As the science of transformation of matter, chemistry provides knowledge, innovation and practice that are fundamental to the current efforts to achieve sustainability in the face of challenges that include multiple environmental crises (including pollution, climate change and biodiversity loss) and looming shortages of ‘critical’ materials. This article presents the case for chemistry and the chemical sciences adopting material stewardship as a central mission, whose aim is to transform and use the Earth's available stock of material resources in ways consistent with ensuring sustainability for people and for the physical and biological systems of the planet on which all life depends. The implications of this mission are examined, including for chemistry's contributions to extending knowledge, processes and products required for stewarding the Earth's physical and biological materials and systems. The mission includes supporting energy transitions necessary to stabilise Earth systems that are increasingly perturbed by anthropogenic effects. An overview is presented of how chemistry's mission of material stewardship interconnects with sustainability frameworks providing broad principles and goals, including the UN's Sustainable Development Goals and the Planetary Boundaries and Human Security frameworks, as well as with specific chemistry movements and orientations (including green, sustainable, circular and one-world chemistry) and enabling tools (e.g. systems thinking, material circularity and life cycle assessment) that provide guiding concepts, pathways and capacities for chemistry's contributions towards sustainability. The utility of the material stewardship mission is exemplified through three case studies, related to a product type, a sustainability tool, and a sustainability movement. The need is emphasised for the chemistry profession to work across disciplines to help shape policy and practice towards a sustainable future. This includes engaging with others in the processes of negotiation that shape global agreements on goals, policies and programmes that impact on sustainability. Critical ones currently in progress include the efforts to find mechanisms to reduce greenhouse gas emissions to limit global warming to the UN's target of not more than 1.5 °C above pre-industrial levels by 2050, and to establish a UN Science-Policy Panel on chemicals.

The planetary boundaries framework defines a safe operating space for humanity. To date, these boundaries have mostly been investigated separately, and it is unclear whether breaching one boundary can lead to the transgression of another. By employing a dynamic global vegetation model, we systematically simulate the strength and direction of the effects of different transgression levels of the climate change boundary (using climate output from ten phase 6 of the Coupled Model Intercomparison Project models for CO₂ levels ranging from 350 ppm to 1000 ppm). We focus on climate change-induced shifts of Earth's major forest biomes, the control variable for the land-system change boundary, both by the end of this century and, to account for the long-term legacy effect, by the end of the millennium. Our simulations show that while staying within the 350 ppm climate change boundary co-stabilizes the land-system change boundary, breaching it (>450 ppm) leads to critical transgression of the latter, with greater severity the higher the ppm level rises and the more time passes. Specifically, this involves a poleward treeline shift, boreal forest dieback (nearly completely within its current area under extreme climate scenarios), competitive expansion of temperate forest into today's boreal zone, and a slight tropical forest extension. These interacting changes also affect other planetary boundaries (freshwater change and biosphere integrity) and provide feedback to the climate change boundary itself. Our quantitative process-based study highlights the need for interactions to be studied for a systemic operationalization of the planetary boundaries framework.

Plastics are an international governance priority because of extensive and resource-intensive production, uncontrolled environmental releases, and failure to control the chemicals within the materials. We examine the evidence that plastics have exceeded the planetary safe operating space, discussing how plastics pollution affects multiple Earth system processes along the impact pathway from resource extraction and production to release to environmental fate and impacts. Multiple lines of evidence capture the complex reality of these novel entities; a single planetary boundary quantification would be detrimental. We demonstrate causal links between plastics and other environmental problems, exacerbating the consequences of breaching other planetary boundaries. We propose biophysically defined control variables for the planetary boundaries framework as a way to measure, monitor, and mitigate global plastics pollution. We call for urgent action, recognizing plastics pollution not only as a waste management problem but as an integrative part of climate change, biodiversity, and natural-resource-use policy.

