www.thelancet.com/planetary-health Vol 8 October 2024 e813 The Lancet Planetary Health Commission Lancet Planet Health 2024; 8: e813–73 Published Online September 11, 2024 https://doi.org/10.1016/ S2542-5196(24)00042-1 Amsterdam Institute for Social Science Research, University of Amsterdam, Amsterdam, Netherlands (Prof J Gupta PhD, D Ciobanu MSc, K Prodani MSc, C Rammelt PhD, J Scholtens PhD, P Fezzigna MSc, G Gentile MSc); IHE-Delft Institute for Water Education, Delft, Netherlands (Prof J Gupta); Fenner School of Environment & Society, Australian National University, Canberra, ACT, Australia (Prof X Bai PhD, S J Lade PhD); School of Geography, Development and Environment, University of Arizona, Tucson, AZ, USA (Prof D M Liverman PhD, L Gifford PhD); Potsdam Institute for Climate Impact Research, Leibniz Association, Potsdam, Germany (Prof J Rockström PhD, L S Andersen PhD, S Loriani PhD, B Sakschewski PhD, Prof R Winkelmann PhD); Institute of Environmental Science and Geography (Prof J Rockström) and Institute of Physics and Astronomy (Prof R Winkelmann), University of Potsdam, Potsdam, Germany; State Key Laboratory of Cryospheric Science, Northwest Institute of Eco- Environment and Resources, Chinese Academy of Sciences, Lanzhou, China (Prof D Qin PhD, Prof C Xiao PhD); China Meteorological Administration, Beijing, China (Prof D Qin, X Xu PhD); University of Chinese Academy of Sciences, Beijing, China A just world on a safe planet: a Lancet Planetary Health–Earth Commission report on Earth-system boundaries, translations, and transformations Joyeeta Gupta, Xuemei Bai, Diana M Liverman, Johan Rockström, Dahe Qin, Ben Stewart-Koster, Juan C Rocha, Lisa Jacobson, Jesse F Abrams, Lauren S Andersen, David I Armstrong McKay, Govindasamy Bala, Stuart E Bunn, Daniel Ciobanu, Fabrice DeClerck, Kristie L Ebi, Lauren Gifford, Christopher Gordon, Syezlin Hasan, Norichika Kanie, Timothy M Lenton, Sina Loriani, Awaz Mohamed, Nebojsa Nakicenovic, David Obura, Daniel Ospina, Klaudia Prodani, Crelis Rammelt, Boris Sakschewski, Joeri Scholtens, Thejna Tharammal, Detlef van Vuuren, Peter H Verburg, Ricarda Winkelmann, Caroline Zimm, Elena Bennett, Anders Bjørn, Stefan Bringezu, Wendy J Broadgate, Harriet Bulkeley, Beatrice Crona, Pamela A Green, Holger Hoff, Lei Huang, Margot Hurlbert, Cristina Y A Inoue, Şiir Kılkış, Steven J Lade, Jianguo Liu, Imran Nadeem, Christopher Ndehedehe, Chukwumerije Okereke, Ilona M Otto, Simona Pedde, Laura Pereira, Lena Schulte-Uebbing, J David Tàbara, Wim de Vries, Gail Whiteman, Cunde Xiao, Xinwu Xu, Noelia Zafra-Calvo, Xin Zhang, Paola Fezzigna, Giuliana Gentile Executive summary The health of the planet and its people are at risk. The deterioration of the global commons—ie, the natural systems that support life on Earth—is exacerbating energy, food, and water insecurity, and increasing the risk of disease, disaster, displacement, and conflict. In this Commission, we quantify safe and just Earth-system boundaries (ESBs) and assess minimum access to natural resources required for human dignity and to enable escape from poverty. Collectively, these describe a safe and just corridor that is essential to ensuring sustainable and resilient human and planetary health and thriving in the Anthropocene. We then discuss the need for translation of ESBs across scales to inform science-based targets for action by key actors (and the challenges in doing so), and conclude by identifying the system transformations necessary to bring about a safe and just future. Our concept of the safe and just corridor advances research on planetary boundaries and the justice and Earth-system aspects of the Sustainable Development Goals. We define safe as ensuring the biophysical stability of the Earth system, and our justice principles include minimising harm, meeting minimum access needs, and redistributing resources and responsibili- ties to enhance human health and wellbeing. The ceiling of the safe and just corridor is defined by the more stringent of the safe and just ESBs to mini- mise significant harm and ensure Earth-system stability. The base of the corridor is defined by the impacts of minimum global access to food, water, energy, and infrastructure for the global popula- tion, in the domains of the variables for which we defined the ESBs. Living within the corridor is neces- sary, because exceeding the ESBs and not meeting basic needs threatens human health and life on Earth. However, simply staying within the corridor does not guarantee justice because within the corridor resources can also be inequitably distributed, aggravating human health and causing environmental damage. Procedural and substantive justice are necessary to ensure that the space within the corridor is justly shared. We define eight safe and just ESBs for five domains— the biosphere (functional integrity and natural ecosystem area), climate, nutrient cycles (phosphorus and nitrogen), freshwater (surface and groundwater), and aerosols—to reduce the risk of degrading biophys- ical life-support systems and avoid tipping points. Seven of the ESBs have already been transgressed: functional integrity, natural ecosystem area, climate, phosphorus, nitrogen, surface water, and groundwater. The eighth ESB, air pollution, has been transgressed at the local level in many parts of the world. Although safe boundaries would ensure Earth-system stability and thus safeguard the overall biophysical conditions that have enabled humans to flourish, they do not necessarily safeguard everyone against harm or allow for minimum access to resources for all. We use the concept of Earth-system justice—which seeks to ensure wellbeing and reduce harm within and across generations, nations, and communities, and between humans and other species, through procedural and distributive justice—to assess safe boundaries. Earth-system justice recognises unequal responsibility for, and unequal exposure and vulnera- bility to, Earth-system changes, and also recognises unequal capacities to respond and unequal access to resources. We also assess the extent to which safe ESBs could minimise irreversible, existential, and other major harms to human health and wellbeing through a review of who is affected at each boundary. Not all safe ESBs are just, in that they do not minimise all significant harm (eg, that associated with the climate change, aerosol, or nitrogen ESBs). Billions of people globally do not have sufficient access to energy, clean water, food, and other resources. For climate change, for example, tens of millions of people are harmed at lower levels of warming than that defined in the safe ESB, and thus to avoid significant harm would require a more stringent ESB. In other domains, the safe ESBs align with the just ESBs, although some need to be modified, or complemented with local standards, to prevent significant harm (eg, the aerosols ESB). https://doi.org/10.1016/S2542-5196(24)00042-1 https://doi.org/10.1016/S2542-5196(24)00042-1 http://crossmark.crossref.org/dialog/?doi=10.1016/S2542-5196(24)00042-1&domain=pdf e814 www.thelancet.com/planetary-health Vol 8 October 2024 The Lancet Planetary Health Commission (Prof D Qin, X Xu); Australian Rivers Institute, Griffith University, Brisbane, QLD, Australia (B Stewart-Koster PhD, Prof S E Bunn PhD, S Hasan PhD, C Ndehedehe PhD); Future Earth Secretariat, Stockholm, Sweden (J C Rocha PhD, L Jacobson MSc, D Ospina MSc, W J Broadgate PhD, S J Lade, S Pedde PhD); Stockholm Resilience Centre, Stockholm University, Stockholm, Sweden (J C Rocha, D I Armstrong McKay PhD, Prof B Crona PhD, S J Lade, L Pereira PhD); Global Systems Institute (J F Abrams PhD, D I Armstrong McKay, Prof T M Lenton PhD) and Business School (Prof G Whiteman PhD), University of Exeter, Exeter, UK; Georesilience Analytics, Leatherhead, UK (D I Armstrong McKay); Center for Atmospheric and Oceanic Sciences (Prof G Bala PhD) and Interdisciplinary Centre for Water Research (T Tharammal PhD), Indian Institute of Science, Bengaluru, India; EAT, Oslo, Norway (F DeClerck PhD); Alliance of Bioversity and CIAT, CGIAR, Montpellier, France (F DeClerck); Center for Health & the Global Environment, University of Washington, Seattle, WA, USA (Prof K L Ebi PhD); Institute for Environment and Sanitation Studies, University of Ghana, Legon, Ghana (Prof C Gordon PhD); Graduate School of Media and Governance, Keio University, Fujisawa, Japan (Prof N Kanie PhD); Functional Forest Ecology, University of Hamburg, Hamburg, Germany (A Mohamed PhD); International Institute for Applied Systems Analysis, Laxenburg, Austria (Prof N Nakicenovic PhD, C Zimm PhD); Coastal Oceans Research and Development in the Indian Ocean East Africa, Mombasa, Kenya (D Obura PhD); Copernicus Institute of Sustainable Development, Utrecht University, Utrecht, Netherlands (Prof D van Vuuren PhD, Prof H Bulkeley PhD); PBL Netherlands Environmental Assessment Agency, The Hague, Netherlands (Prof D van Vuuren, We examine the implications of achieving the social SDGs in 2018 through an impact modelling exercise, and quantify the minimum access to resources required for basic human dignity (level 1) as well as the minimum resources required to enable escape from poverty (level 2). We conclude that without social transformation and redistribution of natural resource use (eg, from top consumers of natural resources to those who currently do not have minimum access to these resources), meeting minimum-access levels for people living below the minimum level would increase pressures on the Earth system and the risks of further transgressions of the ESBs. We also estimate resource-access needs for human populations in 2050 and the associated Earth-system impacts these could have. We project that the safe and just climate ESB will be overshot by 2050, even if everybody in the world lives with only the minimum required access to resources (no more, no less), unless there are transformations of, for example, the energy and food systems. Thus, a safe and just corridor will only be possible with