claim: it later emerged that its creator Dr Michael Mann had spliced too [sic] datasets together – tree-rings showing temperatures going back hundreds of years, then recent thermometer readings for the more recent decades.
evidence: He said that there was nothing "hidden or inappropriate" about it, and that his method of combining proxy data had been corroborated by numerous statistical tests and matched thermometer readings taken over the past 150 years.
category: Climatic Research Unit documents