Hockey Stick Reduced to Sawdust

Von Storch et al (ScienceExpress, Sept. 30) first looked at the likelihood of being able to get an accurate climate signal from historical proxy data (tree rings, boreholes, ice cores etc.) by estimating the amount of statistical “noise” inherent in such data.  They discovered that the amount of noise was such that it was likely that hockey-stick like reconstructions had severely underestimated past climate variability.  This would explain why the hockey stick failed to show evidence of the Medieval Climate Optimum and Little Ice Age, for which there is plenty of historical evidence. In a commentary on Von Storch et al’s paper, Osborn and Briffa, prominent paleo-climatologists from the <?xml:namespace prefix = st1 ns = “urn:schemas-microsoft-com:office:smarttags” />University of East Anglia, stress the importance of the findings.  They say, “The message of the study by von Storch et al. is that existing reconstructions of the NH temperature of recent centuries may systematically underestimate the true centennial variability of climate” and, “If the true natural variability of NH temperature is indeed greater than is currently accepted, the extent to which recent warming can be viewed as “unusual” would need to be reassessed.” In an interview with the German newspaper Der Spiegel, Von Storch commented, “We were able to show in a publication in `Science' that this graph contains assumptions that are not permissible. Methodologically it is wrong: rubbish.”  Von Storch also pointed out the IPCC’s role in cutting off questioning on the subject: “It remains important for science to point out the erroneous nature of the Mann curve. In recent years it has been elevated to the status of truth by the UN appointed science body, the Intergovernmental Panel on Climate Change (IPCC).  This handicapped all that research which strives to make a realistic distinction between human influences and climate and natural variability.” Von Storch also commented on Mann’s defense of his now discredited graph.  “His influence in the community of climate researchers is great,” he said.  “And Mann rejects any reproach most forcefully. His defensiveness is understandable.  Nobody likes to see his own child die. But we must respect our credibility as research scientists. Otherwise we play into the hands of those skeptics of global climate change who imagine a conspiracy between science and politics.” Mann commented to The New York Times that it was “unfortunate” he had not been asked to review the paper.<?xml:namespace prefix = o ns = “urn:schemas-microsoft-com:office:office” />