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Individuals with posttraumatic stress disorder (PTSD) may use cannabis to reduce symptoms yet are also at risk for developing problematic use. This review outlines theories, summarizes recent empirical studies, and discusses clinical implications of cannabis use and PTSD recovery.Although naturalistic studies and open trials find a relationship between cannabinoids and PTSD symptom reduction, methodological limitations preclude definitive conclusions. The only randomized controlled trial to date found cannabis had no greater effect on PTSD symptoms than placebo.Rigorous studies of the long-term impact of cannabis use on PTSD recovery are needed. Clinicians and researchers must weigh the potential therapeutic effect against the costs and risks associated with long-term cannabis use. Clinicians should consider all available PTSD treatment options, along with client level factors such as the function of cannabis use, motivation to change use, and the potential impact of cannabis on treatment engagement when making clinical recommendations.

In this Matters Arising, we respond to a recent article by Bachmann et al.1 We argue that dealing with plastics pollution as a novel entity within the planetary boundaries framework needs to consider the entirety of the plastics life cycle, from resource extraction to impacts on earth system processes. Singling out LCA quantifications to set a boundary for recycling plastics is not only an unviable myth but may be a dangerous approach. Bachmann et al.1 argue that it is possible to maintain business as usual and move the economy ‘towards circular plastics’ while staying within planetary boundaries. The authors’ solutions rest on poorly operationalized terms and unrealistic estimates, which over-state what technological solutions can achieve and risk locking the world into an even more plastic-intensive future. We see major flaws in their baseline assumptions and aim to better define and contextualize plastics pollution within Earth systems.

A 3-year IUPAC project Systems Thinking in Chemistry for Sustainability: Toward 2030 and Beyond (STCS 2030+, IUPAC Project #2020-014-3-050) [1] launched in late 2020 is breaking important new ground in addressing chemistry’s orientations, roles, and responsibilities in the 21st Century and helping to map out implications for chemistry education, research, and practice. In taking on this ambitious task, STCS 2030+ draws on expertise available within IUPAC’s own structures, as a project co-sponsored by three IUPAC standing committees: the Committee on Chemistry Education (CCE), the Committee on Chemistry and Industry (COCI) and the Interdivisional Committee on Green Chemistry for Sustainable Development (ICGCSD). The project is also working with other organizations, such as the International Organization for Chemical Sciences in Development (IOCD), which is a co-supporter, and involves collaborators with individuals from organizations that include the Stockholm Resilience Centre [2], the American Chemical Society (ACS) Green Chemistry Institute [3], the International Year of Basic Sciences for Sustainable Development (IYBSSD 2022-23) [4], and chemistry educators and chemical industry from around the world.

To explore participant experiences of an online co-design process to develop a web-based preventative mental health and well-being intervention targeting primary producers in rural Australia.Rural Victoria, Australia.Participants from a primary producer background, including horticulture, fisheries, animal cultivation and farm consultancy, were eligible for the study if they had participated in both the co-design and beta testing processes for a primary producer platform.A qualitative study using semi-structured phone-based interviews was undertaken. A reflexive inductive approach to data analysis was employed to develop themes.Eleven participants were interviewed, with an average age of 51 years, of which 7 were female. Five main themes were developed. These included: (1) participant diversity, (2) impact of online delivery on co-design participation, (3) experiences of the co-design process, (4) maintaining a shared vision and goals and (5) acting on the co-design recommendations. Use of online methods was a clear enabler to engage participants who were geographically dispersed and offers an alternative to more conventional approaches to co-design using face-to-face methods. Some aspects of participant engagement may need a greater focus when conducted online compared with face-to-face.Using an online co-design method to develop a preventative mental health and well-being web-based platform for primary producers was novel. Findings address a gap in the literature around the experience of participants engaging in a co-design process and identify opportunities to improve participant engagement and experience with the online format.

