Reply to S. Fred singer

We are perplexed by Singer's resurrection of these issues in Eos, 3 years after he first raised them in the Wall Street Journal [Singer, 1996a]; especially since Singer has already repeated these criticisms in Science [Singer, 1996b] and Physics Today [Singer, 1997], and since they have been rebutted by us in each of these publications [Santer, 1996; Wigley et al, 1996; Wigley and Santer, 1997]. As noted by the Editor-in-Chief of Eos [Spilhaus, 1999], one of Eros's criteria for publication of commentary on "scientific issues pertaining to global warming" is that the contributed material "should bring new information to this discourse"Singer's recent contributions to Eos [Singer, 1999a, b] fail to meet this criterion. In summary, we categorically refute Singer's criticisms once again: the IPCC's "discernible human influence" conclusion was not based on a single research paper, and the differences between a figure in that paper and a figure in Chapter 8 of the SAR are not an example of what Singer has previously called "scientific cleansing." Both of Singer's criticisms are without any merit whatsoever.