radical societal transformations and techno- logical changes. Living within the safe and just corridor requires operationalisation of ESBs by key actors across all levels, which can be achieved via cross-scale translation (whereby resources and responsibilities for impact reductions are equitably shared among actors). We focus on cities and businesses because of the magni- tude of their impacts on the Earth system, and their potential to take swift action and act as agents of change. We explore possible approaches for translating each ESB to cities and businesses via the sequential steps of transcription, allocation, and adjustment. We high- light how different elements of Earth-system justice can be reflected in the allocation and adjustment steps by choosing appropriate sharing approaches, informed by the governance context and broader enabling conditions. Finally we discuss system transformations that could move humanity into a safe and just corridor and reduce risks of instability, injustice, and harm to human health. These transformations aim to minimise harm and ensure access to essential resources, while addressing the drivers of Earth-system change and vulnerability and the institu- tional and social barriers to systemic transformations, Panel 1: Glossary ESBs: Quantitative (when possible) and qualitative descriptions of boundaries beyond which the stability and resilience of Earth-system processes is threatened and humans might be substantially harmed. ESBs go beyond planetary boundaries by combining elements from the local to global level with knowledge from biophysical and social science domains. Safe ESBs: ESBs that, if adhered to, would maintain and enhance the biophysical stability of the Earth system over time, thereby safeguarding the Earth system’s functions and ability to support humans and all other living organisms.10 Just ESBs: ESBs that, if adhered to, would ensure an Earth- system state that minimises the risk of significant harm to present and future generations, countries, and communities. Just ESBs can be expanded to minimise risk to species and ecosystems. Earth-system justice: Building on epistemic justice and local-to-global justice scholarship, Earth-system justice includes procedural justice (access to information, decision- making, civic space, and courts) and substantive justice in terms of ensuring access to basic resources and services while ensuring no significant harm and allocation of the remaining resources, risks, and responsibilities. Achieving Earth-system justice involves multiple, systemic transformations that address drivers of Earth-system change and vulnerability, and includes addressing the barriers to, and responsibility for, such changes. It also requires addressing the mechanisms that govern the allocation of resources, as well as identifying who is responsible for Earth-system change, and how.11 The scope of Earth-system justice is framed by three overarching criteria: interspecies justice, intergenerational justice, and intragenerational justice. Safe and just corridor: A clearly defined space in which pathways of future human development are both safe and just over time, and that acknowledges that the Earth’s natural resources (including carbon, nutrients, water, and land) are finite and have to be justly shared between people and nature.12 The ESBs10 we have defined provide the ceiling of the corridor, and the total pressure on the Earth system if all people have minimum access to basic resources13 is the base. Global commons: The “planet’s natural resources—the ecosystems, biomes and processes that regulate the stability and resilience of the Earth system”.14 The stability and resilience of the Earth system is vital to all and dependent upon the global commons. Local commons across the planet are fundamental building blocks of the global commons. Just minimum access: Minimum access refers to the level of essential necessary resources and services (eg, water, food, energy, infrastructure) that all people are entitled to. Two different levels have been quantified for each Earth-system domain. Level 1 (dignity) describes the minimum access needed to lead a basic dignified life beyond mere survival (including, for example, access to a toilet). Level 2 describes a higher level of minimum access to resources that would be needed to enable an escape from poverty. ESBs=Earth-system boundaries. www.thelancet.com/planetary-health Vol 8 October 2024 e815 The Lancet Planetary Health Commission L Schulte-Uebbing PhD); Swiss Federal Institute for Forest, Snow and Landscape Research, Birmensdorf, Switzerland (Prof P H Verburg PhD); Institute for Environmental Studies, Vrije Universiteit Amsterdam, Amsterdam, Netherlands (Prof P H Verburg); Bieler School of Environment and Department of Natural Resource Sciences, McGill University, Montreal, QC, Canada (Prof E Bennett PhD); Centre for Absolute Sustainability and Section for Quantitative Sustainability Assessment, Department of Environmental and Resource Engineering, Technical University of Denmark, Kongens Lyngby, Denmark (A Bjørn PhD); Center for Environmental Systems Research, University of Kassel, Kassel, Germany (Prof S Bringezu PhD); Department of Geography, Durham University, Durham, UK (Prof H Bulkeley); Global Economic Dynamics and the Biosphere Programme, Royal Swedish Academy of Sciences, Stockholm, Sweden (Prof B Crona); Advanced Science Research Center at the Graduate Center, City University of New York, NY, USA (P A Green ME); Wegener Center for Climate and Global Change, University of Graz, Graz, Austria (H Hoff PhD, Prof I M Otto PhD); National Climate Center, Beijing, China (L Huang PhD); Johnson- Shoyama Graduate School of Public Policy, University of Regina, Regina, SK, Canada (Prof M Hurlbert PhD); Center for Global Studies, Institute of International Relations, University of Brasília, Brasília, Brazil (C Y A Inoue PhD); Institute for Management Research, Radboud University, Nijmegen, Netherlands (C Y A Inoue); Scientific and Technological Research Council of Turkey, Ankara, Türkiye (Prof Ş Kılkış PhD); Center for Systems Integration and Sustainability, Department of Fisheries and Wildlife, Michigan State University, East Lansing, MI, USA (Prof J Liu PhD); Institute of Meteorology and Climatology, Department of Ecosystem Management, Climate and Biodiversity, BOKU University, Vienna, Austria (I Nadeem PhD); and include reducing and reallocating consumption, changing economic systems, technology, and governance. Introduction Planetary health is acutely under threat in the Anthropocene, with the causes and impacts of this threat inequitably distributed.1 Roughly 9 million premature deaths annually are linked to exposure to air and water pollution, 3·2 billion people are affected by land degrada- tion, and many millions are affected by zoonotic disease, rising temperatures, and extreme weather events.2–5 People living in historically marginalised locations (eg, former colonies), especially people living in poverty, are particu- larly at risk. Economic growth trajectories (which dominate global economic policy) pose even greater risks through destabilisation of the global commons—ie, the biosphere, climate, and cryosphere, and nutrient and water cycles.1,6–9 Integration of socioeconomic concerns into Earth-system boundaries (ESBs)—limits that should be adhered to in order to maintain the stability of the planet and safety of humans10—will facilitate reaching a stable state of the Earth system and thereby promote human health and wellbeing (panel 1). This Commission reports on work from the Earth Commission, an international, transdisciplinary group of scholars that informs the creation of science-based targets and transformations to protect critical global commons. This work seeks to define safe and just ESBs intended to guide human development across eight dimensions for five Earth-system domains— climate, biosphere (functional integrity and natural ecosystem area), freshwater (surface and ground), nutrient cycles (nitrogen and phosphorus), and aerosols. The ESBs are defined at the global scale, with some derived and aggregated from local-scale boundaries (eg, river basin scale), making them operational at sub- global levels (from regional to local). Our ESBs integrate Earth-system and social and health perspectives by using, for the first time, the same units of quantification for both. Identification of safe ESBs is essential for governing the local to the global commons and for protecting plane- tary health. Transgression of safe boundaries in the Amazon or Arctic regions, for example, could affect the ability of future generations to live healthy lives and prosper,8,15,16 and of nations to achieve the UN’s Sustainable Development Goals (SDGs). Although defining safe ESBs is intended to maintain Earth-system stability, remaining within these boundaries will not necessarily prevent harm to human health. A justice approach, by contrast, requires at least boundaries that minimise significant harm to human health and wellbeing and to other species (panel 2) while ensuring access to necessary resources and services. Current environmental pressures are highly unequal, with the richest 10% of the global population consuming as much energy as the poorest 80%17 and being responsible for more emissions than the other 90%.18 Between 23% and 62% of the global popu- lation does not have adequate access to resources to meet basic needs.13 The inequalities are stark between the wealthiest regions (eg, North America, Europe, Australia) and the poorest regions (eg, sub-Saharan Africa, South Asia, Central America). Meeting the critical material needs of people who currently do not have the minimum required access to resources without transformations and redistribution of resources would increase the pressure on the Earth system.13 Thus, ensuring Earth-system stability and resilience requires addressing issues of social justice, underlying drivers and pressures, and distributional and technical aspects