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The global context has shifted dramatically since publication of the first EAT–Lancet Commission in 2019, with increased geopolitical instability, soaring food prices, and the COVID-19 pandemic exacerbating existing vulnerabilities and creating new challenges. However, food systems remain squarely centred at the nexus of food security, human health, environmental sustainability, social justice, and the resilience of nations. Actions on food systems strongly impact the lives and wellbeing of all and are necessary to progress towards goals highlighted in the Sustainable Development Goals, the Paris Agreement, and the Kunming–Montreal Global Biodiversity Framework. Although current food systems have largely kept pace with population growth, ensuring sufficient caloric intake for many, they are the single most influential driver of planetary boundary transgression. More than half of the world's population struggles to access healthy diets, leading to devastating consequences for public health, social equity, and the environment. Although hunger has declined in some regions, recent increases linked to expanding conflicts and emergent climate change impacts have reversed this positive trend. Obesity rates continue to rise globally, and the pressure exerted by food systems on planetary boundaries shows no signs of abating. In this moment of increasing instability, food systems still offer an unprecedented opportunity to build the resilience of environmental, health, economic, and social systems, and are uniquely placed to enhance human wellbeing while also contributing to Earth-system stability. This updated analysis builds upon the 2019 EAT–Lancet Commission, expanding its scope and strengthening its evidence base. The first Commission defined food group ranges for a healthy diet and identified the food systems' share of planetary boundaries. In this Commission, we add an analysis of the social foundations for a just food system, and incorporate new data and perspectives on distributive, representational, and recognitional justice, providing a global overview on equity in food systems. Substantial improvements in modelling capacity and data analysis allow for the use of a multimodel ensemble to project potential outcomes of a transition to healthy and sustainable food systems. The planetary health diet (PHD) remains a cornerstone of our recommendations and can be seen as a framework within which diverse and culturally appropriate diets can exist. Robust updated evidence reinforces a strong association with improved health outcomes, large reductions in all-cause mortality, and a substantial decline in the incidence of major diet-related chronic diseases. The reference PHD emphasises a balanced dietary pattern that is predominantly plant-based, with moderate inclusion of animal-sourced foods and minimal consumption of added sugars, saturated fats, and salt. Successful implementation of the PHD requires careful consideration of cultural contexts and the promotion of culturally appropriate and sustainable dietary traditions. This diversity of contexts, bounded by the PHD's reference values, represents substantial flexibility and choice across cultures, geographies, and individual preferences. However, when confronted by climate, biodiversity, health, and justice crises, transformation will require urgent and meaningful changes in our individual and collective behaviours and our culture of unhealthy, unjust, and unsustainable food production and consumption. For the first time, we quantify the global food systems' share of all nine planetary boundaries. These food system boundaries confirm that food is the single largest cause of planetary boundary transgressions, driving the transgression of five of the six breached boundaries. In addition, food systems exert a notable impact on the transgressed climate boundary and on the ocean acidification boundary. Unsustainable land conversion, particularly deforestation, remains a major driver of biodiversity loss and climate change, highlighting the need for zero conversion of all remaining intact ecosystems. Food systems account for the near totality of nitrogen and phosphorus boundary transgression, emphasising the improvements needed in nutrient management, efficient nutrient redistribution, and circular nutrient systems. The massive use of novel entities in food production, processing, and packaging (ranging from plastics to pesticides) remains a major concern but is alarmingly understudied. Our assessment of justice integrates three dimensions—distributive, representational, and recognitional—within a human rights framing that includes the rights to food, a healthy environment, and decent work. Analyses reveal important inequities in access to healthy diets, decent work conditions, and healthy environments, disproportionately affecting marginalised groups in low-income regions. We therefore propose nine social foundations that enable these rights to be met, and are able to assess the global status of six. Enabling access to, affordability of, and demand for healthy diets is paramount. Equally crucial is the right to live and work within a non-toxic environment and a stable climate system, as we recognise the profound impact of environmental degradation on human health and wellbeing. Furthermore, a living wage and meaningful representation would allow individuals to actively participate in building healthy, sustainable, and just food systems. However, nearly half of the world's population falls below these social foundations, undermining their ability to meet basic human rights. At the same time, the dietary patterns of most (6·9 billion people) of the world exert pressures that threaten further planetary boundary transgression. The destabilising effect of unhealthy overconsumption on the Earth's systems highlights the importance of viewing healthy diets not just as a human right, but also as a shared responsibility.

