The UN sustainable development goals (SDGs) and the Paris climate target require a holistic transformation towards human well-being within planetary boundaries. However, there are growing debates on how to best pursue these targets. Proposed transformation strategies include market- and technology-driven green-growth, shifting towards a sufficiency-oriented post-growth economy, and a transformation driven primarily by strong government action. Here we quantify three alternative sustainable development pathways (SDPs), Economy-driven Innovation, Resilient Communities, and Managing the Global Commons, that reflect these different societal strategies. We compare the quantifications from two integrated assessment models and two sectoral models of the buildings and materials sectors across a broad set of indicators for sustainable development and climate action. Our global multi-scenario and multi-model analysis shows that all three SDPs enable substantial progress towards the human development goals of the SDGs. They simultaneously limit global warming and prevent further environmental degradation, with the sufficiency-oriented Resilient Communities scenario showing the lowest peak warming and lowest reliance on carbon dioxide removal as well as the largest improvements in biodiversity intactness. The SDPs also alleviate the concerns about the biogeophysical and technological feasibility of narrowly-focused climate change mitigation scenarios. However, the shifts in energy and food consumption patterns assumed in the SDPs, ranging from moderate in Economy-driven Innovation to very ambitious in Resilient Communities, also lead to increased challenges regarding socio-cultural feasibility.

IPCC Assessment Reports provide timely and accurate information on anthropogenic climate change to policy makers and the public. The reports are written by hundreds of scientists in a voluntary, collaborative effort. Growing amounts of literature and complex procedural and administrative requirements, however, make this effort a substantial management challenge next to a scientific one. During the 5th Assessment Cycle, IPCC Working Groups II and III initiated a program that recruited volunteer scientific assistants who provided technical and logistical support to author teams. In this paper we describe and analyze strengths and weaknesses of this 'Chapter Scientist program', based on an extensive survey among Chapter Scientists (CS) and interviews with other stakeholders. We conclude that the program was a useful innovation that that enabled authors to focus more on their core scientific tasks and that contributed to improving the quality of the assessment. We highly recommend similar programs for future scientific assessments. Key criteria for success that we identified are (a) involvement of early-career scientists as CS, (b) close integration of CS in the assessment process, (c) recruitment of CS through an open call to achieve transparency, and (d) provision of funds for such a program to support travel costs and compensation of CS

Studies of the negotiation process in the context of climate change have been limited. This report argues that it is necessary to cope not only with the complexity of the substantial issues related to climate change (scientific, technical, economic, political, and social) but also with the complexity of this multiparty international negotiation process and with the uncertainty of the negotiation outcome. Preparing decision makers for negotiations requires developing a tool kit that includes strategies for dealing with complexity; creating such a tool kit requires collecting knowledge through the systematic study of relevant negotiations. Analyzing the documents and transcripts from previous climate change negotiations is necessary but insufficient. In this report, I argue the need to employ innovative approaches to understanding the complexity of the climate change negotiation. For this reason, I conducted a series of games that simulated United Nations–sponsored climate change negotiations. In these games, variables were manipulated to explore the impact of various conditions on negotiating behaviors, processes, and outcomes. The results offer insights that may help researchers and negotiators develop practical strategies to cope with the complexity of international climate change negotiations. Among these are propositions about reframing the “North–South divide” and about encouraging “threshold states” to assume the role of the bridge between various groups and coalitions in the international system.

