No fraud in hacked climate emails

A report by the Pew Center on Global Climate Change finds no evidence for fraud or scientific misconduct in the emails hacked from the University of East Anglia’s Climate Research Unit. To quote the Pew report:

Although a small percentage of the emails are impolite and some express animosity toward opponents, when placed into proper context they do not appear to reveal fraud or other scientific misconduct by Dr. Jones or his correspondents.

An allegation that an analysis was deliberately fudged arises from a misunderstanding. Allegations that data were suppressed are incorrect. Allegations that papers sceptical of climate change were suppressed, and allegations of unethical behaviour, are also not substantiated. The case for human-caused global warming is not significantly undermined.

The Pew Center, located near Washington DC, is an independent, non-partisan organisation dedicated to bridging among climate science, policy and practical measures. The Pew Center has conducted its own examination of the emails, but official inquiries are also being conducted by the University of East Anglia and by the United Nations. The emails in contention were hacked from the East Anglia unit late last year. From a much larger number of emails, the hackers posted about 1,000. Of these perhaps one or two dozen are controversial. Many of those involved the Director of the CRU, Dr Phil Jones.

Perhaps the most serious allegation has been that an analysis of data was manipulated to obscure an alleged decline in temperature which, it is also alleged, would undermine the case for global warming. Since the emails are private correspondence that are at times terse it is possible to misinterpret them.

Based on what was in published papers before and after this email, Pew explains that the data that were allegedly “hidden” were a particular set of tree-ring data that were inconsistent with actual temperature measurements in the same area, the latter showing no decline. Jones said in an email he had found a “trick” to “hide the decline”. As Pew points out, “trick” is to be interpreted (based on publications) as meaning in this context “clever solution” rather than a “devious ploy”. “Hide the decline” is to be interpreted as “explain the discrepancy” between the tree-ring results and the actual temperature measurements. There was no actual decline to be hidden, and no data were suppressed. It is worth quoting the Pew report in full on this point.

In an email dated Nov. 12, 1999, Prof. Phil Jones stated that he had used a “trick” to “hide the decline.” The email does not say what decline he was talking about, so it has been widely misreported that he was hiding a decline in temperatures. Those reports are not correct, nor is it accurate to say that he was actually hiding data, even though he chose the word. The word “trick” was used as it is in common parlance to mean a clever solution to a problem (e.g., “I know a trick to get that stain off your shirt.”). The decline he said he was hiding referred to one series of high-latitude tree ring data from 1960 to 1994 that did not follow measured temperatures at the same locations, even though they had followed measured temperatures for about a century before 1960. That set of tree ring data incorrectly implied a downward temperature trend after 1960. It cannot be said that Jones was literally hiding this fact because two years before he wrote this email he was a co-author on the first paper to document this “divergence” issue. That paper, published in Nature in February of 1998, concluded publicly that these post-1960 tree ring data produce inaccurate temperature estimates. Hence, “hiding” this decline simply meant following the advice that Jones and colleagues had already aired in the peer-reviewed literature two years earlier. Many more papers have since been published on the same topic.

So what Jones was referring to was the need to explain why one data set (out of many) that is a proxy for temperature (i.e. tree-ring data) were inconsistent with actual temperature measurements. Subsequent investigation revealed the source of the discrepancy. That is good and proper science. If the data look dodgy for any reason, find out why, and document what you find. If what you find allows, compensate for the problem you have found, though that is not always possible.

Pew’s interpretation is based on what was published in peer-reviewed papers before and after the email, which make clear what Jones was referring to. It must be remembered that the emails were private correspondence among experts very familiar with the topic and each other, so they are often terse and laden with jargon and colloquialisms.

Regarding the alleged suppression or deletion of data, some of the data the CRU receives may not be publicly released, by requirement of the countries of origin. Some data (about 5 per cent) were deleted in the 1980s from a database collated by CRU staff. The data were deleted because they did not pass quality control processes. The original data, from weather stations, are still available. As Pew notes, the deletion was done at a time before climate became such a politically heated issue, and “the scientists did not foresee the need to archive every bit of data regardless of its scientific value”. It is not very reasonable to suggest that because the CRU is publicly funded it should have retained every last scrap of data it dealt with even from those less fraught times.

The remaining allegations concern two papers that the correspondents regarded as not having been properly (or at all) peer reviewed before publication, and as having serious flaws, and whether one of the journals involved should be boycotted because it had failed to maintain professional standards. Regarding the first paper, the publisher eventually admitted that the paper should not have been published in the form it was, because its conclusions were not justified by its content. Before he made that admission, he had blocked a restructuring of the editorial board designed to prevent recurrences of the problem, prompting several members of the editorial board to resign, because they did not want to be associated with a journal that was unwilling to maintain professional peer review standards. The second paper was not reviewed at all, and the editor of the journal (Energy and Environment) openly stated that she was following her political agenda, according to Pew senior scientist Jay Gulledge.

The emails include discussion of the possibility of avoiding referring to the two papers and of not submitting papers to the first journal (Climate Research). There is nothing untoward about either suggestion. It is not unusual for scientists not to refer to papers they regard as flawed and they are under no general obligation to (though editors sometimes ask them to do so, and allow them to state their objections). Scientists also send their papers to those journals they consider will give their paper the highest exposure to the relevant audience, and a journal’s reputation in the field is a normal consideration in that decision.