Climate Resilient Development Pathways (CRDP) is a promising concept for cities to integrate climate change mitigation and adaptation to achieve sustainable development for all. Although CRDP aims to leverage synergies and co-benefits while limiting trade-offs between a city’s many objectives, there is no framework or approach for planning and implementing CRDP. A structured approach is needed to move from theory to practice. In this perspective paper, we outline three functional elements, or building blocks, for a CRDP planning framework. The building blocks are (1) identifying and evaluating interactions between adaptation, mitigation and sustainable development, (2) addressing time and uncertainty in planning, and (3) delivering specialized information for CRDP. These building blocks are informed by practice, drawing lessons from literature on recent efforts to integrate climate adaptation and mitigation in European cities, and from our experiences with adaptive pathways planning and climate services development. As cities and scholars are turning their attention to CRDP planning, the building blocks can help focus priority areas for development, informed by practice.

Sea level rise (SLR) will affect Europe's coasts over the coming decades and beyond, giving rise to ongoing challenges in governing coastal and marine areas. Progress is being made in adapting to and addressing these challenges at both national and sub-national levels across all major European sea basins. This paper assesses progress in coastal adaptation governance in Europe by, first, characterising the socio-economic and political contexts in European sea basins and then by reviewing coastal-adaptation-relevant policy frameworks in place at regional and national levels within each of these sea basins. The regional frameworks reviewed are derived from regional sea conventions and are assessed for their legal status and their inclusion of SLR information. The national coastal policy frameworks reviewed include national adaptation plans focusing on coastal areas and marine spatial planning instruments for all European member states, as well as public financing arrangements for coastal adaptation, focusing on flood risk reduction measures. Key national policies for coastal adaptation are assessed for which coastal hazards they address, the extent to which they incorporate sea level rise information and their inclusion of SLR-specific adaptation measures. Finally, the paper presents governance challenges that arise due to the complexity of adaptation to SLR, i.e. time horizon and uncertainty, cross-scale and cross-domain coordination, and equity and social vulnerability, and discusses examples illustrating how each of these challenges is being addressed in different European sea basins. The paper finds that for all basins, regional policy frameworks generally do not include specific provisions for SLR or coastal adaptation, while at the national level, significant progress on SLR governance is being made. For all basins except for the Black Sea, all countries have reported observed and future SLR hazards and have adopted adaptation strategies. The inclusion of adaptation measures specific to SLR is less advanced, as most sea basins have at least one country that does not include specific SLR adaptation measures in either their adaptation strategies or their marine spatial plans. Regarding SLR governance challenges, key examples of how these are being addressed include approaches for incorporating flexibility into coastal planning, e.g. dynamic adaptation pathways in the Netherlands or dike crest widening in Germany, as well as co-development of nature-based adaptation solutions in Italy. Examples of addressing equity and social vulnerability challenges include the emerging issue of climate ligation illustrated through several court cases on liability for SLR-related damage.

In the process of transitioning into resilient urban areas, cities face a wide variety of challenges in relation to adaptation, mitigation and sustainable development. Commonly these challenges are addressed in a merely isolated fashion, or only two out of the three objectives are tackled simultaneously. It is pivotal to take a systemic approach over time in order to maximise synergies and minimise trade-offs between these different policy objectives. Climate Resilient Development Pathways (CRDPs) aim to integrate adaptation, mitigation and sustainable development into flexible pathways over time, while considering (deep) uncertainties regarding climate change, as well as other sources of uncertainty. Climate resilient development pathways seek to support integrated planning and implementation of climate action. Currently no comprehensive framework exists for operationalising CRDPs. There is a need to develop a methodology for the practical pursuit of climate resilient development pathways.