Ecosystems are under multiple stressors, and impacts can be measured with multiple variables. Humans have altered mass and energy flows of basically all ecosystems on Earth towards dangerous levels. However, integrating the data and synthesizing conclusions is becoming more and more complicated. Here we present an automated and easy-to-apply R package to assess terrestrial biosphere integrity that combines two complementary metrics. (i)The BioCol metric that quantifies the human colonization pressure exerted on the biosphere through alteration and extraction (appropriation) of net primary productivity.(ii)The EcoRisk metric that quantifies biogeochemical and vegetation structural changes as a proxy for the risk of ecosystem destabilization.Applied to simulations with the dynamic global vegetation model LPJmL5 for 1500–2016, we find that large regions presently (period 2007–2016) show modification and extraction of >20 % of the preindustrial potential net primary production. The modification (degradation) of net primary production (NPP) as a result of land use change and extraction in terms of biomass removal (e.g., from harvest) leads to drastic alterations in key ecosystem properties, which suggests a high risk of ecosystem destabilization. As a consequence of these dynamics, EcoRisk shows particularly high values in regions with intense land use and deforestation and in regions prone to impacts of climate change, such as the Arctic and boreal zone.The metrics presented here enable spatially explicit global-scale evaluation of historical and future states of the biosphere and are designed for use by the wider scientific community, being applicable not only to assessing biosphere integrity but also to benchmarking model performance.The package will be maintained on GitHub and through that we encourage its future application to other models and data sets.

The new global Feedback-based knowledge Repository for IntegrateD Assessments version 2.1 (FRIDAv2.1) Integrated Assessment Model (IAM) seeks to study the dynamics of the coupled human-Earth system. Connecting anthropogenic emissions to the resultant climate response is one part of the two-way feedback within this system, with the resultant climate impacts the other. This paper documents both the Climate Module within FRIDAv2.1, and the modified version separately simulated as a standalone simple climate model termed FRIDA-Clim version 1.0.1. This approach, based loosely on the existing FaIR simple climate model, simulates the key radiative forcings and the resultant temperature response, with process-based representations of the carbon cycle across the ocean, land, and atmosphere. When connected within the FRIDA IAM, it features deep connections to the other modules, being affected by processes such as water use for irrigation and land use change. In both uses, i.e. with the climate response interactively connected to the upstream human drivers and downstream climate impacts within the FRIDA IAM (coupled) and when ran separately as FRIDA-Clim driven by exogenous forcings (uncoupled), its climate drivers are simplified as compared to FaIR. This is to allow for this reduced set of key drivers to be interactively simulated within FRIDA, tightly coupling the evolution of the social and climate systems within the full model. Both the Climate Module and FRIDA-Clim are fully calibrated to accurately reproduce observations of key climate variables, with a systematic exploration of the uncertainty in the climate response. Together with the rest of the FRIDA model, this module is used to incorporate climate change systematically in the FRIDA System Dynamics IAM. As a standalone climate model, FRIDA-Clim comprises a simple climate model, enabling fast calculation of the global climate response to forcing; to explore this, the response of the model to both idealised CO2 emissions experiments and plausible future scenarios is also presented here. This setup will allow FRIDA-Clim to contribute to inter-model simple climate modelling initiatives, helping to explore the structural uncertainty in this modelling domain.

