Have IPCC SPMs shifted towards discussing more solutions in the past two decades?

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E. Gusheva, J. Lilliestam, F. Bock, F. Bold, S. Weko, F. Wu, S. Pfenninger This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7574973/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 12 You are reading this latest preprint version Abstract The Intergovernmental Panel on Climate Change (IPCC) regularly publishes summaries for policymakers (SPMs) based on its assessments of climate change science following the principle of policy-neutrality. As the urgency of climate change grows, there have been calls for IPCC assessments to be more solution-oriented, which means to assess specific policy instruments. Yet, there is a scholarly debate regarding whether and how it is possible to discuss specific policy instruments while staying policy-neutral. To inform this debate we conduct a content analysis of all Working Group III SPMs published in the last two decades. Dividing SPM content into strategic, argumentative and practical knowledge on mitigation policy instruments, we find that there is limited coverage of practical knowledge with only small changes over time. This suggests that IPCC assessments have not become more solution-oriented while abiding by their policy-neutrality principle. On the other hand, we find that SPMs have shifted from emphasizing the cost-effectiveness of mitigation towards emphasizing projections of required emissions reductions. Part of these changes may be explained through the evolution of ideas in global climate negotiations. Regardless of whether it chooses to amend its policy-neutrality principle, we recommend that the IPCC still shift more to discussing solutions. For example, the IPCC could better support the growing ecosystem of national and local boundary organizations which can broker context-specific knowledge on policy instruments. Earth and environmental sciences/Climate sciences Earth and environmental sciences/Environmental sciences Earth and environmental sciences/Environmental social sciences Social science/Environmental studies Scientific community and society/Scientific community Scientific community and society/Social sciences Scientific Advice Policymaking Advice IPCC Climate Change Mitigation Science-Policy Interface Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction Human-induced climate change is accelerating with looming threats to human wellbeing 1 . This increase in urgency is met with calls for climate action to take place at record speed. Intergovernmental Panel on Climate Change (IPCC) assessments have an important role to play in accelerating climate change mitigation by providing timely scientific input to policymaking. The IPCC has a long history of providing scientific knowledge to policymakers via its assessment reports (ARs), starting from the very first assessment cycle in 1990. All ARs contain summaries for policymakers (SPMs) that emphasize high-level findings. Because of its status as a global boundary organization 2,3 , fostering knowledge exchange between scientists and policymakers, IPCC assessments have unmatched legitimacy 4 impacting both science 5 and policymaking 6 , especially through its SPMs. The SPMs serve multiple audiences and can inform policymaking on international, national and local levels 7 . On an international level, statements from the SPM are quoted in international negotiations within the Conferences of the Parties (COPs) 8–10 supporting global treaties like the Paris Agreement 11 . While SPMs are the most widely used IPCC documents to guide policy development, they are often rewritten as locally-relevant summaries instead of being cited directly, especially for local policymaking 12 . Despite its function in the science-policy interface, many scholars highlight challenges for the IPCC to be policy-relevant 13–15 . The challenge lies in the difficulty of providing useful knowledge for policymaking, in the form of discussing specific policy instruments, without crossing the line into policy-prescription. While some suggest that the IPCC ought to re-consider its policy-neutrality principle 16,17 , others are strongly in favour of maintaining its policy-neutrality principle stating that it is possible to both discuss specific policy instruments and remain policy-neutral 18,19 . Thus, there is a scholarly debate regarding whether the IPCC ought to reform its policy-neutrality principle to remain policy-relevant, i.e. to discuss more specific policy instruments. Still, the ability of IPCC SPMs to discuss specific policy instruments may be limited not only because of the policy-neutrality principle, but also due to the SPMs’ statement-by-statement approval process, which naturally favors the least context-specific wording. Past studies on the content of IPCC assessments focus on investigating the epistemic diversity of the ARs 20–22 , finding gaps in the representation of scientific fields and disciplines. Further, a content analysis of the framing of SPMs suggests that IPCC assessments may miss and underrepresent the worldviews of some of the poorest and most vulnerable people to climate change 23 . Similarly, linguistic analyses question the readability of SPMs 24,25 . However, existing research does not help to empirically inform the scholarly debate on the IPCC’s policy-neutrality principle. Here we present a content analysis of IPCC Working Group 3 SPMs from 2001-2022, tasked with assessing the science on mitigating climate change. Our results map out the kinds of knowledge covered in the SPMs and how it has evolved over time. Our research has a knowledge perspective 26 , building an understanding of the kinds of knowledge that can be found in global scientific assessments and an empirical understanding of the topics found in climate change mitigation assessments. Most importantly, this paper discusses whether and how IPCC assessments can cover specific policy instruments while remaining policy-neutral. Background The IPCC assessments are the most well-established example of scientific global environmental assessments 27 . Their task is to conduct a comprehensive assessment of policy-relevant science on climate change 28 . Over the last 30 years, the IPCC has performed six assessment cycles. With reform suggestions dating back to the very first assessment cycle 29 , 30 , the IPCC has continuously been working to improve its processes and products to, among other things, maintain and improve the policy-relevance of its work. Policy-relevant scientific assessments provide knowledge that is useful for policymaking. The establishment of policy-relevance, however, is contextual and relational 31 . Two ways in which IPCC assessments ensure the policy-relevance of their work is via their scoping and approval processes. During both these processes, scientists conducting the assessment interact with policymakers with the intention of ensuring the policy-relevance of their work. For example, during the scoping process, the outline of the ARs is shaped both by IPCC scientists and member country government representatives 32 . Similarly, IPCC scientists and member country representatives participate in a formal statement-by-statement negotiation and approval process of the SPMs 32 where the policy-relevance of text can also be subject to negotiation. Thus, the SPMs particularly embody policy-relevant knowledge in IPCC assessments 33 . Still, scholars express concern regarding the policy-relevance of IPCC assessments, arguing that the IPCC’s modus operandi is ill-suited to the knowledge needs of national and local policymakers who are spearheading climate change mitigation 13 , 14 , 34 , 35 . This may be because most of these national and local policymakers are not included in the above-mentioned scoping and approval processes. In light of their exclusion, there have been recent calls to transition toward a more solution-oriented assessment 16 , 36 – 38 , i.e. an assessment that entails more content on policies like regulatory mechanisms and market-based instruments 37 . While, prior to the sixth assessment cycle, the term ‘solution-oriented’ was not used 15 , 39 , the obstacles for policymakers to use knowledge provided in IPCC assessments is not new, nor is the idea that the assessments should do a better job at informing on specific policy options. When discussing specific policy instruments, the IPCC has a principle against policy-prescriptiveness and for policy-neutrality, historically linked to the US government’s efforts to limit the influence of the IPCC 3 . The policy-neutrality principle means that IPCC assessments should not recommend specific policy instruments for mitigation. On the other hand, the opposite concept, policy-prescription, implies that they should. There is a scholarly debate regarding whether IPCC assessments should abandon or maintain the policy-neutrality principle. Proponents for maintaining the policy-neutrality principle 18 , 19 , 36 – 38 , 50 , 51 reason that the credibility and legitimacy established by this principle is imperative for the IPCC 52 . They suggest that IPCC assessments can and do discuss specific policies in a relative manner by mapping policy instruments to projected outcomes 18 , 19 . Thus, IPCC assessments ought to map out the solutions space for climate change mitigation, without influencing the decision of how to navigate that solution space as that is the responsibility of policymakers. Proponents for abandoning the policy-neutrality principle 16 , 17 , 40 – 44 reason that scientific knowledge is value-laden since it it is the product of human choices and it is normative because it frames both the problem and the policy solutions discussed even when it strives for scientific objectivity 45 – 49 . Yet scientific knowledge is seldom reflexive of the values it embeds, making policy-neutrality an unachievable ideal. Discussing detailed policy instruments is very context-dependent and difficult to do on a global level, leaving IPCC assessments with only one choice - to focus on decontextualized mitigation strategies, such as global carbon pricing 42 . In turn, these proponents suggest that moving toward policy-prescription can help make IPCC assessments more actionable when the assessments can freely recommend detailed policy measures. Both proponents for and against abandoning the policy-neutrality pricinple, however, tend to agree on two issues. First, they agree that IPCC assessments should be more transparent and reflexive about the values embedded (and omitted) in the knowledge they synthesize 16 , 37 . Second, they agree on the need for more inclusivity in terms of epistemic diversity of the literature considered in the assessments and working with stakeholders outside the organization so as to ensure many voices get heard 19 , 40 , 51 . Rooted in this debate, scholars present diverging outlooks for the future of IPCC assessments. For example, the pathways “Moderate path” 51 and “Diversifying viewpoints” 14 , the perspective “Consensus-building” 43 and the reform agendas “Back to basics” and “Enhanced dialogue” 13 all highlight the importance of maintaining policy-neutrality. While outlooks like the perspective “Critical debate” 43 , the pathways “Radical path” 51 and “Advocating for change” 14 and the reform agendas “Polycentric knowledge production” and “Action-oriented IPCC” 13 mention the need to re-consider the policy-neutrality principle. To summarize, IPCC assessments are policy-neutral and non-prescriptive in terms of policy action, but at the same time there are intensifying calls for them to transition to solutions, which means for them to discuss more specific policy instruments to better support the transition to climate neutrality in the coming decades. The debate points to a disagreement about the extent to which it is possible to discuss specific policy instruments while upholding the policy-neutrality principle. To inform this debate, we present an empirical investigation of knowledge on policy instruments in the SPMs and how that has changed over time. It sheds light on whether, as some suggest possible, IPCC assessments have historically become more solution-oriented while remaining policy-neutral. Methods We conduct a content analysis of AR3-AR6 WG3 SPMs. First we code the text as topics and calculate intercoder agreement to establish the validity of the coding. Next, we analyze topic distribution and test hypotheses about its behaviour over time as a way of explaining SPM content development across assessment cycles. Coding We coded all statements by hand, applying a one-statement-one-topic rule. This allowed us to cover the meaning of each statement, which would not be possible with automated methods like a keyword-driven analysis from a topic modelling algorithm. In the words of the