A place in the sun

The scientists in “climategate” did not fudge the data, a report finds
Apr 15th 2010

RON OXBURGH, breezily pushing his bicycle through a clot of journalists outside the press briefing he had just given, is a busy man happy to hurry. Critics of his investigation into the scientific probity of the Climatic Research Unit (CRU) at the University of East Anglia will hold that haste against him. In his time Lord Oxburgh has been head of the earth sciences department at Cambridge, chief scientific adviser to Britain’s defence ministry and, briefly, chairman of Shell. In March he was asked to lead an inquiry into the CRU’s main scientific findings, a matter of much debate ever since apparently hacked e-mails from the unit were made public less than five months ago. That he has reported so soon, and in a way that supports the CRU researchers, will be seen by many critics as de facto evidence of a whitewash.

Lord Oxburgh and his colleagues were not concerned with whether CRU’s scientific findings, which are based on records of temperature change from instruments and natural proxies, were correct. They were looking to see if the analysis had been biased and manipulated.

The inquiry panel looked at 11 CRU publications from the past 20 years, spent days talking to the researchers and looking at other documentation, and concluded that if there was any malpractice at CRU they probably would have found it. They found no such thing. Instead they found “dedicated if slightly disorganised researchers ill-prepared for public attention”.

The panel did express considerable surprise at the fact that the unit did not collaborate closely with professional statisticians. This is despite the fact that their work was “basically all statistics”, as one member of the panel, statistician David Hand, of Imperial College, London, put it. The report found that the CRU scientists would, had they been more statistically au fait, have done some things differently. The panel doubted that better methods would have materially changed the results.

Bloggers and others, mostly outside academia, who criticise CRU’s work and other climate science tend to lay much stress on statistical shortcomings. Dr Hand, who has a particular interest in scientific and financial fraud, has read a lot of this work. Dr Hand admires the meticulous work of Steve McIntyre, a mining consultant and blogger, who unearthed statistical problems in another climate analysis. This was a 1998 paper, not produced by CRU, that is now known as “the hockey stick”. Those problems served to enhance the prominence of recent warming in a thousand-year reconstruction of the northern hemisphere’s temperature, and have become a cause célèbre among sceptics.

When the Oxburgh report refers to the possibility of “inappropriate statistical tools…producing misleading results” in climate science, it is the hockey stick that it has in mind. But Dr Hand sees no evidence of anything as worrying as this in the CRU work. His concerns centred mostly on questions about the selection of data sets and the need for studies that showed how sensitive the results were to different selections of data. These are, in effect, what some critics are offering (though with what the report calls “a rather selective and uncharitable approach”), and the antagonism irritates Dr Hand. “What I want to do”, he says, “is bang their heads together and say ‘Sit down together and work out what’s going on’.”

Although the panel said the CRU scientists were careful with caveats, people who subsequently made use of their results, including the Intergovernmental Panel on Climate Change, sometimes oversimplified issues, underplaying possible errors. It also noted that the CRU should have archived data and algorithms better, but that this was a conclusion more easily drawn in hindsight. Having been in both academia and industry, Lord Oxburgh said he has no doubt that in industry, where companies, not researchers, own the data, the record-keeping would have been better, but that the team would have done much less good research. And looking back on his own academic work he showed a certain solidarity with his subject’s sloppiness: “I’m very grateful that the isotopic composition of helium has not become a key matter of public interest.”