In a letter to the editor dated Jan. 8, an individual named Ed Welge does a grave disservice to your readers by making false and defamatory statements about me and my colleagues. There are too many flat-out lies in his piece to go through all of them, but I will address two of the most outrageous examples:
1. The National Academy of Sciences reviewed and indeed affirmed our work in 2006 in a widely reported study [e.g. “Past Few Decades Warmest on Record, Study Confirms,” Washington Post, June 23, 2006]. Members of the panel, furthermore said that they “saw nothing that spoke ... of any manipulation” and that the study was “an honest attempt to construct a data analysis procedure.” Welge’s attempt to imply otherwise is offensive.
2. Mr. Welge’s statement that the “IPCC has abandoned the use of Mann’s hockey-stick in all its publications” is a lie. Our original reconstruction was incontrovertibly shown in the most recent IPCC 4th assessment report of 2006, along with a dozen other reconstructions developed since our original work (the plot in question can be found here in the posted online version of the report: http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch6s6-6.html#6-6-1).
Furthermore, the fact that multiple independent studies now confirmed our original conclusions, led the IPCC to extend our original conclusions, finding that recent warmth is not only likely unprecedented over the past millennium as we had concluded, but in fact, even further back than that.
Those, such as Mr. Welge, who spread false information about science and scientists — whether knowingly, or by simply uncritically parroting the disinformation of others — do great harm to the public discourse on vital issues such as climate change.
Michael E. Mann
Professor, Dept. of Meteorology, Penn State University
Director, Penn State Earth System Science Center