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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.

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

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.

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.

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.

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.

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 ...

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

In the Anthropocene, social processes have become critical to understanding planetary-scale Earth system dynamics. The conceptual foundations of Earth system modelling have externalised social processes in ways that now hinder progress in understanding Earth resilience and informing governance of global environmental change. New approaches to global modelling are needed to address these challenges, but the current modelling landscape is highly diverse and heterogeneous, ranging from purely biophysical Earth System Models, to hybrid macro-economic Integrated Assessments Models, to a plethora of models of socio-cultural dynamics. World-Earth models, currently not yet available, will need to integrate all these elements, so future World-Earth modellers require a structured approach to identify, classify, select, and combine model components. Here, we develop taxonomies for ordering the multitude of societal and biophysical subsystems and their interactions. We suggest three taxa for modelled subsystems: (i) biophysical, where dynamics is usually represented by natural laws of physics, chemistry or ecology (i.e., the usual components of Earth system models), (ii) socio-cultural, dominated by processes of human behaviour, decision making and collective social dynamics (e.g., politics, institutions, social networks), and (iii) socio-metabolic, dealing with the material interactions of social and biophysical subsystems (e.g., human bodies, natural resource and agriculture). We show how higher-order taxonomies for interactions between two or more subsystems can be derived, highlighting the kinds of social-ecological feedback loops where new modelling efforts need to be directed. As an example, we apply the taxonomy to a stylised World-Earth system model of socially transmitted discount rates in a greenhouse gas emissions game to illustrate the effects of social-ecological feedback loops that are usually not considered in current modelling efforts. The proposed taxonomy can contribute to guiding the design and operational development of more comprehensive World-Earth models for understanding Earth resilience and charting sustainability transitions within planetary boundaries and other future trajectories in the Anthropocene.

Coherently addressing the 17 Sustainable Development Goals requires planning tools that guide policy makers. Given the integrative nature of the SDGs, we believe that integrative modelling techniques are especially useful for this purpose. In this paper, we present and demonstrate the use of the new System Dynamics based iSDG family of models. We use a national model for Tanzania to analyse impacts of substantial investments in photovoltaic capacity. Our focus is on the impacts on three SDGs: SDG 3 on healthy lives and well-being, SDG 4 on education, and SDG 7 on energy. In our simulations, the investments in photovoltaics positively affect life expectancy, years of schooling and access to electricity. More importantly, the progress on these dimensions synergizes and leads to broader system-wide impacts. While this one national example illustrates the anticipated impact of an intervention in one specific area on several SDGs, the iSDG model can be used to support similar analyses for policies related to all the 17 SDGs, both individually and concurrently. We believe that integrated models such as the iSDG model can bring interlinks to the forefront and facilitate a shift to a discussion on development grounded in systems thinking.

We discuss the role of expert modelling in sustainability using a framework designed to improve the effectiveness of the modelling process. Based on the development of a set of reflective questions that can be used at certain key stages in the lifecycle of projects developing such models, we discuss how using the framework would lead to improvements in the coupling of the process of expert modelling with the process of intervention, which is implied by the existence of the expert modelling project. This questioning pushes the development of a framework beyond considerations of ontology and epistemology into issues of axiology and praxis; extending the notion of contested modelling beyond the narrow scientific sense to a wider social setting. Our framework has been developed through a case study analysis of the effectiveness of four research initiatives that have used expert modelling to address the complexity of intervention in a sustainability context. Copyright © 2014 John Wiley & Sons, Ltd.

There is a need for more integrated research on sustainable development and global environmental change. In this paper, we focus on the planetary boundaries framework to provide a systematic categorization of key research questions in relation to avoiding severe global environmental degradation. The four categories of key questions are those that relate to (1) the underlying processes and selection of key indicators for planetary boundaries, (2) understanding the impacts of environmental pressure and connections between different types of impacts, (3) better understanding of different response strategies to avoid further degradation, and (4) the available instruments to implement such strategies. Clearly, different categories of scientific disciplines and associated model types exist that can accommodate answering these questions. We identify the strength and weaknesses of different research areas in relation to the question categories, focusing specifically on different types of models. We discuss that more interdisciplinary research is need to increase our understanding by better linking human drivers and social and biophysical impacts. This requires better collaboration between relevant disciplines (associated with the model types), either by exchanging information or by fully linking or integrating them. As fully integrated models can become too complex, the appropriate type of model (the racehorse) should be applied for answering the target research question (the race course).

