Hundreds of private e-mails and documents hacked from a computer server at a British university are causing a stir among global warming skeptics, who say they show that climate scientists conspired to overstate the case for a human influence on climate change.
The e-mails, attributed to prominent American and British climate researchers, include discussions of scientific data and whether it should be released, exchanges about how best to combat the arguments of skeptics, and casual comments — in some cases derisive — about specific people known for their skeptical views. Drafts of scientific papers and a photo collage, portraying climate skeptics on an ice floe, were also among the hacked data.
In one e-mail exchange, a scientist writes of using a statistical “trick” in a chart illustrating a recent sharp warming trend. In another, a scientist refers to climate skeptics as “idiots.”
Some skeptics asserted Friday that the correspondence showed a effort to withhold scientific information. “This is not a smoking gun, this is a mushroom cloud,” said Patrick J. Michaels, a climatologist who has long faulted evidence pointing to human-driven warming and is criticized in the documents.
Portions of the correspondence portrays the scientists as feeling under siege by the skeptics’ camp and worried that any stray comment or data glitch could be turned against them.
The cache of e-mails also includes references to journalists, including this reporter, and queries from journalists related to articles they were reporting.
Officials at the University of East Anglia confirmed in a statement released on Friday that files had been stolen from a university server and that the police had been brought in to investigate the breach. They added, however, that they could not confirm that all the material circulating on the Internet was authentic.
But several scientists and others contacted by the Times confirmed that they were the authors or recipients of specific e-mails included in the file.
The revelations are bound to inflame the public debate as hundreds of negotiators prepare to hammer out an international climate accord at meetings in Copenhagen next month, and at least one scientist speculated that the timing was not coincidental.
The documents will undoubtedly raise questions about the quality of research on some specific questions and the actions of some scientists. But the evidence pointing to a growing human contribution to global warming is so broad and deep that the hacked material is unlikely to erode the overall argument.
In several e-mail exchanges, Kevin Trenberth, a climatologist at the National Center for Atmospheric Research, and other scientists discussed whether a string of recent years of relatively stable temperatures undermined scientific models that predict long-term warming.
“The fact is that we can’t account for the lack of warming at the moment and it is a travesty that we can’t,” Dr. Trenberth wrote.
Other scientists went on to rebut him, saying that the fluctuations were not inconsistent with a continuing warming trend.
Dr. Trenberth said Friday that he was appalled at the release of the e-mails, which he said were private discussions.
But he added that he thought the revelations might backfire against climate skeptics. If anything, he said, he thought that the messages showed “the integrity of scientists.”
Still, some of the comments might lend themselves to sinister interpretations.
In a 1999 e-mail exchange about charts showing climate patterns over the last two millennia, Phil Jones, a longtime climate researcher at the East Anglia climate center, said he had used a “trick” employed by another scientist, Michael Mann, to “hide a decline” in temperatures.
Dr. Mann, a professor at Pennsylvania State, confirmed in an interview that the e-mail was real but said the choice of words was poor. The term “trick” referred to a technical adjustment that was standard procedure and did not affect the results, he said.
“It sounds incriminating, but when you look at what you’re talking about, there’s nothing there,” Dr. Mann said.
Dr. Jones, writing in an e-mail, declined to be interviewed and pasted in attached the university’s statement.
Stephen McIntyre, a blogger who has for years been using his Web site, climateaudit.org, to challenge data used to chart climate patterns and came in for heated criticism in some e-mails, called the revelations “quite breathtaking.”
But several scientists whose names appear repeatedly in the e-mails said they merely revealed that scientists are human beings, and did nothing to undercut the body of research on global warming.
“Science doesn’t work because we’re all nice,” said Gavin A. Schmidt, a climatologist at NASA whose e-mail exchanges with colleagues over a variety of recent climate studies were included in the cache. “Newton may have been an ass, but the theory of gravity still works.”
He said the breach at the University of East Anglia was discovered after hackers who had gained access to the correspondence sought Tuesday to hack into a different server supporting realclimate.org, a blog unrelated to NASA that he runs with several other scientists pressing the case for global warming.
The intruders sought to create a mock blog post there and to upload the full batch of files from Britain – nearly 200 megabytes’ worth.
That effort was thwarted, Dr. Schmidt said, and scientists immediately notified colleagues at the Climatic Research Unit at the University of East Anglia. Nearly all the material in the hacked files, which quickly spread to a variety of ?servers, originated with or was sent to climate scientists at the school.
The first posts that revealed details from the files appeared on Thursday at The Air Vent, a Web site devoted to skeptics arguments. Almost instantly readers there and elsewhere began posting excerpts that they felt illustrated scientific bias or dishonesty.
At first, said Dr. Michaels, the climatologist who has faulted some of the science undergirding the global warming consensus, his instinct was to ignore the correspondence as “just the way scientists talk.”
But on Friday, he said, after reading more deeply, he felt that some exchanges reflected a concerted effort to block the release of data for independent review.
He said that some e-mails mused about a way to discredit him by challenging the veracity of his doctoral dissertation at the University of Wisconsin by claiming he knew his research was wrong.
“This shows these are people willing to bend rules and go after other people’s reputations in very serious ways,” he said.