In a commentary attached above the letter, Dr. Stavins noted that:

I want to emphasize that the IPCC’s Working Group III “Technical Summary” and the underlying Working Group III report of 15 chapters were completely untouched by the government approval process of the Summary for Policymakers. So, the crucial IPCC products—the Technical Summary and the 15 chapters of WG 3—retain their full scientific integrity, and they merit serious public attention.

… The process of the government approval sessions was exceptionally frustrating, and the outcome of that process—the final SPM—was in some regards disappointing. Two weeks ago, immediately after returning from Berlin, I sent a letter to the Co-Chairs of Working Group III—Ottmar Edenhofer, Ramon Pichs-Madruga, and Youba Sokona—expressing my disappointment with the government approval process and its outcome in regard to the part of the assessment for which I had primary responsibility, SPM.5.2, International Cooperation. At the time, I did not release my letter publically, because I did not want to get in the way of the important messages that remained in the SPM and were receiving public attention through the Working Group III release.

With two weeks having passed, it is now unlikely that the broader release of my letter will obscure the news surrounding the Working Group III release, and—mportantly—it could be constructive to the process going forward, as the IPCC leadership and others think about the path ahead for future climate assessments.

—Dr. Stavins

In the letter, Dr. Stavins expresses his “disappointment and frustration with the process and outcome of the government approval meetings in Berlin this past week.”

… none of what I have to say should be taken as reflecting negatively on you (the Co-Chairs of Working Group 3), the WG 3 Technical Support Unit (TSU), nor the overall leadership of the IPCC. On the contrary, I thought that all of you did a remarkable job over the five years of work on AR5, as well as during the week in Berlin. The problems about which I’m writing arose despite, not because of your excellent leadership and support.

More broadly, the problems I identify in this letter are not a consequence of personal failings of any of the individuals involved. My intent is not to criticize the country representatives, the IPCC leadership, the TSU, the Lead Authors, or the Coordinating Lead Authors. The problems I seek to identify are structural, not personal.

… I fully understand that the government representatives were seeking to meet their own responsibilities toward their respective governments by upholding their countries’ interests, but in some cases this turned out to be problematic for the scientific integrity of the IPCC Summary for Policymakers. Such involvement—and sometimes interference—with the scientific process of the IPCC was particularly severe in section SPM.5.2 on international cooperation. It is to that section of the SPM that I now turn.

… I understand that country representatives were only doing their job, so I do not implicate them personally; however, the process the IPCC followed resulted in a process that built political credibility by sacrificing scientific integrity.

… No institution can be all things for all people, and this includes the IPCC. In particular, in the case of the IPCC’s review of research findings on international cooperation, there may be an inescapable conflict between scientific integrity and political credibility. If the IPCC is to continue to survey scholarship on international cooperation in future assessment reports, it should not put country representatives in the uncomfortable and fundamentally untenable position of reviewing text in order to give it their unanimous approval. Likewise, the IPCC should not ask lead authors to volunteer enormous amounts of their time over multi-year periods to carry out work that will inevitably be rejected by governments in the Summary for Policymakers.

… More broadly, I urge the IPCC to direct public attention to the documents produced by the lead authors that were subject to government (and expert) comment, but not subject to government approval. I believe that tremendous public good would arise from publicizing the key findings of the Technical Summary and the individual chapter Executive Summaries, instead of the Summary for Policymakers. I know that as the leaders of the IPCC, you see it to be your responsibility to convey to the public (and policy makers) the results of the hard scientific work that the hundreds of lead authors put into the report over the past five years, and not simply the constrained version of the Summary for Policymakers produced over the past week.

The mission of the IPCC is important, and the scientific work carried out by the hundreds of lead authors of AR5 Working Group 3 was solid and important, as validated by the Technical Summary and the underlying chapters. I hope this letter can be constructive and helpful for the future work of the IPCC.