IPCC chief Rajendra Pachauri has a theory on Climategate:

Dr Pachauri, speaking to The Times on Saturday before travelling to Paris to brief President Sarkozy, suggested that the fossil fuel lobby could be behind a hacking incident last month that led to the publication of thousands of leaked e-mails between climate scientists. He said that it was entirely possible that “corporate interests” had had a hand in the leak.
Dr Pachauri, who was in London for a lecture at the Wellcome Trust organised by the BBC World Service, demanded an immediate investigation into the hacking of e-mails from the University of East Anglia’s climatic research unit, which he branded an “illegal act”.
He said: “One needs firstly to find out personally who is responsible, who the culprits are and what were their motives. And unless we do that it is likely that similar things will happen in the future.”
A prominent climate change sceptic, Steve McIntyre, told The Times yesterday that he was “unaware of any evidence that the fossil fuel lobby had anything to do with this and I doubt that they did”.
Dr Pachauri dismissed the suggestion that biased research had crept into the IPCC’s most recent report on the science of climate change. A complex system of checks and balances was in place to prevent bias being insinuated into the panel’s work, he said.