Socio-political factors in Integrated Assessment Models (IAMs), and their scenario narratives often lack transparency for policymakers and interdisciplinary scholars. As these tools increasingly support sustainable development goals, their assumptions and methodologies require scrutiny, particularly from social scientists. We address critiques of climate isolationism, overemphasis on technological transitions, and insufficient inter- and transdisciplinarity, advocating for robust interdisciplinary integration and clearer methodological transparency. Our recommendations stem from expert interviews and over 200 stakeholders across 30 countries from 2019 to 2024, emphasizing the need for cohesive theory and comprehensive social science engagement to refine these critical tools. Our main case study uses a new scenario set, the Sustainable Development Pathways (SDPs), that made substantial efforts to address social sciences critiques. The SDPs consist of both narratives and IAM-quantified target-seeking scenarios that are supported by social science concepts and theories to ensure not only theoretical coherence, but also their credibility among policymakers. As such tools are increasingly used to facilitate policies and actions for sustainability transformation, questions are raised about how they can effectively represent the complexities behind the current polycrisis that is marked by the climate crisis, biodiversity loss, economic inequality and social injustice. The paper concludes by reflecting on the remaining challenges and open questions related to the role of exogenous sociopolitical factors, the potential for scenarios to transcend political ideologies, and the need for ongoing adaptation of SDPs to reflect the dynamic global context. It calls for continued engagement and exploration of these issues to ensure the scientific representation of sustainable and equitable futures.

The energy sector plays an important role in Mexico’s development trajectory. Mexico makes an interesting case study because it shows how difficult it is to reduce fossil energy dependence despite geographic and climatic conditions that favour renewable energy deployment and use. Resolving path dependencies and the related carbon lock-in are key to Mexico’s sustainable energy transition. This applied teaching guide contemplates the use of a case-illustration typology to identify and discuss how the politics about carbon lock-in affects Mexico’s sustainable energy transition. This methodology is an innovative endeavour that aims to apply the case study in classrooms with the intention to encourage discussions and solution-oriented approaches when tangible actions are identified by the educator and students. This methodology elevates the case study to a “living” case study that leads to recommended actions. The applied teaching guide allows educators, who are mostly researchers, to reflect on how Mexico’s case study could be explained not only to promote the students’ understanding of the challenges, but also to provide educators/researchers the skills on how to effectively disseminate knowledge. Mexico’s carbon lock-in involves oil and oil-run power plants that are costly to build but relatively inexpensive to operate. To conclude, this case study identifies potential entry points for transitioning towards sustainable energy in Mexico—resources that can promote the use of clean energy despite carbon lock-in. For example, focusing on electrification—particularly the carbon-intensive sectors—can help Mexico transit towards sustainable energy despite institutional constraints. Complementing this case study is a teaching guide with recommendations for using Mexico’s energy transition in courses on sustainability. By understanding how to explain the case study, the educator/researcher can better structure the complexity of the case study. This approach introduces a “learning activation framework” to identify emerging opportunities that can advance sustainable energy transitions in different cases of carbon lock-in. The framework also gives students a chance to help dismantle or cope with carbon lock-ins. Mexico’s energy transition makes a valuable teaching example because its energy transition is part of a broader developmental goal. This teaching guide’s systematic approach can maximise the students’ learning experience.

The complexity of linking sustainability with transformation necessitates a critical re-evaluation of the ways the actors, processes, issues, structures, and outcomes related to the transformation to sustainability (T2S) can be understood. At the same time, achieving T2S is highly dependent on policies based on technical solutions that can prompt needed behavioural change, whereas these technical solutions are not always compatible with both planetary and societal boundaries. Therefore, achieving T2S also calls for evaluating the normative foundations of policies and actions. This paper contends that T2S is significantly defined by the multiplicity of negotiation processes. This justifies a deeper look at T2S from the perspective of negotiation studies. T2S is composed of different phases, each of which has a different set of actors, resources, and audiences. This paper introduces a theoretical model as an analytical meta-framework to structure how T2S unfolds in an orchestrated manner. This model builds on negotiation theories to focus on the actors’ perspectives on T2S. It proposes the division of the transformation process into phases—entry point, learning, sequencing, disrupting, and fortifying. Each of these phases is analysed to determine the “quality” of cooperation that can help fulfil the tasks required to master the so-called “cognitive games” of T2S (ripeness game, power game, bargaining game, policy game, scaling game). Moreover, insights are presented to explain how the designated milestones can be achieved to indicate the advancement to the next phase and eventually entrench the transformation process. The findings resulting from the analysis of the phases of T2S present potential lessons and opportunities for both theorists and practitioners/policymakers.