Socio-political factors in Integrated Assessment Models (IAMs), and their scenario narratives often lack transparency for policymakers and interdisciplinary scholars. As these tools increasingly support sustainable development goals, their assumptions and methodologies require scrutiny, particularly from social scientists. We address critiques of climate isolationism, overemphasis on technological transitions, and insufficient inter- and transdisciplinarity, advocating for robust interdisciplinary integration and clearer methodological transparency. Our recommendations stem from expert interviews and over 200 stakeholders across 30 countries from 2019 to 2024, emphasizing the need for cohesive theory and comprehensive social science engagement to refine these critical tools. Our main case study uses a new scenario set, the Sustainable Development Pathways (SDPs), that made substantial efforts to address social sciences critiques. The SDPs consist of both narratives and IAM-quantified target-seeking scenarios that are supported by social science concepts and theories to ensure not only theoretical coherence, but also their credibility among policymakers. As such tools are increasingly used to facilitate policies and actions for sustainability transformation, questions are raised about how they can effectively represent the complexities behind the current polycrisis that is marked by the climate crisis, biodiversity loss, economic inequality and social injustice. The paper concludes by reflecting on the remaining challenges and open questions related to the role of exogenous sociopolitical factors, the potential for scenarios to transcend political ideologies, and the need for ongoing adaptation of SDPs to reflect the dynamic global context. It calls for continued engagement and exploration of these issues to ensure the scientific representation of sustainable and equitable futures.

Operating within safe and just Earth system boundaries requires mobilizing key actors across scale to set targets and take actions accordingly. Robust, transparent and fair cross-scale translation methods are essential to help navigate through the multiple steps of scientific and normative judgements in translation, with clear awareness of associated assumptions, bias and uncertainties. Here, through literature review and expert elicitation, we identify commonly used sharing approaches, illustrate ten principles of translation and present a protocol involving key building blocks and control steps in translation. We pay particular attention to businesses and cities, two understudied but critical actors to bring on board.

Interactions of global change science, business and policymakers play a crucial role in shaping today’s regulatory frameworks for corporate sustainability. Our research question is why sustainability might actually be undermined by the ways that some prominent interfaces are informing corporate sustainability. Concentrating on ‘science-based’ initiatives that prescribe quantitative target-setting, business-driven task forces that define frameworks for businesses to assess and disclose information on strategies and targets, and the European Union (EU) as a supranational policymaking power, we scrutinise concepts, debates and developments involving these three globally influential non-state actors. Although the conceptualisation of sustainability as a safe and just space is well established in academic and policy contexts, key premises are being lost in translation at science–business–policy interfaces, delaying or actually deflecting regulation of business. We call for science–business–policy interfaces to conceptualise corporate sustainability as business contributing to mitigating planetary biophysical pressures and securing social foundations worldwide. In this context, we argue that the research basis for ‘safe and just’ cannot be reduced to simplistic and separate quantifications. Treating global sustainability goals as an itemised checklist for business action, and using scientifically narrow and overly reductive approaches to quantification and target-setting, fall short of this systemic understanding of corporate sustainability. The recognition of risks of unsustainability and the desire for sustainable value creation can act as drivers for change. Paradoxically, today’s business concept of ‘sustainable value’ actually undermines the potential for transformations to sustainability, and the dominant finance-driven treatment of ‘sustainability risks’ fall far short of capturing the hazards of continued unsustainabilities. In examining what the EU is actually doing, we find that the EU’s unprecedented attempts at regulating business for sustainability are being thwarted through powerful lobby interests, the outcomes of the science–business–policy interface, and the EU’s own fixation on economic growth and finance. Sustainability involves dealing justly with today’s unsafe conditions, and dealing safely with unjust conditions. This requires radically more innovative responses from business, truly sustainability-oriented adaptive leadership from policymakers, and critically reflexive transdisciplinary engagement by a much wider range of sustainability scholars.

