Many countries in the EU develop ‘National Climate Scenarios’ and related products that can be used for impact and risk assessments and the exploration of adaptation measures. At the same time, within the EU and its associated countries, many regions still rely on globally available climate projections to make a first estimate of regional risk.
Advances are being made in downscaling climate projections, implementation of hazard specific climate impact modelling chains, multi-risk climate assessment and equally relevant the communication of the risk assessment outcomes to sectoral end-users. Yet, common challenges still encountered by the providers and users of scenarios are the communication of uncertainties, requests for very high spatial and temporal resolutions, advice on the use of climate scenarios, interactions with users, integration of climate scenarios with impact information, the value and quality of data for multi-hazard and -risk assessment and how to deal with new scientific insights.
The Horizon Europe project CLIMAAX aimed to address some of the challenges associated with implementing regional climate risk assessments by developing a climate risk assessment framework and toolbox to assess climate risks for a variety of hazards, relying on climate projections from European and global repositories.
For this session we encourage submissions on constructing, delivering, using national climate scenarios and implementing regional climate risk assessments, including:
• Challenges in the provision of National climate information – including information gaps and the challenges in communication and providing information in ways that is relevant and accessible;
• Understanding user needs and the way users use climate scenarios, and the role of co-development of climate information and services;
• Best practices to bridge the gap between large scale climate projections and local relevance for multi-risk assessment (particularly examples that have used the CLIMAAX-developed Handbook and Framework)
• Comparisons of approaches in different countries, and examples of cross-border assessments;
• Future outlook and new opportunities in the science of scenario products drawing from novel types of information or techniques, e.g. Extreme event Attribution, decadal predictions, high resolution models, AI/ML, and new insights in the climate system and/or policy developments
The EU Horizon Europe project CLIMAAX (CLIMAte risk and vulnerability Assessment framework and toolboX) provides financial, analytical and practical support to European regions looking to develop their Climate Risk Assessment (CRA) and management plans. More than sixty regions have been conducting CRAs within the project following a comprehensive online handbook developed by the project. An open-source approach, complemented by a community of practice, aims to democratise access to CRA resources and supports the sharing of experience among practitioners.
The CLIMAAX Handbook encompasses:
- the CLIMAAX Framework, a structured approach to conducting a multi-hazard CRA that supports improved coherence across (EU) countries and regions;
- a toolbox with workflows and examples, offering a starting point for regions to access hazard, exposure and vulnerability information and combine them into a quantitative risk assessment; and
- supporting resources, including information on technical requirements, guidance on the selection of climate model data and scenarios, dataset availability, and support offerings.
The Handbook aims to harmonise the practice of CRA across Europe while allowing for the inclusion of local knowledge to ensure regional relevance. Emphasis is placed on stakeholder engagement and the prioritisation of multiple climate hazards in a key risk assessment step. The Handbook contains workflows that create a quantitative foundation for the analysis of risk, implemented as Jupyter notebooks and based on established Python data processing libraries. These workflows allow users to retrieve, process, and visualise hazard, exposure, and vulnerability data and combine them into indicators of risk. Access to European- and global-scale datasets from open data providers is preconfigured for seven hazards (floods, heavy rainfall, heatwaves, drought, wildfire, snow, and wind) and various types of non-climatic information, e.g., on population and infrastructure. Users are encouraged to integrate their own regional data to further refine the analysis and bridge the gap between the large and the local scale.
We introduce the CLIMAAX Handbook, discuss the project’s operationalisation strategy, reflect on the challenges involved in making the Handbook relevant and accessible to CRA practitioners, and illustrate how we collaborate with participating regions to share their experiences in applying it.
How to cite: Polster, C. and Wetterhall, F. and the CLIMAAX Handbook team: Supporting regional climate risk assessments with the CLIMAAX Handbook, EMS Annual Meeting 2026, Utrecht, Netherlands, 6–11 Sep 2026, EMS2026-610, https://doi.org/10.5194/ems2026-610, 2026.
