Non-technical summary: The world is facing multiple interconnected crises, from climate change and economic instability to social inequalities and geopolitical tensions. These crises do not occur in isolation; instead, they interact, reinforce each other, and create unexpected ripple effects – forming what is known as a polycrisis. Traditional ways of analysing problems often fail to grasp these interdependencies, making it difficult to find effective responses. We draw on system archetypes to describe and exemplify three polycrisis patterns. These provide a structured way to analyse how multiple crises unfold and interact, as well as insights into how to navigate such complexity.

Technical summary: The concept of a polycrisis describes the complex interconnections between global issues, which can lead to unexpected emergent behaviours and the possible convergence of undesirable impacts. Understanding these dynamics is crucial for anticipating compounded effects and for identifying leverage points for effective intervention. We propose that system archetypes – generic structures in system dynamics that capture recurring patterns of behaviour – can serve as a useful analytical tool to study polycrises. Specifically, we reinterpret three key system archetypes in this context: Converging Constraints (based on the Limits to Growth system archetype), Deepening Divides (based on Success to the Successful system archetype), and Crisis Deferral (drawing from the Policy Resistance system archetype). These patterns illustrate how resource limitations, structural inequalities, and short-term solutions can sustain or worsen crisis dynamics. Using real-world examples, we show how polycrisis patterns can be employed to map feedback structures between interacting crises and to guide effective interventions. Our work contributes to a more structured and systemic understanding of polycrises, by providing a tool to help researchers and policymakers better anticipate, navigate, and mitigate their effects.

Social media summary: ‘Polycrisis patterns reveal how crises like climate change, economic instability, and inequality interact, amplifying their impacts’.

Food production and trade are key drivers of environmental change worldwide. Global initiatives emphasize the need to shift towards healthier and more sustainable diets, with increased consumption of fruits and vegetables (F&V). However, F&V cultivation relies on diverse high-value crop species that often require intensive fertilization and irrigation for optimum yield and quality, as well as a large labor force. This generates trade-offs across scales between the impacts in the production regions and the global need to increase F&V production. Through multi-actor dialogues, we analysed the social-ecological dynamics of the F&V agriculture system in Southeast Spain, which crucially supplies F&V to Northern Europe. Using a new approach combining the 3Horizons method and system thinking tools, our results reveal the agricultural system's context-specific structures as a foundation for exploring transformative opportunities. We found that the agricultural system a) is sustained in a governance model that lacks cooperation and fosters polarized views, 2) surpasses the biophysical limits, and 3) relies on immigrant low-wage labor. Additionally, our results underscore the need to share the responsibilities and costs of the food-system transformation across the supply chain actors, focusing on the potential of retailers, governance institutions at multiple scales, collective structures of farmer producers, and auxiliary industries to support sustainable and just transformative changes.

Non-technical summary Achieving sustainability on the ground poses a challenge in decoding globally defined goals, such as sustainable development goals, and aligning them with local perspectives and realities. This decoding necessitates the understanding of the multifaceted dimensions of the sustainability challenges in a given context, including their underlying causes. In case studies from Brazilian drylands, we illustrate how an enhanced multiscale participatory method, combined with systems thinking tools, can shed light on systemic structures that currently entrench unsustainable development trajectories. This method offers insights into co-designing potential pathways toward sustainable futures and unlocking transformative capacities of the local population. Technical summary Translating United Nations global sustainable development goals (SDGs) into actions that address local realities and aspirations is an urgent challenge. It requires new thinking and approaches that foster the discussion about the main challenges to implementing the SDGs at multiple levels. This paper presents a novel multiscale participatory approach that combines the popular Three Horizons diagram with the formalism of causal loop diagrams in systems thinking. We present results from six multi-stakeholder dialogues held across drylands in Brazil with a focus on desired futures aligned with SDGs. Focusing on identifying the root causes and systemic structures of unsustainability, participants identified lock-ins, leverage points, and interventions for how these could be changed. The core lock-ins are the discontinuity of public policies, and the historical land and power concentration reinforced by the current expansion of large-scale agricultural, mining, and energy projects. The proposed interventions are structural and - if implemented - would contribute to achieving SDGs in an integrated manner. The unique approach developed in this study can provide leverage as it bridges the inclusivity of participatory visioning with the change potential of systems thinking tools to tackle root causes and unleash societal transformations. Social media summary We are not achieving SDGs. Understanding root causes of unsustainability is critical to move toward sustainable and just futures.

