The U.K.'s University of East Anglia says the director of its Climatic Research Unit is stepping down pending an investigation into allegations stemming from the recent publication of his and other climate scientists' private emails.

Phil Jones, the director of the global research centre on climate change, announced that he would stand aside until an independent review determined whether he overstated the case for man-made climate change.

The university said Peter Liss will become acting director of the climate research unit.

Hundreds of private emails of British and U.S. scientists were posted online after hackers broke into one of the Climatic Research Unit's servers about a week and a half ago. The emails appear to show some of the scientists have overstated the threat of man-made global warming.

Jones's announcement came days after Pennsylvania State University announced that it would be looking into the work of one of its scientists, Michael Mann, whose correspondence was also among the emails hackers released. Mann is the director of Penn State's Earth System Science Center.

"The university is looking into this matter further, following a well-defined policy used in such cases," said a statement from Penn State.

The university said that a 2006 report by the National Academy of Sciences into Mann's work in reconstructing global temperatures over the last 1,000 years — known as the "hockey stick" diagram — found that Mann's work was scientifically sound and supported by evidence.

The hackers reportedly stole more than a decade of correspondence between leading U.K. and U.S. scientists and posted about 1,000 emails and 3,000 documents on websites.

Skeptics of climate science have seized on the documents — at least some of which have been confirmed as authentic — as evidence that some scientists have overstated the case for global warming and have attempted to alter how global temperature data was presented.

Researchers working with the Intergovernmental Panel on Climate Change have dismissed the posting of documents as an attempt to derail discussions on dealing with global warming, in advance of the upcoming global climate summit in Copenhagen.

Earlier Tuesday, Nicholas Stern, a British economist who wrote a U.K. government report on climate change, said the hackers who published the emails had muddled the debate at a critical moment.

"It has created confusion, and confusion never helps scientific discussions," Stern told reporters.

Stern was launching a report on climate change at the London School of Economics, where he is chairman of its research institute on global climate change.

"People have a right to speak up, but if they are muddled and confused, I do not believe they have the right to be called anything but muddled and confused," he said.

"The degree of skepticism [on climate change] among real scientists is very small."

With files from The Associated Press