Climategate
Thousands of emails stolen from a British climate research unit weeks before the Copenhagen summit, presented as proof that the temperature record was fabricated. Eight inquiries found no fabrication. The phrases that made the story famous meant something other than what they were said to mean.
Why this verdict
Debunked by eight separate investigations in two countries — parliamentary, university, governmental and independent — none of which found evidence of fraud, data manipulation or suppression of the temperature record, though several criticised the unit's handling of freedom-of-information requests.
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01The claim
That emails and files taken from the Climatic Research Unit at the University of East Anglia in November 2009 show that climate scientists manipulated temperature data, conspired to suppress dissenting research and to subvert peer review, and evaded freedom-of-information law to conceal it — and therefore that the scientific case for human-caused warming is a coordinated fraud.
02Where it came from
A server at the CRU was breached and more than a thousand emails and two thousand documents were copied and posted, first to a hacked climate-science website and then across sceptic blogs, in the weeks before the Copenhagen climate conference opened on 7 December 2009. The framing came with the release: selected phrases were circulated as self-evidently incriminating, above all Phil Jones's reference to a 'trick' to 'hide the decline', and the columnist James Delingpole supplied the name that stuck.
03What the record shows
✕ DEBUNKED — Investigated and refuted. Here is what actually happened.
Eight investigations examined the allegations: the House of Commons Science and Technology Committee, the Oxburgh international science assessment panel, the Muir Russell Independent Climate Change Email Review, two Pennsylvania State University inquiries into Michael Mann, the US Environmental Protection Agency in its denial of petitions to reconsider the endangerment finding, and the Department of Commerce Inspector General. None found evidence of scientific fraud or of manipulation of the temperature record. The Muir Russell review, the most thorough, concluded that the scientists' rigour and honesty were not in doubt, while criticising the unit sharply for a defensive and unhelpful approach to disclosure requests.
The individual phrases dissolve on inspection. 'Hide the decline' refers to the divergence problem — a known and published issue in which tree-ring density series diverge from instrumental temperatures after about 1960 — and the 'trick' was the standard, and disclosed, practice of plotting the instrumental record alongside the proxy series rather than extending a proxy known to be unreliable. It concerned the presentation of a proxy reconstruction, not the temperature record itself.
The independent check settled the substance. The Berkeley Earth project, funded partly by donors sceptical of the consensus and led by a physicist who had publicly doubted the surface record, rebuilt the global temperature series from raw station data using different methods. It reproduced the existing results.
No perpetrator was ever identified. Norfolk police closed the investigation in 2012, finding the attack had been carried out remotely and that no one at the university was involved.
04What it cost
The timing worked. The story ran through the Copenhagen negotiations, and polling in the United States and Britain recorded a measurable fall in public confidence in climate science over the following year. That effect substantially decayed, but the vocabulary did not: 'Climategate' remains the standard shorthand, and the inquiries that cleared the scientists are cited far less often than the emails that accused them. The episode also had a cost inside science — the reviews' criticism of CRU's obstruction of data requests was fair, and the affair pushed climate science toward the open-data practices it should have adopted earlier.
05Connections
06Sources
Primary document · 2010
The Independent Climate Change E-mails Review
Primary document · 2011
Inspector General's letter to Senator Inhofe on the CRU emails
Government · 2010
The disclosure of climate data from the Climatic Research Unit at the University of East Anglia — Eighth Report of Session 2009–10
Government · 2010
Denial of Petitions for Reconsideration of the Endangerment and Cause or Contribute Findings
Encyclopedia
Climatic Research Unit email controversy