The current crop of models assessed by the Intergovernmental Panel on Climate Change (IPCC) to produce their assessment reports lack endogenous process-based representations of climate-driven changes to human activities, especially beyond the purely economic consequences of climate change. These climate-driven changes in human activities are critical to understanding the co-evolution of the climate and human systems. Earth System Models (ESMs) that represent the climate system and Integrated Assessment Models (IAMs) that represent the human system are typically separate, with assumptions that create coherency coordinated through RCPs and SSPs in ScenarioMIP, the core scenario analysis protocol. This divide limits understanding of climate-human feedback. An alternative aggregated approach, which couples human and natural systems (CHANS) such as the one used to build the Feedback-based knowledge Repository for IntegrateD Assessments “FRIDA” v2.1 IAM documented here, integrates climate and human systems into a unified global model, prioritizing feedback dynamics while maintaining interpretability. FRIDA represents the Earth's radiation balance, carbon cycle, and relevant portions of the water cycle alongside human demographics, economics, agriculture, and human energy use. Built using the System Dynamics method, it contains seven interconnected modules. Each subsystem is calibrated to data and validated to ensure structurally appropriate behaviour representation. FRIDA demonstrates that an aggregate, feedback-driven modelling approach, capturing CHANS interconnections with rigorous measurements of uncertainty, is possible. It complements conventional IAMs by highlighting missing feedback structures that affect future projections. Our work with FRIDA suggests SSP1-Baseline, SSP2-Baseline, and SSP5-Baseline are all overly optimistic on the prospects for future economic growth due to these feedbacks, while SSP3-Baseline and SSP4-Baseline, the SSPs with the highest challenges to adaptation, align more closely with our results. Future work will further refine climate impact representations, energy modelling, policy scenario creation, and stakeholder engagement for informed policymaking.

Feedbacks from the climate to other components of the coupled human-Earth system are expected to strongly influence the co-evolution of human society and its environment. Representing these feedback loops between climate and society, via the Earth system's response to human activities and the subsequent effect back onto social systems, is essential in order to fully explore the dynamics of the coupled system. However, focus on these feedbacks has traditionally been limited, or excluded, in prior Integrated Assessment Models (IAMs) and IAM-based modelling protocols. This limits the understanding of the effects of climate change and the response of the overall system to future emissions scenarios and policies. The new IAM Feedback-based knowledge Repository for IntegrateD Assessments version 2.1 (FRIDAv2.1), documented and explored within this paper collection, seeks to address this by internalising the feedbacks between subcomponents of the human-Earth system. Within this new IAM, these connections are therefore a key part of the structure, and are documented and discussed here. FRIDA represents these climate-to-society feedbacks, conceptualised as climate impacts, through global impact functions. Where possible, they are based on estimates from existing literature, reframed as functions of global climate variables to facilitate their representation within FRIDA. Other impact channels, with insufficient background literature to inform their structure and parameter values, are incorporated via the internal calibration of the IAM. Since the systematic representation of climate damages within an IAM is a relatively novel endeavour, the approach is constrained by literature limitations and necessary simplifications. In addition, the high level of abstraction of the FRIDA model imposes limits on the set of impacts which can reasonably be implemented, and the level of process detail amongst those included. Nevertheless, FRIDA's endogenous representation of climate feedbacks to human and natural systems enables valuable insights and intuition building on an underexplored topic. The general nature of the climate damage functions aggregated and documented here allows for their incorporation within other models and frameworks.

Social norms are a key socio-cultural driver of human behaviour and have been identified as a central process in potential social tipping dynamics. They play a central role in governance and thus represent a possible intervention point for collective action problems in the Anthropocene, such as natural resource management. A detailed modelling framework for social norm change is needed to capture the dynamics of human societies and their feedback interactions with the natural environment. To date, resource use models often incorporate social norms in an oversimplified manner, as a robust and detailed coupled social–ecological model, scaling from the local to the global world–Earth scale, is lacking. Here we present a multi-level network framework with a complex contagion process for modelling the dynamics of descriptive and injunctive social norms. The framework is complemented by social groups and their attitudes, which can significantly influence the adoption of social norms. We integrate the modelling concept of norms together with an additional individual learning component into a model of coupled social–ecological dynamics with a closed feedback loop, implemented in the copan:CORE framework for world–Earth modelling. We find that norms generally bifurcate the behaviour space into two extreme states: one sustainable and one unsustainable. Reaching a sustainable (i.e. safe) state becomes more likely with low thresholds of conforming to sustainable norms, as well as lower consideration rates of own resource harvesting success. Modelling both descriptive and injunctive norms independently and dynamically introduces additional intermediate states, e.g. when there are countervailing norms. The shape of the bifurcation depends on the number of groups and members and thus on the social network topology. Where groups are very inert in changing their attitudes and thus consistently convey the same norm, multiple stable basins for sustainability levels are found. Groups influence the dynamics by facilitating or inhibiting the contagion of sustainable behaviour by communicating their norms. The success of a generic social norm intervention is also found to be highly dependent on the group topology. Our findings suggest that explicitly modelling social norm processes together with social groups enriches the dynamics of social–ecological models and determines safe operating spaces. Consequently, both should be taken into account when representing human behaviour in coupled world–Earth models.