A transition to a decentralised, decarbonised energy system for the domestic sector is constrained by the difficulty of obtaining energy balance between fluctuating demand and the intermittent, non-dispatchable power supply delivered by most renewables. A microgrid system including a mix of renewable generation technologies, energy storage and demand response (DR) systems has been modelled using a linear programming approach, based on real world data of residential energy consumption and weather variables. This model allows the exploration of the effects of fluctuations in demand and supply, microgrid scale and configuration, energy management options and alternative optimisation criteria. The model demonstrates quantitatively that a mixed-renewables microgrid system can reduce demand fluctuations and improve energy balance. Peak demand hour fluctuations were reduced by up to 19% for a simulated microgrid containing 144 households with one renewable unit and four batteries per household, with a renewables mix of 83% photovoltaic (PV) panels and 17% wind turbines. With this system, the demand on macrogrid energy supply was reduced by 16%, CO2 emissions associated with energy use were reduced by 10% for all hours of operation, and by 74% during the hours of renewable supply. These findings suggest that microgrids using contemporary technologies can contribute significantly to CO2 mitigation targets.

The Integrated History and future of People on Earth (IHOPE) initiative is a global network of researchers and research projects with its International Program Office (IPO) now based at the Stockho ...

The organic component of atmospheric reactive nitrogen plays a role in biogeochemical cycles, climate and ecosystems. Although its deposition has long been known to be quantitatively significant, it is not routinely assessed in deposition studies and monitoring programmes. Excluding this fraction, typically 25-35%, introduces significant uncertainty in the determination of nitrogen deposition, with implications for the critical loads approach. The last decade of rainwater studies substantially expands the worldwide dataset, giving enough global coverage for specific hypotheses to be considered about the distribution, composition, sources and effects of organic-nitrogen deposition. This data collation and meta-analysis highlights knowledge gaps, suggesting where data-gathering efforts and process studies should be focused. New analytical techniques allow long-standing conjectures about the nature and sources of organic N to be investigated, with tantalising indications of the interplay between natural and anthropogenic sources, and between the nitrogen and carbon cycles.

This review considers the ways in which atmospheric organic nitrogen has been measured and linked to potential sources. Organic N exists in gas, particle and dissolved phases and represents a large (ca. 30%) fraction of total airborne nitrogen, but with large variability in time and space. Although some components (e.g. amines) have been the subject of several studies, little information is available for the many other components of organic N that have been identified in individual measurements. Measurements of organic N in precipitation have been made for many decades, but both sampling and chemical analytical methods have changed, resulting in data that are not directly comparable. Nevertheless, it is clear that organic N is ubiquitous and chemically complex. We discuss some of the issues which have inhibited the widespread adoption of organic N as a routine analyte in atmospheric sampling, and identify current best practice. Correlation analysis is the most widely used technique for attributing likely sources, examining the co-variation in time and/or space of organic N with other components of precipitation or particulate matter, yet the shortcomings of such simple approaches are rarely recognised. Novel measurement techniques which can identify, if not yet quantify, many of the components of particulate or dissolved organic N greatly enhance the data richness, thereby permitting powerful statistical analyses of co-variation such as factor analysis, to be employed. However, these techniques also have their limitations, and whilst specific questions about the origin and fate of particular components of atmospheric organic N may now be addressed, attempts to quantify and attribute the whole suite of materials that comprise atmospheric organic N to their sources is still a distant goal. Recommendations are made as to the steps that need to be taken if a consistent and systematic approach in identifying and quantifying atmospheric organic N is to progress. Only once sources have been recognised can any necessary control measures to mitigate adverse effects of atmospheric organic N on human health or ecosystem function be determined.

Complex Earth system models, and their various sub-components, are not yet subject to rigorous evaluation against observations as much as they should be, despite the existence of hundreds of proposed diagnostics. A concerted process is urgently needed to make this the norm, not the exception. Earth Observation, field observations and palaeo data can be applied to contexts as diverse as wildfire, marine ecosystems, the land carbon cycle, and greenhouse gases. Model evaluation (by comparing models and benchmark data) and model weighting (defining the ‘quality’ of models on the basis of such a comparison) should be considered as separate issues. Systematic approaches to parameter optimization, such as the adjoint technique, allow structural differences between models to be identified and limitations to be addressed. Such methods are established in atmospheric tracer transport and carbon cycling; research carried out in the QUEST programme has demonstrated their applicability for climate modelling. Although it is impossible to devise a foolproof metric for the ability of models to predict the future, relevant metrics could be based on their ability to simulate the past. Furthermore, it should be possible to extend parameter optimization techniques to assimilate data from the past. There are limits to what can be achieved by benchmarking against a mean state, when it is a change in state that is of greatest interest. It is useful to benchmark individual processes rather than aggregate properties. Coupling good components does not automatically result in a good Earth System model, so for complex models, a two-stage process is needed: first, benchmarking the components in stand-alone mode, and second, using the same benchmarks in coupled mode.

