Let me say at the outset that I can only comment on the participatory approach and how it may be improved, as the scientific data and models discussed in this manuscript are beyond the scope of my area of expertise.

It would be useful to have a clear definition of what the authors mean by the participatory process. Participatory processes enable ordinary people to collectively identify problems, gather information, analyse, design and identify solutions which has value to them and their network. As such an authentic participatory process includes stakeholders in all phases of the research - identification of the problem, design and dissemination of the research.

A better definition for this project would be one developed by Harris (2019) specifically for environmental communication: “Participatory Environmental Communication integrates interdisciplinary knowledge, inspires collaboration and dialogue, and utilises information networks to catalyse the agency of ordinary people towards collective action.”

A participatory process that engages stakeholders in all aspects of the research would be difficult to fully enact in scientific research such as this which requires a high level of expertise and scientific knowledge in the field of hydrology as stated by the researchers in the following quotes:Scientists or experts have to decide on what and how to produce climate change risk information before they communicate it to local stakeholders., “An interdisciplinary team of two sociologists and us, two hydrologists, designed and conducted the participatory process.” ... “The aim of all workshops was that stakeholders jointly develop climate change adaptation strategies, learn about other perspectives and network.”It is evident that the participatory process was limited to the dissemination of knowledge - “to what effect is communicated”—  to raise awareness about uncertainties and enable stakeholders to make more informed decisions in their respective roles and engage better discussions during the subsequent workshops in the participatory process of the project KlimaRhön.

I suggest that the authors clarify:

1. How did the participants contribute (or not) to the design of the research i.e choice of study area, method, or other input into the research design?
2. What was the contribution of the sociologists in the interdisciplinary team?
3. How did the process benefit the stakeholders to make informed decisions in their respective roles?
4. Did the stakeholders jointly develop climate change adaptation strategies, learn about other perspectives and network.”?

Some of these questions can be answered by conducting a focus group or distributing  a qualitative research questionnaire  in which the stakeholders are asked how the process benefited them to make informed decisions in their respective roles and develop climate change adaptation strategies and learn about other perspectives and network.”

Their comments can then be included in the manuscript. The voices of the participants would increase the credibility of the participatory process.

As a communication scholar with no expertise in this area, I found it difficult to navigate the data-laden research results and terminology despite the authors’ attempts to simplify the terminology and research results. Since the manuscript will be published in EGUsphere, the comprehensive engagement with data is valid. However, I would recommend less reliance on technical explanations, if they were to publish this for wider public consumption.

Note: This reviewer has proposed a model for participatory environmental communication which the authors may like to  consult for future projects. See

Harris, U. S. (2019). Participatory media in environmental communication: engaging communities in the periphery. (Routledge studies in environmental communication and media). London; New York: Routledge, Taylor and Francis Group.

General comments

The paper aims to present an approach for quantifying and communicating climate change-related uncertainties and outputs of models to stakeholders as part of a participatory climate change adaptation process. The paper provides information about the context and the participatory process used in this study, the variables used, and how results are communicated and perceived by the audience, and it discusses issues around communicating uncertainty.

The topic of the manuscript is helpful for scientists who want to identify ways to better communicate uncertainty to stakeholders, such as the uncertainty relating to climate change. The adopted approach and the study's outcomes provide insights into how communication can shape stakeholders' understanding and subsequently influence decision-making on adaptation strategies. In addition, the study provides valuable information on aspects that should be considered when designing content to visualise uncertainty.

However, the manuscript should be improved to bring out the valuable points it discusses in a more structured manner, increasing the impact of the study and broadening the readership.

First, as a general comment, the paper would benefit from some serious editing; the text is too long, and the story gets easily lost. Providing the information more concisely will make it a more valuable contribution. Specific suggestions on how the manuscript can be improved are included below.

Specific comments

The paper's objective relates to two distinct tasks: (a) how to assess climate change hazards with their uncertainties from multi-model outputs and (b) how to communicate this information in a climate adaptation-focused participatory process. However, considering how the information is presented in the paper sections, it is unclear how these tasks are addressed and what the key messages are. It might help readers to follow the study more effectively if the structure of the paper was slightly re-organised. As a suggestion, the authors could distinguish the two tasks and provide details on the approach and results for each. For example, in chapter 3, where the adopted approach is presented, there could be two different clearly labelled sections, one for each objective, providing details on the methodology used to address these. Similarly, in chapter 5, the discussion could address the two distinct tasks more explicitly.

The paper includes an abstract and a plain-language summary; however, there is no significant difference between these two sections. From a typical reader’s perspective and if the authors consider the need for a plain language summary, I suggest focusing on the problem this study tries to solve and why this study is important and reference the adopted approach and results using simple language to allow an average reader to understand. In addition, making reference to the usability of such an approach in a different context would also add value. In the case of the abstract, and aiming to help the readers identify the essence of the study and remember the key points, the authors could consider adding details to clarify the study's objectives and overall contribution.