AR5 SPM, “mitigation is a human intervention to reduce the sources or enhance the sinks of greenhouse gases” 52 . Yet, for such an important issue, the concept of climate change mitigation lacks a widely agreed upon theoretical underpinning 53 . Hence, it was necessary to build a codebook from scratch. Using an inductive coding process, we developed a codebook that captures the topics of the SPMs in what Braun and Clarke refer to as “domain summaries” 54 . We created the codebook working solely with the AR5 SPM because it was the latest published and longest SPM at the time of designing the research, so we assumed it contained the largest diversity of topics of all SPMs. That assumption proved to be true, which suggests that our results would have showed even greater diversity of themes in AR6 had we based the codebook on the AR6 SPM. The two criteria we followed when creating the codebook were that it should be large enough to capture the full spectrum of SPM content and specific enough to allow for mutually exclusive coding, i.e. that the boundaries between topic definitions are unambiguous. We iterated the codebook development four times with feedback from two independent coders who practiced applying the codebook on five pages of the AR5 SPM. The resulting codebook features 24 topics (Table 2 , see Table S1 for full codebook including examples, inclusion and exclusion criteria). Table 2 Codebook of WG3 SPMs Topic Definition Actors Statements that focus on governments, organizations or individuals as contributors to climate change mitigation Background information Information about the past or definitions which sets the context for nearby statements Barriers to mitigation Statements regarding the challenges which hinder climate change mitigation action Behavioural change strategies Statements that outline approaches which lower the extent of human activity as a way of mitigation climate change Burden sharing Statements that outline the distribution of mitigation efforts across regions because of the variance of regional mitigation costs or other drivers of mitigation potential Co-benefits Statements on positive (un)intended consequences of climate change mitigation Costs and cost-effectiveness Statements about the costs and cost-effectiveness of climate change mitigation Emissions drivers Statements about the factors driving greenhouse gas emissions Emissions projections Statements that explain how greenhouse gases emissions are likely to develop in the future based on current measures Equity Statements about the fairness of climate change mitigation Historic emissions Statements about past emissions as recorded in the greenhouse gases inventory International policy Statements about initiatives or policies that can be or have been implemented internationally Introductory information General statements which introduce the concept of climate change mitigation and call for climate change motivation Methodological considerations Statements which outline or discuss the way the scientific evidence was created, assessed and its limitations Mitigation drivers Statements about factors driving greenhouse gas emissions reduction Negative emissions strategies Statements that outline approaches which increase greenhouse gases capture and storage as a way of mitigation climate change Policy outcome Statements that describe the outcome of implemented climate change mitigation measures Public policy Statements about policies that can be implemented on a national or local level Side effects Statements on negative (un)intended consequences of climate change mitigation Targets Statements which focus on feasible or necessary climate change mitigation policy targets Technological change strategies Statements that outline technological change approaches which decarbonize energy sources and carriers or increase the efficiency of human activity Timeline Statements about the timeline of climate change mitigation policy Undefined effects Statements on both positive and negative (un)intended consequences of climate change mitigation Undefined strategies General statements about mitigation strategies or statements that mix multiple mitigation strategies At least two coders (the codebook developer and an independent coder, five coders in total) coded each text to ensure the reliability of the coding. The independent coders were first trained on a small sample of SPM statements to practice applying the codebook (four independent coders for four SPMs). We then tasked the independent coders to code all the statements in one SPM on their own. Afterward, we compared our coding and resolved intercoder disagreements by engaging in a discussion until reaching consensus. Thus, our analysis is based on the coding performed by and agreed upon by both the codebook developer and the independent coders. Last, three topics (‘Background information’, ‘Introductory information’ and ‘Methodological considerations’ in Table 2 ) refer to contextual information, so we omitted them from the analysis (see distribution of ommitted topics in Table S2). The coded topics are deposited on the 4TU database and will be made open access. Evaluation We analyse the codes in three ways: first, a frequency analysis, including of topics grouped into larger themes; second, a linear regression to examine changes through time; and finally, an exploration of whether topic distribution over time is consistent with two possible explanations for the observed trends. For the first analysis we counted the frequency of topic occurrence within each SPM separately, and on average by giving equal weight to the distribution in each SPM. In addition, we induced overarching themes and analyzed their patterns of change over time. The overarching themes arise from the logic that not all scientific knowledge is directly actionable for policy. Rather, some knowledge only has conceptual impact 44 , whereby it provokes debate on policy but does not driectly inform its development. Thus we distinguish between three knowledge type themes: argumentative knowledge (that justifies the case for mitigation policy), strategic knowledge (that broadly guides on the direction of mitigation policy) and practical knowledge (that directly informs the development of mitigation policy). We classified all topics in knowledge type themes by analyzing the raw data, i.e. the underlying SPM text. To test the sensitivity of our findings to our classification, we experimented with four alternative classifications. We found that our theme distribution remains the same despite the perturbations, providing proof that our results do not hinge on a single strict arrangement of topics into themes (see Note S1 for full description of sensitivity analysis results). As a second analysis, to identify broad trends in the data that are concealed by SPM-to-SPM variation, we fit linear regression models to four topic distribution values across four SPMs. We calculate trendlines, their slope coefficients and the goodness of fit (R²) for linear regression models of topic distributions. The topics whose regression models had the largest slope coefficients and highest goodness of fit are those with the clearest and strongest change over time. Last, we test two ideas as possible explanations for trends in SPM content development as identified with the regression models. The first idea is that developments in global climate policy drive SPM content development. The second idea is that the passing of time drives SPM content development due to the increasing urgency of climate change and the progress through time in implementation of mitigation measures. For the first idea, we look at global climate treaties as milestones of international climate policy with a specific focus on the Kyoto Protocol and the Paris Agreement 11 . Different principles govern these treaties, pointing to a progression in central intellectual ideas regarding mitigation 53 . For example, the costs of mitigation and burden sharing between countries was especially politically relevant in the 1990s 54 , 55 . The Kyoto Protocol emphasized cost-effectiveness by prioritizing emissions reductions where it is cheapest and it distinguished between the responsibilities of developed and developing countries 56 , 57 . However, over time, the framing of mitigation has progressed from a ‘zero-sum game’, as evidenced in publications by international organizations 53 , to one where the cost-effectiveness of mitigation is established. Further, over time, it has become more politically relevant to emphasize global targets like the temperature goals in the Paris Agreement. That is not to say that the Kyoto Protocol did not include targets, but they were country-specific rather than global 57 . Because of the Paris Agreement's bottom-up approach with a ratchet mechanism 58 , continuous accounting of necessary emissions reductions is important. This drove the production of quantitative emissions projections to operationalize the shift from vague stabilization goals to specific temperature outcomes 59 . Given these developments, we conceptualize the topics ‘Costs and cost-effectiveness’ and ‘Burden sharing’ as related to ideas in the Kyoto Protocol, and a the topics ‘Targets’ and ‘Emissions projections’ as related to ideas in the Paris Agreement. We assess the development of the Kyoto-associated and Paris-associated topics across the SPMs and evaluate how much content development can be explained with it by calculating the share of content captured by these topics. Further, we test whether international climate policy can explain content development by checking whether the topic distribution over time matches with the timeline of international climate treaties. Specifically, we hypothesize that the prevalence of the Kyoto-associated topics decreases over time while the prevalence of the Paris-associated topics increases. For the second idea, we look at how the progression of time might explain SPM content development across assessment cycles given the increased urgency of climate change and progress achieved in implementing mitigation policy. Specifically, we form hypotheses about how topic prevalence ought to have developed over time and then test whether the analysis supports or rejects the hypotheses. Because of the increased urgency of climate change, we hypothesize that there is increased prevalence of ‘Negative emissions strategies’ and ‘Timeline’ as negative emissions strategies become more necessary to deal with delayed action 60 , and increased prevalence of ‘Targets’ since more an more countries have set targets 61 . Because of progress in implementation, we hypothesize that there is increased prevalence of ‘Public policy’ as more policy instruments are considered 62 , and an increased prevalence of ‘Policy outcome ’as more ex-post policy analyses are conducted 63 , and an increased prevalence of ‘Barriers to mitigation’ as more challenges are encountered while implementing policies in the real world 64 . Results Practical knowledge is sparse with no change over time SPM content reflects three types of knowledge: argumentative knowledge to justify policy (red in Fig. 1 ), strategic knowledge to guide policy (yellow in Fig. 1 ), and practical knowledge to develop policy (blue in Fig. 1 ). Let us take the example of decarbonizing electricity production to illustrate the difference between these three types of knowledge. First, the SPMs contain statements that stress the benefits of reducing air pollution when switching to electricity from renewables (coded as ‘Co-benefits’). This is argumentative knowledge because it can be used to advocate for policies but does not guide their development or implementation. Next, in the SPMs, there are statements for a switch from coal-based electricity to electricity from renewable energy sources (coded as ‘Technological change strategies’). This represents strategic knowledge since it informs policy makers what needs in the energy transition to be done, but not how to stimulate it. Last, the SPMs also include statements discussing policies, such as tax credits or support schemes, to incentivize investment in renewable electricity production (coded as ‘Public policy’). This is practical knowledge since the information can not only be used to steer the direction but also to directly develop policy and actually trigger the changes found to be beneficial in the first to knowledge type groups. Practical knowledge is least prevalent of the three knowledge types in the SPMs. This is true on average across all assessment cycles and within each cycle (Fig. 2 ). The sensitivity analysis shows that this remains true with alternative topic classifications (details in Note S1): our finding is robust and not sensitive to argument definitions. Thus, the majority of SPM content is of little direct practical use to develop