Among the scientists whose emails were disclosed, the CRU's researchers said in a statement that the emails had been taken out of context and merely reflected an honest exchange of ideas. Michael Mann, director of Pennsylvania State University's Earth System Science Center, said that sceptics were "taking these words totally out of context to make something trivial appear nefarious" and called the entire incident a careful, "high-level, orchestrated smear campaign to distract the public about the nature of the climate change problem". Kevin E. Trenberth of the National Center for Atmospheric Research said that he was appalled at the release of the emails but thought that it might backfire against climate sceptics, as the messages would show "the integrity of scientists". He also said that climate change sceptics had selectively quoted words and phrases out of context and that the timing suggested an attempt to undermine talks at the December 2009 Copenhagen global climate summit. Tom Wigley, a former director of the CRU and now head of the US National Center for Atmospheric Research, condemned the threats that he and other colleagues had received as "truly stomach-turning", and commented: "None of it affects the science one iota. Accusations of data distortion or faking are baseless. I can rebut and explain all of the apparently incriminating e-mails that I have looked at, but it is going to be very time consuming to do so." In relation to the harassment that he and his colleagues were experiencing, he said: "This sort of thing has been going on at a much lower level for almost 20 years and there have been other outbursts of this sort of behaviour – criticism and abusive emails and things like that in the past. So this is a worse manifestation but it's happened before so it's not that surprising."