Human societies are changing where and how water flows through the atmosphere. However, these changes in the atmospheric water cycle are not being managed, nor is there any real sense of where these changes might be headed in the future. Thus, we develop a new economic theory of atmospheric water management, and explore this theory using creative story-based scenarios. These scenarios reveal surprising possibilities for the future of atmospheric water management, ranging from a stock market for transpiration to on-demand weather. We discuss these story-based futures in the context of research and policy priorities in the present day.

Humanity is modifying the atmospheric water cycle, via land use, climate change, air pollution, and weather modification. Historically, atmospheric water was implicitly considered a ‘public good’ since it was neither actively consumed nor controlled. However, given anthropogenic changes, atmospheric water can become a ‘common-pool’ good (consumable) or a ‘club’ good (controllable). Moreover, advancements in weather modification presage water becoming a ‘private’ good, meaning both consumable and controllable. Given the implications, we designed a theoretical framing of atmospheric water as an economic good and used a combination of methods in order to explore possible future scenarios based on human modifications of the atmospheric water cycle. First, a systematic literature search of scholarly abstracts was used in a computational text analysis. Second, the output of the text analysis was matched to different parts of an existing economic goods framework. Then, a group of global water experts were trained and developed story-based scenarios. The resultant scenarios serve as creative investigations of the future of human modification of the atmospheric water cycle. We discuss how the scenarios can enhance anticipatory capacity in the context of both future research frontiers and potential policy pathways including transboundary governance, finance, and resource management.

Story-based scenarios reveal novel future pathways for the management of the atmospheric water cycle.

Multiple global crises – including the pandemic, climate change, and Russia's war on Ukraine – have recently linked together in ways that are significant in scope, devastating in effect, but poorly understood. A growing number of scholars and policymakers characterize the situation as a ‘polycrisis’. Yet this neologism remains poorly defined. We provide the concept with a substantive definition, highlight its value-added in comparison to related concepts, and develop a theoretical framework to explain the causal mechanisms currently entangling many of the world's crises. In this framework, a global crisis arises when one or more fast-moving trigger events combine with slow-moving stresses to push a global system out of its established equilibrium and into a volatile and harmful state of disequilibrium. We then identify three causal pathways – common stresses, domino effects, and inter-systemic feedbacks – that can connect multiple global systems to produce synchronized crises. Drawing on current examples, we show that the polycrisis concept is a valuable tool for understanding ongoing crises, generating actionable insights, and opening avenues for future research.

The term ‘polycrisis’ appears with growing frequently to capture the interconnections between global crises, but the word lacks substantive content. In this article, we convert it from an empty buzzword into a conceptual framework and research program that enables us to better understand the causal linkages between contemporary crises. We draw upon the intersection of climate change, the covid-19 pandemic, and Russia's war in Ukraine to illustrate these causal interconnections and explore key features of the world's present polycrisis.

Multiple global crises – including the pandemic, climate change, and Russia's war on Ukraine – have recently linked together in ways that are significant in scope, devastating in effect, but poorly understood. A growing number of scholars and policymakers characterize the situation as a ‘polycrisis’. Yet this neologism remains poorly defined. We provide the concept with a substantive definition, highlight its value-added in comparison to related concepts, and develop a theoretical framework to explain the causal mechanisms currently entangling many of the world's crises. In this framework, a global crisis arises when one or more fast-moving trigger events combines with slow-moving stresses to push a global system out of its established equilibrium and into a volatile and harmful state of disequilibrium. We then identify three causal pathways – common stresses, domino effects, and inter-systemic feedbacks – that can connect multiple global systems to produce synchronized crises. Drawing on current examples, we show that the polycrisis concept is a valuable tool for understanding ongoing crises, generating actionable insights, and opening avenues for future research.

No longer a mere buzzword, the ‘polycrisis’ concept highlights causal interactions among crises to help navigate a tumultuous future.

We identify a set of essential recent advances in climate change research with high policy relevance, across natural and social sciences: (1) looming inevitability and implications of overshooting the 1.5°C warming limit, (2) urgent need for a rapid and managed fossil fuel phase-out, (3) challenges for scaling carbon dioxide removal, (4) uncertainties regarding the future contribution of natural carbon sinks, (5) intertwinedness of the crises of biodiversity loss and climate change, (6) compound events, (7) mountain glacier loss, (8) human immobility in the face of climate risks, (9) adaptation justice, and (10) just transitions in food systems.