policymaking, but rather serves as evidence to advocate for mitigation policymaking and as a general guide on its direction. While the SPMs touch upon what changes are needed to mitigate climate change, they shy away from discussing the tools needed to set those changes in motion. As an illustration, the SPMs state that certain manufacturing processes can be electrified but they do not discuss what actions managerial decision-making would need to take towards abandoning fossil-fuel manufacturing processes for carbon-neutral ones (such as electricity-based solutions). Knowledge type distribution is strikingly consistent across assessment cycles with strategic and argumentative knowledge making up the majority of SPM content. The largest change is between AR3 and AR4 yet the relative ranking of knowledge types remains. This shows that all three knowledge types have been consistently covered in the last two decades, with strategic and argumentative knowledge being strongly dominant. Shift from discussing cost-effectiveness to calculating past and present emissions While the distribution of knowledge type themes is stable across assessment cycles, many specific topics exhibit large SPM-to-SPM variation. The main trend in content development is a shift from emphasis on costs and general approaches (top of Fig. 3 ) to calculating past emissions, future projections with and without additional mitigation (bottom of Fig. 3 ). These topics have the highest regression slope coefficients with a high goodness of fit (see Table S4 for specific numbers) and thus display both the clearest and the strongest changes over time. Over time the SPMs exhibit a trend toward higher numerical precision and specificity. The top three topics with a positive change across assessment cycles are related to quantifications (‘Emissions projections’, ‘Historic emissions’, ‘Targets’). Specifically, the SPMs increasingly focus on quantifying how bad climate change will get if we don’t increase mitigation efforts (‘Emissions projections’) and calculating the amount of emissions reductions related to temperature goals (‘Targets’). Not all topics concerning quantitative knowledge exhibit a positive trend (e.g. ‘Cost and cost-effectiveness’), but enough do to identify a pattern. On the other hand, two of the top three topics with a negative change across assessment cycles are general and non-specific (‘Undefined strategies’ and ‘Undefined effects’), hinting to a drop in vague statements which suggests that there is a trend toward higher specificity. Shift from ideas associated with the Kyoto Protocol to ideas associated with the Paris Agreement The trends of content development in the SPMs can be understood under the lens of global climate agreements. Two major international treaties took place during the period we studied (AR3-AR6): the Kyoto Protocol and the Paris Agreement. We identify topics associated with the ideas that prevailed during the time the treaties took place. The Kyoto-associated topics view mitigation as a global commons problem with tension between developing and developed countries and pays great attention to mitigation incentives. Thus, we see statements on how high-income and low-income countries differ in their capacity for carrying out mitigation (‘Burden sharing’) statements on the economic costliness (‘Costs and cost-effectiveness’) of mitigation in the SPMs (see Fig. 4 a). On the other hand, the Paris-associated topics emphasize accountability with a view toward a specific temperature goal, which is reflected in statements quantifying the expected emissions with (‘Targets’) and without additional mitigation (‘Emissions projections’). To illustrate, the Kyoto-associated topics emphasize that energy efficiency measures can result in economic benefits greater than direct costs (coded as ‘Costs and cost-effectiveness’) while the Paris-associated topics zoom in on the estimated emissions reduction that can be achieved via energy efficiency measures (coded as ‘Targets’). The distribution of the topics associated with these two treaties explains idea evolution in the SPMs over time; however, it is limited in explaining less than 15% of SPM content on average (see Fig. 4 b). We see a clear decreasing trend for the Kyoto-associated topics and an increasing trend for the Paris-associated topics, suggesting a gradual evolution of ideas over time. There is a sharp increase in the prevalence of topics associated with the Paris-associated topics in the SPM published after the Paris Agreement (AR6). There is a sharp drop in the prevalence of the Kyoto-associated topics in the subsequent SPM (AR4). This hints at a possible pattern whereby SPMs published after the global agreements surge with ideas related to these agreements and then level off in subsequent assessment cycles[1] . Some trends associated with increasing urgency and progress in implementation Given the passing of time, we expect SPM content to reflect progress in policy implementation over time. For example, as elaborated in the methods section, we hypothesize that there is more content on policy analysis (‘Public policy’), and more content on positive examples of implemented policies (‘Policy outcome’), and more content on aspects challenging the implementation of policy (‘Barriers to mitigation’) across assessment cycles. Similarly, given the increasing urgency of climate change as time passes, we hypothesize that SPMs cover more statements including specific deadlines (‘Timeline’) and the common goals associated with them (‘Targets’) as well as strategies to cope with failure to mitigate on time (‘Negative emissions strategies’) across assessment cycles. The hypotheses relating to topics ‘Targets’, ‘Negative emissions strategies’, ‘Policy outcome’ and ‘Barriers to mitigation’ are met, but those relating to ‘Timeline’ and ‘Public policy’ are not (see Fig. 5 ). This suggests that the increasing urgency and progress in implementation somewhat explains SPM content development, but not very strongly as we expect. While we expected there to be more content in the SPMs covering specific public policy instruments and more content outlining a timed schedule of mitigation action, there is a slightly decreasing trend across assessment cycles for these topics. Discussion and conclusion In this paper we investigate the content of Working Group III SPMs and show how it has changed over time. Our research has two main contributions. First, our results help empirically evaluate whether IPCC assessments have responded to calls to shift their focus towards solutions by providing more content on specific policy instruments. Second, we show how ideas in IPCC assessments have co-evolved with global climate change politics, reflecting to what extent they are keeping up with developments in global negotiations and the increasing urgency of climate change. Our results indicate that there has not been a shift towards solutions in the SPMs, and especially not in the sixth assessment cycle. We find that practical knowledge (largely composed of analysis of policy instruments) is scarce in the SPMs and it has not increased mentionably over time. This implies that SPMs have not shifted towards ”what works” or how to actually decarbonize societies over time. Thus, requests for a shift towards solutions 16 , 37 , 38 have not had an impact, despite an increase in scientific publications on mitigation solutions 65 . We find a very limited shift towards solutions even if we broaden the term ‘solution-oriented’ beyond analyses of policy instruments to include more general information on mitigation strategies, which is strategic (“how to mitigate”) instead of practical (“what works”) knowledge. Out of all topics on mitigation strategies, only the "negative emissions strategies" topic exhibits a positive trend across assessment cycles. This suggests that, under the more generous definition of ‘solution-oriented’, there has only been a shift towards solutions related to negative emissions. While we find that there is no shift towards solutions in the SPMs, this is not necessarily generalizable to IPCC assessments overall. There may have been a shift towards solutions in the full reports that did not make its way into the more politically contentious SPMs, but a contents analysis of the full reports was out of scope of our research. We encourage similar research to undertake the task of assessing this to be able to generalize about IPCC assessments overall. Further, our content analysis is of a quantitative character, so it may miss nuanced changes in how policy intruments are covered in the SPMs. For example, there may have still been a shift toward more policy-specificity without there being any relative growth in the share of policy-related topics in the SPMs. Such a shift toward more policy-specific content may also be interpreted as a shift towards solutions in the SPMs. Future research employing a discourse analysis, possibly with automated methods that also enable analysis of the vastly longer reports, can address this issue The key implication of our findings is that the IPCC SPMs have not become more solution-oriented while remaining policy-neutral and with the current SPM scoping and approval processes. Therefore the empirical evidence supports the logic that IPCC assessments may need to re-consider their policy-neutrality principle or its approval and scoping processeses to enable a shift toward solutions. So far, this shift has not happened – and maybe it could not – within the existing task description of the IPCC. We find that ideas in SPMs have co-evolved with changes in global climate policy. In particular, we show a shift from Kyoto-associated topics, focused on the cost-effectiveness of mitigation and burden-sharing between countries, to Paris-associated topics, emphasizing accountability and (national) target-setting through calculations of past and estimated emissions. This corresponds to the shift in global climate policy, from the global commons framing of the Kyoto Protocol to the NDC-centred approach of the Paris Agreement. However, the shift has not been all-encompassing as our results show that content on costs and burden sharing is still strong in AR6. This indicates that the SPMs, like documents from other international organizations, have historically moved to more discursive diversity on climate change mitigation rather than just changing the paradigm 53 . Additionally, our results hint that global climate policy development may drive SPM content, but more research is needed to understand the link between the two. We demonstrate that Kyoto-associated topics were prevalent in AR3, right after the Kyoto Protocol was adopted, and then had a substantial drop in AR4. Similarly, the prevalence of the Paris-associated topics shot up in AR6 right after (and not before) the Paris Agreement was adopted. This hints at the possibility that SPM content may be driven by global climate policy and not vice versa. Previous research on the Special Report on 1.5 has found that IPCC assessments were shaped by political negotiations 52 , 66 . However, future research with a broader scope including the content of AR2 before the Kyoto Protocol and the upcoming AR7 can shed light whether this is a pattern. Last, we find that the SPMs are increasingly covering topics relevant to the urgency of climate mitigation, for example emissions reductions needed to achieve the Paris Agreement temperature goal and negative emissions approaches, and topics focused on implementation, for example ex-post policy evaluations and barriers to climate action. This suggests that the SPMs are co-evolving with dominant ideas in international climate change mitigation policy, even though they are not shifting to solutions. While we build an empirical overview of changes in SPM topic prevalence over time, we are limited in explaining the causes for those changes. We experiment with two ideas related to changes in international politics (shift from Kyoto Protocol to Paris Agreement) and the passing of time (increase in urgency and progress in implementation). But this only offers an explanation for some of the topic changes we observe. Future research can link changes in SPM topic prevalence to changes in scientific output, geopolitical developments or IPCC authorship and procedures. One idea could be doing interviews with IPCC authors delving into the underlying reasons for the (lack of) changes in SPM topic prevalence. Thus, our findings empirically demonstrate that the IPCC changed its focus on some topics, suggesting that it can do so in the future. While we set out to empirically examine the policy-neutrality debate, we ultimately suggest that the IPCC ought to emphasize the topic of policy instruments to maintain policy-relevance for national and local policymakers, regardless of whether it is in a