Overview

This chapter outlines the process of the report writing of the Intergovernmental Panel on Climate Change (IPCC) and discusses, through specific examples, how these reports are produced within, and shaped by, political and scientific contexts. The IPCC produces Assessment Reports, Special Reports, and Methodological Reports, which are central to the institution’s operations and perceived impact. There are also sub-elements of these reports – Summary for Policymakers and Technical Summary – which fulfil important stand-alone roles. The process of writing these reports is well-institutionalised and involves maintaining a balance between scientific credibility and policy relevance. The reports produced are therefore accountable to, and co-produced with, scientific and policy communities. The chapter shows how the framing of IPCC reports has changed over time and continues to evolve. This also raises questions about the future of IPCC reports in relation to IPCC processes and in response to diversifying audiences and new media.

5.1 Introduction

At its inception in 1988, the IPCC was tasked with providing regular, comprehensive scientific assessments on climate change. The production of these reports is the central purpose and mandate of the IPCC (Agrawala, Reference Agrawala1998b). Since then, the IPCC has produced 6 full Assessment Reports, as well as 14 Special Reports, and 6 Methodology Reports (see Table 5.1 for a list of all reports produced to date).¹

IPCC reports are produced within a well-institutionalised architecture and through processes that aim to maintain scientific integrity and policy relevance. The effort to be ‘neutral, policy-relevant but not policy-prescriptive’ (IPCC, 2021b) guides their production, organisation and reception. In other words, through their connection to scientific and policy worlds, IPCC reports are accountable to both. This chapter outlines the processes of commissioning and designing different IPCC report styles, and their roles and functions. It expands on how the IPCC’s unique situation between science and policy has led to its reports evolving in line with changing policy expectations and developments in scientific knowledge. It shows that IPCC reports have a broad audience and that the challenges to keeping them relevant comes from both political and scientific arenas.

5.2 Types and Styles of Reports

The periodic IPCC assessments are made up of four reports: individual reports for Working Group (WG) I – The Physical Science Basis; WGII – Impacts, Adaptation, and Vulnerability; and WGIII – Mitigation of Climate Change; and a Synthesis Report. With an increasing body of published literature to draw upon, the size of Assessment Reports has grown. Thus the WGI report in the First Assessment Report (AR1) in 1990 was around 400 pages in length compared to over 1500 pages for WGI in AR6 in 2021. Since AR2, the three WGs are brought together in a shorter Synthesis Report, which aims to highlight the most important cross-cutting aspects (IPCC, 2013a). These reports are comprehensive updates of knowledge on climate change, each with a different set of authors and a different literature base.

The IPCC has also produced 14 Special Reports to date. Special Reports are led by either one WG or else by a combination of WGs. Although the context for these Special Reports differs, their collective role is to provide more detailed information, in between the Assessment Reports, on specific topics deemed particularly relevant by its member governments (Fogel, Reference Fogel2005, and see Chapter 20). All IPCC reports include a Summary for Policymakers (SPM) – a shorter summary of the main policy-relevant findings (around 30 pages), and a Technical Summary (TS) – a longer and more detailed summary with technical detail that cannot be included in the SPM. The IPCC also produces Methodological Reports in the form of practical guidelines. Most recently in this category has been the Methodology Report on Short-lived Climate Forcers, and updated IPCC Guidelines on National Greenhouse Gas Inventories.

The production of IPCC reports is a well-documented process (see Hughes, Reference Hughes2012; IPCC, 2013a; Livingston et al., Reference Livingstone2018; De Pryck, Reference De Pryck2021a). The process of report preparation is generally the same for all Assessment, Special, and Methodological Reports (see Figure 3.1 in Chapter 3). Reports are scoped and their draft outline determined. The outline is approved by the Panel in Plenary, a process that is important because agreement on the outline is considered to increase the likelihood that the final report will be accepted (Hughes, Reference Hughes2012). Following approval of the outline by the Panel, Coordinating Lead Authors, Lead Authors, and Review Editors are nominated and selected. Authors then start to prepare the report based on the scoping outline and an assessment of the relevant underlying literature. The draft report undergoes two external review rounds following the First Order Draft (FOD) by experts and following the Second Order Draft (SOD) by both governments and experts. At the time of the SOD, the summary sections of the report (the SPM for Assessment and Special Reports, or the Overview Section of Methodology Reports) are prepared and circulated for review (see Chapter 11). Based on these expert and government reviews the Final Draft is prepared. The summary sections of the report are sent out for one final government review (the Final Government Distribution) in advance of the final Approval/Acceptance Plenary (see Chapter 20).