of how resources are produced, distrib- uted, and consumed. In this Commission, we define a safe and just corridor (panel 1) with a ceiling defined by the more stringent of the safe and just ESBs (ie, the lower of the two ESBs).10 The base of this corridor estimates the effects on Earth- system domains of meeting minimum access levels to necessary resources and services (eg, water, food, energy, infrastructure) for all people, which allows consistent assessment of the corridor space within which justice, health, and wellbeing is possible for current and future generations (figure 1). Under current social and environmental conditions, all humans cannot live healthy lives within the safe and just corridor.13 Systemic transformations of underlying drivers of Earth-system change and vulnerability is needed to reduce harm and to enable everyone to live within this corridor. An Earth-system justice approach (panel 1), which offers an analytical and evaluative tool consisting of just ends (targets) and just means (levers), could enable living within the ESBs.11,19 Transformations would require mobilisation of societal actors who, informed by knowledge of their fair shares of ESBs through cross-scale translation, act to limit their resource Panel 2: Defining significant harm • Harm: negative effects (including on health) on humans, communities, and countries as a result of Earth-system changes due to human activities pushing the Earth system outside of the safe and just Earth-system boundaries. • Significant harm: existential or irreversible negative effects on people, communities, or countries, such as substantial loss of life, deterioration of health, chronic disease, injury, malnutrition, displacement, loss of livelihood or income, loss of access to nature’s contributions to people, or loss of land. • No significant harm principle: states and other actors responsible for anthropogenic Earth-system change have a duty to refrain from causing significant harm; to prevent, reduce, and control the risk of causing significant harm; and to repair or compensate for significant harm already inflicted. e816 www.thelancet.com/planetary-health Vol 8 October 2024 The Lancet Planetary Health Commission School of Environment & Science, Griffith University, Nathan, QLD, Australia (C Ndehedehe); School of Policy Studies, University of Bristol, Bristol, UK (Prof C Okereke PhD); Soil raphy and Landscape Group (S Pedde) and Environmental Systems Analysis Group (L Schulte-Uebbing, Prof W de Vries PhD), Wageningen University & use and broader impact on the planet. Cities and busi- nesses are key actors driving anthropogenic pressures, but have received less attention in sustainability assess- ments than countries. The unique challenges associated with these actors need to be understood and resolved in translation methods, and approaches that reflect the specific environmental, social, and economic contexts of cities and businesses need to be developed. We discuss how ESBs can be translated across scales (ie, from individuals to cities, businesses, organisations, countries, and other administrative and political boundaries), aiming to assign ESB-aligned resource budgets and responsibilities equitably, with components of distributional justice addressed through the iterative process of allocation and adjustment. We also assess how Earth-system justice can be reflected in these alloca- tions via sharing approaches, efficient governance, and enabling conditions for cities and businesses to imple- ment cross-scale translation. Other frameworks on anthropogenic pressures include the Limits to Growth,20,21 the 2001 Amsterdam Declaration on Earth Systems Science,22 Planetary Boundaries,7,9 the UN 2030 Agenda (and associated SDGs),6 and Doughnut Economics23,24 (developed in response to Planetary Boundaries). Whereas Planetary Boundaries only assess safe biophysical boundaries at the global scale, Doughnut Economics combines the nine Planetary Boundaries with 12 human and social foundations to create a safe and just space for humanity. Although Doughnut Economics’ safe and just indicators25 include justice elements, our work goes further by quantifying these elements in the same units as the safe ESBs and by operationalising and quantifying justice issues.26,27 Consumption corridors28,29 are a related concept, but the Earth Commission takes a more holistic Earth-system approach. We build upon SDGs6 that aspire towards a fundamen- tally new direction of development for the benefit of all people and the planet. We further operationalise the SDGs by providing the scientific underpinning for identifying the safe and just corridor that needs to be achieved to avoid triggering events that have irreversible impacts on the biophysical systems in the Earth system and signifi- cant harm to people while assuring that all people have access to basic needs such as water, energy, and food. Our translation framework builds on existing approaches30,31 to incorporate social and environmental impacts and the socioeconomic and ecological context, reflecting equity and justice principles. We build on transformation scholarship,32–34 with an increased focus on drivers that push humanity outside the safe and just corridor.35 The remainder of this Commission is organised into four parts (figure 1). In part 1, we describe our theoretical framework and methods. In part 2, we present the quan- tifications of safe and just ESBs with a spatially explicit approach that allow identification of where ESBs are transgressed and which people are most exposed to associated deleterious effects on health and other harms. We also quantify the base and ceiling of the safe and just corridor in the same units for today and 2050, with the base representing the impact on the Earth system if all people had equal access to a minimum level of resources and the ceiling defined by the safe and just ESBs. In part 3, we discuss challenges, approaches, and enabling conditions in translating the ESBs to cities and businesses, and in part 4 we identify fundamental trans- formations needed to keep humanity within the safe and just corridor. Figure 1: Visualisation of the concept of the safe and just corridor We quantified eight safe and just ESBs, indicating the maximum pressure that can be exerted on that domain that is both safe and just for people and the planet. These ESBs form the ceiling of a safe and just corridor, for which the base is the level of pressure that would be exerted on the Earth system to ensure universal provision of minimum access to food, water, energy, and infrastructure. ESB=Earth-system boundary. Quantification of Earth-system pressure for each domain Corridor Safe boundary Maximum pressure to maintain Earth-system stability Just boundary Maximum pressure to minimise significant harm to people ESB Stricter safe and just boundaries Safe and just corridor Space between foundation of minimum access for all and ESB ESB>minimum access for all The corridor exists ESBESB: no safe or just corridor Minimum access for all e820 www.thelancet.com/planetary-health Vol 8 October 2024 The Lancet Planetary Health Commission and use expert elicitation within the Earth Commission. Rockström and colleagues found, for example, that for climate, the safe ESB of 1·5°C does not prevent wide- spread and significant harm to current generations, let alone future ones, and propose that the safe and just ESB should be 1°C.10 Second, as appropriate, we comple- ment the safe ESBs with international health standards for these domains that should be adhered to (eg, guidelines for drinking water quality) in order to avoid significant harm. Third, for each domain, we map the spatial distri- bution of the risk of harm, a function of the nature and degree of biophysical change (ie, hazard), the extent to which people are exposed to biophysical changes (ie, exposure), and vulnerability (ie, susceptibility and capacity to adapt). We map exposure to biophysical hazards based on population distributions to show where sub-global boundaries have already been transgressed (exposing people to harm) and the unequal distribution of exposure (appendix pp 11–12). We overlay poverty as a proxy for vulnerability to map the geography of injustice when exposed populations are also poor. Our justice approach has several limitations. First, although staying within just ESBs could avoid harm to substantial proportions of the human population, it does not guarantee just outcomes, as noted in our discussion of each domain. Second, the high levels of aggregation and the use of poverty to indicate vulnerability overlook more detailed analyses of distributional justice in terms of which social subgroups (and other species) are most harmed and under what scenarios, as well as more complex drivers of vulnerability or responsibility for exposure and vulnerability. Third, we have not explored future scenarios in which social conditions have changed or the risk that mitigation policies could increase expo- sure and vulnerability for some people. We try to avoid a trade-off between interspecies, intergenerational, and intragenerational justice by calling for transformations that ensure human health and wellbeing while staying within a safe and just corridor. Aligned with the SDGs of eradicating poverty, reducing inequality, and ensuring access to food, energy, water, and infrastructure for all people, we investigate the Earth- system implications of providing access to resources to those who do not have access as of 2018. We use two levels of just minimum access to key resources and services for water, food, energy, and infrastructure: basic dignity (level 1), and escape from poverty (level 2).13 Informed by proposals such as the Decent Living Standards73 rather than monetary measures of poverty, the basic dignity level is rooted in human rights,74–78 including the rights to clean water, energy, food, and housing, and enables a dignified life beyond mere survival. Level 2 describes increased access to resources to