policy-prescriptive or policy-neutral manner. In addition, we find that there is consensus among scholars for the IPCC to be more transparent about the value-ladenness of its work 67 , put more effort in promoting a more diverse evidence base 68 , 69 and dialogues with stakeholders outside of the assessment 19 . Given the divisions in the debate on whether the IPCC should abandon its policy-neutrality or not, we stress that the IPCC need not be all things to all people 14 . For example, it is imaginable that the IPCC itself maintains its policy-neutral function, while focusing more on synthesising the scientific evidence of policy effectiveness and effects. It can let other boundary organizations in their specific international, national and local contexts expand on its assessments to offer science-based policy advice. For example, The Subsidiary Body for Scientific and Technological Advice (SBSTA) provides advice at COPs based on the IPCC assessments 2 , 3 . Further, in some countries there are national boundary organizations creating assessments tailored to national contexts akin to those by the IPCC 3 . The IPCC may consider taking a more proactive role acting as a network facilitator and support other boundary organizations. As an example, the IPCC could consider fostering exchange of scientific knowledge on policy instruments between national knowledge brokers like the OECD’s approach in education 70 . This could be in addition to or instead of its global-level assessments which can miss context-dependance when discussing policy-instruments. We conclude that the SPMs have not shifted towards discussing more solutions, but have kept up with the times by switching their focus from ideas associated with the Kyoto Protocol to ideas associated with the Paris Agreement. Our empirical findings suggest that it has not been possible for IPCC assessments to discuss more specific policy instruments in the SPMs within their current working procedures. Regardless of whether the IPCC chooses to reform, we stress that it is still important for IPCC SPMs to strive to cover more content on specific policy instruments. 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13:02:56","extension":"html","order_by":15,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":148846,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-7574973/v1/c2bf8c742c01d5a1d1ea453b.html"},{"id":92718524,"identity":"cdb2c2e1-4972-4f4f-8e22-a865a1a6c900","added_by":"auto","created_at":"2025-10-03 13:03:01","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":238703,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eDistribution of SPM content on average. Topics(left) are shown alongside the themes(right) they are classified in. The box size corresponds to average prevalence per SPM (see Table S3 for the results in tabular format).\u003c/em\u003e\u003c/p\u003e","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-7574973/v1/d428edd0c24d68c9e902a4d4.png"},{"id":92718504,"identity":"e4a0c293-1035-4ed3-8f57-94f92fc7e83d","added_by":"auto","created_at":"2025-10-03 13:02:54","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":57667,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eDistribution of SPM content across assessment cycles\u003c/em\u003e\u003c/p\u003e","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-7574973/v1/8f42865957ff27711c14d8ec.png"},{"id":92718508,"identity":"0465961b-3971-420f-89b8-4dbffae0ce07","added_by":"auto","created_at":"2025-10-03 13:02:55","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":278025,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eChange in topic prevalence over time. The red box marks the topics with the clearest decreasing trend over time. The blue box marks the topics with the clearest increasing trend over time. The transparency of the line represents the fit of the regression trendline to raw data (R²) whereby transparent lines have a lower fit than opaque lines.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"floatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-7574973/v1/a4bb498d08f804a87177ecdf.png"},{"id":92718505,"identity":"2919502a-d2d2-40cf-a061-ae664e06176d","added_by":"auto","created_at":"2025-10-03 13:02:54","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":35357,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003ePrevalence of topics associated with ideas in the Kyoto Protocol and Paris Agreement and their distribution in the SPMs across assessment cycles.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"floatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-7574973/v1/23a06d0740513e9cf9ac546b.png"},{"id":92718510,"identity":"3c392a3f-d798-4166-822f-c50cb4602ff4","added_by":"auto","created_at":"2025-10-03 13:02:55","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":128011,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eDifferences between expected and observed SPM content development across assessment cycles due to passing of time and increasing of urgency. The observed values are based on linear regression models depicting the trend in topic distribution across assessment cycles, as shown in Figure 3. The expected values are the authors’.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"floatimage5.png","url":"https://assets-eu.researchsquare.com/files/rs-7574973/v1/18a06fe673b56294f33b707d.png"},{"id":92720569,"identity":"2f4367a7-6cf8-4749-932f-8f94e31af69a","added_by":"auto","created_at":"2025-10-03 13:26:58","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1216230,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7574973/v1/875c6161-7f11-40ce-9b6f-a272e0d86f4b.pdf"},{"id":92718514,"identity":"14ca29a3-2c66-47e1-9434-e654b7f12f90","added_by":"auto","created_at":"2025-10-03 13:02:55","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":2298827,"visible":true,"origin":"","legend":"","description":"","filename":"SupplementaryMaterial.docx","url":"https://assets-eu.researchsquare.com/files/rs-7574973/v1/c36a0cc9cbb6704f43a58422.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Have IPCC SPMs shifted towards discussing more solutions in the past two decades?","fulltext":[{"header":"Introduction","content":"\u003cp\u003eHuman-induced climate change is accelerating with looming threats to human wellbeing\u003csup\u003e1\u003c/sup\u003e. This increase in urgency is met with calls for climate action to take place at record speed. Intergovernmental Panel on Climate Change (IPCC) assessments have an important role to play in accelerating climate change mitigation by providing timely scientific input to policymaking. The IPCC has a long history of providing scientific knowledge to policymakers via its assessment reports (ARs), starting from the very first assessment cycle in 1990. All ARs contain summaries for policymakers (SPMs) that emphasize high-level findings. Because of its status as a global boundary organization\u003csup\u003e2,3\u003c/sup\u003e, fostering knowledge exchange between scientists and policymakers, IPCC assessments have unmatched legitimacy\u003csup\u003e4\u003c/sup\u003e impacting both science\u003csup\u003e5\u003c/sup\u003e and policymaking\u003csup\u003e6\u003c/sup\u003e, especially through its SPMs.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe SPMs serve multiple audiences and can inform policymaking on international, national and local levels\u003csup\u003e7\u003c/sup\u003e. On an international level, statements from the SPM are quoted in international negotiations within the Conferences of the Parties (COPs)\u003csup\u003e8\u0026ndash;10\u003c/sup\u003e supporting global treaties like the Paris Agreement\u003csup\u003e11\u003c/sup\u003e. While SPMs are the most widely used IPCC documents to guide policy development, they are often rewritten as locally-relevant summaries instead of being cited directly, especially for local policymaking\u003csup\u003e12\u003c/sup\u003e.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eDespite its function in the science-policy interface, many scholars highlight challenges for the IPCC to be\u0026nbsp;policy-relevant\u003csup\u003e13\u0026ndash;15\u003c/sup\u003e. The challenge lies in the difficulty of providing useful knowledge for policymaking, in the form of discussing specific policy instruments, without crossing the line into policy-prescription. While some suggest that the IPCC ought to re-consider its policy-neutrality principle\u003csup\u003e16,17\u003c/sup\u003e, others are strongly in favour of maintaining its policy-neutrality principle stating that it is possible to both discuss specific policy instruments and remain policy-neutral\u003csup\u003e18,19\u003c/sup\u003e. Thus, there is a scholarly debate regarding whether the IPCC ought to reform its policy-neutrality principle to remain policy-relevant, i.e. to discuss more specific policy instruments. Still, the ability of IPCC SPMs to discuss specific policy instruments may be limited not only because of the policy-neutrality principle, but also due to the SPMs\u0026rsquo; statement-by-statement approval process, which naturally favors the least context-specific wording.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003ePast studies on the content of IPCC assessments focus on investigating the epistemic diversity of the ARs\u003csup\u003e20\u0026ndash;22\u003c/sup\u003e, finding gaps in the representation of scientific fields and disciplines. Further, a content analysis of the framing of SPMs suggests that IPCC assessments may miss and underrepresent the worldviews of some of the poorest and most vulnerable people to climate change\u003csup\u003e23\u003c/sup\u003e. Similarly, linguistic analyses question the readability of SPMs\u003csup\u003e24,25\u003c/sup\u003e. However, existing research does not help to empirically inform the scholarly debate on the IPCC\u0026rsquo;s policy-neutrality principle.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eHere we present a content analysis of IPCC Working Group 3 SPMs from 2001-2022, tasked with assessing the science on mitigating climate change. Our results map out the kinds of knowledge covered in the SPMs and how it has evolved over time. Our research has a knowledge perspective\u003csup\u003e26\u003c/sup\u003e, building an understanding of the kinds of knowledge that can be found in global scientific assessments and an empirical understanding of the topics found in climate change mitigation assessments. Most importantly, this paper discusses whether and how IPCC assessments can cover specific policy instruments while remaining policy-neutral.\u003c/p\u003e"},{"header":"Background","content":"\u003cp\u003eThe IPCC assessments are the most well-established example of scientific global environmental assessments\u003csup\u003e\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e\u003c/sup\u003e. Their task is to conduct a comprehensive assessment of policy-relevant science on climate change\u003csup\u003e\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e\u003c/sup\u003e. Over the last 30 years, the IPCC has performed six assessment cycles. With reform suggestions dating back to the very first assessment cycle\u003csup\u003e\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e,\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e\u003c/sup\u003e, the IPCC has continuously been working to improve its processes and products to, among other things, maintain and improve the policy-relevance of its work.