Storylines are introduced in climate science to provide unity of discourse, integrate the physical and socioeconomic components of phenomena, and make climate evolution more tangible. The use of this concept by multiple scholar communities and the novelty of some of its applications renders the concept ambiguous nonetheless, because the term hides behind a wide range of purposes, understandings, and methodologies. This semi‐systematic literature review identifies three approaches that use storylines as a keystone concept: scenarios—familiar for their use in IPCC reports—discourse‐analytical approaches, and physical climate storylines. After screening peer‐reviewed articles that mention climate and storylines, 270 articles are selected, with 158, 55, and 57 in each category. The results indicate that each scholarly community works with a finite and different set of methods and diverging understandings. Moreover, these approaches have received criticism in their assembly of storylines: either for lacking explicitness or for the homogeneity of expertise involved. This article proposes that cross‐pollination among the approaches can improve the usefulness and usability of climate‐related storylines. Among good practices are the involvement of a broader range of scientific disciplines and expertise, use of mixed‐methods, assessment of storylines against a wider set of quality criteria, and targeted stakeholder participation in key stages of the process.

Climate services are high on the international agenda for their potential to help combat the effects of climate change. However, climate science is rarely directly incorporated into the decision-making processes of societal actors, due to what has been identified as the usability gap. This gap is partially due to a failure to timely and meaningfully engage users in the production of climate services, as well as misperceptions as to which users can best benefit from climate service uptake. In this article, we propose user selection and engagement guidelines that integrate important values from participatory science such as those of legitimacy, representativity, and agency. The guidelines consist of 5 + 1 steps: defining why, where, whom, which attributes, and which intensity and how to select and engage with stakeholders. While these steps may be initially implemented by an ideally interdisciplinary team of scientists and service designers, the final step consists of an iterative process by which each decision is agreed on together with the identified users and stakeholders under a coproduction approach. We believe this systematic user selection and engagement practice is key to support the design of climate services aligned to the actual needs of a wide and inclusive range of empowered societal agents. Significance Statement: A review of the climate science and services literature and related research projects reveals that, despite the insistence to include users in all stages of the research process, users are often involved only sporadically and inconsistently and when there is little room to change the climate service suitable for decision-making. Here, we argue that a reason for this is the lack of user selection and engagement guidelines. Failure to implement a research design strategy for these decisions can lead to a lack of usability and applicability of the produced climate-related services, as well as hampering their long-term uptake. These guidelines can thus support the development of usable, coproduced, actionable climate science.

The Next Generation of Earth Modeling Systems (nextGEMS) project aimed to produce multidecadal climate simulations, for the first time, with resolved kilometer-scale (km-scale) processes in the ocean, land, and atmosphere. In only 3 years, nextGEMS achieved this milestone with the two km-scale Earth system models, ICOsahedral Non-hydrostatic model (ICON) and Integrated Forecasting System coupled to the Finite-volumE Sea ice-Ocean Model (IFS-FESOM). nextGEMS was based on three cornerstones: (1) developing km-scale Earth system models with small errors in the energy and water balance, (2) performing km-scale climate simulations with a throughput greater than 1 simulated year per day, and (3) facilitating new workflows for an efficient analysis of the large simulations with common data structures and output variables. These cornerstones shaped the timeline of nextGEMS, divided into four cycles. Each cycle marked the release of a new configuration of ICON and IFS-FESOM, which were evaluated at hackathons. The hackathon participants included experts from climate science, software engineering, and high-performance computing as well as users from the energy and agricultural sectors. The continuous efforts over the four cycles allowed us to produce 30-year simulations with ICON and IFS-FESOM, spanning the period 2020–2049 under the SSP3-7.0 scenario. The throughput was about 500 simulated days per day on the Levante supercomputer of the German Climate Computing Center (DKRZ). The simulations employed a horizontal grid of about 5 km resolution in the ocean and 10 km resolution in the atmosphere and land. Aside from this technical achievement, the simulations allowed us to gain new insights into the realism of ICON and IFS-FESOM. Beyond its time frame, nextGEMS builds the foundation of the Climate Change Adaptation Digital Twin developed in the Destination Earth initiative and paves the way for future European research on climate change.

