An independent report into the leak of hundreds of e-mails from one of the world's leading climate research centers on Wednesday largely vindicated the scientists involved, saying they acted honestly and that their research was reliable.
But the panel of inquiry did chide scientists at the University of East Anglia's Climatic Research Unit for failing to share their data with critics.
"We find that their rigor and honesty as scientists are not in doubt," said panel chairman Muir Russell. "But we do find that there has been a consistent pattern of failing to display the proper degree of openness."
Russell's inquiry is the third major investigation into the theft and dissemination of more than 1,000 e-mails taken from a back-up server at the university.
They caused a sensation when they were published online in November: They captured researchers speaking in scathing terms about their critics, discussing ways to stonewall skeptics of man-made climate change, and talking about how to freeze opponents out of peer-reviewed journals.
The ensuing scandal energized skeptics and destabilized the U.N. climate change conference at Copenhagen. The research center's chief, Phil Jones, stepped down while Russell, a former vice-chancellor of the University of Glasgow in Scotland, was brought in to investigate.
Russell's carefully worded report said there was no evidence Jones had destroyed evidence that he knew critics were seeking under the Freedom of Information Act. But it did say he had pushed colleagues to delete e-mails that he thought might provide ammunition to skeptics.
The panel also said that "we found a tendency to answer the wrong question or to give a partial answer" to information requests.
And it criticized the university for being "unhelpful" in dealing with Freedom of Information Act requests — an issue Britain's data-protection watchdog has already flagged.
'Trick' wording reviewed
The inquiry also revisited the now infamous e-mail exchange between Jones and a colleague in which the climatologist refers to a "trick" used to "hide the decline" in a variable used to track global temperatures.
Some skeptics took that as proof that scientists were faking global temperature trends.
Russell's report rejected that conclusion, but did say that the resulting graph — which graced the front cover of the World Meteorological Organization's 1999 report on climate change — was "misleading" because it wasn't explicit enough about the way in which the underlying data had been chopped and spliced together.
Finally, the report largely forgave the intemperate language in many of the e-mails. Exchanges widely reported in the media had one scientist cheering the death of a prominent skeptic and another jokingly referring to the possibility of taking out a mafia hit on a colleague.
Russell said the extreme comments and jokes were typical of e-mail communications — and understandable given the politicized nature of climate research.
The panel's report said the e-mails contained nothing to overturn the case for man-made global warming put forward by the United Nations' Intergovernmental Panel on Climate Change. "We did not find any evidence of behavior that might undermine the conclusions of the IPCC," it stated.
University of East Anglia Vice-Chancellor Edward Acton dismissed concerns about possible deleted e-mails, saying that the report had "completely exonerated" Jones, who would now return to the Climatic Research Unit as director of research — a new position that Acton said would free him from administrative duties.
Acton also said the university has since overhauled the way it dealt with requests for data.
Russell's report follows a British parliamentary inquiry that largely backed the scientists involved and another independent investigation that gave a clean bill of health to the science itself.
Jones' critics were only partially mollified. Canadian economics professor Ross McKitrick welcomed the conclusion that the 1999 chart was misleading. But he still said that the inquiry seemed "unduly concerned to downplay the problems they found" and offer excuses for the researchers involved.
E-mails 'a game-changer,' expert says
It has been difficult to gauge the impact of the scandal, which played widely in the British and U.S. media. In Britain, there is some evidence that public concern over global warming has been diluted, although not by much.
An Ipsos MORI poll published last month suggested that 78 percent of Britons believed that the world's climate was changing, compared with 91 percent five years earlier. Seventy-one percent of respondents expressed concern about global warming, versus 82 percent in 2005. The pollster surveyed 1,822 people aged 15 and over in interviews between January and March 2010.
Some scientists have said the scandal has made it impossible for researchers to hide data from their critics and pushed those who do believe in the dangers of man-made global warming to be more vocal about their doubts.
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"The release of the e-mails was a turning point, a game-changer," Mike Hulme, a professor of climate change at the University of East Anglia, told The Guardian newspaper before the Russell report was released. "Already there is a new tone. Researchers are more upfront, open and explicit about their uncertainties, for instance."
Bob Ward, the policy director of the Grantham Research Institute on Climate Change at the London School of Economics, agreed that openness was the now order of the day.
"There is a need to re-establish trust," he said.
Other investigations have also dealt with various aspects of the issue over the past nine months. Two U.S. university reviews of Penn State University professor Michael Mann — a prominent player in the controversy — have cleared him of wrongdoing.
An AP review of the e-mails, published in December, said they didn't support claims that the science of global warming was being faked.