enable activities considered neces- sary to break out of poverty and other deprivations,79 and to potentially empower people to make use of their resources to achieve certain capabilities and thus ensure broader wellbeing.80 In this Commission, we go beyond previous work that quantified the impact of providing minimum access to resources for those without access in 2018 to estimate the impacts in 2050. The technical methods have been previously described.13 Previous analyses have shown that seven of the eight globally defined safe and just ESBs have already been transgressed,10 even though the minimum access to resources has not been met for billions of people. We conduct novel analyses to visualise a safe and just corridor in which the ceiling is the more stringent of the safe and just ESBs, and the base is defined as the impact on the Earth system if all humans consumed resources at level 2 of minimum access and no more (figure 4). These analyses involve the conversion of the safe and just ESBs to common units of impact on the Earth system (as per Rammelt and colleagues13) to visualise the base and ceiling of the corridor. Our translation approach is based on literature reviews and expert elicitation. Key steps of translation include transcription, allocation, and adjustments underpinned by different sharing approaches and expressed with Panel 3: Safe and just ESBs* • Climate: a maximum of 1·0°C of global warming • Biosphere: • Natural ecosystem area: >50–60% should be largely intact, depending on spatial distribution (upper end recommended) • Functional integrity: >20–25% of each km² should comprise natural or semi-natural vegetation • Freshwater: • Surface water flow: <20% monthly flow alteration (aligned with WHO and UN Environment Programme quality standards) • Groundwater: annual drawdown from natural and anthropogenic factors does not exceed recharge (aligned with WHO and UN Environment Programme quality standards) • Nutrients: • Nitrogen: surplus <57 (uncertainty range 34–74) Tg per year (total input <134 [85–170] Tg per year) • Phosphorus: surplus <4·5–9 (the ESB itself is the uncertainty range) Tg per year (mined input <16 [uncertainty range 8–17] Tg per year); aligned with local boundary to avoid eutrophication (<50–100 mg per m³) • Aerosols and air pollution: annual mean interhemispheric aerosol optical depth difference <0·15 (aligned with an annual limit of 15 μg/m³ of particulate matter smaller than 2·5 µm in diameter). Seven of the eight globally defined ESBs have already been crossed. At the local level, in more than 50% of land area, at least two local ESBs have been transgressed, with 86% of humans living in these areas. ESBs=Earth-system boundaries. *ESBs were first presented in Rockström et al, 2023.10 www.thelancet.com/planetary-health Vol 8 October 2024 e821 The Lancet Planetary Health Commission enacting metrics.81 Our transformation narrative is based on an extensive literature review, expert elicitation, and our Earth-system justice framework. By expert elicitation, we mean the expert judgement of the Earth Commission and five working groups representing a wider commu- nity of social and natural scientists, including young scholars in the secretariat of the Earth Commission— more than 100 scholars in total. Part 2: Safe and just ESBs and the safe and just corridor In this section, we present eight safe and just ESBs for five domains (panel 3). We analyse the Earth-system implications of meeting the minimum access to resource needs of people in 2018 and in 2050 (with some assump- tions about changes in technology and redistribution). We also introduce an outlook for safe and just ESBs for some novel entities (panel 4). The biosphere The biosphere has multiple dimensions, including evolutionary processes and innumerable ecological func- tions94 that underpin life on Earth and contribute to social, cultural, and economic aspects of wellbeing.95,96 Loss of biodiversity affects the natural world and human wellbeing, notably through the loss of nature’s contribu- tions to people (NCP), including pollination, soil fertility, and pest and disease control, all of which affect human health, healthy food production, food security, and liveli- hoods.97 More than 75% of important food crops rely on animal pollination, and pollinators are crucial for healthy and varied diets and for biofuels, fibres, and construction materials.98 Safe ESBs The biosphere is adaptive, serving as a stock and flow regulator for Earth-system processes such as carbon, water, and nutrient cycles. Changes in species’ composi- tion, distribution, and richness can affect local and global processes.94 To ensure safe biosphere ESBs, it is necessary to secure largely intact natural ecosystems that assure Earth-system functions (eg, secure stocks and flows of carbon, water, and nutrients, and halt species extinction); to promote functional integrity of all landscapes and seascapes globally to secure local and global contributions to human wellbeing; and to ensure contributions to Earth-system functions through the provisioning of NCP, or meeting the requirements of interspecies justice.99  The biosphere has different facets,100 each with different boundaries that can vary based on the specific characteristics of the local ecosystem. We capture the main components by identifying safe boundaries for two complementary and synthetic measures of biodiversity: the area of largely intact natural ecosys- tems, and the functional integrity of ecosystems heavily modified by human pressures.10,101 Use of both of these measures ensures a minimum level of functional composition, diversity, and richness of ecological communities crucial for regulating nutrient cycles, water flows, and carbon stocks and flows on a global scale, and for supporting the provision of NCP, which underpins the wellbeing of local people and their quality of life. For the area of natural ecosystems, we estimated the minimum global boundary based on experiments in conservation planning in the literature.102,103 About 45–50% of the world’s ice-free land surface is largely intact.104,105 Our estimated safe ESB is that around 50–60% of global land surface should be in largely intact, natural condition to halt species extinction, secure biosphere contributions to climate regulation, and stabilise regional water cycles.10 The amount of intact natural land as of 2018 was around Panel 4: Exploring novel entities for future analysis We acknowledge that there are other domains for which we have not quantified Earth-system boundaries but which we would like to explore in the future. For example, evidence on the diverse risk potentials of novel entities (eg, emerging pollutants and contaminants, radioactive waste, heavy metals, antibiotics, microplastics) for people (eg, effects on fertility, health, and food security) is increasing.82–85 Progress towards quantifications of the Earth-system boundaries for novel entities highlight the need for a differentiated approach to capture complexity and the absence of prehuman background levels.82,86–88 Tracking trends on the release and production of novel entities (eg, production, volume, and emission or release quantities of chemicals and plastics, as well as different impacts) and establishing control variables indicates that humanity has crossed the novel entity boundary. The long-term effects of many novel entities could continue to pose a threat even if actions to control production and release were taken today.87 Knowledge gaps relating to the scale and scope of impacts of novel entities remain. Only a few thousand of the roughly 140 000 (and increasing) synthetic chemicals have been tested for toxic effects on other organisms,84,87 and possible interactions across these entities are unknown. Novel entities can harm human health through uptake via various channels (eg, water, air,89 food, food packaging, cosmetics, clothing). For example, microplastics have been detected worldwide90 and in human blood.91 Microplastics and nanoplastics can alter the intestinal flora, potentially leading to diabetes, obesity, and chronic liver disease.92 Water in plastic bottles often has higher concentrations of microplastics than processed tap water.92 Antimicrobial-resistant bacteria have been detected in more than a quarter of the studied rivers, reflecting the pharmaceutical fingerprint of nearby populations.93 These issues are closely linked to justice and access concerns relating to technology choice and management capacity, and economic means and information. e822 www.thelancet.com/planetary-health Vol 8 October 2024 The Lancet Planetary Health Commission 15% below this ESB, but could be increased through restoring degraded ecosystems or previously converted ecosystems,102,103,106 with conservation efforts distributed across all ecoregions. Strassburg and colleagues102 estimated that restoration of 15% of converted lands in priority areas could avoid 60% of expected extinctions and sequester 299 gigatonnes of carbon dioxide. Our estimate for the safe ESB is higher than a previous calculation of the minimum area needed for conservation,107 in which it was estimated that 44% of the terrestrial surface would need to be intact to safeguard species ranges. However, that estimate is focused only on species diversity and not the important Earth-system functions and functional contributions of the biosphere. Furthermore, these conservation areas are concentrated in some regions, resulting in critical shortages of NCP in other regions. For the functional integrity of human-modified ecosys- tems, we systematically analysed six critical NCP at local scales to assess the minimum characteristics (area, quality, spatial configuration) required to avoid the loss of their contribution to human health and wellbeing (including pollination, pest and disease control, water- quality regulation, soil protection, natural hazards mitigation, and recreation). Our findings suggest that a safe boundary of at least 20–25% of natural or semi- natural