Natural resource management requires cross‐sectoral policy integration because the scope of current environmental and sustainability issues surpasses traditional sectoral boundaries. While the emergence of policy networks in such cases has been observed in the policy integration literature, little is known about how these networks are formed and how they influence the processes and outputs of policy integration. Accordingly, the main aim of this article is to combine the policy integration and policy network literatures to answer two research questions: How can the formation of a policy network for the case of forest and water policy integration be explained? What are the effects of the policy network on policy integration outputs? We use qualitative interviews and social network analysis to inform the study of two regional case studies in Germany and Spain. Our results show the relevance of a policy broker in steering the interactions between forest and water policy actors, combined with the presence of synergetic interdependencies, which facilitated the activation of the network. Additionally, the activities performed contributed to ideational homogenization between the forest and water sectors in terms of problem definition and preferred solutions, despite initial divergences. We conclude that a policy network perspective is an important contribution to the policy integration literature because it allows differentiating the influence of actor‐level and network‐level factors on integrated processes and outputs. In conclusion, both actors and their relationships should be accounted for as key intermediary variables to better understand and steer policy integration between natural resource sectors.

Climate variability and change poses unprecedented challenges to food security, with shifting temperature trends, altered precipitation regimes, and the intensification of extreme events such as heatwaves, droughts, and floods. Multi-annual climate variability further exacerbates these challenges, underscoring the need for decision-makers to access actionable climate information to inform long-term adaptation strategies. However, multi-annual predictions remain constrained by their modest forecast skill and considerable uncertainty, limiting their use in decision-making. This study presents the co-production of climate services using multi-annual predictions to enhance food security in Tanzania and Malawi, developed as part of the EU-funded H2020 project FOCUS-Africa. These services are based on an interactive online platform to deliver deterministic and probabilistic predictions of key variables, including mean temperature, precipitation, temperature extremes, and drought conditions for the coming years. To ensure transparency, forecast quality metrics are provided to guide users in assessing the quality and reliability of the climate information. Complementary co-designed bulletins summarize these predictions in accessible language, fostering engagement and practical application through in-person workshops and feedback sessions. This paper demonstrates how co-production can help address the emerging demand for climate information to support food security decisions at multi-annual timescale. Our findings highlight the effectiveness of stakeholder engagement in tailoring climate services to user needs. This study also identifies critical challenges in the co-production process and outlines strategies to overcome them, offering valuable insights for advancing climate services for supporting multi-annual decisions in other sectors and contexts.

The Next Generation of Earth Modeling Systems (nextGEMS) project aimed to produce multi-decadal climate simulations, for the first time, with resolved kilometer-scale (km-scale) processes in the ocean, land, and atmosphere. In only three years, nextGEMS achieved this milestone with the two km-scale Earth system models, ICOsahedral Non-hydrostatic model (ICON) and Integrated Forecasting System coupled to the Finite-volumE Sea ice-Ocean Model (IFS-FESOM). nextGEMS was based on three cornerstones: 1) developing km-scale Earth system models with small errors in the energy and water balance, 2) performing km-scale climate simulations with a throughput greater than one simulated year per day, and 3) facilitating new workflows for an efficient analysis of the large simulations with common data structures and output variables. These cornerstones shaped the timeline of nextGEMS, divided into four cycles. Each cycle marked the release of a new configuration of ICON and IFS-FESOM, which were evaluated at hackathons. The participants in hackathons included experts from climate science, software engineering, and high-performance computing, as well as users from the energy and agricultural sectors. The continuous efforts over the four cycles allowed us to produce 30-year simulations of ICON and IFS-FESOM, spanning the period 2020–2049 under the SSP3-7.0 scenario. The throughput was about 500 simulated days per day on the Levante supercomputer of the German Climate Computing Center (DKRZ). The simulations employed a horizontal grid of about 5 km resolution in the ocean and 10 km resolution in the atmosphere and land. Aside from this technical achievement, the simulations allowed us to gain new insights into the realism of ICON and IFS-FESOM. Beyond its timeframe, nextGEMS builds the foundation of the Climate Change Adaptation Digital Twin developed in the Destination Earth initiative and paves the way for future European research on climate change.