Climate hazards impose inevitable pressures on natural and managed ecosystems, human infrastructures, natural resources, socio-economic functioning, and security within the water-energy-food-ecosystem nexus. In this context, Climate Risk Assessment (CRA) plays a vital role in providing a better perspective on hazard, vulnerability, exposure, and essential responses for developing adaptation strategies. Considering different modelling assumptions, parameterization and initialization, climate projections entail specific geographical biases and uncertainties. Although bias-adjusting of climate projections before conducting CRA is recommended, a critical question emerges to delineate which climate models/scenarios should be chosen not only to provide the least bias/uncertainty but also to improve reliability for such regional CRA.
The CLIMAAX project provides an open-access toolbox for conducting CRA for a variety of climate hazards (e.g., river and coastal flooding, heavy precipitation, drought, heatwaves, wind, snow, and wildfire). Among them a specific workflow is designed to address how to select climate model projections/scenarios for each NUTS2 region throughout Europe. The workflow is hosted on an interactive platform characterizing (i) bias and (ii) uncertainty currently for precipitation and surface temperature. It relies on a consolidated precalculated dataset and provides rapid calculation and graphical display of bias and uncertainty of climate projections with an easy-to-use GUI to facilitate understanding of climate model skills, their optimal use and exploitation to conduct CRA at regional scales for a wide community of users and practitioners. The first part of the workflow identifies which climate model has the lowest biases in precipitation and temperature. It starts by selecting the region of interest and EURO-CORDEX models. The biases of precipitation and temperature are calculated in percentages and degrees Celsius, respectively, for historical records simulated by climate models in comparison to either Eobs or ERA5 reanalysis datasets. The second part of the workflow provides an absolute or a relative range of precipitation and temperature accumulated in five 20-year windows in the period of 1986 - 2100. As an example, this study demonstrates the application of the workflow to a specific region to showcase its usefulness in the CRA process. Finally, this workflow plays a key role in evaluating biases, understanding uncertainties, reducing uncertainty ranges, which can result in more valuable and credible CRAs.
Link to the current version of the workflow:
https://handbook.climaax.eu/dashboards/bias-uncertainty/
Acknowledgments: This research work was carried out as part of the CLIMAAX project with funding received from the European Union’s Horizon Europe – the Framework Programme for Research and Innovation (2021-2027) under grant agreement No. 101093864.
How to cite: Niazkar, M., Rivosecchi, A., Polster, C., Ferrari, L., Aslam, M. F., Trabucco, A., and Pal, J.: Evaluating Climate Model Bias and Uncertainty for Regional Climate Change Risk Assessment, EMS Annual Meeting 2026, Utrecht, Netherlands, 6–11 Sep 2026, EMS2026-689, https://doi.org/10.5194/ems2026-689, 2026.
Effective climate change adaptation requires climate information that is not only scientifically robust but also aligned with the diverse needs of end users operating at regional, national, and local scales. These needs vary widely across sectors such as public authorities, municipalities, emergency services, critical infrastructure operators, and insurance providers, creating challenges related to spatial and temporal resolution, uncertainty communication, data formats, and interpretability. In this contribution, we synthesise insights from several ongoing projects to examine how different types of climate information can be tailored to support efficient climate risk assessment and adaptation decision-making.
ILMOS Uusimaa project focuses on municipal-scale adaptation, producing high-resolution climate projections, economic impact assessments of adaptation measures, and storyline-based Climate Digital Twin simulations of extreme events to support practical decision-making. These results demonstrate the importance of kilometre-scale data, impact-oriented indicators, and clear narratives when engaging local actors.
Sector-specific requirements are further illustrated by projects addressing critical infrastructure and financial risk. MAWECLI and WIND‑IMPACT investigate single and compound weather hazards relevant for nuclear safety and electricity networks, respectively, combining physical and statistical modelling, extreme value analysis, and advanced uncertainty quantification. These projects emphasize the need for rare-event statistics, physically consistent simulations, and explicit treatment of compound and cascading risks. Meanwhile, PIISA focuses on co-developing climate-resilient insurance solutions, where probabilistic risk information, loss data, and comparability across regions and hazards are essential.
Finally, the CLAIMS and Climate Digital Twin Storyline analyses of extremes showcase how event-based attribution and counterfactual simulations can make climate change impacts tangible by quantifying how specific events differ between past, present, and warming scenarios. Across all projects, common challenges emerge in balancing resolution and computational cost, integrating uncertainties into decision processes, and translating complex climate data into actionable knowledge. Our synthesis highlights pathways for bridging global climate information with end-user-relevant, locally actionable climate risk assessments.
