The "rigour and honesty" of the scientists at the centre of a row over climate research, sparked when hundreds of emails were stolen from a world-renowned research centre, is not in doubt, an independent review said today.
But the review into the "climategate" affair, led by Sir Muir Russell, found the scientists at the University of East Anglia's climatic research unit (CRU) had not been sufficiently open about their studies.
The row was sparked when 13 years of emails were hacked from the server at the university and posted online, where they were seized upon by climate change sceptics who claimed they showed scientists manipulating and suppressing data to back up a theory of man-made climate change.
The review also found that a graph referred to in a now infamous email from the centre's head, Professor Phil Jones, in which he described a "trick" to "hide the decline" in data on temperatures, was "misleading" because it did not make plain what the scientists had done.
The graph which showed global temperature rises, and which was used in a report published in 1999 by the World Meteorological Organisation (WMO), did not show temperature data from tree-rings once they diverged from actual measurements in the 1960s, falling while real temperatures rose.
The review said it was not misleading to omit part of the tree ring temperature series but the process should have been made plain in the graph, caption or text.
The investigation cleared the researchers of other allegations levelled at the CRU by sceptics, including the suggestion the emails showed researchers were subverting the scientific peer review process to ensure papers they disagreed with were not published.
The scientists did not misuse the process by which the key international body on climate change prepares its reports on the impacts of global warming for governments, the review found.
But Sir Muir's inquiry found there was "unhelpfulness" in CRU's response to Freedom of Information requests, and evidence that emails might have been deleted to make them unavailable for any subsequent request.
The CRU was "unhelpful and defensive" in response to reasonable requests for information about the weather stations used to gather the temperature records.
But the review found that raw data frequently requested by sceptics from which global land temperatures were calculated was directly available from other sources, and the "code" to make the calculations, which they have also demanded was published, could be worked out independently.
Announcing the findings of the review, Sir Muir said: "Climate science is a matter of such global importance that the highest standards of honesty, rigour and openness are needed in its conduct.
"On the specific allegations made against the behaviour of CRU scientists, we find that their rigour and honesty as scientists are not in doubt."
Sir Muir said the allegation that the CRU had "something to hide" and its research into changes in global temperature could not be trusted because the scientists were concealing or manipulating data "does not stand up".
The panel conducted their own analysis of the data, which they said took "minutes" to download from publicly-accessible sources, without reference to what CRU had done with it and came up with similar results.
Anyone "competent" to analyse the data could have done so, and "very clearly nothing was hidden", according to one of the reviewers, Professor Peter Clarke of the University of Edinburgh.
The review also dismissed the allegation that work using tree-rings to reconstruct temperatures in the time before thermometers had selected data to produce the outcome the scientists were looking for.
Sir Muir said the review panel had not found any evidence that CRU scientists who contributed to the Intergovernmental Panel on Climate Change (IPCC) assessments had influenced them in any way that undermined the key reports prepared for governments.
But the review made "significant criticisms" of CRU's failure to be open about its research and its actions in withholding data.
And other institutions needed to learn the lessons of the "climategate" affair, including the need to be open and communicate research effectively to the public, as a failure to do so can seriously damage reputations.
Sir Muir said: "There seems no doubt that CRU got themselves into a position that they were unhelpful in response to legitimate requests, and there are plenty of references to anxiety about what critics would use the data for."
He said responding to freedom of information requests was ultimately the responsibility of the university's vice chancellor, and CRU should make sufficient information available alongside publications to enable others to replicate the results.
But the review also acknowledged that many of the attacks on the climate science the unit produces have not followed the "conventional scientific methods" of challenging evidence and offering alternative theories.
And it said the growing influence of the "blogosphere" allowed "unmoderated comment" to sit alongside peer-reviewed scientific papers, in what Sir Muir said had become a very polarised debate.
Sir Muir urged scientists: "Don't fall into the habit of not being open or concealing things, and try to find ways of engaging people on ground that generally advances science."
He said there was a need to find a public space in which research on areas such as climate science could be subject to a "unthreatened, mature yet challenging dialogue".
Fellow review panel member Professor Geoffrey Boulton said online blogs would not entirely take over the role of science - pointing out that cures for disease, circulation of the blood or the building to the Forth road bridge would never have come out of the blogosphere.
But he said it was no longer acceptable for groups of scientists to debate theories among themselves and then make papal-style pronouncements which people would be expected to accept.
"We have to move science from a private enterprise to a public enterprise," he said.
Sir Muir said the £200,000 review tested how data was handled, looked at the influence of CRU on the IPCC's key Forth Assessment report published in 2007, spoke to IPCC authors and sought independent input into how scientific peer review worked from the editor of medical journal The Lancet.
He insisted that such steps gave authority to the conclusions of the 160-page report, and should "stop in their tracks those who have made up their minds that this is a whitewash, without waiting to see what we have done".
He said: "I think it is inevitable that people who have made up their minds have made up their minds. But this is certainly not a whitewash."
The University of East Anglia's vice chancellor, Edward Acton, said Prof Jones, who found himself at the centre of the furore over the hacked emails and stood down from his post while three investigations into the affair were conducted, had been offered a new role as director of research at CRU.
Prof Acton said it was not a demotion but would remove some of the administrative duties from Prof Jones, leaving him free to concentrate on directing and carrying out climate research.
Prof Acton said the review published today had exonerated UEA climate scientists, but accepted the conclusion that the university should and could have been "more proactively open", especially, he said, as it had nothing to hide.
And he said he hoped the review's publication would "finally lay to rest conspiracy theories, untruths and misunderstandings" that had been circulating, and that the "wilder assertions" about the climate science community would now stop.
Prof Jones issued a statement which said: "I am, of course, extremely relieved that this review has now been completed.
"We have maintained all along that our science is honest and sound and this has been vindicated now by three different independent external bodies.
"There are lessons to be learned from this affair and I need time to reflect on them before speaking in public, particularly given the scope of this report.
"Meanwhile, I would like to thank those who have supported me over this period and now I would like to concentrate on my new role as director of research in the Climatic Research Centre, which will allow me to focus my full attention on the science of climate change."
Bob Ward, policy and communications director at the Grantham Research Institute on Climate Change and the Environment at LSE, said the Muir Russell inquiry had lifted the cloud of suspicion which had hung over the research community for months.
"The reputation of the whole of climate research has been tarnished by speculation over the emails, but the inquiry's findings demonstrate that the integrity of climate science is intact.
"It is clear that greater transparency is required in climate research because of the intense public interest in it, and its profound implications for society.
"However, it is also now very apparent that many so-called 'sceptics' owe a huge apology to the public for having wrongly presented the email messages as evidence that climate change is a hoax carried out by a conspiracy of dishonest scientists," he said.
Professor Steve Smith, president of the body that represents vice chancellors, Universities UK, said attempts to create controversy and undermine researchers eroded public trust in science.
"We cannot have a situation where researchers, dealing with controversial areas of study, are faced with a barrage of requests for information on early drafts of research and discussions, with the sole aim of disrupting that work."
He said universities supported the principles of the Freedom of Information Act (FoIA) but said there were questions about the application of the act to research data and called for clarification from the Information Commissioners' Office about the treatment of material relating to research, and how best to respond to orchestrated campaigns and harassment.