The Intergovernmental Panel on Climate Change Assessment Reports provides the scientific foundation for international climate negotiations and constitutes an unmatched resource for researchers. However, the assessment cycles take multiple years. As a contribution to cross- and interdisciplinary understanding of climate change across diverse research communities, we have streamlined an annual process to identify and synthesize significant research advances. We collected input from experts on various fields using an online questionnaire and prioritized a set of 10 key research insights with high policy relevance. This year, we focus on: (1) the looming overshoot of the 1.5°C warming limit, (2) the urgency of fossil fuel phase-out, (3) challenges to scale-up carbon dioxide removal, (4) uncertainties regarding future natural carbon sinks, (5) the need for joint governance of biodiversity loss and climate change, (6) advances in understanding compound events, (7) accelerated mountain glacier loss, (8) human immobility amidst climate risks, (9) adaptation justice, and (10) just transitions in food systems. We present a succinct account of these insights, reflect on their policy implications, and offer an integrated set of policy-relevant messages. This science synthesis and science communication effort is also the basis for a policy report contributing to elevate climate science every year in time for the United Nations Climate Change Conference.

We highlight recent and policy-relevant advances in climate change research – with input from more than 200 experts.

Improving the flow of information between governments and local communities is paramount to achieving effective climate change mitigation and adaptation. We propose five pathways to deepen participation and improve community-based climate action. The pathways can be summarized as visualization, simulations to practice decision-making, participatory budgeting and planning, environmental civic service, and education and curriculum development. These pathways contribute to improving governance by consolidating in governments the practice of soliciting and incorporating community participation while simultaneously giving communities the tools and knowledge needed to become active contributors to climate change adaptation and mitigation measures.

Community participation is considered a key component in the design of responses to climate change. Substantial engagement of local communities is required to ensure information flow between governments and communities, but also because local communities are the primary sites of adaptation action. However, frontline communities are often excluded from decision-making and implementation processes due to political choices or failures to identify ways to make participatory frameworks more inclusive. Climate action requires the active engagement of communities in making consequential decisions, or what we term deepened participation. We propose five pathways to deepen participation: visualization, simulations to practice decision-making, participatory budgeting and planning, environmental civic service, and education and curriculum development. The five pathways identify strategies that can be incorporated into existing organizational and institutional frameworks or used to create new ones. Shortcomings related to each strategy are identified. Reflection by communities and governments is encouraged as they choose which participatory technique(s) to adopt.

Climate action requires the active engagement of communities. Learn five pathways to get started deepening participation.

A widely held belief is that once the impacts of warming are experienced more directly and substantially, especially by affluent populations, the necessary support for a politics prioritising ambitious emissions reductions will follow. But consideration of the indirect socioeconomic impacts of warming suggests this could be false hope.

There is some evidence to support the common intuition that, as the direct impacts of warming intensify – particularly in the affluent Global North – a politics ambitious enough to confront the climate emergency may finally find support. However, it seems at least equally likely that the opposite trend will prevail. This proposition can be understood by considering various indirect impacts of warming, including the widening of socioeconomic inequalities (within and between countries), increases in migration (intra- and inter-nationally) and heightened risk of conflict (from violence and war through to hate speech and crime). Compiling these impacts reveals a considerable and highly inconvenient overlap with key drivers of the authoritarian populism that has proliferated in the 21st century. It highlights the risk of a socio-ecological feedback loop where the consequences of warming create a political environment entirely at odds with that required to reduce emissions. Such a future is, of course, far from inevitable. Nonetheless, the risks highlight the urgent need to find public support for combined solutions to climate change and inequality, which go well beyond the status-quo. This is necessary not only for reasons of economic and climate justice, but in order to mitigate political barriers to carbon mitigation itself.

As the impacts of warming are experienced more directly and substantially, we may vote for precisely the wrong people.

We summarize what we assess as the past year's most important findings within climate change research: limits to adaptation, vulnerability hotspots, new threats coming from the climate–health nexus, climate (im)mobility and security, sustainable practices for land use and finance, losses and damages, inclusive societal climate decisions and ways to overcome structural barriers to accelerate mitigation and limit global warming to below 2°C.

We synthesize 10 topics within climate research where there have been significant advances or emerging scientific consensus since January 2021. The selection of these insights was based on input from an international open call with broad disciplinary scope. Findings concern: (1) new aspects of soft and hard limits to adaptation; (2) the emergence of regional vulnerability hotspots from climate impacts and human vulnerability; (3) new threats on the climate–health horizon – some involving plants and animals; (4) climate (im)mobility and the need for anticipatory action; (5) security and climate; (6) sustainable land management as a prerequisite to land-based solutions; (7) sustainable finance practices in the private sector and the need for political guidance; (8) the urgent planetary imperative for addressing losses and damages; (9) inclusive societal choices for climate-resilient development and (10) how to overcome barriers to accelerate mitigation and limit global warming to below 2°C.

