The Gateway to UN System’s Work on Climate Change interviewed Rajendra K. Pachauri , Chairman of the Intergovernmental Panel on Climate Change (IPCC). The IPCC is the international body that provides a clear assessment of the current state of knowledge in climate change and its potential environmental and socio-economic impacts.

Gateway: How significantly has the science advanced since the last report was issued in 2007?

Pachauri: While preparing the Fifth Assessment Report, AR5,  we are taking into account all the new knowledge contained in publications which have come out in recent years since the completion of the Fourth Assessment Report (AR4). We believe the assessment of new publications will help us fill up some existing gaps and add to the body of knowledge that already exists in this entire field. There are over 800 authors and review editors who are engaged in various tasks involved in assessing thousands of publications, and I am sure, their efforts would result in an outstanding and robust AR5.

Gateway: Preparations for the next IPCC report are underway.  In what ways do you expect the fifth assessment will be different from the previous reports?

Pachauri: The Fifth Assessment Report will provide much greater emphasis on several specific topics and would certainly have a larger focus on the regional aspects of climate change. Some of the topics that will be  dealt  with  in  depth  in the AR5 relate to clouds and aerosols, geo-engineering  options,  sustainability  and  equity  issues, and in general, a greater focus on socio-economic implications of climate change.  Further, all the three Working Groups will also deal consistently with a set of agreed cross-cutting issues such as ocean acidification and Article 2 of the UN Framework Convention on Climate Change.

Gateway: Who are the experts involved in the review process of the report and how have they been selected?

Pachauri: The review process generally takes place in three stages: expert review of IPCC Reports, government/expert review of IPCC Reports, and government review of the Summaries for Policymakers and Overview Chapters and/or the Synthesis Report.

The IPCC Procedures require a wide circulation process, ensuring representation of independent experts who are not involved in the preparation of that particular chapter from developing and developed countries and countries with economies in transition. The aim is to involve as many experts as possible in the IPCC process.

The review process is objective, open and transparent. For the reviews, the Working Group/Task Force Bureaus are required to seek the participation of reviewers  encompassing the range of scientific, technical and socio-economic views, expertise, and geographical representation and it is also required to actively undertake to promote and invite as wide a group of experts as possible. Any  expert can sign up to review the drafts, making the IPCC report process one of the most open and inclusive in the world of science.

Gateway: How does the IPCC assess the state of climate change science?

Pachauri: In Assessment Reports, Synthesis Reports, and Special Reports, Coordinating Lead Authors, Lead Authors, and Review Editors of chapter teams are required to consider the range of scientific, technical and socio-economic views, expressed in balanced assessments.  Authors are required to use calibrated uncertainty language that expresses the diversity of the scientifically and technically valid evidence, based mainly on the strength of the evidence and the level of agreement in the scientific, technical, and socio-economic literature.

Steps involved in this process are: 1) Compilation of lists of potential Coordinating Lead Authors, Lead Authors, Contributing Authors, Review Editors and of Government Focal Points; 2) Selection of Coordinating Lead Authors, Lead Authors and Review Editors; 3) Preparation of draft Report; 4) Review by experts first, and then by governments and experts; 5) Preparation of final draft Report; and 6) Acceptance of Report at a Session of the Working Group(s) or the Panel respectively.  

In preparing the first draft, and at subsequent stages of revision after review, Lead Authors are required to clearly identify disparate views for which there is significant scientific or technical support, together with the relevant arguments.

Summary sections of Reports approved by the Working Groups and accepted by the Panel will principally be the Summaries for Policymakers, prepared by the respective Working Groups based on their full scientific, technical and socio-economic Assessments, and Summaries for Policymakers of Special Reports prepared by the Working Groups. The Summaries for Policymakers are subject to a final line by line approval by a full Session of the Working Group.

The Synthesis Report will synthesise and integrate materials contained within the Assessment Reports and Special Reports, and should be written in a non-technical style suitable for policymakers. It is required to address a broad range of policy-relevant but policy-neutral questions approved by the Panel. An approval and adoption procedure will allow Sessions of the Panel to approve the Summary for Policymakers line by line and to ensure that the Summary for Policymakers and the longer report of the Synthesis Report are consistent, and that the Synthesis Report is consistent with the underlying Assessment Reports and Special Reports from which the information has been synthesized and integrated.

Gateway: There are still quite a number of climate change skeptics in the world. Do you expect that the new report will significantly change the discussion over the science?

Pachauri: Science thrives on debate and discussion and we in the IPCC welcome the opportunity to engage in debate on the subject of climate change. Given the fact that the AR5 will undoubtedly have a substantial amount of new information, there would be undoubtedly much debate and discussion of the findings that are produced.  I would like to emphasize that the whole process of preparation of IPCC Reports is characterized by discussion which takes place within and across author teams and a rigorous process of review which serves the purpose of incorporating diverse points of view at various stages of drafting of the report. It is difficult to say how AR5 will change the discussion of science, but the work of the IPCC has already created large scale awareness on various aspects of climate change across the globe.

Gateway: Is the IPCC going to do anything different for communications on the IPCC report?   What will the IPCC do to rebut criticism, such as the criticism that was leveled against the last report?

Pachauri: A communications strategy has just been approved in June 2012, as action to implement one of the recommendations of the InterAcademy Council .

An IPCC assessment is a mammoth undertaking in terms of the scope of the science covered and the number of people involved. The process is robust in terms of selecting authors, covering relevant literature, elaborating the report, bringing in outside experts to review it and so on. In any human endeavor there is always scope for improvements and since AR4 we have made a number of changes to our procedures with this in mind based on the InterAcademy Council review.

Producing a report culminates in an exhaustive process of approval by our member governments.  This results in an important level of political buy-in from the people who have commissioned the report. The IPCC has a transparent and careful process to examine allegations of errors, and to issue errata if necessary, which can arise in reports of this size and complexity.

The AR5 comes out between September 2013 and October 2014 in three parts, one for each working group, finishing with the Synthesis Report.  Each of these provides an opportunity to present the Panel’s findings in detail.  As each part of the report is approved we will present it to the media, but will also have a global outreach programme bringing the assessment to policymakers and the scientific community around the world at international meetings and dedicated events.