\u003c/p\u003e\u003cp\u003ePolicy-relevant scientific assessments provide knowledge that is useful for policymaking. The establishment of policy-relevance, however, is contextual and relational\u003csup\u003e\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e\u003c/sup\u003e. Two ways in which IPCC assessments ensure the policy-relevance of their work is via their scoping and approval processes. During both these processes, scientists conducting the assessment interact with policymakers with the intention of ensuring the policy-relevance of their work. For example, during the scoping process, the outline of the ARs is shaped both by IPCC scientists and member country government representatives\u003csup\u003e\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e\u003c/sup\u003e. Similarly, IPCC scientists and member country representatives participate in a formal statement-by-statement negotiation and approval process of the SPMs\u003csup\u003e\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e\u003c/sup\u003e where the policy-relevance of text can also be subject to negotiation. Thus, the SPMs particularly embody policy-relevant knowledge in IPCC assessments\u003csup\u003e\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eStill, scholars express concern regarding the policy-relevance of IPCC assessments, arguing that the IPCC’s modus operandi is ill-suited to the knowledge needs of national and local policymakers who are spearheading climate change mitigation\u003csup\u003e\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e,\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e,\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e,\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e\u003c/sup\u003e. This may be because most of these national and local policymakers are not included in the above-mentioned scoping and approval processes. In light of their exclusion, there have been recent calls to transition toward a more solution-oriented assessment\u003csup\u003e\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e,\u003cspan additionalcitationids=\"CR37\" citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e–\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e\u003c/sup\u003e, i.e. an assessment that entails more content on policies like regulatory mechanisms and market-based instruments\u003csup\u003e\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e\u003c/sup\u003e. While, prior to the sixth assessment cycle, the term ‘solution-oriented’ was not used\u003csup\u003e\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e,\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e\u003c/sup\u003e, the obstacles for policymakers to use knowledge provided in IPCC assessments is not new, nor is the idea that the assessments should do a better job at informing on specific policy options.\u003c/p\u003e\u003cp\u003eWhen discussing specific policy instruments, the IPCC has a principle against policy-prescriptiveness and for policy-neutrality, historically linked to the US government’s efforts to limit the influence of the IPCC\u003csup\u003e\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u003c/sup\u003e. The policy-neutrality principle means that IPCC assessments should not recommend specific policy instruments for mitigation. On the other hand, the opposite concept, policy-prescription, implies that they should.\u003c/p\u003e\u003cp\u003eThere is a scholarly debate regarding whether IPCC assessments should abandon or maintain the policy-neutrality principle. Proponents for maintaining the policy-neutrality principle\u003csup\u003e\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e,\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e,\u003cspan additionalcitationids=\"CR37\" citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e–\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e,\u003cspan citationid=\"CR50\" class=\"CitationRef\"\u003e50\u003c/span\u003e,\u003cspan citationid=\"CR51\" class=\"CitationRef\"\u003e51\u003c/span\u003e\u003c/sup\u003e reason that the credibility and legitimacy established by this principle is imperative for the IPCC\u003csup\u003e\u003cspan citationid=\"CR52\" class=\"CitationRef\"\u003e52\u003c/span\u003e\u003c/sup\u003e. They suggest that IPCC assessments can and do discuss specific policies in a relative manner by mapping policy instruments to projected outcomes\u003csup\u003e\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e,\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e\u003c/sup\u003e. Thus, IPCC assessments ought to map out the solutions space for climate change mitigation, without influencing the decision of how to navigate that solution space as that is the responsibility of policymakers.\u003c/p\u003e\u003cp\u003eProponents for abandoning the policy-neutrality principle\u003csup\u003e\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e,\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e,\u003cspan additionalcitationids=\"CR41 CR42 CR43\" citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e–\u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e\u003c/sup\u003e reason that scientific knowledge is value-laden since it it is the product of human choices and it is normative because it frames both the problem and the policy solutions discussed even when it strives for scientific objectivity\u003csup\u003e\u003cspan additionalcitationids=\"CR46 CR47 CR48\" citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e–\u003cspan citationid=\"CR49\" class=\"CitationRef\"\u003e49\u003c/span\u003e\u003c/sup\u003e. Yet scientific knowledge is seldom reflexive of the values it embeds, making policy-neutrality an unachievable ideal. Discussing detailed policy instruments is very context-dependent and difficult to do on a global level, leaving IPCC assessments with only one choice - to focus on decontextualized mitigation strategies, such as global carbon pricing\u003csup\u003e\u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e\u003c/sup\u003e. In turn, these proponents suggest that moving toward policy-prescription can help make IPCC assessments more actionable when the assessments can freely recommend detailed policy measures.\u003c/p\u003e\u003cp\u003eBoth proponents for and against abandoning the policy-neutrality pricinple, however, tend to agree on two issues. First, they agree that IPCC assessments should be more transparent and reflexive about the values embedded (and omitted) in the knowledge they synthesize\u003csup\u003e\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e,\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e\u003c/sup\u003e. Second, they agree on the need for more inclusivity in terms of epistemic diversity of the literature considered in the assessments and working with stakeholders outside the organization so as to ensure many voices get heard\u003csup\u003e\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e,\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e,\u003cspan citationid=\"CR51\" class=\"CitationRef\"\u003e51\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eRooted in this debate, scholars present diverging outlooks for the future of IPCC assessments. For example, the pathways “Moderate path”\u003csup\u003e\u003cspan citationid=\"CR51\" class=\"CitationRef\"\u003e51\u003c/span\u003e\u003c/sup\u003e and “Diversifying viewpoints”\u003csup\u003e\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u003c/sup\u003e, the perspective “Consensus-building”\u003csup\u003e\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e\u003c/sup\u003e and the reform agendas “Back to basics” and “Enhanced dialogue”\u003csup\u003e\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u003c/sup\u003e all highlight the importance of maintaining policy-neutrality. While outlooks like the perspective “Critical debate”\u003csup\u003e\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e\u003c/sup\u003e, the pathways “Radical path”\u003csup\u003e\u003cspan citationid=\"CR51\" class=\"CitationRef\"\u003e51\u003c/span\u003e\u003c/sup\u003e and “Advocating for change”\u003csup\u003e\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u003c/sup\u003e and the reform agendas “Polycentric knowledge production” and “Action-oriented IPCC”\u003csup\u003e\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u003c/sup\u003e mention the need to re-consider the policy-neutrality principle.\u003c/p\u003e\u003cp\u003eTo summarize, IPCC assessments are policy-neutral and non-prescriptive in terms of policy action, but at the same time there are intensifying calls for them to transition to solutions, which means for them to discuss more specific policy instruments to better support the transition to climate neutrality in the coming decades. The debate points to a disagreement about the extent to which it is possible to discuss specific policy instruments while upholding the policy-neutrality principle. To inform this debate, we present an empirical investigation of knowledge on policy instruments in the SPMs and how that has changed over time. It sheds light on whether, as some suggest possible, IPCC assessments have historically become more solution-oriented while remaining policy-neutral.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003eWe conduct a content analysis of AR3-AR6 WG3 SPMs. First we code the text as topics and calculate intercoder agreement to establish the validity of the coding. Next, we analyze topic distribution and test hypotheses about its behaviour over time as a way of explaining SPM content development across assessment cycles.\u003c/p\u003e\u003cp\u003eCoding\u003c/p\u003e\u003cp\u003eWe coded all statements by hand, applying a one-statement-one-topic rule. This allowed us to cover the meaning of each statement, which would not be possible with automated methods like a keyword-driven analysis from a topic modelling algorithm. In the words of the AR5 SPM, “mitigation is a human intervention to reduce the sources or enhance the sinks of greenhouse gases”\u003csup\u003e\u003cspan citationid=\"CR52\" class=\"CitationRef\"\u003e52\u003c/span\u003e\u003c/sup\u003e. Yet, for such an important issue, the concept of climate change mitigation lacks a widely agreed upon theoretical underpinning\u003csup\u003e\u003cspan citationid=\"CR53\" class=\"CitationRef\"\u003e53\u003c/span\u003e\u003c/sup\u003e. Hence, it was necessary to build a codebook from scratch.\u003c/p\u003e\u003cp\u003eUsing an inductive coding process, we developed a codebook that captures the topics of the SPMs in what Braun and Clarke refer to as “domain summaries”\u003csup\u003e\u003cspan citationid=\"CR54\" class=\"CitationRef\"\u003e54\u003c/span\u003e\u003c/sup\u003e. We created the codebook working solely with the AR5 SPM because it was the latest published and longest SPM at the time of designing the research, so we assumed it contained the largest diversity of topics of all SPMs. That assumption proved to be true, which suggests that our results would have showed even greater diversity of themes in AR6 had we based the codebook on the AR6 SPM. The two criteria we followed when creating the codebook were that it should be large enough to capture the full spectrum of SPM content and specific enough to allow for mutually exclusive coding, i.e. that the boundaries between topic definitions are unambiguous. We iterated the codebook development four times with feedback from two independent coders who practiced applying the codebook on five pages of the AR5 SPM. The resulting codebook features 24 topics (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e2\u003c/span\u003e, see Table \u003cspan refid=\"MOESM1\" class=\"InternalRef\"\u003eS1\u003c/span\u003e for full codebook including examples, inclusion and exclusion criteria).\u003c/p\u003e\u003cdiv class=\"gridtable\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eCodebook of WG3 SPMs\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"2\"\u003e\u003c/colgroup\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eTopic\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eDefinition\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eActors\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eStatements that focus on governments, organizations or individuals as contributors to climate change mitigation\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBackground information\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eInformation about the past or definitions which sets the context for nearby statements\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBarriers to mitigation\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eStatements regarding the challenges which hinder climate change mitigation action\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBehavioural change strategies\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eStatements that outline approaches which lower the extent of human activity as a way of mitigation climate change\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBurden sharing\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eStatements that outline the distribution of mitigation efforts across regions because of the variance of regional mitigation costs or other drivers of mitigation potential\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCo-benefits\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eStatements on positive (un)intended consequences of climate change mitigation\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCosts and cost-effectiveness\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eStatements about the costs and cost-effectiveness of climate change mitigation\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eEmissions drivers\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eStatements about the factors driving greenhouse gas emissions\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eEmissions projections\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eStatements that explain how greenhouse gases emissions are likely to develop in the future based on current measures\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eEquity\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eStatements