The United Nations official panel on climate change has responded to claims that the case for human influence on global warming has been exaggerated.
The Intergovernmental Panel on Climate Change said it was standing by findings that a rise in the use of greenhouse gases was a factor.
It was responding to a row over the reliability of data from East Anglia University's Climatic Research Unit.
Leaked e-mail exchanges prompted claims that data had been manipulated.
Professor Jean-Pascal van Ypersele, vice-chairman of the IPCC, said it was no coincidence the information was released in the run-up to the Copenhagen climate summit, which starts tomorrow.