habitat per km² in human-modified lands (ie, urban and agro-ecosystems) is needed to support both Earth-system NCP and local NCP, in addition to the functions provided by largely intact lands.101 Our estimates are consistent with other evidence proposing that more than 20% of natural or semi-natural habitat is needed per km² globally to maintain NCP, especially those related to food production.101,108–110 The exact area, quality, and spatial configuration required varies by contribution and location, and thus could not be esti- mated on a global scale, necessitating local translation, assessment of local context, demand for specific NCP, and application of best practices. The amounts of natural or semi-natural habitat needed could range from 6–15% in some landscapes (eg, riparian ecosystems, agricul- tural landscapes with high crop diversity) to 50% in others (eg, in sloping landscapes, or landscapes where erosion or natural hazards are frequent).101 Many of the functional biological groups that provide local NCP are either non-mobile, or move very short distances (eg, pollinating insects and pest-regulating predators and parasitoids that move up to 2000 m), and thus NCP provisioning is driven by the spatial configuration of the habitat and its accessibility to beneficiaries.101 Additionally, NCP are most used where humans are present, notably agricultural lands dependent on polli- nation and pest control, or urban ecosystems where recreational spaces support human physicial and mental health. We emphasise that the ESB of 20–25% natural or semi-natural habitats per km² is a boundary limit to ensure just NCP provision. 10% of natural or semi- natural habitat per km² is a sharper threshold, below which evidence suggests that many NCP would almost no longer be provided.101 Both biosphere boundaries are spatially defined and therefore require spatially differentiated responses (figure 5). Expansion of intact natural ecosystems could Figure 5: Spatial distribution of biosphere functional integrity in working lands The map shows a proximate measure of the functional integrity of human-modified lands (agriculture, cities), indicating the proportion of natural land within 1 km² of each 10 m² pixel plotted. The lower the functional integrity, the lower the likelihood that nature’s contribution to people (eg, pollination, pest and disease control, water-quality regulation, soil protection, natural hazards mitigation, and recreation) will be provided. The Earth-system boundary for functional integrity is 20–25%, a level at which many of nature's contributions to people are substantially diminished. Data source: Mohamed et al, 2024.101 Areas in white were not assessed because of insufficient data, because of cloud coverage, or because of desert or ice cover. 0 25 50 75 Functional integrity per km2 (%) www.thelancet.com/planetary-health Vol 8 October 2024 e823 The Lancet Planetary Health Commission limit people’s access to land for agriculture or other activi- ties, but could simultaneously help people who are dependent on resources from natural areas.111,112 Therefore, locations for restoration should be chosen within integrated land-use planning approaches to avoid trade-offs while optimising synergies. In human-modi- fied lands, the functional integrity of ecosystems often determines peoples’ access to locally constrained NCP. To identify where people have insufficient local access to NCP in human-modified ecosystems, we used spatially explicit estimates of the proportion of natural or semi- natural habitat in human-modified landscapes at scales of 1 km² and global gridded population models to esti- mate the number of people with insufficient access to local NCP. Just ESBs Our Earth-system justice analysis of the safe boundary for natural ecosystem area suggests that adhering to it would reduce harm to other species and to future genera- tions. However, distributional challenges would raise concerns from an intragenerational justice perspective. Protection and restoration of largely intact natural areas is often targeted at biodiversity-rich habitats located in low-income countries,102 where vulnerable populations might reside with high dependence on biodiversity locally. More than 80% of global biodiversity is in the territories of Indigenous peoples.113 Previous initia- tives to reserve a certain proportion of the planet for nature were criticised for ignoring social issues and justice, notably the proposals to conserve half of the world’s land and half of the oceans.114,115 Scholars emphasise the potential risks associated with reserving a proportion of the world for non-human nature to human rights and food production, and the risk of increased land prices, land grabbing and displace- ment,116 and related equity challenges117 potentially affecting a billion people.118 However, the continued loss of largely intact nature puts biodiversity and climate security at risk, with growing evidence that overcon- sumption of unhealthy diets is a greater risk to environmental security than lack of productive land is to food security.119 More than 3·2 billion people are affected by degraded lands120 and could benefit from the restoration of ecosystem integrity. Billions of people rely on natural medicines, the availability of which is now threatened by biodiversity loss.121 Biodiversity loss affects water quality, and loss of mangroves could expose hundreds of millions of people to floods and cyclones.121 Such losses in combination with rising temperature increase human exposure to zoonotic pathogens122,123 and increase the risk of new pandemics. Furthermore, decreases in the prevalence of infectious diseases globally could be slowed or reversed because of deforestation.124,125 These risks underscore how biodiver- sity loss undermines progress towards many social Sustainable Development Goals (SDGs).3 Adherence to our safe ESB requires that 50–60% of terrestrial area should be left largely intact as natural land but with the caveat that this should be done through just transformations that avoid negative impacts on liveli- hoods. This proposal would require the area of largely intact natural land (as of 2020) to be expanded by about 15% through restoration. How this expansion would affect countries, communities, and people depends on land rights, the implementation of the boundary,126 and how natural area is defined. People should not be excluded from largely intact natural ecosystem areas when it is possible to live with nature without destroying it—eg, various Indigenous peoples have often sustainably maintained largely intact areas.127,128 If, on average, 50–60% of the global land area should remain largely intact, to avoid an inequitable distribu- tion of the responsibility,10 the just boundary (ie, that which, if adhered to, would ensure no significant harm) needs to be at the upper end of this range, and the burden of action to restore largely intact land should be placed on those with the greatest responsibility for damaging biodiversity and the greatest capabilities, and based on inclusive conservation.129 A 15% restoration is adequate if focused on the most biodiverse regions, where even a smaller percentage of restoration effort can yield substantial biodiversity benefits; however, these regions could have high opportunity costs because they might be valuable for other economic activities, such as agriculture or urban development. Therefore, restoration efforts are also needed in less biodiverse regions, where more restoration is necessary because such restoration is less efficient in terms of biodiversity benefits per unit of effort compared with the most biodiverse regions. Restoration efforts in less biodiverse regions will also ensure that wealthier regions contribute more to restoration efforts than poorer regions. Restoration areas need to be chosen carefully, and these decisions should account for the interests of the most vulnerable communities and densely populated areas where the risk of land conflict is high.130 The safe boundary for functional integrity contributes to interspecies justice through the high value of small patches and landscape elements for species conservation, but its exact contribution is uncertain and context dependent. This boundary targets intragenerational justice by ensuring universal access to NCP within a 1 km² spatial scale. It also enhances intergenerational justice by supporting agro-ecosystems and the func- tioning of urban systems, and by increasing ecosystem resilience against the effects of climate change on future NCP provisioning. Adherence to this ESB would reduce local food shortages, deaths caused by flooding and land- slides, and agricultural runoff, which would in turn have beneficial effects on water quality, human health, and infrastructure. However, adherence to the ESB could also put a heavy burden on the local people responsible for e824 www.thelancet.com/planetary-health Vol 8 October 2024 The Lancet Planetary Health Commission executing this goal, because ensuring functional integrity involves navigating complex ecological interactions and managing the direct impact of these interactions on local communities, while also addressing long-term sustainability challenges and balancing multiple envi- ronmental objectives. We propose that the just boundary for functional integrity is aligned with the safe boundary,10 but warn against increasing the burden of action on poor and marginalised people. There has been serious and accelerated loss of functional integrity across Europe, India, China, and the Americas over the past 50 years or so (figure 6A). Millions of people are exposed to this loss and associated impacts on NCP, such as pollination or watershed protection (figure 6B). In some cases, such losses are concentrated where poor people live (figure 6C). However, people far beyond the affected regions can also be harmed—for example, epidemics and loss of food security associated with loss of functional integrity in one region can exacerbate