Kunnas has written a comment (1) on our recently published policy analysis of whether humanity is currently outside the planetary boundary for novel entities. (2) We welcome continued scientific discussion, and we note that Kunnas supports our overall conclusion that the world is now outside the Safe Operating Space in terms of novel entities. We see support for our line of argument in Kunnas’ statement that there is a need to reduce the influx of new chemical substances and other novel entities, such as plastics, until societies can deal with the backlog of substances on the market that have not been subject to risk or safety assessment and consequent sound management.Kunnas points out, and we agree, that we do not show where a quantitative boundary for novel entities is. In our view, quantifying a single boundary for the multitude and diversity of novel entities is an intractable problem. As such, we have as a first step rather characterized a multidimensional dynamic boundary. This characterization lets us evaluate several control variables that indicate that the planetary boundary has been crossed: the paper demonstrates how novel entities have resulted in many globally observed biological, chemical, and geophysical changes that move the planet away from Holocene conditions. The characterization is precautionary (in both the lay and policy senses), recognizing that when threats are serious or irreversible, the fact that risks are uncertain and cannot be quantified should not mean that measures to prevent harm can be postponed. It is also pragmatically aligned with other principles of environmental responsibility and intergenerational equity, and plain old-fashioned prevention of large-scale environmental damage. With this characterization of the planetary boundary for novel entities, we recommend that operational guardrails for novel entities can and should be defined starting with the approaches available, as illustrated in our paper, (2) and evolve as scientific evidence increases and additional biophysical issues emerge.We understand the wishes and needs by many to quantify the impacts of individual novel entities (and combinations), particularly under many current regulatory frameworks. Many approaches are being explored; for example, Kosnik et al. (3) explains that evaluating chemical pollution pressure on ecosystems and related capacities to cope with this pressure requires the consideration of appropriate spatiotemporal scales. Spatial units such as watersheds or catchments, come with their own (local) boundary where anthropogenic disturbance changes system functioning. This means that a simple spatial aggregation is not an appropriate way to derive a global boundary. (3) We agree with Kunnas that it is important to consider differences across novel entities in terms of their effects, environmental behavior, and other properties, but we also clearly note the lack of data that currently prevents such a comprehensive analysis for most novel entities.Kunnas also brings up the crucial point of what should be the minimum components of a risk assessment that takes the planetary boundary perspective into account, stating that “toxicity and persistence is not enough to rule out unintended consequences”. As we discuss in the paper, the planetary boundary framework recognizes that novel entities have the potential to create effects on end points that go beyond toxicity and direct human and ecosystem health impacts. Ozone layer thinning and ongoing climate change are both examples of end points in the realm of the geophysical processes of the planet with far-reaching consequences for humans and all other life on the planet. Therefore, chemical risk assessments need to include aspects of relevance for the planetary boundary threat they might cause, a planetary boundary profiling. (4,5)Finally, we wish to respond to Kunnas’ suggestion that ”the long-run goal should be to eliminate the Novel entities category altogether”. This may well be where the discussion shifts from defining a planetary boundary to a matter of societal self-constraint. In our paper, we are not calling for zero production of novel entities. As long as there is technologically enabled innovation, individual novel entities and combinations will arise, and a novel-entities category is likely to be a vitally important part of the planetary boundaries’ framework to keep novel entities and their impacts under monitoring. When an issue becomes a “known known”, as in the case of the role of CFCs in the breaching of the ozone depletion boundary, it shifts into the domain of management and harm mitigation. Until then, the novel-entities category provides an important call to action that recognizes the complex and dynamic planetary dimensions of chemical pollution.In conclusion, we would like to again emphasize that the current rapidly increasing rate of production and releases of larger volumes and higher numbers of novel entities with diverse risk potentials far exceed societies’ ability to conduct safety-related assessments as well as to monitor and soundly manage novel entities as a whole. Recognizing that the planet Earth has finite carrying capacities for novel entities and their diverse impacts, we again call on leaders of policymaking, business, and civil societies to take urgent action to reduce the harm associated with exceeding the boundary by reducing the production and releases of novel entities.