How to cite: Mäkelä, A., Luomaranta, A., Rantanen, M., and Gregow, H.: From global climate data to actionable local risk information: lessons from multi-sectoral adaptation activities in Finland, EMS Annual Meeting 2026, Utrecht, Netherlands, 6–11 Sep 2026, EMS2026-808, https://doi.org/10.5194/ems2026-808, 2026.
Global climate datasets are increasingly accessible, but their utility depends on how well they can be adapted to the conditions of specific sectors and places. This study presents the Phase 2 outcomes of the Climate Resilience Enhancement in Dairy Farming (CliResDairy) project in Aydin, Türkiye, showing how large-scale climate projections can be systematically downscaled and applied to local agricultural risk assessment.
Aydin’s dairy sector, dominated by small and medium scale farms, is highly sensitive to climate hazards but historically lacked localized adaptation planning. We used the CLIMAAX Handbook to move beyond high-level screening, developing a targeted risk assessment specifically for Aydin’s dairy sector. The methodology integrated EURO-CORDEX (EUR-11) multi-model projections (RCP4.5 and RCP8.5) with high-resolution regional and local data. We localized the data by pairing regional hazards with district level indicators, including livestock density, topography, and the availability of on farm cooling systems.
The multi-risk assessment evaluated heatwaves, agricultural drought, extreme precipitation, and river flooding. Converting climatic variables into sector-specific indicators allowed the study to quantify concrete local impacts: heat stress alone could cut milk yields by 250 liters per cow annually in the hardest-hit districts. This comes alongside declining fertility rates and the rising cost of keeping cows cool. Agricultural drought modeling indicated up to 60% yield losses for vital forage crops under rainfed conditions. Additionally, customized rain-on-grid hydrodynamic modeling revealed a 20-30% increase in 100 year river flood depths, directly threatening farm infrastructure.
Field visits, surveys, and a stakeholder workshop involving 124 participants, all from producers to policymakers, were used to ground-truth climate data and translate it into meaningful economic and operational impact indicators.
The CliResDairy project validates the CLIMAAX methodology under real regional conditions. The results demonstrate that spatial downscaling is achievable when multi model climate ensembles are paired with local infrastructure data and direct stakeholder input. This combination produces adaptation strategies that are grounded in measurable risk and immediately applicable to the farming operations most exposed to climate change.
How to cite: Karaman, Ç., Cerit, H., Koç, E., Köse Kiper, E. İ., and Demir, N.: From Climate Projections to Farm-Level Risk: A Multi-Hazard Assessment for Dairy Farming in Aydin, Türkiye, EMS Annual Meeting 2026, Utrecht, Netherlands, 6–11 Sep 2026, EMS2026-419, https://doi.org/10.5194/ems2026-419, 2026.
Agricultural systems are increasingly threatened by climate change, which is aggravating the challenge of meeting international food production goals while respecting planetary resource boundaries. Europe is already experiencing more frequent and intense drought events, with damages to the agricultural sector projected to escalate in the near future. Semi-arid regions will be more prone to water shortages and will be forced to reduce allocations to irrigation to satisfy other public needs. At the same time, seasonal water scarcity is becoming more frequent in historically wet regions, hindering the potential of rainfed systems to satisfy the growing agricultural production demand. In this context, a transition towards more drought-resilient agricultural systems and land planning is urgently needed to limit losses across the European food production system.
To help guide these urgent adaptation efforts, we present an interactive workflow developed within the CLIMAAX project quantifying the potential lost-opportunity cost of not investing in adequate irrigation systems under climate change. Our tool is applicable from the municipality to the national level and allows stakeholders to assess the potential economic losses caused by climate change on crop yields in rainfed agricultural systems. The workflow applies the CLIMAAX risk framework methodology and defines risk as the combination of projected variations in crop yields due to climate change (hazard), current agricultural production (exposure) and existing irrigation availability (vulnerability).