vulnerability in many other regions.132 There will be significant trade-offs regarding the current use of land and water in areas with low functional integrity that will require substantial transfor- mations. Although wealthier areas have higher capacity to tackle the problem, a degraded biosphere dispropor- tionately affects vulnerable people with low adaptive capacity,111 people who consume directly from local ecosystems,133 Indigenous people, and people who depend on natural medicines.120 About 1·2 billion people, or 30% of the population across tropical countries, directly depend on NCP.111 In such areas, meeting these stringent ESBs could benefit many people, but could also create injustice if people’s needs for basic food, fuel, and infrastructure are not taken into account. Strategies to protect or restore ecosystems should account for Figure 6: Exposure and vulnerability to loss of functional integrity (A) Biosphere functional integrity for terrestrial ecosystems combining natural and human-modified lands. Areas with <20–25% functional integrity are outside the Earth-system boundary.100,101 (B) Plot of functional integrity with population (0·25° resolution) as a proxy of exposure to loss of nature’s contribution to people. Each colour break represents the intersection of both distributions using quartiles. Values of population are log transformed. (C) Plot of functional integrity with poverty (a proxy of vulnerability). Poverty is measured as the proportion of people at the second level administrative unit who live under the US$1·90 poverty line as of 2018 (data source: World Bank 2021131). The proportions were calculated in a log-transformed population, with 0·1, 2·0, 30·0 reflecting the 25%, 50%, and 75% quantiles of the poverty distribution respectively. (D) The 15 countries with the highest absolute population living with <20% functional integrity. (E) The 15 countries with the largest relative population living with <20% functional integrity. A D B C 0 0·25 0·50 0·75 1·00 Functional integrity 0 2 7 9 20 0 0·395 0·806 0·998 1·000 Functional integrity Po pu la tio n (lo g) 0 0·2 0·4 0·6 1·0 0 0·1 2·0 30·0 100 Poverty rate (%) M ea n in te gr ity India China Pakistan Egypt Nigeria USA Japan Iran Mexico Russia Iraq Türkiye Morocco Thailand Indonesia Qatar Kuwait Egypt Syria United Arab Emirates Iraq Pakistan Moldova Romania Armenia Saudi Arabia Tunisia Jordan Morocco Cyprus 0 500000000 1000000000 People living with <20% functional integrity E 0 25 50 75 100 Population (%) www.thelancet.com/planetary-health Vol 8 October 2024 e825 The Lancet Planetary Health Commission justice concerns and people’s wellbeing to minimise trade-offs between biodiversity conservation and the fulfilment of basic human needs.126 Climate Global warming threatens the stability of the Earth system and the lives and livelihoods of present and future generations.3,134 Extreme temperatures cause millions of deaths every year, and heat-related mortality is rising.135 Droughts and floods affect crop production and drinking water worldwide, and livelihoods and food security have been lost in coastal communities as a result of warming oceans and loss of coral reefs. Vector-borne and water-borne diseases, such as dengue fever, malaria, and cholera, are a particular risk for poor and marginal- ised people and those in places with weak health systems.3 WHO estimates that climate change will cause 250 000 additional deaths every year between 2030 and 2050134 due to malnutrition, malaria, diarrhoea, and heat stress. These estimates might be underesti- mates. Springmann and colleagues project that there could be as many as 529 000 premature adult deaths by 2050 due to food shortages alone.136 Increasing carbon dioxide concentrations could reduce the nutritional value of cereal crops and protein availability by 20% during the coming century.137,138 Safe ESB Anthropogenic emission of greenhouse gases (predom- inantly carbon dioxide and methane) has caused global surface temperatures to increase by at least 1·1°C rela- tive to pre-industrial global mean temperatures.139 This increase is already having observable negative effects on people and ecosystems, with much more severe impacts likely to manifest with increases of 2°C or higher.3 How much global warming and climate change affect current and future generations depends on choices made within the coming decades.140 To avoid the potential negative impacts, the 2015 Paris Agreement set out to limit global warming to “well below 2°C”, while aiming for warming of no more than 1·5°C.141 However, current policies are projected to lead to warming of around 2·6°C by 2100, and even ambitious net-zero targets, if actually achieved, are likely to lead to around 1·9–2·0°C of warming by 2100.142 Recent extreme weather, such as 2023’s record-breaking temperatures across multiple regions, the South Asian heatwave of 2022, and the North American heatwaves in 2021, also call into question whether current limits are in fact safe. The Earth Commission set the safe climate ESB at 1·5°C (1–2°C) of warming but suggested that the just limit should be lower: 1°C.10 The safe limit was drawn from an analysis16 based primarily on the notion that the likelihood of passing multiple climate tipping points would become moderate with 1°C of warming and high with 1·5°C warming; the analysis also incorporated Earth-system impacts unrelated to tipping points that affect biosphere functioning (eg, some areas that absorb some human carbon dioxide emissions— natural carbon sinks—absorb less when warming is higher than 1°C and are projected to start emitting carbon dioxide when warming increases beyond 1·5°C),143–148 the average temperature range of the Holocene (with temperatures not increasing above 0·5–1°C relative to the pre-industrial period during the past 12 000 years or so), and the temperature range of previous interglacial periods (<1·5–2·1°C).149–153 The safe ESB also aligns with the IPCC’s reasons for concern—which include increasing risks to endangered species and unique systems, damages from extreme climate events, effects that fall most heavily on low- income countries and the poor within countries, global aggregate impacts, and large-scale high-impact events—several of which become high risk or very high risk beyond 1·5°C.140,154 By integrating this state-of-the art knowledge on climate tipping elements with the IPCC assessments and incorporating the role of the cryo- sphere in Earth-system stability, the resulting ESBs closely reflect previous assessments of climate risk, with a boundary of a 1·5°C increase purported to be substantially safer for the biosphere (eg, avoiding extinctions) than a 2°C increase,143 and the range of 1°C–2°C reflecting climate limits proposed since 1990.155 Figure 7 shows the spatial distribution of key climate tipping elements proposed by Armstrong McKay and colleagues.16 Although some of the impacts of passing climate tipping points would be global (eg, rising sea levels resulting from the collapse of ice sheets, carbon release from forest dieback or permafrost thaw leading to amplified global warming), others would be felt primarily locally (eg, coral ecosystem collapse, extra-polar glacier loss reducing water supplies, loss of Amazon biocultural diversity). The climate system also has considerable inertia that varies among the subsystems, with the atmosphere exhibiting the least and the cryosphere the most.156 This characteristic of the climate system means that the greenhouse gas emissions that are driving climate change will continue to drive changes in the future on long time scales, even if emissions are substantially reduced.156 Adding further to the complexity is the strong spatial heterogeneity within these climate subsystems and their sub-components globally, which mean that global sums and averages of realised and committed changes can convey an exaggerated sense of security. For example, the planet does not warm uniformly, meaning that a global mean annual temper- ature increase of 1·5°C will result in larger temperature increases in polar regions and on land, with subsequent impacts on the biosphere. Committed change is of particular importance when considering climate tipping elements and their effective irreversibility. With e826 www.thelancet.com/planetary-health Vol 8 October 2024 The Lancet Planetary Health Commission the 2024 level of mean warming (around 1·2°C), some tipping point temperature thresholds could be breached, as is shown by examples of major long-term committed changes in ice sheets and the terrestrial biosphere from previous emissions (Winkelmann et al, unpublished). Figure 8 shows the difference in realised versus committed changes for land carbon and ice sheets for a fixed global warming level under a high emissions scenario in 2100 (specifically Representative Concentration Pathway [RCP] 8.5, a high-emissions climate-change scenario for future greenhouse gas concentrations used by the IPCC, which, in this experimental set-up, corre- sponded to an increase of around 4·7°C in global mean temperature compared with that in 1850–1900). Greenland and west Antarctica are committed to far more ice loss than is predicted to occur by 2100 (figure 8; with subse- quent implications for sea-level rise), and similarly local land carbon losses and gains become far more pronounced (Winkelmann et al, unpublished). Such committed changes in land carbon suggest that major changes in ecosystem distributions and processes might unfold with West Antarctic ice sheet East Antarctic subglacial basins Boreal permafrost Boreal permafrost Greenland ice sheet East Antarctic ice sheet Amazon rainforest Atlantic meridional overturning circulation Labrador Sea, Subpolar gyre convection Arctic winter sea ice Boreal permafrost Boreal forest Boreal forest Sahara and West African monsoon Boreal permafrost Extra-polar mountain glaciers Extra-polar mountain glaciers Extra-polar mountain glaciers Barents Sea ice Extra-polar mountain glaciers Low-latitude coral