Reports are presented at the final plenary for approval by governments. In the case of the WG and Synthesis reports this takes place at the WG and Panel Plenary Sessions, respectively (see IPCC, 2013a). The SPM undergoes line-by-line ‘approval’ – meaning that it is subject to in-depth discussion, and agreed upon between the Panel and the report’s authors. The underlying report is ‘accepted’ – which means it has not been subject to as detailed scrutiny as the SPM, but still presents what is deemed to be ‘a comprehensive, objective and balanced view of the subject matter’ (IPCC, 2013a). The longer Synthesis Report has the special status of being ‘adopted’ section by section. The TS is prepared by the authors alone, but is an integrated part of the full report, and thus accepted alongside the full report. The different methods of approval may also have an effect on how a report is read, as well as who the audience is deemed to be. For example, policymakers may refer mainly to the SPM for top level messaging, the language of which has been agreed upon in plenary. However, more technical information on specific topics may be found in the TS or in the underlying chapters.

A core aspect of IPCC reports is that they are co-produced between governments, IPCC authors and other experts partaking in the review process. In doing this, the IPCC both entrenches and performs its mandate to be ‘policy relevant, but never policy prescriptive’ and produces a report which is accountable to, and yet also an outcome of, scientific and policy worlds. The next section outlines and provides some examples of how the IPCC’s connections to both science and policy have also had tangible impacts on the framing and outcome of products.

5.3 Framing Products in Changing Contexts

The climate change policy landscape has changed considerably since the IPCC was founded in 1988. The exact nature of the connection between the IPCC and its policy context is much commented on and debated both within critical social science circles and the IPCC itself (e.g. Haas & Stevens, Reference Haas, Stevens, Lidskog and Sundqvist2011; Lidskog & Sundqvist, Reference Lidskog and Sundqvist2015). Yet the products of the IPCC have undoubtedly been shaped by this context. An example of this would be the early reorganisation of the WG structure (see Agrawala, Reference Agrawala1998b; Skodvin, Reference Skodvin2000b). In AR1, published in 1990, the job of assessing possible Response Strategies lay with WGIII. But with the establishment in 1991 of the Intergovernmental Negotiating Committee (INC) – the precursor to the UN Framework Convention on Climate Change (UNFCCC) – the task of dealing with policy responses was passed to this new political body. As Skodvin (Reference Skodvin2000b: 121) notes, ‘the establishment of a negotiating committee enabled the IPCC to reorganise itself, withdraw from the (explicit) advisory function and reformulate its task to a provision of assessments for all WGs’.

Following the Paris Agreement in 2015 and the end of the 5th Assessment Cycle (AR5), the IPCC was again subject to discussion over its future and the structure of its products. The bottom-up nature of the Paris Agreement based on Nationally Determined Contributions (NDCs), in comparison to the top-down nature of the Kyoto Protocol, was identified as a reason for the need to reassess the nature of the IPCC’s products to better suit this new climate politics (Provost, Reference Provost2019). Many critical scholars argue that broad global assessments of climate are no longer politically relevant, and provide suggestions about how IPCC reports might evolve. These suggestions include dividing reports up into several diverse assessments (e.g. Beck et al., Reference Beck, Borie and Chilvers2014), producing shorter, more focused reports on specific topics and geographical contexts (Devès et al., Reference Devès, Lang, Bourrelier and Valérian2017), or engaging in more ex-post assessment of policies (Carraro et al., Reference Carraro, Edenhofer, Flachsland, Kolstad, Stavins and Stowe2015). Related to this, calls have been made for a ‘solutions turn’ in environmental assessments – assessments which, through collaborative processes, can evaluate the potential associated with different policy alternatives and their consequences (Kowarsch et al., Reference Kowarsch, Jabbour and Flaschland2017; see Chapter 21). This sentiment has also been recognised by the current IPCC Chairman, Hoesung Lee (see De Pryck & Wanneau, Reference De Pryck and Wanneau2017).

It is not always easy to assess the ways in which changes in policy expectations and in broader policy context shape the framing of IPCC reports. The periodic Assessment Reports provide comprehensive updates on the state of the science of climate change and of knowledge about socio-economic impacts, adaptation processes and mitigation options. Other reports, for example Methodological and Special Reports, are more closely connected to the policy discourse and focus on specific topics identified by the countries in Plenary.