about the fairness of climate change mitigation\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHistoric emissions\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eStatements about past emissions as recorded in the greenhouse gases inventory\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eInternational policy\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eStatements about initiatives or policies that can be or have been implemented internationally\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eIntroductory information\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eGeneral statements which introduce the concept of climate change mitigation and call for climate change motivation\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMethodological considerations\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eStatements which outline or discuss the way the scientific evidence was created, assessed and its limitations\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMitigation drivers\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eStatements about factors driving greenhouse gas emissions reduction\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNegative emissions strategies\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eStatements that outline approaches which increase greenhouse gases capture and storage as a way of mitigation climate change\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePolicy outcome\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eStatements that describe the outcome of implemented climate change mitigation measures\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePublic policy\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eStatements about policies that can be implemented on a national or local level\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSide effects\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eStatements on negative (un)intended consequences of climate change mitigation\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eTargets\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eStatements which focus on feasible or necessary climate change mitigation policy targets\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eTechnological change strategies\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eStatements that outline technological change approaches which decarbonize energy sources and carriers or increase the efficiency of human activity\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eTimeline\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eStatements about the timeline of climate change mitigation policy\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eUndefined effects\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eStatements on both positive and negative (un)intended consequences of climate change mitigation\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eUndefined strategies\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eGeneral statements about mitigation strategies or statements that mix multiple mitigation strategies\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/div\u003e\u003cp\u003eAt least two coders (the codebook developer and an independent coder, five coders in total) coded each text to ensure the reliability of the coding. The independent coders were first trained on a small sample of SPM statements to practice applying the codebook (four independent coders for four SPMs). We then tasked the independent coders to code all the statements in one SPM on their own. Afterward, we compared our coding and resolved intercoder disagreements by engaging in a discussion until reaching consensus. Thus, our analysis is based on the coding performed by and agreed upon by both the codebook developer and the independent coders. Last, three topics (‘Background information’, ‘Introductory information’ and ‘Methodological considerations’ in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e2\u003c/span\u003e) refer to contextual information, so we omitted them from the analysis (see distribution of ommitted topics in Table S2). The coded topics are deposited on the \u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003e4TU\u003c/span\u003e database and will be made open access.\u003c/p\u003e\u003cp\u003eEvaluation\u003c/p\u003e\u003cp\u003eWe analyse the codes in three ways: first, a frequency analysis, including of topics grouped into larger themes; second, a linear regression to examine changes through time; and finally, an exploration of whether topic distribution over time is consistent with two possible explanations for the observed trends.\u003c/p\u003e\u003cp\u003eFor the first analysis we counted the frequency of topic occurrence within each SPM separately, and on average by giving equal weight to the distribution in each SPM. In addition, we induced overarching themes and analyzed their patterns of change over time. The overarching themes arise from the logic that not all scientific knowledge is directly actionable for policy. Rather, some knowledge only has conceptual impact\u003csup\u003e\u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e\u003c/sup\u003e, whereby it provokes debate on policy but does not driectly inform its development. Thus we distinguish between three knowledge type themes: argumentative knowledge (that justifies the case for mitigation policy), strategic knowledge (that broadly guides on the direction of mitigation policy) and practical knowledge (that directly informs the development of mitigation policy). We classified all topics in knowledge type themes by analyzing the raw data, i.e. the underlying SPM text. To test the sensitivity of our findings to our classification, we experimented with four alternative classifications. We found that our theme distribution remains the same despite the perturbations, providing proof that our results do not hinge on a single strict arrangement of topics into themes (see Note S1 for full description of sensitivity analysis results).\u003c/p\u003e\u003cp\u003eAs a second analysis, to identify broad trends in the data that are concealed by SPM-to-SPM variation, we fit linear regression models to four topic distribution values across four SPMs. We calculate trendlines, their slope coefficients and the goodness of fit (R²) for linear regression models of topic distributions. The topics whose regression models had the largest slope coefficients and highest goodness of fit are those with the clearest and strongest change over time.\u003c/p\u003e\u003cp\u003eLast, we test two ideas as possible explanations for trends in SPM content development as identified with the regression models. The first idea is that developments in global climate policy drive SPM content development. The second idea is that the passing of time drives SPM content development due to the increasing urgency of climate change and the progress through time in implementation of mitigation measures.\u003c/p\u003e\u003cp\u003eFor the first idea, we look at global climate treaties as milestones of international climate policy with a specific focus on the Kyoto Protocol and the Paris Agreement\u003csup\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/sup\u003e. Different principles govern these treaties, pointing to a progression in central intellectual ideas regarding mitigation\u003csup\u003e\u003cspan citationid=\"CR53\" class=\"CitationRef\"\u003e53\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eFor example, the costs of mitigation and burden sharing between countries was especially politically relevant in the 1990s\u003csup\u003e\u003cspan citationid=\"CR54\" class=\"CitationRef\"\u003e54\u003c/span\u003e,\u003cspan citationid=\"CR55\" class=\"CitationRef\"\u003e55\u003c/span\u003e\u003c/sup\u003e. The Kyoto Protocol emphasized cost-effectiveness by prioritizing emissions reductions where it is cheapest and it distinguished between the responsibilities of developed and developing countries\u003csup\u003e\u003cspan citationid=\"CR56\" class=\"CitationRef\"\u003e56\u003c/span\u003e,\u003cspan citationid=\"CR57\" class=\"CitationRef\"\u003e57\u003c/span\u003e\u003c/sup\u003e. However, over time, the framing of mitigation has progressed from a ‘zero-sum game’, as evidenced in publications by international organizations\u003csup\u003e\u003cspan citationid=\"CR53\" class=\"CitationRef\"\u003e53\u003c/span\u003e\u003c/sup\u003e, to one where the cost-effectiveness of mitigation is established. Further, over time, it has become more politically relevant to emphasize global targets like the temperature goals in the Paris Agreement. That is not to say that the Kyoto Protocol did not include targets, but they were country-specific rather than global\u003csup\u003e\u003cspan citationid=\"CR57\" class=\"CitationRef\"\u003e57\u003c/span\u003e\u003c/sup\u003e. Because of the Paris Agreement's bottom-up approach with a ratchet mechanism\u003csup\u003e\u003cspan citationid=\"CR58\" class=\"CitationRef\"\u003e58\u003c/span\u003e\u003c/sup\u003e, continuous accounting of necessary emissions reductions is important. This drove the production of quantitative emissions projections to operationalize the shift from vague stabilization goals to specific temperature outcomes\u003csup\u003e\u003cspan citationid=\"CR59\" class=\"CitationRef\"\u003e59\u003c/span\u003e\u003c/sup\u003e. Given these developments, we conceptualize the topics ‘Costs and cost-effectiveness’ and ‘Burden sharing’ as related to ideas in the Kyoto Protocol, and a the topics ‘Targets’ and ‘Emissions projections’ as related to ideas in the Paris Agreement. We assess the development of the Kyoto-associated and Paris-associated topics across the SPMs and evaluate how much content development can be explained with it by calculating the share of content captured by these topics. Further, we test whether international climate policy can explain content development by checking whether the topic distribution over time matches with the timeline of international climate treaties. Specifically, we hypothesize that the prevalence of the Kyoto-associated topics decreases over time while the prevalence of the Paris-associated topics increases.\u003c/p\u003e\u003cp\u003eFor the second idea, we look at how the progression of time might explain SPM content development across assessment cycles given the increased urgency of climate change and progress achieved in implementing mitigation policy. Specifically, we form hypotheses about how topic prevalence ought to have developed over time and then test whether the analysis supports or rejects the hypotheses. Because of the increased urgency of climate change, we hypothesize that there is increased prevalence of ‘Negative emissions strategies’ and ‘Timeline’ as negative emissions strategies become more necessary to deal with delayed action\u003csup\u003e\u003cspan citationid=\"CR60\" class=\"CitationRef\"\u003e60\u003c/span\u003e\u003c/sup\u003e, and increased prevalence of ‘Targets’ since more an more countries have set targets\u003csup\u003e\u003cspan citationid=\"CR61\" class=\"CitationRef\"\u003e61\u003c/span\u003e\u003c/sup\u003e. Because of progress in implementation, we hypothesize that there is increased prevalence of ‘Public policy’ as more policy instruments are considered\u003csup\u003e\u003cspan citationid=\"CR62\" class=\"CitationRef\"\u003e62\u003c/span\u003e\u003c/sup\u003e, and an increased prevalence of ‘Policy outcome ’as more ex-post policy analyses are conducted\u003csup\u003e\u003cspan citationid=\"CR63\" class=\"CitationRef\"\u003e63\u003c/span\u003e\u003c/sup\u003e, and an increased prevalence of ‘Barriers to mitigation’ as more challenges are encountered while implementing policies in the real world\u003csup\u003e\u003cspan citationid=\"CR64\" class=\"CitationRef\"\u003e64\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003ePractical knowledge is sparse with no change over time\u003c/p\u003e\u003cp\u003eSPM content reflects three types of knowledge: argumentative knowledge to \u003cem\u003ejustify\u003c/em\u003e policy (red in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e), strategic knowledge to \u003cem\u003eguide\u003c/em\u003e policy (yellow in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e), and practical knowledge to \u003cem\u003edevelop\u003c/em\u003e policy (blue in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Let us take the example of decarbonizing electricity production to illustrate the difference between these three types of knowledge. First, the SPMs contain statements that stress the benefits of reducing air pollution when switching to electricity from renewables (coded as ‘Co-benefits’). This is argumentative knowledge because it can be used to advocate for policies but does not guide their development or implementation. Next, in the SPMs, there are statements for a switch from coal-based electricity to electricity from renewable energy sources (coded as ‘Technological change strategies’). This represents strategic knowledge since it informs policy makers what needs in the energy transition to be done, but not how to stimulate it. Last, the SPMs also include statements discussing policies, such as tax credits or support schemes, to incentivize investment in renewable electricity production (coded as ‘Public policy’). This is practical knowledge since the information can not only be used to steer the direction but also to directly develop policy and actually trigger the changes found to be beneficial in the first to knowledge type groups.