Climate tipping points occur when change in a part of the climate system becomes self-perpetuating beyond a forcing threshold, leading to abrupt and/or irreversible impacts. Synthesizing paleoclimate, observational, and model-based studies, we provide a revised shortlist of global ‘core’ tipping elements and regional ‘impact’ tipping elements and their temperature thresholds. Current global warming of ~1.1°C above pre-industrial already lies within the lower end of some tipping point uncertainty ranges. Several more tipping points may be triggered in the Paris Agreement range of 1.5-2°C global warming, with many more likely at the 2-3°C of warming expected on current policy trajectories. In further work we use these estimates to test the potential for and impact of tipping cascades in response to global warming scenarios using a stylised model. This strengthens the evidence base for urgent action to mitigate climate change and to develop improved tipping point risk assessment, early warning capability, and adaptation strategies.Preprint: https://doi.org/10.1002/essoar.10509769.1

We submit that the safe operating space of the planetary boundary of novel entities is exceeded since annual production and releases are increasing at a pace that outstrips the global capacity for assessment and monitoring. The novel entities boundary in the planetary boundaries framework refers to entities that are novel in a geological sense and that could have large-scale impacts that threaten the integrity of Earth system processes. We review the scientific literature relevant to quantifying the boundary for novel entities and highlight plastic pollution as a particular aspect of high concern. An impact pathway from production of novel entities to impacts on Earth system processes is presented. We define and apply three criteria for assessment of the suitability of control variables for the boundary: feasibility, relevance, and comprehensiveness. We propose several complementary control variables to capture the complexity of this boundary, while acknowledging major data limitations. We conclude that humanity is currently operating outside the planetary boundary based on the weight-of-evidence for several of these control variables. The increasing rate of production and releases of larger volumes and higher numbers of novel entities with diverse risk potentials exceed societies’ ability to conduct safety related assessments and monitoring. We recommend taking urgent action to reduce the harm associated with exceeding the boundary by reducing the production and releases of novel entities, noting that even so, the persistence of many novel entities and/or their associated effects will continue to pose a threat., Environmental Science & Technology, 56 (3), ISSN:0013-936X, ISSN:1520-5851

Plastics are novel entities that have exceeded the planetary safe operating space due to extensive and resource-intensive production, uncontrolled environmental releases, and failure to control the chemicals within the materials. This paper examines evidence and discusses how plastics pollution affects Earth-system processes along the impact pathway from production, to release, to environmental fate and impacts of plastics and their additives. Multiple lines of evidence are necessary to capture the complex reality of these substances and attempts to quantify a singular boundary would be detrimental to the global governance of plastics. We demonstrate causal links between plastics and other major environmental problems at the global scale, exacerbating the consequences of breaching other planetary boundaries, especially climate change and biodiversity loss. We propose ways to translate these assessments into control variables for the globally and biophysically defined planetary boundaries framework that can be utilized to tackle plastics pollution. Efforts should be oriented towards further developing and monitoring a set of control variables that describe the actual state of the system along the impact pathway. We call for experts and policymakers to take urgent action, considering plastics pollution not only as a waste management problem but as an integrative part of climate change, biodiversity and natural resource use policy.

Quality infrastructure plays a key role in sustainable development. Achieving a harmonious relationship between humanity and nature requires better measurement, monitoring and management of environmental processes, from local to global scales. Human-caused climate change, biodiversity loss, perturbation of Earth’s biogeochemical cycles, and chemical pollution are global environmental processes where unsustainability has become evident. This report describes issues in the quality infrastructure for these processes.

Cities are vital for achieving the Sustainable Development Goals (SDG), but different local strategies to advance on the same SDG may cause different ‘spillovers’ elsewhere. Research efforts that support governance of such spillovers are urgently needed to empower ambitious cities to ‘account globally’ when acting locally on SDG implementation strategies.

