A guest post by Dennis Bray and Hans von Storch

The July 2008 newsletter of the American Physical Society (APS) opened a debate concerning the IPCC consensus related to anthropogenic induced climate change. We responded with a brief comment concerning the state and changing state of consensus as indicated by two surveys of climate scientists. Data was presented concerning climate scientists assessments of the understanding of atmospheric physics, climate related processes, climate scientists level of agreement with the IPCC as representative of consensus and of the level of belief in anthropogenic warming. (The full manuscript is available here .) Our comment was summarily dismissed by the editors as polemic, political and unscientific. The following is a brief account of this episode.

The APS Forum on Physics and Society states “The Forum on Physics and Society is a place for discussion and disagreement on scientific and policy matters”. The Forum on Physics and Society, Newsletter, July 2008 began a debate “concerning one of the main conclusions” of the IPCC. The intended debate was clearly evident in the statement,

There is a considerable presence within the scientific community of people who do not agree with the IPCC conclusion that anthropogenic CO2 emissions are very probably likely to be primarily responsible for global warming …

There is no reference as to how this statement was determined or its validity known. It is very probably likely to be primarily ethereal.

The intended debate seemed to be aimed at prompting a discussion, or perhaps as the two papers to date seem to suggest, an evaluation of the methods employed in reaching the IPCC conclusion. Two invited articles were published to set off the debate, one pro and one contra to the IPCC conclusion. Oddly enough, neither paper appears to be authored by a climate scientist per se although both present a detailed discussion of atmospheric physics. Subsequent contributions were invited from the “physics” community for “comments or articles that are scientific in nature.”

So here we have two editors (who are themselves not climate scientists) soliciting invited papers from authors who, as far as we know, have never had any peer reviewed publications pertaining to climate science, setting off a debate concerning the consensus in the climate sciences by what appears to be a mere declaration of the current state of the consensus. The editors of the newsletter should be commended however for at least stating that the “correctness or fallacy of that [the IPCC] conclusion has immense implications for public policy.”

Our interests were drawn by statements found on the web page: 1. the Forums declaration that it is “a place for discussion and disagreement on scientific and policy matters”, and 2. the statement “There is a considerable presence within the scientific community of people who do not agree with the IPCC conclusion that anthropogenic CO2 emissions are very probably likely to be primarily responsible for global warming …”. We have been working for some time in the area of assessing the levels of consensus in the climate science community and therefore decided to submit a brief (and rapidly rejected) comment (PDF.) to the debate.

Our stance concerning “consensus” (on any matter) is:

1. Consensus and certainty are two different concepts, which sometimes are parallel, although often not.

2. Consensus is simply a level of agreement among practitioners and might be subject to change over time.

3. Consensus is a level of agreement in belief of the relevance of the theory to the issue and the casual relationship inherent in the theory

and in particular reference to climate science

4. Climate change science is considered to be multidisciplinary and therefore the knowledge claims comprising the consensus is considered to be multidimensional, that is, not able to be captured in a single statement.

In short, consensus is not as simple as a yes – no response. It is a negotiated outcome of multiple levels of expertise.

Now, returning to our submission, or more precisely, the rejection of our submission, the first rejection arrived in a matter of hours. Short and to the point, it said:

The original invitation was for participation in a scientific debate, not a political one. As your attached piece is not primarily of a scientific nature, we cannot consider it for publication in our newsletter. In my editorial comments for the July 2008 issue, I emphasized that we are not interested in publishing anything of a polemical or political nature.

The “emphasized” points are of interest. The paper was neither polemic nor political, as we invite the readers of the blog to verify, however giving the editors the benefit of the doubt, we asked for clarification. Again the APS response was quite rapid:

Your article [...] is not about technical issues concerning climate research. Instead, it is about the opinions of scientists. I would be glad to consider publication of articles, comments, or letters from you that address specific technical issues connected with climate research.

Now, aren’t the “opinions of scientists” the foundation of consensus? The “opinions of scientists” in our analysis represent not a political statement but a scientific comment. The data is empirical and the paper was deliberately devoid of political or polemic statement. Our paper does definitely not address a specific technical issue but it does provide a collective peer assessment of a number of specific technical issues (such as: representation of hydrodynamics and greenhouse gases). Indeed, our concern was to substantiate quantitatively the loose assertion of an anonymous APS officer:

There is a considerable presence within the scientific community of people who do not agree with the IPCC conclusion that anthropogenic CO2 emissions are very probably likely to be primarily responsible for global warming.

An estimate based on data can be read in our short comment.