This research presents a novel approach to operationalise climate resilient development pathways, using the well-established method for adaptation pathways, so-called “dynamic adaptation policy pathways (DAPP)”, as a starting point. The CRDP process starts by envisioning multiple desirable futures and understanding the decision context and current policy objectives and actions for adaptation, mitigation and development. Thereafter the synergies and trade-offs are assessed between the different climate actions, as well as tipping points are identified – meaning points in time when new actions will be required. Consequently, alternative actions are co-developed for the future to pursue desirable pathways. The final outcome is a pathways map, as well as an implementation and monitoring plan. An urban case-study to demonstrate the applicability of climate resilient development pathways is presented for the city of Cork in Ireland.

CRDPs can be created for different climate-related impacts such as flood and heat, as well as for a wide variety of development issues. The main target groups of the approach are decision makers and/or (urban) planners, although a wider engagement is recommended for different steps during the co-creation process of the pathways. Climate resilient development pathways support integrated climate action planning, interlacing adaptation, mitigation and sustainable development through designing flexible pathways over time that provide insights into the range of options to achieve resilient urban futures.

To achieve climate resilient societies, climate adaptation, mitigation, and sustainable development (AMD) are all necessary. The concept of “climate resilient development pathways” (CRDP) recognizes this as intertwined challenges. However, no systematic procedure exists for the creation and appraisal of CRDP that fully acknowledges interactions and integrates adaptation, mitigation, and sustainable development over time. Taking the established Dynamic Adaptive Pathways Planning (DAPP) approach as a starting point, this paper presents a novel and stepwise approach for climate resilient development adaptive pathways planning, or in short: CRDAPP. Key novelties of this approach are: a) visioning to design CRD strategies while dealing with complexity, b) performance and target tipping points to sequence measures, and c) AMD interaction typologies to build and evaluate pathways. We illustrate the approach through a qualitative example case study in Cork City, Ireland. The CRDAPP steps are carried out for the city, with multiple pathways designed and critical decisions over time identified. The resulting CRDP provide insights into the range of options for Cork on how to combine mitigation, adaptation, and sustainable development actions over time, in order to work toward different future states of the city. Herewith, the CRDP concept is operationalised and turned into a systematic stepwise approach that can support decisionmakers to integrate adaptation, mitigation, and sustainable development action over time and under uncertainty into their planning processes.

This paper presents an analysis of future research and development needs to assess the effectiveness of nature-based solutions for climate adaptation in watersheds at scale using hydrological models. Two main questions are addressed: To what extent are hydrological model approaches able to support decision making on nature-based solutions and adaptation, and how well is this hydrological analysis embedded in the broader planning process? To support the research, case studies in Bhutan, Zimbabwe and the Netherlands are presented. The Climate Risk Informed Decision Analysis approach is used to structure the planning process. All three case studies demonstrate how the hydrological system and full landscape of land and water use in watersheds can be simulated to better understand hydrometeorological hazards under current and future climate. Also, simulations of nature-based solutions are demonstrated, which need creativity and profound expert knowledge. In contrast to the assessment of grey infrastructure, no rules or guidance exists for the hydrological assessment of nature-based solutions. Physically-based models are better able to support the understanding of the functioning of the ecohydrological system and, therefore, the effectiveness of adaptation using nature-based solutions. There are however trade-offs between the computational complexity, the computation time and the multiple scenarios and sensitivity analyses of adaptation options needed for climate stress testing. Often there is a lack of monitoring data for verification of model outcomes. Several recommendations on how to improve modelling in an adaptation process are given. In addition, it is recommended to develop and rectify a set of nature-based solutions performance indicators, rules and algorithms to be adopted in models in order to quantify the effectiveness of these solutions.

