential for future errors is minimised."

One of the areas in which the IPCC has come in for criticism concerns its use of data from non-peer-reviewed sources such as the WWF report in which originated the erroneous Himalayan melting date of 2035.

But Dr Pachauri said the organisation had to use such sources - sometimes they were all that was available. It was just that on this occasion, its strict procedures had not been followed.

"The media and several other people have completely misunderstood the need for using non peer-reviewed literature," he said.

"The loose term that's used is 'grey literature' as though this is grey muddied water flowing down the drains.

"But I'd like to highlight what non-peer-reviewed literature constitutes: reports from the International Energy Agency, the OECD, the UN Food and Agriculture Organization, the World Bank, the Asian Development Bank... and some NGOs - there are some highly prestigious NGOS that are doing detailed academic work, and you cannot ignore this."

Thought sought

Professor Shapiro said that in due course, the review panel would hear more critical testimony.

"We will not have time to hear from every critic of the IPCC," he said.

"But we will try to put together some public sessions of those who are I would say 'thoughtful critics' - very very respectable and highly thought of scientists with criticisms of the organisation - we definitely want to hear that."

In addition, the panel's website invites comments from anyone.

The panel, which comprises eminent scientists and economists from both the developed and developing worlds including Nobel prize-winning ozone chemist Mario Molina, has until the end of August to prepare its report.

Its conclusions will be peer-reviewed before being presented at the IPCC's October meeting, the point at which Dr Pachauri and his team are due to finalise plans for the fifth assessment report, due in 2013.

Richard.Black-INTERNET@bbc.co.uk