reefs Low-latitude coral reefs A B Figure 7: Map showing global core (A) and regional impact (B) climate tipping elements. Passing the tipping point of any element would lock-in negative ecological and societal impacts in the vicinity of the element in both (A) and (B), as well as on a global scale for those in (A). Reproduced from Armstrong McKay et al, 2022,16 with permission from the American Association for the Advancement of Science. www.thelancet.com/planetary-health Vol 8 October 2024 e827 The Lancet Planetary Health Commission substantial time lags. Furthermore, simulated land-carbon gains (Winkelmann et al, unpublished) hinge upon central assumptions of land-surface models (standalone or employed in Earth-system models), notably the strength of future carbon dioxide fertilisation of plants. By incorporating the latest data on regional and global land carbon sink saturation,146,157–160 we found that constraining carbon dioxide fertilisation rates to 2020 rates would lead to the global land turning from a carbon sink to a carbon source within the next 10–20 years, with substantial Figure 8: Directly realised (A) and potentially committed (B) in change of land carbon and ice thickness under RCP8.5 in 2100 RCP 8.5 is the Intergovernmental Panel on Climate Change representative concentration pathway in which emissions continue to rise through the 21st century. A global vegetation model and an ice sheet model were used for both (A) and (B); hatches represent areas where different simulations disagree qualitatively with the mean sign of change. Directly realised change refers to change in land carbon and ice thickness between 2020 and 2100. Committed change describes the change of land carbon and ice thickness between 2020 and 2100 with long-term equilibrium of the climate (ie, a constant climate and atmospheric carbon dioxide commitment; appendix p 12). Adapted from Rockström et al, 2023.10 A B Change in ice thickness (m) –2000 –1000–2500 –1500 –500 5000 Change in stored carbon (kg/m2) –4000 4000–2000 20000 e828 www.thelancet.com/planetary-health Vol 8 October 2024 The Lancet Planetary Health Commission carbon release projected from almost the entire global land surface (figure 8). These projections underline the need for stringent ESBs that account for the increased risks to intergenerational equity resulting from committed changes (figures 8, 9). Passing climate tipping points will similarly lock in many negative impacts over long time- scales, underlining the importance of the safe climate ESB. Just ESB The proposed safe ESB for climate change of no more than 1·5°C of warming meets the criteria for intraspecies justice in that, if adhered to, it would prevent climate tipping points from being passed and avoid many committed changes that could affect many habitats and people, and could also minimise degradation and vulnerability of other domains (eg, biosphere exposure to droughts, and water-resource constraints), helping advance interspecies justice. However, many species have already been harmed in terms of habitat loss with less than 1°C of warming.154 The safe 1·5°C ESB for climate does not address inter- generational justice. With a global temperature rise of 1·0°C, the committed rise in sea levels threatens places home to hundreds of millions of people, and 565 million people are exposed to at least 1 day a year with wet bulb temperatures (a measure of heat stress combining temperature and humidity) greater than 32°C (figure 9). The safe working time for outdoor activities declines substantially with wet bulb temperatures of greater than 32°C,162 while 35°C represents a limit of human physiological adaptability (although this limit could be several degrees lower).163,164 The risks posed by rising sea levels particularly affect populations living along low-lying coastal areas, island nations, coastal cities, and regions where poor people live in the lowest areas and might not receive storm warn- ings. Exposure within countries varies greatly, with low islands facing saltwater intrusion and storm damage, whereas Arctic Indigenous communities face existential risk to their lands, cultures and wellbeing from ice loss, permafrost melting, and rising sea levels.3 Vulnerability to rising sea levels can be reduced through warning systems, social support, and appropriate infrastructure, but there are limits to adaptation. Adherence to the safe climate ESB would also not provide intragenerational justice: 100 million people are already exposed to heat stress with global warming of 1·2°C—largely as a result of increases in wet bulb temperatures, especially in large cities where urban heat islands amplify exposure, and for people who cannot afford cooling and shade, lack access to water, are elderly or ill, or work outside.3,165 We thus set the just ESB at 1°C of warming or less, recognising that even at this level, hundreds of millions of people are negatively affected.154 Additionally, the risk of several harm-related IPCC reasons for concern (eg, unique threatened systems including Arctic Indigenous communities, Figure 9: Total population (A) and relative population (B) living on land exposed to potential future sea level rises The figure is based on 2010 populations and a temperature stabilisation of 2°C by 2100 for the top affected countries in (A). Both the potential impact by 2100 and the additional committed impact on a multi-century time scale are graphed. Adapted from Strauss et al, 2021.161 Marshall Islands Maldives Tokelau Netherlands Guyana Kiribati Bangladesh Thailand Northern Mariana Islands Guernsey Macau Bahamas Nauru Palau Suriname Micronesia Iraq Cayman Islands Gibraltar Cocos Islands Cook Islands Bonaire, Sint Eustatius, and Saba Bahrain China Bangladesh India Viet Nam Thailand Indonesia Philippines Netherlands Japan Egypt Iraq Myanmar Germany USA UK Malaysia Taiwan Brazil Mozambique North Korea South Korea Pakistan Nigeria 100806040200100 000 1 000 000 Population (2010) vulnerable to future sea level rises Proportion of population (2010) vulnerable to future sea level rises (%) 10 000 000 100 000 000 A B Multi-centennial timescale By 2100 www.thelancet.com/planetary-health Vol 8 October 2024 e829 The Lancet Planetary Health Commission extreme events, uneven impacts on vulnerable commu- nities, aggregate economic impacts) coming to pass becomes moderate or high with global warming within the 1·0–1·5°C range.140,154 We mapped the spatial distribution of harm by using rises in sea levels and extreme temperatures (both wet bulb temperatures and mean annual temperature [figures 10, 11]). Previous analyses made efforts to link future rises in sea levels to end-of-century temperature stabilisation targets,153,161,166 inferring impacts on decadal to multi-centennial timescales by taking into account committed change. A consistent way to illus trate the impact on populations at these timescales is to quantify the number of people inhabiting land today that will be exposed to inundation in the future. If popula- tions (as of 2010) were exposed to the impact of rising sea levels and its distribution across the most affected countries under a 2°C temperature stabilisation target in 2100, in absolute and relative terms, China, Bangladesh, India, and Viet Nam would have the highest number of people exposed to rising sea levels (figure 9), with coastal impacts having wider implications for economies. Figure 9B shows the projected distribution in 2100 of populations potentially affected by rising sea levels with global warming of 2°C. The Marshall Islands, the Maldives, Tuvalu, the Netherlands, and Guyana are Figure 10: Distribution of harm from wet bulb temperatures Scenarios of exposure to the maximum wet bulb temperature in a 1·2°C world (A) and 2°C world (B), with exposure approximated as the number of people living in countries affected by different levels of temperature. In (C) and (D) exposure is plotted against the proportion of people living in poverty (ie, below the US$1·90 poverty line as of 2018 [data source: World Bank 2021]),131 with poverty as a proxy of vulnerability. In (A), (B), (C), and (D), each colour break represents the intersection of both distributions using quartiles. (E) and (F) graph the countries with the highest total and relative population affected by high wet-bulb temperatures in a 1·2°C world, and (G) and (H) graph the countries with the highest total and relative population affected by high wet-bulb temperatures in a 2°C world. 0 6.9 10·0 13·0 17·0 4 9 20 30 40 Maximum wet bulb temperature (°C) Po pu la tio n (lo g) 0 6.9 10·0 13·0 17·0 2 9 20 30 40 Maximum wet bulb temperature (°C) Po pu la tio n (lo g) 12 27 28 30 38 0 0·1 2·0 30·0 100 Poverty rate (%) M ax im um w et bu lb te m pe ra tu re (° C) 12 27 29 31 37 0 0·1 2·0 30·0 100 Poverty rate (%) M ax im um w et bu lb te m pe ra tu re (° C) A B C D E G HF China India Pakistan DR Congo Sudan Nigeria Viet Nam Yemen Iran Saudi Arabia Niger Mali Afghanistan Ethiopia South Sudan Qatar United Arab Emirates Oman Central African Republic Pakistan Sudan DR Congo Yemen Viet Nam South Sudan Republic of the Congo Saudi Arabia Chad Niger Mali China India Pakistan Nigeria DR Congo Sudan Ethiopia Niger Viet Nam Yemen Mexico Mali Iran Chad Cameroon South Sudan Qatar United Arab Emirates Central African Republic Niger Yemen Chad Sudan Oman Pakistan Mali DR Congo Burkina Faso Eritrea Viet Nam 0 100 200 People exposed (millions) 0 50 7525 100 Proportion of population exposed (%) People exposed (millions) Proportion of population exposed (%) 0 100 300200 0 5025 75 100 e830 www.thelancet.com/planetary-health Vol 8 October 2024 The Lancet Planetary Health Commission five countries with much of their territory exposed to rising sea levels. Over the next 200–2000 years, high proportions of the populations of the Bahamas, Cocos (Keeling) Islands, and Suriname will be affected (assuming the 2010 population). Many regions are already facing extreme tempera- tures.3 Figure 10 shows maximum wet bulb temperatures for a scenario