While chemicals are vital to modern society through materials, agriculture, textiles, new technology, medicines, and consumer goods, their use is not without risks. Unfortunately, our resources seem inadequate to address the breadth of chemical challenges to the environment and human health. Therefore, it is important we use our intelligence and knowledge wisely to prepare for what lies ahead. The present study used a Delphi-style approach to horizon-scan future chemical threats that need to be considered in the setting of chemicals and environmental policy, which involved a multidisciplinary, multisectoral, and multinational panel of 25 scientists and practitioners (mainly from the United Kingdom, Europe, and other industrialized nations) in a three-stage process. Fifteen issues were shortlisted (from a nominated list of 48), considered by the panel to hold global relevance. The issues span from the need for new chemical manufacturing (including transitioning to non-fossil-fuel feedstocks); challenges from novel materials, food imports, landfills, and tire wear; and opportunities from artificial intelligence, greater data transparency, and the weight-of-evidence approach. The 15 issues can be divided into three classes: new perspectives on historic but insufficiently appreciated chemicals/issues, new or relatively new products and their associated industries, and thinking through approaches we can use to meet these challenges. Chemicals are one threat among many that influence the environment and human health, and interlinkages with wider issues such as climate change and how we mitigate these were clear in this exercise. The horizon scan highlights the value of thinking broadly and consulting widely, considering systems approaches to ensure that interventions appreciate synergies and avoid harmful trade-offs in other areas. We recommend further collaboration between researchers, industry, regulators, and policymakers to perform horizon scanning to inform policymaking, to develop our ability to meet these challenges, and especially to extend the approach to consider also concerns from countries with developing economies.

Chemistry needs to play a central role in achieving ‘net zero’ emissions of greenhouse gases (GHGs) into the atmosphere to prevent changes to the climate that will have catastrophic impacts for humanity and for many ecosystems on the planet. International action to limit global warming to 1.5 °C has framed as a key goal the reduction of global emissions to as close to zero as possible by 2050, with any remaining emissions re-absorbed from the atmosphere. Chemistry underpins innovative approaches to reducing emission of the key GHGs, comprising CO₂, CH₄, N₂O and fluorinated gases, and to the recapture of gases already in the atmosphere. Rapid progress is needed in the application of green and sustainable chemistry and material circularity principles in developing these approaches worldwide. Of critical importance will be the incorporation of systems thinking, recognition of planetary boundaries that define safe operating spaces for Earth systems, and an overall reorientation of chemistry towards its roles in stewardship of the Earth's material resources and in sustainability for people and the planet.

This planetary boundaries framework update finds that six of the nine boundaries are transgressed, suggesting that Earth is now well outside of the safe operating space for humanity. Ocean acidification is close to being breached, while aerosol loading regionally exceeds the boundary. Stratospheric ozone levels have slightly recovered. The transgression level has increased for all boundaries earlier identified as overstepped. As primary production drives Earth system biosphere functions, human appropriation of net primary production is proposed as a control variable for functional biosphere integrity. This boundary is also transgressed. Earth system modeling of different levels of the transgression of the climate and land system change boundaries illustrates that these anthropogenic impacts on Earth system must be considered in a systemic context.

Science-Based Targets (SBTs) are being developed for companies to contribute to global sustainability goals, including for ‘nature’. The literature has not yet explored multiple understandings of SBTs. We adopt an interpretive approach, using Q methodology to explore framings of SBTs amongst 22 scientists and practitioners engaged in SBT development. Results show two distinct framings: ‘we need science-based targets to help economic systems move towards global sustainability’ and ‘the system itself is unsustainable and needs to change – science-based targets can help’, with areas of agreement and disagreement. They lean towards reformist or radical discourse, at times weaving them together. What kinds of ‘transformation’, if any, are SBTs capable of driving? Conceptualising SBTs as a boundary object, we suggest that sustainability transformations involve paradoxical tensions, including where actors appeal to the powerful to drive change, but this inhibits the most radical discourses. We conclude with potential implications for sustainability science and governance.