The global demand for agricultural commodities has driven extensive land conversion to agriculture in Brazil, especially in the MATOPIBA region. This area encompasses the Rio Grande Basin, a major tributary of the São Francisco Basin that is known for expanding intensive irrigated agriculture and hydropower generation. However, recent data reveal declining precipitation and aquifer recharge, potentially exacerbating ongoing water and land conflicts. This study investigates the long-term sustainability of agricultural expansion amid the worsening water scarcity using a system dynamics model. Findings suggest that rising costs and decreasing profits due to irrigation water shortages may hinder the expansion of irrigated land. By 2040, the irrigation demand may remain partly unmet, while downstream flow and baseflow could decrease. Additionally, agricultural expansion will significantly raise energy demand, posing a developmental challenge. We suggest that ensuring the sustainability of the Rio Grande Basin depends on improved water management and exploring alternative energy sources to address existing constraints.

The challenge of pursuing sustainable development highlights the relevance of the complex mechanisms through which natural and social selection processes affect and are affected by the economic system. Current economic development is unsustainable because it fails to generate long-term systemic compatibility between firms and their natural and social environment. This paper evaluates the issue from an evolutionary perspective by conceptualising unsustainability as the emergence of negative macro-selection effects, arising from both the natural and social domains, and argues for a methodological need for closer integration of system dynamics modelling within the evolutionary field. The Earth4All model is then used to illustrate the complex interactions between economic, social, and natural selection processes. The model results illustrate that the current global development trajectory is strongly unsustainable from both a natural and a social perspective, leading to the emergence of relevant natural and social macro-selection mechanisms, whose systemic interactions bring further complex adverse effects.

How climate change is framed within CAs is critical for both the democratic legitimacy and transformative potential of CAs. Narrow technical frames can exclude valid perspectives and policy options and close down debate on broader systemic and potentially more transformative issues. Conversely, such ‘system-supporting’ framings may yield more specific and applicable policy recommendations, increasing the likelihood of implementation. In this study, we present a framework and approach to analyse framings in climate assemblies. We apply this framework to examine the evidence provided to a German, a UK and a Global citizen assembly. Our analysis suggests that despite differences in scale, remit and commissioning bodies, evidence in these three assemblies had a similar range of framings. General evidence most frequently incorporated frames related to safety, governance, and fairness. Although all assemblies incorporated some degree of system-challenging frames, many of them were used little. Topic-specific evidence on energy in both the German and UK assemblies almost exclusively used energy technologies frames, potentially at the expense of critical perspectives. Interestingly, we did not observe major differences in the amount of system-challenging frames used between the assemblies commissioned by civil society actors and those commissioned by parliament; however, we observed some differences in the way some frames were used. We propose that integrating system-challenging frames with actionable steps could enhance the transformative potential of future assemblies. Our framework can be used to study how the framing of evidence influences deliberations and outcomes and to assess assemblies’ claims to provide balanced information.

The United Nations Sustainable Development Goals (SDGs) include social and ecological goals for humanity. Navigating towards reaching the goals requires the systematic inclusion of perspectives from a diversity of voices. Yet, the development of global sustainability pathways often lacks perspectives from the Global South. To help fill this gap, this paper introduces a participatory approach for visioning and exploring sustainable futures - the Three Horizons for the Sustainable Development Goals (3H4SDG). 3H4SDG facilitates explorations of (a) systemic pathways to reach the SDGs in an integrated way, and (b) highlights convergences and divergences between the pathways. We illustrate the application of 3H4SDG in a facilitated dialogue bringing together participants from four sub-regions of Africa: West Africa, Central Africa, East Africa, and Southern Africa. The dialogue focused on food and agricultural systems transformations. The case study results incorporate a set of convergences and divergences in relation to the future of urbanization, population growth, consumption, and the role of agriculture in the African economy. These were subsequently compared with the perspectives in global sustainability pathways, including the shared socioeconomic pathways (SSPs). The study illustrates that participatory approaches that are systemic and highlight divergent perspectives represent a promising way to link local aspirations with global goals.