with 1·2°C and 2°C warming. The human climate niche167 describes the relationship between mean annual temperature, which has varied little for thousands of years, and relative human population density. For most of human history, human population density has been greatest in a rather narrow part of the available climate space in which mean annual temperature is roughly between 11°C and 15°C.167 Climate and demographic change can increasingly expose people to temperatures outside this human climate niche. The simplest way to quantify this increasing exposure to conditions outside of the niche is to assess who would be exposed to unprecedented mean annual temperatures higher than 29°C (figure 11). In absolute numbers, India will have the highest number of people exposed to mean annual temperatures higher than 29°C if global temperatures warm by 1·5°C. South Asia, southeast Asia, west Africa, and the Arabian Peninsula would have large areas of land with mean annual temperatures exceeding 29°C. Several western African countries (eg, Burkina Faso) could find most of their territory being pushed outside the human climate niche.168 Carbon budget estimates published in 2020 suggested that the most industrialised countries are responsible for 92% of global carbon dioxide emis- sions whereas the least industrialised countries are responsible for a much smaller fraction.169 These quanti- fications exemplify the unequal share of responsibility in terms of causing global warming—and, by extension responsibility for solving it—with implications for inter- generational and intragenerational justice. Nutrient cycles Nitrogen and phosphorus are essential macronutrients for plants—and thus for food production. Excess nutrient inputs and limited waste recycling result in substantial negative effects on the health of people and ecosystems. Many regions in Europe, North America, and Asia are well beyond proposed safe limits, while many regions in low-income and middle-income countries (LMICs) do not have sufficient fertiliser to ensure that food produc- tion meets people’s needs. Safe ESB for nitrogen Nitrogen is essential for crop production. Excess input not taken up by crops (ie, nitrogen surplus) can pollute terrestrial ecosystems, freshwater, groundwater, and drinking water via eutrophication, leading to substantial environmental damage.170–174 Agriculture is the primary source of freshwater nitrogen pollution (accounting for around 75%), followed by domestic sources including sewage (23%) and industrial sources (2%).175 In the ocean, excess nitrogen has led to a more than nine-times increase in hypoxic coastal sites since 1950, with complex effects on fisheries.176 To avoid significant harm to ecosystems and people, we set a global safe nitrogen ESB of 61 TgN per year of agricultural surplus from all sources (corresponding to total nitrogen inputs of 143 TgN per year at current nitrogen use efficiencies).10 This safe ESB was based on an analysis published after the early planetary boundary quantifications,7,9,177 in which regional environmental thresholds for two environmental systems (nitrogen runoff to surface water of around 2·5 mg nitrogen per L, and nitrogen emissions and deposition to terres- trial ecosystems of 5–20 kg nitrogen per hectare per year, depending on biome) were identified and associated critical losses, surpluses, and inputs were calculated regionally before aggregation to a global value.172–174 Figure 11: Spatial distribution of harm from mean annual temperature >29°C in a 1·5°C world (A) and countries with the highest absolute population (B) and relative population (C) exposed to these mean annual temperatures Po pu la tio n (lo g) >29°C 29 >29<29 0 7 20 India Thailand Sudan Nigeria Niger Burkina Faso Mali Saudi Arabia Chad Colombia Cambodia Yemen Ghana United Arab Emirates Indonesia 0 20 40 60 80 People exposed (millions) 0 0·5 1·0 1·5 Proportion of population exposed (%) Dominican Republic Djibouti United Arab Emirates Burkina Faso Niger Sudan Mali Thailand Chad Mauritania Somalia Saudi Arabia Oman Guinea Ghana A B C www.thelancet.com/planetary-health Vol 8 October 2024 e831 The Lancet Planetary Health Commission Just ESB for nitrogen The safe ESB for nitrogen seeks to reduce environ- mental degradation and effects on human wellbeing as a result of loss of ecosystem services (eg, fisheries). Our justice analysis suggests that the adherence to the safe nitrogen ESB could contribute to achieving interspecies justice by limiting ecosystem degradation of surface water and terrestrial ecosystems. However, as well as avoiding future tipping points, intergenerational and intragenerational justice require active restoration of already degraded ecosystems caused by past nitrogen pollution. Nitrogen pollution also directly harms human health. Exposure to high concentrations of nitrates and nitrite in drinking water—which some of the world’s most vulner- able populations have to deal with178—can cause infant methaemoglobinaemia, and is connected to adverse reproductive effects, colorectal cancer, and thyroid disease.179 Excess agricultural nitrogen usage from manure and synthetic fertilisers leads to emissions of nitrogen oxides, and nitrogen dioxide pollution from all sources is linked with around 4 million new cases of paediatric asthma a year.180 Fine particulate matter with a diameter of less than 2·5 µm (PM2·5) of agricultural origin, largely derived from ammonia, contributes roughly 20% of the approximately 3·3 million deaths per year associated with PM2·5.181 The safe ESB thus needs to be complemented with locally applicable health standards for nitrogen to set the just ESB. For water, we used the threshold from WHO’s standards for drinking water quality of 50 mg nitrate per L (ie, equivalent to 11·3 mg nitrogen per L).182 When applied to nitrate leaching to groundwater as a third environmental system threshold, this globally amounts to a safe surplus limit of 117 TgN per year, but in surface water it is less stringent than the safe threshold of roughly 2·5 mg nitrogen per L.172–174 Incorporation of this standard for groundwater would reduce the sub- global critical nitrogen surplus in some regions (figure 12) and slightly lower the global safe and just ESB to 57 TgN per year (134 TgN per year in total inputs).10,172 Local standards for nitrogen with regard to air quality are not directly included in our analysis of safe and just ESBs for nitrogen but are incorporated in the proposed just ESB for air pollution (discussed later in this Part), in which concentrations of PM2·5 are used as a comprehen- sive indicator. Figure 12 shows the spatial variation in where esti- mated critical nitrogen surplus is exceeded on agricultural lands as of 2010.172 We use these data as a proxy for the potential harm caused by nitrogen pollu- tion, because, to our knowledge, global limits for the direct and indirect effects of nitrogen pollution on human health and wellbeing have not yet been suffi- ciently quantified. Excess nitrogen surplus is highest in China, south and west Asia, Europe, and North America, and mostly associated with intensive agriculture, whereas concentrations of nitrogen are below the critical limit across most of sub-Saharan Africa, Latin America, and southeast Asia (figure 12), where farmers tend to have insufficient access to fertilisers. Figure 13 depicts the distribution of nitrogen pollu- tion impacts as of 2010 relative to population distribution and poverty (as a proxy for vulnerability to harm from exposure to nitrogen pollution). This figure shows exposure to local nitrogen pollution only. It does Figure 12: Map depicting the spatial variation in excess nitrogen surplus Nitrogen surplus is calculated with respect to nitrogen runoff to surface water, emissions, and deposition to terrestrial ecosystems, and nitrate leaching to groundwater. Nitrogen surplus is used as a proxy for potential harm caused by nitrogen pollution. Data for current nitrogen surplus on agricultural land (ie, arable and intensively managed grassland; measured in kg per Ha per year) are from the IMAGE model.183 For each grid cell, the critical nitrogen surplus (from Schulte-Uebbing et al, 2022)172 was subtracted from the current (2010) nitrogen surplus. Current surplus–critical limit (kg per Ha per year) <–100 −100 to <−50 −50 to <0 0 to <50 50 to <100 ≥100 Not applicable e832 www.thelancet.com/planetary-health Vol 8 October 2024 The Lancet Planetary Health Commission not take into account how pollution also causes harm when transported downstream into shared lakes and oceans or downwind, and thus underestimates true vulnerability to nitrogen pollution. Neither does figure 13 take into account access to nitrogen fertilisers. Unsafe nitrogen surpluses coincide with high popula- tion exposure in China, South Asia, eastern USA, and Europe, and with increased poverty in South Asia, parts of China, and hotspots in central and west Asia. By contrast, areas where nitrogen concentrations are within safe limits and so where nitrogen fertiliser usage could increase include areas of poverty across much of sub-Saharan Africa, northern Latin America, and southeast Asia. Although fertiliser overuse causes interspecies, intra- generational, and intergenerational harm, the biggest challenge related to nutrients and human health is insuf- ficient access to nutrients needed for food security in many regions. For example, much of sub-Saharan Africa does not have access to sufficient and affordable fertilisers to maximise potential agricultural output, contributing to a yield gap.185,186 Intragenerational justice requires more equitable access to nutrients to close large yield gaps in LMICs and to avoid the offshoring of nutrient depletion or pollution from wealthier countries via trade. Production of ammonia for synthetic nitrogen fertilisers is heavily dependent on fossil fuels, and is responsible for roughly 2% of global greenhouse gas emissions.187 Minimising the use of synthetic nitrogen fertiliser could therefore cont