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003ePractical knowledge is least prevalent of the three knowledge types in the SPMs. This is true on average across all assessment cycles and within each cycle (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). The sensitivity analysis shows that this remains true with alternative topic classifications (details in Note S1): our finding is robust and not sensitive to argument definitions. Thus, the majority of SPM content is of little direct practical use to develop policymaking, but rather serves as evidence to advocate for mitigation policymaking and as a general guide on its direction. While the SPMs touch upon what changes are needed to mitigate climate change, they shy away from discussing the tools needed to set those changes in motion. As an illustration, the SPMs state that certain manufacturing processes can be electrified but they do not discuss what actions managerial decision-making would need to take towards abandoning fossil-fuel manufacturing processes for carbon-neutral ones (such as electricity-based solutions).\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eKnowledge type distribution is strikingly consistent across assessment cycles with strategic and argumentative knowledge making up the majority of SPM content. The largest change is between AR3 and AR4 yet the relative ranking of knowledge types remains. This shows that all three knowledge types have been consistently covered in the last two decades, with strategic and argumentative knowledge being strongly dominant.\u003c/p\u003e\u003cp\u003eShift from discussing cost-effectiveness to calculating past and present emissions\u003c/p\u003e\u003cp\u003eWhile the distribution of knowledge type themes is stable across assessment cycles, many specific topics exhibit large SPM-to-SPM variation. The main trend in content development is a shift from emphasis on costs and general approaches (top of Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e) to calculating past emissions, future projections with and without additional mitigation (bottom of Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). These topics have the highest regression slope coefficients with a high goodness of fit (see Table S4 for specific numbers) and thus display both the clearest and the strongest changes over time.\u003c/p\u003e\u003cp\u003eOver time the SPMs exhibit a trend toward higher numerical precision and specificity. The top three topics with a positive change across assessment cycles are related to quantifications (‘Emissions projections’, ‘Historic emissions’, ‘Targets’). Specifically, the SPMs increasingly focus on quantifying how bad climate change will get if we don’t increase mitigation efforts (‘Emissions projections’) and calculating the amount of emissions reductions related to temperature goals (‘Targets’). Not all topics concerning quantitative knowledge exhibit a positive trend (e.g. ‘Cost and cost-effectiveness’), but enough do to identify a pattern. On the other hand, two of the top three topics with a negative change across assessment cycles are general and non-specific (‘Undefined strategies’ and ‘Undefined effects’), hinting to a drop in vague statements which suggests that there is a trend toward higher specificity.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eShift from ideas associated with the Kyoto Protocol to ideas associated with the Paris Agreement\u003c/p\u003e\u003cp\u003eThe trends of content development in the SPMs can be understood under the lens of global climate agreements. Two major international treaties took place during the period we studied (AR3-AR6): the Kyoto Protocol and the Paris Agreement. We identify topics associated with the ideas that prevailed during the time the treaties took place. The Kyoto-associated topics view mitigation as a global commons problem with tension between developing and developed countries and pays great attention to mitigation incentives. Thus, we see statements on how high-income and low-income countries differ in their capacity for carrying out mitigation (‘Burden sharing’) statements on the economic costliness (‘Costs and cost-effectiveness’) of mitigation in the SPMs (see Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ea). On the other hand, the Paris-associated topics emphasize accountability with a view toward a specific temperature goal, which is reflected in statements quantifying the expected emissions with (‘Targets’) and without additional mitigation (‘Emissions projections’). To illustrate, the Kyoto-associated topics emphasize that energy efficiency measures can result in economic benefits greater than direct costs (coded as ‘Costs and cost-effectiveness’) while the Paris-associated topics zoom in on the estimated emissions reduction that can be achieved via energy efficiency measures (coded as ‘Targets’).\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eThe distribution of the topics associated with these two treaties explains idea evolution in the SPMs over time; however, it is limited in explaining less than 15% of SPM content on average (see Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003eb). We see a clear decreasing trend for the Kyoto-associated topics and an increasing trend for the Paris-associated topics, suggesting a gradual evolution of ideas over time. There is a sharp increase in the prevalence of topics associated with the Paris-associated topics in the SPM published after the Paris Agreement (AR6). There is a sharp drop in the prevalence of the Kyoto-associated topics in the subsequent SPM (AR4). This hints at a possible pattern whereby SPMs published after the global agreements surge with ideas related to these agreements and then level off in subsequent assessment cycles[1]\u003ca class=\"FNLink\" href=\"#Fn1\" id=\"#FNLinkFn1\"\u003e\u003c/a\u003e.\u003c/p\u003e\u003cp\u003eSome trends associated with increasing urgency and progress in implementation\u003c/p\u003e\u003cp\u003eGiven the passing of time, we expect SPM content to reflect progress in policy implementation over time. For example, as elaborated in the methods section, we hypothesize that there is more content on policy analysis (‘Public policy’), and more content on positive examples of implemented policies (‘Policy outcome’), and more content on aspects challenging the implementation of policy (‘Barriers to mitigation’) across assessment cycles. Similarly, given the increasing urgency of climate change as time passes, we hypothesize that SPMs cover more statements including specific deadlines (‘Timeline’) and the common goals associated with them (‘Targets’) as well as strategies to cope with failure to mitigate on time (‘Negative emissions strategies’) across assessment cycles.\u003c/p\u003e\u003cp\u003eThe hypotheses relating to topics ‘Targets’, ‘Negative emissions strategies’, ‘Policy outcome’ and ‘Barriers to mitigation’ are met, but those relating to ‘Timeline’ and ‘Public policy’ are not (see Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e). This suggests that the increasing urgency and progress in implementation somewhat explains SPM content development, but not very strongly as we expect. While we expected there to be more content in the SPMs covering specific public policy instruments and more content outlining a timed schedule of mitigation action, there is a slightly decreasing trend across assessment cycles for these topics.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e"},{"header":"Discussion and conclusion","content":"\u003cp\u003eIn this paper we investigate the content of Working Group III SPMs and show how it has changed over time. Our research has two main contributions. First, our results help empirically evaluate whether IPCC assessments have responded to calls to shift their focus towards solutions by providing more content on specific policy instruments. Second, we show how ideas in IPCC assessments have co-evolved with global climate change politics, reflecting to what extent they are keeping up with developments in global negotiations and the increasing urgency of climate change.\u003c/p\u003e\u003cp\u003eOur results indicate that there has not been a shift towards solutions in the SPMs, and especially not in the sixth assessment cycle. We find that practical knowledge (largely composed of analysis of policy instruments) is scarce in the SPMs and it has not increased mentionably over time. This implies that SPMs have not shifted towards ”what works” or how to actually decarbonize societies over time. Thus, requests for a shift towards solutions\u003csup\u003e\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e,\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e,\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e\u003c/sup\u003e have not had an impact, despite an increase in scientific publications on mitigation solutions\u003csup\u003e\u003cspan citationid=\"CR65\" class=\"CitationRef\"\u003e65\u003c/span\u003e\u003c/sup\u003e. We find a very limited shift towards solutions even if we broaden the term ‘solution-oriented’ beyond analyses of policy instruments to include more general information on mitigation strategies, which is strategic (“how to mitigate”) instead of practical (“what works”) knowledge. Out of all topics on mitigation strategies, only the \"negative emissions strategies\" topic exhibits a positive trend across assessment cycles. This suggests that, under the more generous definition of ‘solution-oriented’, there has only been a shift towards solutions related to negative emissions.\u003c/p\u003e\u003cp\u003eWhile we find that there is no shift towards solutions in the SPMs, this is not necessarily generalizable to IPCC assessments overall. There may have been a shift towards solutions in the full reports that did not make its way into the more politically contentious SPMs, but a contents analysis of the full reports was out of scope of our research. We encourage similar research to undertake the task of assessing this to be able to generalize about IPCC assessments overall. Further, our content analysis is of a quantitative character, so it may miss nuanced changes in how policy intruments are covered in the SPMs. For example, there may have still been a shift toward more policy-specificity without there being any relative growth in the share of policy-related topics in the SPMs. Such a shift toward more policy-specific content may also be interpreted as a shift towards solutions in the SPMs. Future research employing a discourse analysis, possibly with automated methods that also enable analysis of the vastly longer reports, can address this issue\u003c/p\u003e\u003cp\u003eThe key implication of our findings is that the IPCC SPMs have not become more solution-oriented while remaining policy-neutral and with the current SPM scoping and approval processes. Therefore the empirical evidence supports the logic that IPCC assessments may need to re-consider their policy-neutrality principle or its approval and scoping processeses to enable a shift toward solutions. So far, this shift has not happened – and maybe it could not – within the existing task description of the IPCC.