In his review of my book Science as a Contact Sport — a personal retrospective account of the development of climate science and policy covering 40 years — Roger Pielke Jr misrepresents my position on advocacy (Nature 464, 352–353; 2010).
Pielke fairly represents my decades-old argument that scientists should avoid policy prescriptions. But he omits my frequently stated context: policy advocacy by scientists is inappropriate in formal assessments, such as those of the Intergovernmental Panel on Climate Change or of the US National Academy of Sciences.
As citizens, scientists may have personal-value positions on policy. But when involved in public advocacy, they must clearly lay out their world views and separate the more objective scientific issue of risk assessment from the value-laden risk-management part. Contrary to Pielke's implication, I am aware of this 'paradox'.
Understanding science does not in itself lead to effective policy. In fact, my book demonstrates that special interest or ideological chicanery is more responsible than scientific ignorance for blocking policy. However, as Pielke notes, I did say that if people better understood what is at stake, they'd be likely to make better risk-management decisions.
I don't recall Schneider discussing advocacy by the IPCC or NAS. I wonder what he makes of the advocacy letters of the US NAS on climate change and the various advocacy efforts of Rajendra Pachauri. I'd guess that he'd say that there is a bright line between science and advocacy and individuals can choose what side of that line to be on in different contexts. Obviously, I don't see science and politics being nearly so distinguishable, for individuals and institutions.
These are the relevant paragraphs in the review that Schneider is responding to (it also refers to Jim Hansen's latest book):
Hansen and Schneider each provide a troubling inside view of the political battle over climate change in their respective books, Storms of My Grandchildren and Science as a Contact Sport. Hansen invokes religious terms, characterizing himself and Schneider as witness and preacher, respectively. Both are evangelists who hold science as an ascendant authority.
The tension between the role of scientists as political advocates and as expert advisers is an undercurrent in both books. Schneider explains that “as scientists, we never recommend which policies should be chosen”; Hansen similarly sees himself as an “objective scientist”. Yet both books largely comprise strong ideological and political commentary based on an unstated assumption that science compels action on climate change. Neither author accepts the label of advocate, claiming to be speaking for science; nor do they see the paradox in their position.
Both scientists express a desire to influence political outcomes. Hansen describes how he hoped to sway the US presidential election in 2004 through his public endorsement of Senator John Kerry over George W. Bush in a speech made in the swing state of Iowa. Schneider relates how, at an IPCC meeting, he may have aided the viability of the Kyoto Protocol after explaining climate science to an African national delegate who later changed his position.