We showcase the application of the workflow in the “Unione dei Comuni della Valcerrina”, a union of municipalities located in southeastern Piedmont, northern Italy. The local economy relies heavily on agriculture and the agri-food sector, with high-value crops such as vineyards and hazelnuts cultivated in the hilly areas, and arable crops grown in the alluvial plains of the River Po. Drought represents an emerging climate risk in the region, for which the local community remains largely unprepared, as evidenced by the limited availability of irrigation infrastructure.
For the case-study, the workflow is expanded to incorporate local data on soil types, crop types and parameters, leading to an improved characterization of the hazard component. In addition, parcel-level information on cropping patterns, average crop yields, and crop market values, are integrated in the risk assessment to provide a more accurate estimation of potential economic losses. Results indicate that losses could reach up to EUR 750,000 over the 2036–2060 time horizon under the RCP4.5 emission scenario. These findings offer valuable economic insights for agricultural stakeholders to evaluate the costs and benefits of investing in irrigation infrastructure and support public authorities in the development of effective drought risk management strategies.
How to cite: Rivosecchi, A., Lucca, E., and Trabucco, A.: The CLIMAAX agricultural drought workflow: design, application and results from the Valcerrina municipalities., EMS Annual Meeting 2026, Utrecht, Netherlands, 6–11 Sep 2026, EMS2026-308, https://doi.org/10.5194/ems2026-308, 2026.
To enhance corporate due diligence and accountability for climate change, in recent years the EU has adopted interconnected legislative instruments such as the Corporate Sustainability Reporting Directive (CSRD) and the EU Taxonomy Regulation. Under this framework, corporations must disclose environmental, social, and governance performance, assessing both their impacts on climate change, water, and pollution and the risks these issues pose to their operations. These reporting needs have created demand for technical skills in climate science and related disciplines. In response, new business activities have emerged: insurance companies have opened climate related branches to support scientific climate risk assessments, and many other companies and startups now provide similar services.related branches to support scientific climate risk assessments, and many other companies and startups now provide similar services.
The value chain used by these companies typically begins with future climate projections from CMIP6 models and proceeds through the computation of hazard metrics to the final estimation of risk in terms of damages, losses, or productivity impacts. Each step introduces its own layer of uncertainty, which cumulatively affects the final results. Consequently, different methodological choices can lead to widely diverging conclusions, from low to very high risk, for the same type of asset. Moreover, to produce results at scale, many private climate risk providers apply standardized workflows that do not adapt to the distinct physical characteristics of different hazards. This lack of hazard specific treatment can further amplify uncertainty and reduce scientific robustness.specific treatment can further amplify uncertainty and reduce scientific robustness.
In this work, we present a comparative analysis of several commercial climate risk assessment solutions, benchmarked against our in-house methodology. We quantify how different methodological choices affect the overall uncertainty of the risk estimate for the same asset. Our results show that the selection of the climate model ensemble, in both size and composition, is the first major source of divergence. The ensembles we evaluated range from 5 to 20 models. In some cases, models are selected based on scientifically robust criteria such as models’ interdependency and equilibrium climate sensitivity. In others, the choice is driven only by the availability of specific climate variables. This latter approach can bias the ensemble toward hotter or colder models and may fail to capture a sufficiently broad range of plausible futures. A second major source of uncertainty arises from the use of fixed thresholds for computing hazard metrics. These thresholds can yield more or less conservative results, meaning that two companies may classify the same asset as either high-risk or low-risk for the very same hazard.house methodology. We quantify how different methodological choicesrisk or lowrisk for the very same hazard.
Overall, our findings highlight the need for a scientifically grounded framework that brings standardization, comparability, and reliability to the entire climate risk assessment chain, ensuring that corporate reporting under EU regulations does not depend excessively on the particular provider selected.
How to cite: Omrani, H. and Cazzaniga, G.: The new business of climate risk assessment: who are the emerging actors and how reliable are their products? , EMS Annual Meeting 2026, Utrecht, Netherlands, 6–11 Sep 2026, EMS2026-24, https://doi.org/10.5194/ems2026-24, 2026.
Against the background of climate warming and increasingly intensified extreme heat events, densely developed cities are facing ever-intensifying heat-risk challenges. In basin cities such as Taipei, restricted ventilation, complex built-environment conditions, and highly concentrated populations further exacerbate heat accumulation and retention. However, conventional meteorological station data are often insufficient to fully capture the heterogeneity of street-scale thermal environments, and they also make it difficult to identify high-risk areas where climatic hazards spatially overlap with socially vulnerable populations. Therefore, this study integrates multi-scale climate information and social vulnerability indicators to assess heat risk, with the aim of improving the local relevance of urban heat-risk identification and decision-making applications.