Sea level rise (SLR) is projected to have severe consequences for people and assets in European coastal areas. Planning for SLR is a critical step to ensure timely and adequate responses. Despite our rapidly increasing understanding of SLR impacts and the need to adapt, few studies have looked at how countries are planning for SLR. We surveyed experts from the 32 European countries with a coastline about how their country is planning for SLR. Our online survey focused on four areas: (1) whether SLR planning exists and at what level of government; (2) which climate information and scenarios are used in planning; (3) what planning horizons and corresponding levels of SLR are used; and (4) how uncertainty in handled and whether high-end sea level rise is being considered in planning. Additionally, we asked experts to assess the status of sea level rise planning in their country. Our results indicate that most coastal countries in Europe are planning for SLR, but 25% still do not. We find that the planning horizon 2100 is most common and many countries are considering around 1m (adjusted for local conditions) of SLR at that point in time. However, there are significant differences between countries, which may lead to unequal impacts, over time. We also find that RCP4.5 and RCP8.5 are the most widely used climate change scenarios, suggesting that countries are considering high-end climate change in planning, although this does not mean they consider high amounts of SLR. Important questions remain about how planning is realized into levels of protection or preparedness and whether the amounts of SLR and planning horizons currently in use will lead countries to act in time.

Planning Support Systems (PSS) are increasingly used to support collaborative planning workshops in urban adaptation practice. Research has focused on developing such tools and evaluating their use in workshops but has not measured tools' effects over time on real planning processes, on the participants involved, and on the final outcomes. The role that tools play in adaptation planning, therefore, remains unclear. A longitudinal case study was made to evaluate a PSS, the Adaptation Support Tool (AST), in a design workshop for sustainable urban water management, in Berlin, Germany. The case study also served to test the evaluation framework and generate insights regarding systematic evaluations of tools in planning processes. The case study was carried out over eighteen months, to capture both the details of the workshop and its longer-term effects on the project and participants. Our results show that the AST's most evident effects were (1) contributory and less tangible in nature (e.g., supporting learning), than directly causal and concrete (e.g., affecting planning decisions), and (2) a function of the process and context in which the workshop took place. This study demonstrates that making systematic, longitudinal evaluations are valuable for studying the role of PSS in urban adaptation planning.

Planning Support Systems (PSS) are a promising tool for involving stakeholders in urban adaptation workshops. Past research has focused on the use and added value of PSS. While earlier studies have widely acknowledged the importance of context in determining the effectiveness of PSS, there has so far been no dedicated study of the influence of context on the use and added value of these tools in real planning workshops. To address this gap, we made an in-depth exploratory case study of a PSS, called the Adaptation Support Tool (AST), used in an adaptation planning workshop in Guayaquil, Ecuador. The workshop used the AST to support collaborative spatial planning for urban water management, at the neighbourhood scale. Interviews, questionnaires, observations and document review were used to investigate the influence of three contextual factors on the use and added value of the AST. The studied contextual factors are: 1) the style of tool use, 2) the phase of planning, and 3) the local project setting. Our findings indicate that the style of tool use and the local project setting were the most important contextual factors in determining the use and added value of the AST during the workshop. Meanwhile, the phase of planning appears to be critical for achieving impacts at the project level. This exploratory case study is a modest first contribution to understanding the influence of context on the use and added value of PSS in practice. Nevertheless, the findings indicate that further exploration of this topic could offer important insights to PSS use in practice. The influence of context on the use and added value of Planning Support Systems in workshops: an exploratory case study of climate adaptation planning in Guayaquil, Ecuador.

In the face of a changing climate, many cities are engaged in adaptation planning and are using participatory workshops to involve stakeholders in these initiatives. Different tools are being used to structure the process and content of participatory planning workshops, but it is unclear what effect the tools have on the workshops and their results. We evaluated three different tools (Group Model Building, the Adaptation Support Tool, and the Stress Test Guideline) and a tool-free approach in repeated simulated workshops, to observe and compare (1) the way workshops played out, and (2) the direct outcomes that were achieved. Tools appear to influence both aspects. Specifically, we measured differences in the learning effects in groups, in the development of shared understanding within groups, in the types of plans that are developed by groups, and in the nature of participation during the workshops. Further research is needed to translate these results into practice, but this is a first step in advancing knowledge about the influence of tools in participatory planning activities.