United Nations officials running negotiations on reducing the impact of global warming have insisted climate change science is robust, despite recent serious errors.
Scientists, politicians and business leaders are meeting in the Indian capital Delhi for the first big conference on climate change since the Copenhagen summit in December.
The chairman of the Intergovernmental Panel on Climate Change Rajendra Pachauri told the BBC that there is a huge volume of evidence which validates the science of global warmng.
Dr Pachauri said there was only one serious mistake in the IPCC report about the rate of melting of Himalayan glaciers and that had been publicly corrected.
UN climate change envoy Yvo de Boer also defended the IPCC, calling its work robust and is underpinning political decision-making in a very, very serious way.
The summit in Denmark failed to reach a comprehensive agreement on tackling climate change. Another major climate conference will be held in Mexico City later this year.