Michael Mann and colleagues intimate that I had an undeclared conflict of interest in reviewing Roger Pielke Jr's book The Climate Fix (Nature 467, 920; 2010), citing alleged connections between me and the George C. Marshall Institute in Arlington, Virginia, reputedly a centre of climate-change scepticism.
Contrary to the authors' assertions, I did not write a report for the Marshall Institute. My relationship with the institute consists solely of participation in a 90-minute discussion in 2006 concerning how Congress deals with scientific issues (see http://go.nature.com/epxft1). Also taking part were a former member of the congressional Office of Technology Assessment and a current senior official of the US National Research Council of the National Academy of Sciences.
The audience in 2006, as I recall, consisted mainly of congressional staff members. I did not mention climate change and I received no payment for my participation.
Science journalists in Washington DC are often invited to address meetings on science-policy issues. I have taken part in similar discussions under the auspices of the Brookings Institution, the American Association for the Advancement of Science, the Association of American Universities, the Association of American Medical Colleges, and at dozens of universities.