The fashion and textiles industry, and policymakers at all levels, are showing an increased interest in the concept of circular economy as a way to decrease business risks and negative environmental impacts. However, focus is placed mainly on the material ‘stuff’ of textile fashion and its biophysical harms. The current material focus has several shortcomings, because fashion is a social-ecological system and cannot be understood merely by addressing its environmental dimensions. In this paper, we rethink the fashion system from a critical social-ecological perspective. The driver-state-response framework shows social drivers and ecological impacts as an adaptive social-ecological system, exposing how these interacting aspects need to be addressed for sustainable and resilient implementation of circular economy. We show how current responses to global sustainability challenges have so far fallen short. Our overall aim is to expand possibilities for reframing responses that better reflect the complex links between the global fashion system, culture and creativity and the dynamics of the living planet. We argue that reducing planetary pressure from the global fashion and textiles industry requires greater recognition of the system’s social drivers with more emphasis on the many cross-scale links between social and ecological dimensions. Resilient decisions aiming for sustainable circularity of the fashion industry must therefore pay attention to social activities beyond the industry value chain, not just material flows within it. Funding: Open access funding provided by Stockholm University. The work presented here was part of a consortium research project between Stockholm Resilience Centre and the Ellen MacArthur Foundation, initiated and funded by H&M Group, the Swedish public limited company. Celinda Palm, Sarah Cornell and Tiina Häyhä’s employment was part-funded through this project.

Green water - soil moisture, evaporation, and precipitation over land - is fundamental to safeguard Earth system functioning. Nonlinear green-water driven changes in climate, ecosystems, biogeochemistry, and hydrology are becoming increasingly evident and widespread. Yet, considerations of continental to planetary scale green-water dynamics are yet to be assessed and incorporated in management and governance. Here, we propose a green water planetary boundary (PB) - as part of the planetary boundary framework that demarcates a global “safe-operating space” for humanity - for assessing green-water related changes that can affect the capacity of the Earth system to remain in Holocene-like conditions. We consider green-water related processes associated with all scales: spatially distributed units, regions or biomes, and the Earth system as a whole. The proposed green water PB variable is selected through expert elicitation based on a set of transparent evaluation criteria that consider both scientific and governability aspects. Finally, we clarify the appropriate use of a green water PB, outline remaining challenges, and propose a research agenda for future navigation and quantitative assessments of the biophysical Earth system scale boundaries of green water changes.

Analysis of Earth system dynamics in the Anthropocene requires explicitly taking into account the increasing magnitude of processes operating in human societies, their cultures, economies and technosphere and their growing feedback entanglement with those in the physical, chemical and biological systems of the planet. However, current state-of-the-art Earth system models do not represent dynamic human societies and their feedback interactions with the biogeophysical Earth system and macroeconomic integrated assessment models typically do so only with limited scope. This paper (i) proposes design principles for constructing world–Earth models (WEMs) for Earth system analysis of the Anthropocene, i.e., models of social (world)–ecological (Earth) coevolution on up to planetary scales, and (ii) presents the copan:CORE open simulation modeling framework for developing, composing and analyzing such WEMs based on the proposed principles. The framework provides a modular structure to flexibly construct and study WEMs. These can contain biophysical (e.g., carbon cycle dynamics), socio-metabolic or economic (e.g., economic growth or energy system changes), and sociocultural processes (e.g., voting on climate policies or changing social norms) and their feedback interactions, and they are based on elementary entity types, e.g., grid cells and social systems. Thereby, copan:CORE enables the epistemic flexibility needed for contributions towards Earth system analysis of the Anthropocene given the large diversity of competing theories and methodologies used for describing socio-metabolic or economic and sociocultural processes in the Earth system by various fields and schools of thought. To illustrate the capabilities of the framework, we present an exemplary and highly stylized WEM implemented in copan:CORE that illustrates how endogenizing sociocultural processes and feedbacks such as voting on climate policies based on socially learned environmental awareness could fundamentally change macroscopic model outcomes. References Donges, J.F. et al.: Taxonomies for structuring models for World-Earth system analysis of the Anthropocene: subsystems, their interactions and social-ecological feedback loops, Earth Syst. Dynam. Disc., in review (2021), DOI: 10.5194/esd-2018-27. Donges, J. F. and Heitzig,et al..: Earth system modeling with endogenous and dynamic human societies: the copan:CORE open World–Earth modeling framework, Earth Syst. Dynam., 11, 395–413, 2020.