This study focuses on Taipei, the capital of Taiwan, to investigate the acute heat impacts faced by densely developed urban areas under a warming climate. Urban heat is not merely a meteorological outcome, but a complex microclimatic phenomenon shaped by the interaction of topographic conditions, built-environment geometry, atmospheric boundary-layer characteristics, and anthropogenic activities. To resolve the high degree of heterogeneity in urban microclimates, long-term observations with high spatial and temporal resolution are essential. This study integrates hourly air temperature data from the High-Density Street-Level Air Temperature Observation Network (HiSAN) in the Taipei metropolitan area for 2022, in situ observations from the Central Weather Administration (CWA), and the Taiwan ReAnalysis Downscaling dataset (TReAD) with a spatial resolution of 2 km. Through spatial interpolation in QGIS and ArcGIS, the study constructs comprehensive spatial models of urban heat distribution.
This study utilizes Daan Forest Park, a characteristic 'cool island' within the Taipei metropolitan area, was selected as the reference point. Monthly mean temperature differences between each observation site and the reference station were calculated to evaluate urban heat intensity, examine the relationship between built-environment characteristics and urban heat intensity, and provide a practical scientific basis for urban climate adaptation and hotspot identification. The analysis was further extended from heat-hazard assessment to risk assessment by overlaying urban heat hotspot distributions with socioeconomic vulnerability indicators, specifically targeting the distribution of older adults and low-income households, in order to identify heat-risk hotspots at different times and priority areas where high heat exposure coincides with high vulnerability. The results show that urban heat hotspots are mostly concentrated in densely built-up areas and exhibit a considerable degree of spatial overlap with areas where older adults and low-income populations are concentrated. This suggests that urban heat risk is determined not only by physical heat exposure but also closely linked to social vulnerability. Consequently,areas where high heat and high vulnerability overlap should be prioritized for subsequent urban climate adaptation and heat-risk management, and locally tailored adaptation and mitigation strategies should be proposed according to differences in built-environment characteristics and population structure across districts.
How to cite: Hsieh, C.-J., Lu, C.-L., Tung, H.-H., Chang, C., and Lin, T.-P.: Integrated Identification of Hazard Impact Areas from Urban Heat and Social Vulnerability: A Case Study of Elderly and Low-Income Populations in Taipei, EMS Annual Meeting 2026, Utrecht, Netherlands, 6–11 Sep 2026, EMS2026-186, https://doi.org/10.5194/ems2026-186, 2026.
Traditional dry-stone terraces, locally known as “xerolithies,” have historically characterised the steep terrains of the Cyclades, including the islands of Syros and Tinos. While initially built to secure arable land and prevent soil erosion in semi-arid environments, their current contribution to alleviating climate-related hazards remains underexplored in scientific literature. As climate change leads to more frequent extreme rainfall events in the Mediterranean, the widespread abandonment of these terraced catchments calls for sophisticated hydrological modelling to assess their present effectiveness in regional water management.
By significantly lowering the effective slope of mountainous island catchments, dry-stone terraces act as a nature-based solution (NBS) to slow rainwater to non-erosive velocities, thereby reducing the rapid flow connectivity over the land. The naturally permeable nature of “xerolithies,” which are built entirely without mortar, allows excess water from seasonal storms to gradually infiltrate through structural gaps rather than swiftly flowing over the low impermeability metamorphic lithology of these islands. This temporary storage of storm runoff plays a crucial role in preventing severe soil erosion within the Cycladic landscape while substantially improving deep water infiltration, increasing soil moisture retention, and supporting vital groundwater recharge.
To precisely quantify these environmental benefits under future climate pressures, high-resolution geospatial terrain data from representative catchments on Syros and Tinos are combined with advanced hydrodynamic modelling frameworks (Barnhart et al., 2020). The methodology employs detailed climate simulations to assess how landscapes respond to extreme weather events (Politi et al., 2022), explicitly comparing scenarios with intact terraces to those with heavily degraded or barren slopes. By modelling intense, low-probability extreme precipitation events based on localized climate projections, the approach monitors peak surface discharge, water flow dynamics, and sediment transport across the islands’ complex topography.
