In your Editorial “Welcome climate bloggers” and News story “Climatologists get real over global warming” (Nature 432, 933 and 937; 2004 10.1038/432933a), the newly created RealClimate blog ( is introduced as a website battling distorted media coverage on global-warming research.

As a member of the climate-research community and inspired by your enthusiastic introduction, I navigated RealClimate with high expectations. I was, however, sadly disappointed by a posting by M. E. Mann on 4 December: “Temperature variations in past centuries and the so-called ‘Hockey Stick’.” Among other data, this included an overview of temperature change during the past millennium as reconstructed by various climate proxies including borehole data.

I cannot comment on the accuracy of the rest of the posting, but I was concerned to find that Figure 1, showing temperature change in the Northern Hemisphere, included an outdated and erroneous reconstruction of borehole data by M. E. Mann et al. (J. Geophys. Res. 108, 4203; 2003). In my view, the website should have used a later version (S. Rutherford and M. E. Mann, J. Geophys. Res. 109, D11107; 2004), which acknowledged an error in the earlier paper, or other more recent reconstructions. To be fair, the authors of the website added a correction after I drew their attention to this.

Your Editorial asserts that there is little reason to doubt that RealClimate's goal, “to provide solid scientific comment to journalists and other interested parties”, can be reached. But you also warn of the dangers of “a rapid-rebuttal service, run with minimal peer review”. Let us hope that future postings on RealClimate will fulfil our high expectations.