Non-technical summary. Transformation of the world towards sustainability in line with the 2030 Agenda requires progress on multiple dimensions of human well-being. We track development of relevant indicators for Sustainable Development Goals (SDGs) 1–7 against gross domestic product (GDP) per person in seven world regions and the world as a whole. Across the regions, we find uniform development patterns where SDGs 1–7 – and therefore main human needs – are achieved at around US$15,000 measured in 2011 US$ purchasing power parity (PPP).

Technical summary. How does GDP per person relate to the achievement of well-being as targeted by the 2030 Agenda? The 2030 Agenda includes global ambitions to meet human needs and aspirations. However, these need to be met within planetary boundaries. In nascent world-earth modelling, human well-being as well as global environmental impacts are linked through economic production, which is tracked by GDP. We examined historic developments on 5-year intervals, 1980–2015, between average income and the advancement on indicators of SDGs 1–7. This was done for both seven world regions and the world as a whole. We find uniform patterns of saturation for all regions above an income threshold somewhere around US$15,000 measured in 2011 US$ PPP. At this level, main human needs and capabilities are met. The level is also consistent with studies of life satisfaction and the Easterlin paradox. We observe stark differences with respect to scale: the patterns of the world as an aggregated whole develop differently from all its seven regions, with implications for world-earth model construction – and sustainability transformations.

Social media summary. Reaching human well-being #SDGs takes GDP levels of $15k. This may help shape transformation to a world that respects #PlanetaryBoundaries.

In 2015 the United Nations adopted the 2030 Agenda with 17 global sustainable development goals (SDGs) to shift the world onto a sustainable path. By referring to the SDGs as indivisible, the Agenda emphasises the interdependence of social and ecological concerns. But what does it mean that the goals are interdependent and how is indivisibility to be handled in research and implementation?

In this dissertation, I investigate how models and participatory methods grounded in systems thinking can be used to facilitate the understanding and realisation of the 2030 Agenda. The dissertation explores and examines: (a) how system dynamics models can be used to represent integrated goals and their synergies at multiple levels, (b) how human well-being can be more inclusively integrated into systems models, and (c) how systems approaches can help to bridge local aspirations to global sustainability goals, incorporating multiple values and worldviews in the operationalisation of the Agenda.

The United Nations 2030 Agenda catalysed the development of global target-seeking sustainability-oriented scenarios representing alternative pathways to reach the Sustainable Development Goals (SDGs). Implementing the SDGs requires connected actions across local, national, regional, and global levels; thus, target-seeking scenarios need to reflect alternative options and tensions across those scales. We argue that the design of global sustainability-oriented target-seeking scenarios requires a consistent process for capturing multiple and contrasting perspectives on how to reach the goals, including the perspectives from multiple scales (e.g. local, national, regional) and geographic regions (e.g. the Global South). Here we propose a novel approach to co-design global target-seeking scenarios, consisting of (a) capturing global perspectives on pathways to the SDGs through a review of existing global scenarios; (b) a multi-stakeholder process to obtain multiple sub-global perspectives on pathways to sustainability; (c) an analysis of convergences, and crucially, divergences between global and regional perspectives on pathways to reach the SDGs, feeding into the design of new target-seeking scenario narratives. As a case study, we use the results of the 2018 African Dialogue on The World in 2050, discussing the future of agriculture and food systems. The identified divergent themes emerging from our analysis included urbanization, population growth, agricultural practices, and the roles of different actors in the future of agriculture. The results challenge some of the existing underlying assumptions of the current sustainability-oriented global scenarios (e.g. population growth, urbanisation, agricultural practices), indicating the relevance and timeliness of the proposed approach. We suggest that similar approaches can be replicated in other contexts to better inform the process of sustainability-oriented scenario co-design across scales, regions and cultures. In addition, we highlight the implications of the approach for scenario quantification and the evolution of modeling tools.