Integrating traditional Cycladic engineering systems (Jiménez De Madariaga, 2021), included in UNESCO’s Representative List of the Intangible Cultural Heritage of Humanity since 2024, into modern water management strategies directly supports the broader goals of European Union climate adaptation projects across the Mediterranean. Additionally, restoring “xerolithies” helps preserve critical ecological microhabitats for local flora and fauna, enhances the productivity of agricultural land, and increases resilience against extreme weather events.
References
Barnhart, K.R., Hutton, E.W.H., Tucker, G.E., Gasparini, N.M., Istanbulluoglu, E., Hobley, D.E.J., Lyons, N.J., Mouchene, M., Nudurupati, S.S., Adams, J.M., Bandaragoda, C., 2020. Short communication: Landlab v2.0: a software package for Earth surface dynamics. Earth Surf. Dynam. 8, 379–397. https://doi.org/10.5194/esurf-8-379-2020
Jiménez De Madariaga, C., 2021. Dry stone constructions – intangible cultural heritage and sustainable environment. JCHMSD 11, 614–626. https://doi.org/10.1108/JCHMSD-12-2020-0180
Politi, N., Vlachogiannis, · D, Sfetsos, · A, Nastos, · P T, 2022. High resolution projections for extreme temperatures and precipitation over Greece. Climate Dynamics 2022 1, 1–35. https://doi.org/10.1007/S00382-022-06590-W
How to cite: Zarikos, I., Politi, N., Vlachogiannis, D., and Sfetsos, A.: The effectiveness of traditional dry-stone wall terraces in water management and flood prevention: The cases of Syros and Tinos islands, Greece, EMS Annual Meeting 2026, Utrecht, Netherlands, 6–11 Sep 2026, EMS2026-526, https://doi.org/10.5194/ems2026-526, 2026.
Climate change is increasing the frequency and intensity of natural hazards leading to long-lasting heatwaves, severe flooding, devastating wildfires, and prolonged droughts. At the same time, many regions and communities in Europe lack the necessary resources and tools to effectively cope with and manage climate risk.
The Horizon Europe project CLIMAAX supports the Mission on Climate Adaptation in enhancing climate resilience for European regions. The project provides financial, analytical, and practical support to 67 European regions to conduct their regional climate risk assessment (CRA) using the CLIMAAX CRA framework and toolbox (CLIMAAX CRA Handbook). The CLIMAAX methodological framework provides a step-by-step guide for harmonized regional CRAs. It is designed to enhance coherent practical CRA implementation based on the latest scientific developments without too many layers of complexity. The online open source Jupyter based CRA toolbox includes data, projections and risk assessment workflows for a variety of climate hazards. Together the framework and handbook support the compilation of regional CRAs.
Part of the project is a cascading fund of about 12 Million Euro. This is used to finance the 67 carefully selected European regions that conduct their own CRA building upon CLIMAAX tools and guidance. By now, the regions have completed two CRA reports. The first based on the EU / global scale datasets that are directly available from the CLIMAAX Handbook. This CRA provides a first risk scan and a scientific benchmark for local findings. However, for some hazards the datasets proofed to be too coarse. For the second CRA report local and higher resolution data is integrated in the assessment. A key-risk assessment dashboard is developed to help regions prioritize risks in consultation workshops with local stakeholders. The focus of the final phase of the CRA projects is on identifying adaptation options.
The level of experience with CRA varies between European regions. From the outcomes so far we see that EU regions are highly capable of implementing their own CRA, where needed with technical support from consortium partners and local research institutes or consultants. The fact that the regions are responsible for their own CRA and its underlying implementation plan results in high quality CRA reports that already start to trigger local climate risk management and adaptation planning.
How to cite: Sperna Weiland, F. and the CLIMAAX project consortium: Enabling consistent science-based climate risk assessment for European regions - CLIMAAX, EMS Annual Meeting 2026, Utrecht, Netherlands, 6–11 Sep 2026, EMS2026-646, https://doi.org/10.5194/ems2026-646, 2026.
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