Fogel (Reference Fogel2005) outlines how the commissioning by the Subsidiary Body for Science and Technology Advice (SBSTA) and preparation of the Special Report on Land Use, Land Use Change, and Forestry in 2000 were directly linked to political debates on the provisions of biotic carbon sequestration in the Kyoto Protocol. This was a highly policy-relevant and politically sensitive report because its approval was in some ways used to help resolve a political debate over what different countries wanted to include in the Kyoto Protocol (see Box 16.2 in Chapter 16). Another more recent example is that of the Special Report on Global Warming of 1.5 °C (SR15), requested in conjunction with the approval of the Paris Agreement in 2015 and published in 2018. The framing of SR15 around a specific temperature target, itself the result of protracted political discussions, revealed the complicated science–policy dynamics surrounding the preparation of IPCC reports, and Special Reports in particular (see Box 5.1 for more details). Methodology Reports are also key to the development and framing of NDCs, and are central to debates in current climate politics surrounding emissions inventories (see Dahan-Dalmedico, Reference Dahan-Dalmedico2008; Yona et al., Reference Yona, Cashore and Bradford2022).

These examples illustrate the tight connections IPCC reports maintain with the political realm and, in particular, with the UNFCCC. In addition, the IPCC also maintains its position as an authoritative body of climate change expertise through its connection to the scientific evidence base (van der Hel & Biermann, Reference van der Hel and Biermann2017). As debates surrounding the preparation of the Special Reports discussed previously show, this is not always a straightforward task. Fogel (Reference Fogel2005) outlines how discussions over the need to focus on ‘scientific and technical’ data over more cultural and socio-economic concerns in the Land Use Report from 2000 also influenced the types of literature assessed and the authors involved in the report preparation. Ultimately, this meant that the focus of the report was more on the technical definition of carbon sinks and involved experts with primarily physical science backgrounds. The SR15 report however is in line with calls for the IPCC to adopt a more solutions-orientated approach (Hulme, Reference Hulme2016). This has led to a reordering of the types of questions and framings within the IPCC itself (for example connecting the work of all three WGs), and the types of knowledge on which the assessment was based (see also Chapter 18).

The type of literature assessed for different IPCC reports to a large degree determines their nature. This is a question that has increasingly occupied IPCC discussions in more recent years in debates about representation between scientific disciplines. The IPCC bases its assessment on syntheses primarily of peer-reviewed literature published in academic journals (although it has in more recent years attempted to open up to a broader evidence base – see Chapter 13). Reliance on the underlying literature means that the IPCC is shaped by what literature is available at the time of writing, and by its framing and language. The structuring and sequencing of IPCC Assessment Reports – moving from WGI to WGIII – reflects a particular problem-solution framing which is largely based on the logic of natural science and a linear model of science to policy (see Beck, Reference Beck2011a).

In a study of AR3, Bjurström and Polk (Reference Bjurström and Polk2011) found a strong bias towards natural scientific and economic literature. This had implications for how the IPCC frames climate change, for example by placing humans outside nature. In a more recent study undertaken on AR5, Fløttum et al. (Reference Fløttum, Gasper and St. Clair2016) suggested that the language of the IPCC reports, while often chosen to ensure policy neutrality, did not successfully communicate the meaning of climate change to people and communities. One way to deal with these issues related to framing, suggested by many commentators, is for the IPCC to draw from a broader range of expertise and, in particular, to pay attention to the interpretative social sciences and humanities disciplines that have historically been absent from IPCC assessments (Carey et al., Reference Carey, James and Fuller2014). The reordering of expertise and of the kinds of questions being asked within research communities following the Paris Agreement may indeed herald a change in the way the IPCC assesses knowledge in the coming years.

5.4 Achievements and Challenges

The IPCC has been a highly productive institution during its 34-year history, and its reports are referenced in contexts as broad as the Fridays for Future movement, and in recent cases of climate litigation. This suggests that the ‘relevance’ of its reports extends far beyond the audiences envisaged by the IPCC itself. In addition, considerable media coverage surrounds their publication (O’Neill et al., Reference O’Neill, Williams and Kurz2015; see Chapter 26). The sheer number and reach of its publications can therefore be seen as a fundamental achievement. The so-called IPCC style of scientific assessment and process, which is tightly tied up with the production of reports, has been used as a model for other kinds of global environmental assessment, such as Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES).

However, the IPCC faces new challenges alongside the changing policy and scientific contexts within which it operates. Diversifying audiences and new social media suggest that new products, alongside the traditional IPCC report, may assume larger significance. These currently include IPCC FAQs and its Interactive Atlas (Lynn & Peeva, Reference Lynn and Peeva2021). This chapter has illustrated how the IPCC’s aim of producing reports that are policy relevant but never policy prescriptive forms a key part of both the preparation of reports, and their positioning in relation to broader political and scientific practice. Within the current political climate, continued strict adherence to the value-free ideal of science could limit the IPCC’s reach because growing numbers of voices call for more direct policy recommendations and messaging (Lynn & Peeva, Reference Lynn and Peeva2021). The IPCC’s reports have forged an authoritative role in today’s society, but to maintain this authority will require diversification and flexibility in the design of future IPCC reports and products.