IPCC Co-Chair calls for re-thinking of policy assessments

When the Working Group III (WGIII) contribution to the IPCC’s Fifth Assessment Report, the most comprehensive assessment of climate change mitigation options to date, was accepted by IPCC member governments in April this year, governments could not agree on parts of its Summary for Policymakers during the approval process. As a result the material was cut. In the current edition of the journal “Science”, a Co-Chair and leading authors of Working Group III re-visit the approval session and comment on deleted content and the strengths and weaknesses of the IPCC process in a series of articles.

“The Science journal editors pose the question if our Summary for Policymakers has become a summary by policymakers,” said Ottmar Edenhofer, Co-Chair of the WGIII. “My answer to this question is ‘no’ – while we would have liked to see more far-reaching consensus, particularly about material on the evaluation of past climate policies, our report including its summaries is firmly based on the science of climate change mitigation. But for the future of the IPCC process, involving the governments of the world, we need to reframe the assessment process of climate policies.”

In a commentary, co-written with Jan Minx, the Head of the Working Group III Technical Support Unit, Edenhofer calls for a clear distinction of roles: scientists as mapmakers, assessing the scientific literature to develop mitigation pathways to alternative climate goals, and policymakers as navigators, deciding on the route of policy implementation in response to climate change.

“The IPCC has a choice,” Edenhofer said. Either it can find a way to present assessment of climate policies in government-approved summary documents or to run the risk of becoming less policy-relevant.

In two further articles, IPCC WGIII authors David Victor, Reyer Gerlagh, and Giovanni Baiocchi, and Navroz Dubash, Marc Fleurbaey, and Sivan Kartha analyze the conflict about country groupings used for the analysis of emissions and the political implications of data presentation.

“The main challenge for the future of the IPCC is not one of organization and procedures,” said Edenhofer. “The real challenge lies in the entanglements of facts and values at the science-policy interface and how the IPCC deals with it. We tried to be explicit about our assumptions and to present a rational debate of facts and values. This enlightened approach came under attack in Berlin.”

In the IPCC process, the full report of each Working Group is accepted in a session of the IPCC member governments. The Summary for Policymakers is approved line-by-line. All government representatives need to agree on the way the information is presented, including graphical representations and wording. If no consensus is reached, the session can decide to delete parts of the Summary for Policymakers. The report’s Technical Summary and the underlying chapters are not affected.

Science Policy Forums: “IPCC lessons from Berlin”

Article #1: "Getting serious about categorizing countries," by D.G. Victor at University of California, San Diego in La Jolla, CA; R. Gerlagh at Tilburg University in Tilburg, Netherlands; G. Baiocchi at University of Maryland in College Park, MD; D.G. Victor; R. Gerlagh; G. Baiocchi at IPCC WGIII in Geneva, Switzerland.

Abstract: www.sciencemag.org/lookup/doi/10.1126/science.1255302

Article #2: "Political implications of data presentation," by N.K. Dubash at Centre for Policy Research in New Delhi, India; M. Fleurbaey at Princeton University in Princeton, NJ; S. Kartha at Stockholm Environment Institute in Stockholm, Sweden; N.K. Dubash; M. Fleurbaey; S. Kartha at IPCC WGIII in Geneva, Switzerland.

Abstract: www.sciencemag.org/lookup/doi/10.1126/science.1255734

Article #3: "Mapmakers and navigators, facts and values," by O. Edenhofer; J. Minx at Potsdam Institute for Climate Impact Research in Potsdam, Germany; O. Edenhofer at Mercator Research Institute on Global Commons and Climate Change in Berlin, Germany; O. Edenhofer; J. Minx at IPCC WGIII in Geneva, Switzerland.

Abstract: www.sciencemag.org/lookup/doi/10.1126/science.1255998