An inquiry cleared British climate researchers of wrongdoing on Wednesday after their hacked emails were leaked and held up by sceptics as evidence they exaggerated the case for man-made global warming.
Former government adviser Ronald Oxburgh, who chaired the panel, said he had found no evidence of scientific malpractice or attempts to distort the facts to support the mainstream view that man's emissions have contributed to rising temperatures.
The affair stoked the global debate on climate change and put pressure on scientists and politicians to defend the case for spending trillions of dollars to cut emissions and help cope with rising temperatures.
Thousands of emails sent between scientists were published on the internet just before the United Nations climate talks in Copenhagen last December.
Campaigners who doubt the science behind manmade global warming said the leaked messages showed that the research unit had taken part in a conspiracy to distort or hype the evidence.
The University of East Anglia appointed Oxburgh to investigate the Climatic Research Unit's methods.
"We saw no evidence of any deliberate scientific malpractice," Oxburgh's inquiry concluded. "Rather, we found a small group of dedicated, if slightly disorganised, researchers.
"We found them to be objective and dispassionate and there was no hint of tailoring results to a particular agenda."
Its strongest criticism was aimed at the unit's handling of statistics. It recommended that the researchers work more closely with professional statisticians in future.
Oxburgh's was the second of three inquiries into the episode to report its findings. Police are also investigating the leak.
Last month, a parliamentary committee cleared the unit of fiddling the evidence, but criticised its handling of requests for information made by outsiders under freedom of information laws.
The third and most comprehensive inquiry, led by former civil servant Muir Russell is due to end in May.
Dr Benny Peiser, director of the Global Warming Policy Foundation, a climate sceptic thinktank, said the inquiry was "rushed and superficial".
"They want to restore the trust of the public and the credibility of the researchers and that is an honourable thing to do," he said. "But they should have done a proper job."