While environmental science, and ecology in particular, is working to provide better understanding to base sustainable decisions on, the way scientific understanding is developed can at times be detrimental to this cause. Locked-in debates are often unnecessarily polarized and can compromise any common goals of the opposing camps. The present paper is inspired by a resolved debate from an unrelated field of psychology where Nobel laureate David Kahneman and Garry Klein turned what seemed to be a locked-in debate into a constructive process for their fields. The present paper is also motivated by previous discourses regarding the role of thresholds in natural systems for management and governance, but its scope of analysis targets the scientific process within complex social-ecological systems in general. We identified five features of environmental science that appear to predispose for locked-in debates: 1) The strongly context dependent behaviour of ecological systems. 2) The dominant role of single hypothesis testing. 3) The high prominence given to theory demonstration compared investigation. 4) The effect of urgent demands to inform and steer policy. This fertile ground is further cultivated by human psychological aspects as well as the structure of funding and publication systems.

Linking knowledge with action for effective societal responses to persistent problems of unsustainability requires transformed, more open knowledge systems. Drawing on a broad range of academic and practitioner experience, we outline a vision for the coordination and organization of knowledge systems that are better suited to the complex challenges of sustainability than the ones currently in place. This transformation includes inter alia: societal agenda setting, collective problem framing, a plurality of perspectives, integrative research processes, new norms for handling dissent and controversy, better treatment of uncertainty and of diversity of values, extended peer review, broader and more transparent metrics for evaluation, effective dialog processes, and stakeholder participation. We set out institutional and individual roadmaps for achieving this vision, calling for well-designed, properly resourced, longitudinal, international learning programs., Environmental Science & Policy, 28, ISSN:1462-9011, ISSN:1873-6416

Direct electrical stimulation of the brain is the gold standard technique used to define functional-anatomical relationships during neurosurgical procedures. Areas that respond to stimulation are considered “critical nodes” of circuits that must remain intact for the subject to maintain the ability to perform certain functions, like moving and speaking. Despite its routine use, the neurophysiology underlying downstream motor responses to electrical stimulation of the brain, such as muscle contraction or movement arrest, is poorly understood. Furthermore, varying and sometimes counterintuitive responses can be seen depending on how and where the stimulation is applied, even within the human primary motor cortex. Therefore, here we review relevant neuroanatomy of the human motor system, provide a brief historical perspective on electrical brain stimulation, explore mechanistic variations in stimulation applications, examine neurophysiological properties of different parts of the motor system, and suggest areas of future research that can promote a better understanding of the interaction between electrical stimulation of the brain and its function.

Earth system science (ESS) has identified worrying trends in the human impact on fundamental planetary systems. In this conceptual article, we discuss the implications of this research for business schools and management education (ME). We argue that ESS findings raise significant concerns about the relationship between business and nature and, consequently, a radical reframing is required to embed economic and social activity within the global sustainability of natural systems. This has transformative implications for ME. To illustrate this reframing, we apply the ESS lenses of social-ecological interdependence, multiscalar relations, environmental governance, and environmental values to the ME functional domains of institutional purpose, social context and engagement, pedagogical practice, curricular design, and research focus. Our work contributes to the literature on business education for sustainability and the business-society-nature nexus. We explore and apply key ESS findings and concepts, discuss normative implications of these ideas, and offer guidance on transformational pathways for business schools and ME.

Science is increasingly able to identify precautionary boundaries for critical Earth system processes, and the business world provides societies with important means for adaptive responses to global environmental risks. In turn, investors provide vital leverage on companies. Here, we report on our transdisciplinary science/business experience in applying the planetary boundaries framework (sensu Rockström et al., Ecol Soc 14, 2009) to define a boundary-compatible investment universe and analyse the environmental compatibility of companies. We translate the planetary boundaries into limits for resource use and emissions per unit of economic value creation, using indicators from the Carnegie Mellon University EIO‑LCA database. The resulting precautionary 'economic intensities' can be compared with the current levels of companies' environmental impact. This necessarily involves simplifying assumptions, for which dialogue between biophysical science, corporate sustainability and investment perspectives is needed. The simplifications mean that our translation is transparent from both biophysical and financial viewpoints, and allow our approach to be responsive to future developments in scientific insights about planetary boundaries. Our approach enables both sub‑industries and individual companies to be screened against the planetary boundaries. Our preliminary application of this screening to the entire background universe of all investable stock‑listed companies gives a selectivity of two orders of magnitude for an investment universe of environmentally attractive stocks. We discuss implications for an expanded role of environmental change science in the development of thematic equity funds.