Science has evidence on barriers to mitigation and how to overcome them to avoid limits to adaptation across multiple fields.

Transforming towards global sustainability requires a dramatic acceleration of social change. Hence, there is growing interest in finding ‘positive tipping points’ at which small interventions can trigger self-reinforcing feedbacks that accelerate systemic change. Examples have recently been seen in power generation and personal transport, but how can we identify positive tipping points that have yet to occur? We synthesise theory and examples to provide initial guidelines for creating enabling conditions, sensing when a system can be positively tipped, who can trigger it, and how they can trigger it. All of us can play a part in triggering positive tipping points.

Recent work on positive tipping points towards sustainability has focused on social-technological systems and the agency of policymakers to tip change, whilst earlier work identified social-ecological positive feedbacks triggered by diverse actors. We bring these together to consider positive tipping points across social-technological-ecological systems and the potential for multiple actors and interventions to trigger them. Established theory and examples provide several generic mechanisms for triggering tipping points. From these we identify specific enabling conditions, reinforcing feedbacks, actors and interventions that can contribute to triggering positive tipping points in the adoption of sustainable behaviours and technologies. Actions that can create enabling conditions for positive tipping include targeting smaller populations, altering social network structure, providing relevant information, reducing price, improving performance, desirability and accessibility, and coordinating complementary technologies. Actions that can trigger positive tipping include social, technological and ecological innovations, policy interventions, public investment, private investment, broadcasting public information, and behavioural nudges. Positive tipping points can help counter widespread feelings of disempowerment in the face of global challenges and help unlock ‘paralysis by complexity’. A key research agenda is to consider how different agents and interventions can most effectively work together to create system-wide positive tipping points whilst ensuring a just transformation.

We identify key actors and actions that can enable and trigger positive tipping points towards global sustainability.

Scaling sustainable behaviour change means addressing politics, power and social justice to tackle the uneven distribution of responsibility and agency for climate action, within and between societies. This requires a holistic understanding of behaviour that bridges the ‘individual’ and ‘systemic’, and acknowledges the need for absolute emissions reductions, especially by high-consuming groups, and in key ‘hotspots’ of polluting activity, namely, travel, diet and housing. It counters the dominant focus on individuals and households, in favour of a differentiated, but collective approach, driven by bold climate governance and social mobilisation to reorient institutions and behaviour towards just transitions, sufficiency and wellbeing.

Sustainable behaviour change has been rising up the climate policy agenda as it becomes increasingly clear that far-reaching changes in lifestyles will be required, alongside shifts in policy, service provision and technological innovation, if we are to avoid dangerous levels of global heating. In this paper, we review different approaches to behaviour change from economics, psychology, sociology and political economy, to explore the neglected question of scalability, and identify critical points of leverage that challenge the dominant emphasis on individual responsibility. Although politically contentious and challenging to implement, in order to achieve the ambitious target of keeping warming below 1.5 degrees, we propose urgent structural interventions are necessary at all points within an ecosystem of transformation, and highlight five key spheres for action: a ‘strong’ sustainability pathway; pursuing just transitions (via changes to work, income and infrastructure); rebalancing political institutions to expand spaces for citizens vis-à-vis elite incumbents; focusing on high polluting actors and activities; and supporting social mobilisation. We call for a move away from linear and ‘shallow’ understandings of behaviour change, dominated by traditional behavioural and mainstreaming approaches, towards a ‘deep’, contextualised and dynamic view of scaling as a transformative process of multiple feedbacks and learning loops between individuals and systems, engaged in a mutually reinforcing ‘spiral of sustainability’.

Scaling behaviour change means addressing power and politics: challenging polluter elites and providing affordable and sustainable services for all.

Modern agriculture is associated with numerous environmental predicaments, such as land degradation, water pollution, and greenhouse gas emission. Socio-economically, it is characterized by a treadmill of technological change, increased mechanization, and economic consolidation, while depressing economic returns to farmers. A root cause is the dominance of annual plants cultivated in monocultures. Annual crops require the yearly clearing of vegetation resulting in soil erosion and other forms of ecosystem degradation. Monocultures are susceptible to agricultural pests and weeds. By contrast, perennial polycultures informed by natural ecosystems, promise more sustainable agroecosystems with the potential to also revitalize the economic foundation of farming and hence rural societies.