Open letter to Science

Science

R. Brooks Hanson

Managing Editor, Physical Sciences, Science

American Association for the Advancement of Science

Liverpool, 22 February 2006

Dear Dr Hanson

In early March, the National Research Council of The National Academies of the United States is convening a committee to study "Surface Temperature Reconstructions for the Past 1,000-2,000 Years". According to the NAS announcement, "the committee will be asked to summarize the current scientific information on the temperature record over the past two millennia, describe the proxy records that have been used to reconstruct pre-instrumental climatic conditions, assess the methods employed to combine multiple proxy data over large spatial scales, evaluate the overall accuracy and precision of such reconstructions, and explain how central the debate over the paleoclimate temperature record is to the state of scientific knowledge on global climate change."

In order for the NAS panel and the invited scientific experts to evaluate the overall accuracy and precision of temperature reconstructions based on multiple proxy data, it is essential that a complete archive of the data is made available. This is particularly relevant for a number of contentious papers published in Science that will feature prominently during the NAS assessment.

We understand that some authors of paleo-climate reconstructions published in Science (Osborn and Briffa, 2006; Thompson et al., 1989; 1997; Esper et al., 2002) have failed to provide complete data archives. We would like to ask Science to ensure that the NAS assessors and scientific experts will have full access to the data and that the authors in question provide a complete archive as required under Science policies.

Yours sincerely

Benny Peiser, Liverpool John Moores University, UK

Sir Colin Berry, Queen Mary, University of London, UK

Freeman Dyson, Institute for Advanced Study, Princeton, USA

Chris de Freitas, The University of Auckland, New Zealand

Mick Fuller, University of Plymouth, UK

Lord Taverne, House of Lords, UK