Global change and governance scholars frequently highlight polycentricity as a feature of resilient governance, but both theoretical and empirical knowledge about features and outcomes of the concept are lacking at the global scale. Here we investigate the structural properties of governance of global nitrogen (N) and phosphorus (P) cycles, two processes in the ‘planetary boundaries’ framework. We have used a mixed-methods approach to institutional analysis, integrating polycentric theory with social network theory in environmental policy and legal studies. We include an actor collaboration case study, the Global Partnership on Nutrient Management (GPNM), to explore governance challenges associated with global N and P cycles. We set the scope for selection of relevant legal instruments using an overview of global N and P flows between Earth system ‘components’ (land, water, atmosphere, oceans, biosphere) and the major anthropogenic N and P perturbations. Our network analysis of citations of global N and P governance exposes the structural patterns of a loose network among the principal institutions and actors, in which legal instruments of the European Union serve as key cross-scale and cross-sectoral ‘gateways’. We show that the current international regimes in place for regulating N- and P-related issues represent a gap in governance at the global level. In addition, we are able to show that the emergence of GPNM provides synergies in this context of insufficient governance. The GPNM can be viewed as a structure of polycentric governance as it involves deliberate attempts for mutual adjustments and self-organised action.

Human activities are disrupting the Earth system's biophysical processes, which underlie human wellbeing. The planetary boundary framework sets 'safe' global limits on these pressures, but a sub-gl ...

International commitment to the appropriately ambitious Paris climate agreement and the United Nations Sustainable Development Goals in 2015 has pulled into the limelight the urgent need for major scientific progress in understanding and modelling the Anthropocene, the tightly intertwined social-environmental planetary system that humanity now inhabits. The Anthropocene qualitatively differs from previous eras in Earth’s history in three key characteristics: (1) There is planetary-scale human agency. (2) There are social and economic networks of teleconnections spanning the globe. (3) It is dominated by planetary-scale social-ecological feedbacks. Bolting together old concepts and methodologies cannot be an adequate approach to describing this new geological era. Instead, we need a new paradigm in Earth System science that is founded equally on a deep understanding of the physical and biological Earth System – and of the economic, social and cultural forces that are now an intrinsic part of it. It is time...

The planetary boundaries framework defines nine Earth system processes that together demarcate a safe operating space for humanity at the planetary scale. Freshwater - the bloodstream of the biosphere - is an obvious member of the planetary boundary framework. Water fluxes and stores play a key role for the stability of the Earth’s climate and the world’s aquatic and terrestrial ecosystems. Recent work has proposed to represent the water planetary boundary through six sub-boundaries based on the five primary water stores, i.e., atmospheric water, soil moisture, surface water, groundwater, and frozen water. In order to make it usable on all spatial scales we examine bottom-up and top-down approaches for quantification of the water planetary boundary. For the bottom-up approaches, we explore possible spatially distributed variables defining each of the proposed sub-boundaries, as well as possible weighting factors and keystone regions that can be used for aggregation of the distributed water sub-boundaries to the global scale. For the top-down approaches, we re-examine the stability of key biomes and tipping elements in the Earth System that may be crucially influenced by water cycle modifications. To identify the most appropriate variables for representing the water planetary boundary, we evaluate the range of explored variables with regard to scientific evidence and scientific representation using a hierarchy-based evaluation framework. Finally, we compare the highest ranked top-down and bottom-up approaches in terms of the scientific outcome and implications for governance. In sum, this comprehensive and systematic identification and evaluation of variables, weighting factors, and baseline conditions provides a detailed basis for the future operational quantification of the water planetary boundary.

