**1. Introduction**

There is an increasing movement of local policy-makers to act against climate change, urging to adapt their cities and improve their resilience with suitable policies [1]. Designing and implementing general local-scale policies requires multidisciplinary studies and taking broad assumptions to address uncertainties, in order to maximize the welfare associated with a desirable outcome, such as improving public transport [2]. Climate change adaptation policy making has additional complexities. In the design phase, which is the scope of this paper, there are uncertainties related to climate predictions, vulnerability, and risk impacts, as well as socio-economic, technological, and environmental future trends that complicate the understanding of the potential outcome of a measure [3]. In addition, they have a cross-sectoral nature and diversity in terms of typology (e.g., structural, nature-based, or digital), scales (from a building to national scale), and timescales (short, medium, and long term) [3]. These

complexities undermine measures' assessment results that consider only one criterion. Therefore, a systematic prioritization assessment is required in order to support the selection of the most suitable set of measures for each city under a changing climate context.

The purpose of the assessment of climate change adaptation measures is to minimize the degree of uncertainty when selecting policies that reduce the impacts of the changing climate [2]. For this purpose, technical and economic assessment approaches are usually considered (or a combination of them), as they provide relevant information about the costs and expected physical effects of the measures. However, in general, the degree of uncertainty of the results is linked to data availability and specific technical expertise to carry out detailed assessments. Therefore, when selecting a method, such limiting factors (i.e., data and skills availability) should be considered.

The present work has been developed in the context of the H2020 project RESCCUE [4], where a number of innovative models and tools were developed in order to help urban areas to become more resilient to climate change. One of the tools is the present methodology that aims to facilitate the ranking of all available adaptation measures considering the particularities of each city. Results are presented for Bristol and Barcelona (Figure 1), two of the three case study cities, to display the different approaches taken by each city.

**Figure 1.** Location of the two cities where the methodology has been applied: (**a**) Bristol, United Kingdom and (**b**) Barcelona, Spain.

Section 2 summarizes the main methods used to evaluate adaptation measures. Section 3 starts with a brief description of the key terminology, and it is followed by the description of the methodological approach, presented by stages. Main methodological differences between Barcelona and Bristol studies are presented in order to compare the different approaches taken. The results for both case studies—Section 4—are also divided by stages. In the discussion, results are commented, as well as the main challenges found when applying the methodology and recommendations for further application of the methodology. The conclusion summarizes the main results.