Contemporary increases in atmospheric carbon dioxide concentration are in large part the result of anthropogenic carbon dioxide emissions from fossil fuel combustion. Scenario analysis is commonly used to generate projections of future carbon dioxide emissions, the resulting atmospheric concentrations and climate impact. In most scenario modelling published to date, carbon dioxide emission scenarios are based on demand-side (socioeconomic and technology) factors. The fossil fuel resource is assumed ample enough that supply-side factors do not drive future emission scenarios. This review of the literature on non-renewable resource extraction rate modelling and empirical studies of the global fossil fuel resource base suggests this assumption is unsafe. Supply-side factors can be expected to drive extraction rates and therefore carbon dioxide emissions as fossil fuel resources become significantly depleted. It is likely that the future carbon dioxide emission trajectory will become dominated by supply-side factors during the 21st century. By omitting this possibility, most scenario analysis is too narrow. An implication of such narrow scenario analysis is that policy driven by the UNFCCC‟s agreement to “avoid dangerous climate change” targets only demand-side factors to the exclusion of supply-side factors. As supply-side factors come to drive the carbon dioxide emission trajectory, policy focus should switch from demand-side factors to supply-side factors.

The concept of ecosystem services is proliferating rapidly in research and policy world- wide and holds strong appeal as a bridging concept between the natural world and society. In apply- ing the concept, we should remain alert to some 'health warnings' from previous experience in envi- ronmental economics. (1) The ecosystem services concept involves a narrowing of focus onto the money value of ecosystems. Researchers and practitioners should reflect on past efforts in integrative benefits analysis. (2) There can be a conceptual disconnection of value from function, particularly when there is a reliance on benefits transfer, yet the value of ecosystem services is conditional on a well-functioning whole ecosystem. (3) The problem of data paucity is stark. While inadequate data and the resulting uncertainty are ubiquitous problems in environmental decision-making, the pow- erful simplicity of one number—the estimated monetary value of a given ecosystem service—may mean that more nuanced precautionary considerations that normally apply in uncertain contexts are bypassed. New challenges arise because values (determined in the past) are applied to a changing and already resource-depleted world. Here I highlight the non-stationary nature of trends, the extent to which models are trusted and its role in uncertainty and risk, and the need for in-depth interdisci- plinary study. Some organisations have already entered into these meta-debates; examples are the joint Environment Agency/Quantifying and Understanding the Earth System (EA/QUEST) project on uplands and the Economic and Social Research Council-Natural Environment Research Council (ESRC-NERC) interdisciplinary workshop series in the UK, and, internationally, the Ecosystem Services Partnership. It is important that this debate is maintained and extended.

Increasing quantities of atmospheric anthropogenic fixed nitrogen entering the open ocean could account for up to about a third of the ocean's external (nonrecycled) nitrogen supply and up to ∼3% of the annual new marine biological production, ∼0.3 petagram of carbon per year. This input could account for the production of up to ∼1.6 teragrams of nitrous oxide (N 2 O) per year. Although ∼10% of the ocean's drawdown of atmospheric anthropogenic carbon dioxide may result from this atmospheric nitrogen fertilization, leading to a decrease in radiative forcing, up to about two-thirds of this amount may be offset by the increase in N 2 O emissions. The effects of increasing atmospheric nitrogen deposition are expected to continue to grow in the future.

Crossing the boundaries in global sustainability The planetary boundary (PB) concept, introduced in 2009, aimed to define the environmental limits within which humanity can safely operate. This approach has proved influential in global sustainability policy development. Steffen et al. provide an updated and extended analysis of the PB framework. Of the original nine proposed boundaries, they identify three (including climate change) that might push the Earth system into a new state if crossed and that also have a pervasive influence on the remaining boundaries. They also develop the PB framework so that it can be applied usefully in a regional context. Science , this issue 10.1126/science.1259855