Over the past 15 years climate tipping points have emerged as both an important research topic and source of public concern. Some articles have suggested that some tipping points could begin within the 1.5-2oC Paris climate target range, with many more potentially starting by the ~3-4oC of warming that current policy is projected to be committed to. Recent work has also proposed that these tipping points could interact and potentially ‘cascade’ – with the impacts of passing one tipping point being sufficient to trigger the next and so on – resulting in an emergent global tipping point for a long-term commitment to a ‘Hothouse Earth’ trajectory of 4+oC (Steffen et al., 2018). However, much of the recent discussion relies largely on a decade-old characterisation of climate tipping points, based on a literature review and expert elicitation exercise. An updated characterisation would fully utilise more recent results from coupled and offline models, model inter-comparisons, and palaeoclimate studies. The ‘tipping cascade’ hypothesis has also not yet been tested, with the suggestion of 2oC as the global tipping point remaining speculative. Furthermore, the definition of what counts as a climate tipping point is often inconsistent, with some purported tipping points represented more accurately as threshold-free positive feedbacks. Here we perform an updated systematic review of climate tipping points, cataloguing the current evidence for each suggested element with reference to rigorously-applied tipping point definitions. Based on this we test the potential for a global tipping cascade using a stylised model, from which we will present preliminary results.ReferencesSteffen, W., et al.: Trajectories of the Earth System in the Anthropocene, Proc. Natl. Acad. Sci., 115(33), 8252–8259, doi:10.1073/pnas.1810141115, 2018.

The planetary boundaries framework has proven useful for many global sustainability contexts, but is challenging to apply to freshwater, which is spatially heterogeneous, part of complex socio-ecological systems and often dominated by local dynamics. To date, the planetary boundary for water has been simplistically defined by as the global rate of blue water consumption, functioning as a proxy for water partitioning in the global hydrological cycle, and considering impacts on rivers’ environmental flow requirements. We suggest the current planetary boundary should be replaced since it does not adequately represent the influence of water in critical Earth System functions such as regional climate and biodiversity. We review the core functions of water in the Earth System and set out a roadmap towards a more robust, holistic, and locally applicable water planetary boundary. We propose defining the boundary using four core functions of water (hydroclimatic regulation, hydroecological regulation, storage, and transport) in conjunction with five water stores (surface water, atmospheric water, soil moisture, groundwater and frozen water). Through the functions, the stores are inextricably interconnected with the atmosphere, land, ocean and biosphere. The roadmap outlined here suggests how to move towards setting six new water planetary sub-boundaries. This ambitious scientific and policy Grand Challenge that could substantially improve our understanding and management of water cycle modifications in the Earth System and provide a complementary approach to existing water management tools.

This paper explores the United Nations’ Sustainable Development Goals (SDGs) in the context of EU action to promote the contribution of business to sustainability. Using the planetary boundaries and the ‘safe and just space’ framework , this paper interrogates what a research-based multidimensional concept of sustainability means for the implementation of the SDGs. We start out with what it means to be operating within the limits of our planet. Moving on to the concept of securing social foundations for humanity now and for the future within planetary boundaries, we discuss what this entails in terms of social justice, touching on a number of issues that do not seem to have been sufficiently integrated in the SDGs and EU’s follow-up. We then explore risks of continued unsustainability, with a particular focus on business. We further discuss EU initiatives to promote sustainable business. We summarise the gaps the paper has identified, in research, both conceptually and applied, in policy, and in strategies for achieving sustainability, concluding with reflections on the unprecedented collaboration across and beyond academia that would be required to implement the SDGs in a manner that ensures sustainability.

We present the results of an extensive review of studies applying integrated food metrics to assess the health and environmental impacts of food, as well as of studies advancing definitions of the components and boundaries of healthy and sustainable food systems and diet. We review the literature in seven identified categories: assessments of health and environmental impacts of common diets, assessments of the environmental implications of shifting to healthier diets and vice-versa, optimization studies, assessments of the effect of following dietary quality indices on the environment, model diets and guiding frameworks, metrics frameworks for integrated food system impact assessments, and metrics frameworks for integrated dietary impact assessments. We critically discuss the approaches to metrics selection, the nature of metrics, the scale at which they operate, data sources, analytical methods, and target audiences. We conclude that there is a need for more holistic and systematic approaches to defining metrics of healthy and environmentally sustainable diets. Based on identified gaps, we propose a set of 10 criteria to guide the development of more integrated and systematic food metrics for human and environmental health in the future.