Dynamic Global Vegetation Models (DGVMs) are established in environmental and agricultural sciences for many purposes, e.g., modelling plant growth and productivity, water and carbon cycles, and biosphere-climate interactions. Nevertheless, DGVMs are still rather limited in terms of simulating mutual interactions between biospheric and human processes. While DGVMs such as the Lund Potsdam Jena managed Land (LPJmL) model have been successfully connected to Integrated Assessment Models (IAMs), the model couplings often remain loose and static over the simulation period. The copan:LPJmL modelling framework is an extension of the copan:CORE framework for integrated and dynamic human-Earth system modelling, and addresses this issue by integrating LPJmL via a new interface, consisting of an LPJmL coupling library and a Python library pycoupler, which together enable LPJmL inputs and outputs to be coupled in copan:LPJmL during the simulation period. It uses the copan:CORE entities and integrates the coupled data into the World (simulation space as a whole) and the (grid) Cell entity, allowing other entities such as Individuals, e.g., for agent-based modelling (ABM), to access them. Besides ABM, this framework allows for a broad range of modelling approaches to be represented with copan:LPJmL, of which we introduce three examples: (1) The model of Integrated Social-Ecological Resilient Land Systems (InSEEDS), which uses a classical ABM approach to model management decisions by farmers, (2) an adaption of an established crop calendar model (Crop Calendar), and (3) a novel Large Language Model (LLM)-driven ABM approach (LLM Fertilization).

The global context has shifted dramatically since publication of the first EAT–Lancet Commission in 2019, with increased geopolitical instability, soaring food prices, and the COVID-19 pandemic exacerbating existing vulnerabilities and creating new challenges. However, food systems remain squarely centred at the nexus of food security, human health, environmental sustainability, social justice, and the resilience of nations. Actions on food systems strongly impact the lives and wellbeing of all and are necessary to progress towards goals highlighted in the Sustainable Development Goals, the Paris Agreement, and the Kunming–Montreal Global Biodiversity Framework. Although current food systems have largely kept pace with population growth, ensuring sufficient caloric intake for many, they are the single most influential driver of planetary boundary transgression. More than half of the world’s population struggles to access healthy diets, leading to devastating consequences for public health, social equity, and the environment. Although hunger has declined in some regions, recent increases linked to expanding conflicts and emergent climate change impacts have reversed this positive trend. Obesity rates continue to rise globally, and the pressure exerted by food systems on planetary boundaries shows no signs of abating. In this moment of increasing instability, food systems still offer an unprecedented opportunity to build the resilience of environmental, health, economic, and social systems, and are uniquely placed to enhance human wellbeing while also contributing to Earth-system stability. This updated analysis builds upon the 2019 EAT–Lancet Commission, expanding its scope and strengthening its evidence base. The first Commission defined food group ranges for a healthy diet and identified the food systems’ share of planetary boundaries. In this Commission, we add an analysis of the social foundations for a just food system, and incorporate new data and perspectives on distributive, representational, and recognitional justice, providing a global overview on equity in food systems. Substantial improvements in modelling capacity and data analysis allow for the use of a multimodel ensemble to project potential outcomes of a transition to healthy and sustainable food systems.