\u003c/p\u003e\u003cp\u003eWe find that ideas in SPMs have co-evolved with changes in global climate policy. In particular, we show a shift from Kyoto-associated topics, focused on the cost-effectiveness of mitigation and burden-sharing between countries, to Paris-associated topics, emphasizing accountability and (national) target-setting through calculations of past and estimated emissions. This corresponds to the shift in global climate policy, from the global commons framing of the Kyoto Protocol to the NDC-centred approach of the Paris Agreement. However, the shift has not been all-encompassing as our results show that content on costs and burden sharing is still strong in AR6. This indicates that the SPMs, like documents from other international organizations, have historically moved to more discursive diversity on climate change mitigation rather than just changing the paradigm\u003csup\u003e\u003cspan citationid=\"CR53\" class=\"CitationRef\"\u003e53\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eAdditionally, our results hint that global climate policy development may drive SPM content, but more research is needed to understand the link between the two. We demonstrate that Kyoto-associated topics were prevalent in AR3, right after the Kyoto Protocol was adopted, and then had a substantial drop in AR4. Similarly, the prevalence of the Paris-associated topics shot up in AR6 right after (and not before) the Paris Agreement was adopted. This hints at the possibility that SPM content may be driven by global climate policy and not vice versa. Previous research on the Special Report on 1.5 has found that IPCC assessments were shaped by political negotiations\u003csup\u003e\u003cspan citationid=\"CR52\" class=\"CitationRef\"\u003e52\u003c/span\u003e,\u003cspan citationid=\"CR66\" class=\"CitationRef\"\u003e66\u003c/span\u003e\u003c/sup\u003e. However, future research with a broader scope including the content of AR2 before the Kyoto Protocol and the upcoming AR7 can shed light whether this is a pattern.\u003c/p\u003e\u003cp\u003eLast, we find that the SPMs are increasingly covering topics relevant to the urgency of climate mitigation, for example emissions reductions needed to achieve the Paris Agreement temperature goal and negative emissions approaches, and topics focused on implementation, for example ex-post policy evaluations and barriers to climate action. This suggests that the SPMs are co-evolving with dominant ideas in international climate change mitigation policy, even though they are not shifting to solutions.\u003c/p\u003e\u003cp\u003eWhile we build an empirical overview of changes in SPM topic prevalence over time, we are limited in explaining the causes for those changes. We experiment with two ideas related to changes in international politics (shift from Kyoto Protocol to Paris Agreement) and the passing of time (increase in urgency and progress in implementation). But this only offers an explanation for some of the topic changes we observe. Future research can link changes in SPM topic prevalence to changes in scientific output, geopolitical developments or IPCC authorship and procedures. One idea could be doing interviews with IPCC authors delving into the underlying reasons for the (lack of) changes in SPM topic prevalence.\u003c/p\u003e\u003cp\u003eThus, our findings empirically demonstrate that the IPCC changed its focus on some topics, suggesting that it can do so in the future. While we set out to empirically examine the policy-neutrality debate, we ultimately suggest that the IPCC ought to emphasize the topic of policy instruments to maintain policy-relevance for national and local policymakers, regardless of whether it is in a policy-prescriptive or policy-neutral manner. In addition, we find that there is consensus among scholars for the IPCC to be more transparent about the value-ladenness of its work\u003csup\u003e\u003cspan citationid=\"CR67\" class=\"CitationRef\"\u003e67\u003c/span\u003e\u003c/sup\u003e, put more effort in promoting a more diverse evidence base\u003csup\u003e\u003cspan citationid=\"CR68\" class=\"CitationRef\"\u003e68\u003c/span\u003e,\u003cspan citationid=\"CR69\" class=\"CitationRef\"\u003e69\u003c/span\u003e\u003c/sup\u003e and dialogues with stakeholders outside of the assessment\u003csup\u003e\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eGiven the divisions in the debate on whether the IPCC should abandon its policy-neutrality or not, we stress that the IPCC need not be all things to all people\u003csup\u003e\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u003c/sup\u003e. For example, it is imaginable that the IPCC itself maintains its policy-neutral function, while focusing more on synthesising the scientific evidence of policy effectiveness and effects. It can let other boundary organizations in their specific international, national and local contexts expand on its assessments to offer science-based policy advice. For example, The Subsidiary Body for Scientific and Technological Advice (SBSTA) provides advice at COPs based on the IPCC assessments\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e,\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u003c/sup\u003e. Further, in some countries there are national boundary organizations creating assessments tailored to national contexts akin to those by the IPCC\u003csup\u003e\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u003c/sup\u003e. The IPCC may consider taking a more proactive role acting as a network facilitator and support other boundary organizations. As an example, the IPCC could consider fostering exchange of scientific knowledge on policy instruments between national knowledge brokers like the OECD’s approach in education\u003csup\u003e\u003cspan citationid=\"CR70\" class=\"CitationRef\"\u003e70\u003c/span\u003e\u003c/sup\u003e. This could be in addition to or instead of its global-level assessments which can miss context-dependance when discussing policy-instruments.\u003c/p\u003e\u003cp\u003eWe conclude that the SPMs have not shifted towards discussing more solutions, but have kept up with the times by switching their focus from ideas associated with the Kyoto Protocol to ideas associated with the Paris Agreement. Our empirical findings suggest that it has not been possible for IPCC assessments to discuss more specific policy instruments in the SPMs within their current working procedures. Regardless of whether the IPCC chooses to reform, we stress that it is still important for IPCC SPMs to strive to cover more content on specific policy instruments. Additionally, the IPCC could strive to become a central clearinghouse amongst the growing ecosystem of national and local boundary organizations. Thus, its policy-relevance to national and local policymakers will be perserved.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eE.G.: Conceptualization, Methodology, Investigation, Writing \u0026ndash; Original Draft, Visualization. J.E.: Conceptualization, Writing \u0026ndash; Review \u0026amp; Editing. F.B.: Investigation, Validation, Writing\u0026mdash;review \u0026amp; editing. F.B.: Investigation, Validation, Writing\u0026mdash;review \u0026amp; editing. S.W.: Investigation, Validation, Writing\u0026mdash;review \u0026amp; editing. F.W.: Investigation, Validation, Writing\u0026mdash;review \u0026amp; editing. S.P.: Conceptualization, Writing \u0026ndash; Review \u0026amp; Editing.\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eThe data is available on the 4TU repository for reviewers to access using the following link: https://data.4tu.nl/private_datasets/HHk-tFCivPnZpuz7Ln4CsRImgv3jGFK7Z58CUq5bThU. It will be made open access once the review process is complete.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eLamb, W. F. \u0026amp; Steinberger, J. K. Human well-being and climate change mitigation. \u003cem\u003eWIREs Clim. Change \u003c/em\u003e\u003cstrong\u003e8\u003c/strong\u003e, e485 (2017).\u003c/li\u003e\n\u003cli\u003eBeck, S. \u0026amp; Mahony, M. The IPCC and the new map of science and politics. \u003cem\u003eWIREs Clim. Change \u003c/em\u003e\u003cstrong\u003e9\u003c/strong\u003e, e547 (2018).\u003c/li\u003e\n\u003cli\u003eHoppe, R., Wesselink, A. \u0026amp; Cairns, R. 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Instruments of lesson-drawing: comparing the knowledge brokerage of the OECD and the World Bank. \u003cem\u003ePolicy Stud. \u003c/em\u003e\u003cstrong\u003e45\u003c/strong\u003e, 839\u0026ndash;859 (2024).\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Footnotes","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003e Note that the Copenhagen Accord (took place between AR4 and AR5), which was not formally adopted like the Kyoto Protocol and the Paris Agreement, did not provoke a dramatic shift in AR5 compared to AR4.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"npj-climate-action","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"npjclimataction","sideBox":"Learn more about [npj Climate Action](https://www.nature.com/npjclimataction)","snPcode":"44168","submissionUrl":"https://submission.springernature.com/new-submission/44168/3","title":"npj Climate Action","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"NPJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Scientific Advice, Policymaking Advice, IPCC, Climate Change Mitigation, Science-Policy Interface","lastPublishedDoi":"10.21203/rs.3.rs-7574973/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7574973/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThe Intergovernmental Panel on Climate Change (IPCC) regularly publishes summaries for policymakers (SPMs) based on its assessments of climate change science following the principle of policy-neutrality. As the urgency of climate change grows, there have been calls for IPCC assessments to be more solution-oriented, which means to assess specific policy instruments. Yet, there is a scholarly debate regarding whether and how it is possible to discuss specific policy instruments while staying policy-neutral. To inform this debate we conduct a content analysis of all Working Group III SPMs published in the last two decades. Dividing SPM content into strategic, argumentative and practical knowledge on mitigation policy instruments, we find that there is limited coverage of practical knowledge with only small changes over time. This suggests that IPCC assessments have not become more solution-oriented while abiding by their policy-neutrality principle. On the other hand, we find that SPMs have shifted from emphasizing the cost-effectiveness of mitigation towards emphasizing projections of required emissions reductions. Part of these changes may be explained through the evolution of ideas in global climate negotiations. Regardless of whether it chooses to amend its policy-neutrality principle, we recommend that the IPCC still shift more to discussing solutions. For example, the IPCC could better support the growing ecosystem of national and local boundary organizations which can broker context-specific knowledge on policy instruments.\u003c/p\u003e","manuscriptTitle":"Have IPCC SPMs shifted towards discussing more solutions in the past two decades?","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-10-03 13:02:49","doi":"10.21203/rs.3.rs-7574973/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-12-19T16:08:27+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-12-11T17:45:47+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"269414439680098961977572151392835037967","date":"2025-11-25T08:19:28+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-11-23T03:43:58+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"328728155958737975023151203713969748557","date":"2025-11-09T18:32:13+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-10-09T13:25:27+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"191471104592226344831293712909219535223","date":"2025-09-23T11:12:32+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"254526694868837359816898116180949158024","date":"2025-09-23T09:09:26+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-09-22T11:49:13+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-09-17T08:22:42+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-09-16T18:25:11+00:00","index":"","fulltext":""},{"type":"submitted","content":"npj Climate Action","date":"2025-09-09T14:27:44+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"npj-climate-action","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"npjclimataction","sideBox":"Learn more about [npj Climate Action](https://www.nature.com/npjclimataction)","snPcode":"44168","submissionUrl":"https://submission.springernature.com/new-submission/44168/3","title":"npj Climate Action","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"NPJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"f08a73ff-d8c8-4764-a1eb-c5ce7a0c4e35","owner":[],"postedDate":"October 3rd, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[{"id":55279528,"name":"Earth and environmental sciences/Climate sciences"},{"id":55279529,"name":"Earth and environmental sciences/Environmental sciences"},{"id":55279530,"name":"Earth and environmental sciences/Environmental social sciences"},{"id":55279531,"name":"Social science/Environmental studies"},{"id":55279532,"name":"Scientific community and society/Scientific community"},{"id":55279533,"name":"Scientific community and society/Social sciences"}],"tags":[],"updatedAt":"2026-04-08T11:08:32+00:00","versionOfRecord":[],"versionCreatedAt":"2025-10-03 13:02:49","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7574973","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7574973","identity":"rs-7574973","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}