Increased efforts are required to prevent further losses to terrestrial biodiversity and the ecosystem services that it provides1,2. Ambitious targets have been proposed, such as reversing the declining trends in biodiversity3; however, just feeding the growing human population will make this a challenge4. Here we use an ensemble of land-use and biodiversity models to assess whether—and how—humanity can reverse the declines in terrestrial biodiversity caused by habitat conversion, which is a major threat to biodiversity5. We show that immediate efforts, consistent with the broader sustainability agenda but of unprecedented ambition and coordination, could enable the provision of food for the growing human population while reversing the global terrestrial biodiversity trends caused by habitat conversion. If we decide to increase the extent of land under conservation management, restore degraded land and generalize landscape-level conservation planning, biodiversity trends from habitat conversion could become positive by the mid-twenty-first century on average across models (confidence interval, 2042–2061), but this was not the case for all models. Food prices could increase and, on average across models, almost half (confidence interval, 34–50%) of the future biodiversity losses could not be avoided. However, additionally tackling the drivers of land-use change could avoid conflict with affordable food provision and reduces the environmental effects of the food-provision system. Through further sustainable intensification and trade, reduced food waste and more plant-based human diets, more than two thirds of future biodiversity losses are avoided and the biodiversity trends from habitat conversion are reversed by 2050 for almost all of the models. Although limiting further loss will remain challenging in several biodiversity-rich regions, and other threats—such as climate change—must be addressed to truly reverse the declines in biodiversity, our results show that ambitious conservation efforts and food system transformation are central to an effective post-2020 biodiversity strategy. To promote the recovery of the currently declining global trends in terrestrial biodiversity, increases in both the extent of land under conservation management and the sustainability of the global food system from farm to fork are required.

Non-technical abstract Individual organisms on land and in the ocean sequester massive amounts of the carbon emitted into the atmosphere by humans. Yet the role of ecosystems as a whole in modulating this uptake of carbon is less clear. Here, we study several different mechanisms by which climate change and ecosystems could interact. We show that climate change could cause changes in ecosystems that reduce their capacity to take up carbon, further accelerating climate change. More research on – and better governance of – interactions between climate change and ecosystems is urgently required.

Near-term gains on socio-economic goals under the 2030 Agenda could reduce the Earth system ‘safety margin’ represented by the nine planetary boundaries. We built an intentionally simple global systems simulation model, Earth3, that combines a socio-economic model of human activity with a biophysical model of the global environment. Earth3 fills a key gap in the family of integrated models, by being capable of simulating the complex dynamic implementation challenge of the full 2030 Agenda. Earth3 generates consistent, transparent pathways from 1980 to 2050 for seven world regions. With these pathways, we assess the extent to which the 14 socio-economic SDGs are achieved and quantify the associated pressure on planetary boundaries to calculate endogenously the extent to which the three environmental SDGs are achieved. Sensitivity analysis indicates uncertainty of the order of ±20% in the number of SDGs achieved and in the biophysical safety margin. The Business-as-Usual scenario indicates that the social and environmental SDGs cannot be achieved together, nor within the planetary boundaries. Combined with an index tracking effects on people’s wellbeing and with simple formulations that keep assumptions transparent, Earth3 can help identify and communicate policies that could improve the global sustainability situation.

Machine learning methods tend to outperform traditional statistical models at prediction. In the prediction of academic achievement, ML models have not shown substantial improvement over logistic regression. So far, these results have almost entirely focused on college achievement, due to the availability of administrative datasets, and have contained relatively small sample sizes by ML standards. In this article we apply popular machine learning models to a large dataset ($n=1.2$ million) containing primary and middle school performance on a standardized test given annually to Australian students. We show that machine learning models do not outperform logistic regression for detecting students who will perform in the `below standard' band of achievement upon sitting their next test, even in a large-$n$ setting., 15 pages, 2 tables, 6 figures. Note that previous versions of this paper contained an error in our codes. The error has been rectified and the paper substantially rewritten