The introduction section seems too long and makes it difficult for the average reader to understand the background, context, and problem this study aims to solve. Also, how it is written makes it difficult for the reader to identify the gap in the literature this paper addresses. The suggestions below can improve the contextualisation of the study and will help the reader follow the next sections better:

• Provide information on existing approaches; this could be a table presenting advantages and disadvantages and highlighting challenges when communicating uncertainties. The proposed table will allow the reader to understand the existing approaches, what is missing, and what this paper seeks to address.
• There is information in other sections of the manuscript that can be used in the Introduction section to improve the contextualisation of the study. For example, in section 5 (§5.1.1 and 5.1.2), information around uncertainty and available models and visualisation formats could be used to set the background, preparing the reader about what is coming up and what this study is trying to achieve. Similarly, information included in section 6 around the theoretical background (1^st paragraph on page 29 - lines 741-752) could be used to shape the contextualisation of the study.
• To reduce the length of this section and improve its readability, I suggest making the presented information more concise and reducing repetition. Removing the 2^nd paragraph on page 3 (lines 76-89) and adding the content as supplementary material would help reduce the length and allow the typical reader to focus on the context of the study.

Section 2 provides information about the case study and the participatory process. The authors could consider if this section could be incorporated into the methodology and results chapters. For example, the case study part §2.1 presents the study area and, therefore, could be part of section 4, which presents the study results. Also, the participatory process part §2.2 discusses the approach adopted in this study and links to the methodological aspects. As a suggestion, this part can be included in Section 3, which discusses the overall methodology. In this way, the information will be presented in a more structured way, allowing an average reader to follow the paper better.

Section 3 presents the approach adopted in the study. This section seems too long and makes it difficult for an average reader to understand the approach and reasoning behind it. I suggest the following changes that will improve the way the information is captured and will enable the reader to understand easily the adopted process, broadening the readership of the manuscript:

• The authors could explain the methodology used per objectives (a and b) as mentioned previously; there could be two different clearly labelled sections, one for each objective, providing details on the methodology used to address these. Also, to allow readers to follow the logic of the methodology more closely, the authors could consider including a graphical abstract of the main steps of their approach per objective.
• Sections 3.1 and 3.2 provide information on the hydrological hazard indicators; although the information is useful, it can distract the reader from understanding the adopted approach. I suggest the authors provide a brief summary in this section and include the information as supplementary material to improve the readability.
• Sections 3.1 and 3.2 provide information on the analysis conducted, addressing the objective (a) of the study; what is missing to allow readers to follow the approach more closely is the output of this task, what this analysis provides and how it feeds into the next step (objective b). Currently, this information is captured in section 3.3; for example, the analysis output was the design of graphics used in the participatory process (as mentioned in §3.3.2, line 325).
• Section 3.3 provides information on communicating the hazard indicators, so it mainly addresses the objective (b) of the study. Although the section provides detailed information on the process followed, how the information is presented can be confusing for an average reader. The authors could consider (as mentioned previously) including the participatory process part §2.2 in this section, as it addresses methodological aspects adopted in this study. The overall process and information could be presented in a graph or a table, showing details on the workshops, timeline, participants, objectives and what has been achieved. Also, the authors could consider adding information to reflect why they chose the specific way of communication to allow the reader to understand the driver behind the specific approach. Furthermore, information relevant to the options provided to stakeholders (mentioned in section 4, page 21) could also be included here. This will improve the paper's readability, allowing the reader to follow the logic of the participatory process more closely.
• Section 3.3 is too long and includes details that can confuse the average reader. To improve the readability, I suggest the authors consider including information that is relevant to the approach only and not the results and presenting it more concisely. For example, the last paragraph of the section on page 18 (lines 442-454) presents some of the results that can be included in section 4 (results).
• The authors could consider adding a more detailed description in Figure 2 (page 13) to allow the reader to understand why the selected multi-model ensemble represents the currently best estimate of future hydrological hazards.
• Average readers might be able to follow the graphs presented in Figure 4 (page 15) more clearly if there was a more thorough explanation of the potential change of groundwater recharge in the caption, as mentioned on page 14 (lines 345-352). A similar approach could be adopted for Figure 5).
• In section 3.3, pages 14-15, lines 359-368, information more relevant to the analysis rather than the communication aspects is included. The authors could consider whether this information can be moved to section 3.1 (as per the previous comment) to allow readers to follow the logic of the methodology more closely.
• To reduce the length of this section, terms and concepts (including Table 1) could be included in the introduction or supplementary material.

Section 4 presents the results of the study. As mentioned in a previous comment, this section could include information about the case study (currently §2.1) at the beginning and then present the results. Figures 6 and 7 could be presented on the same page, allowing the average reader to compare the results easily. The authors could consider adding information on the importance of the results and how these are dependent on the number of participants in the workshops. For example, based on the online participation, the results seem more significant than those from the in-person presentation. There is no information to determine whether the type of participants in the in-person workshop adds value to the results. Also, no information is included regarding the conducted statistical analysis of the results. Finally, the authors could consider a different type of format for Figure 9 (perhaps combining the two visualisations in one) to avoid confusion with the graphs used in the participatory process and help the reader interpret the results. In addition, and as per the GC guidelines, the authors should use in the figures a colour combination that would allow readers with colour vision deficiencies to interpret the findings correctly.

The discussion chapter (Section 5) could be further improved by adding more detail on interpreting the results in the context of the objective of this study rather than referencing the results, which is already done in Section 4. For example, considering the outcome of the workshops, did the authors further explore the stakeholders' views on the communication format that would make more sense to them? How did the authors interpret the results considering the overall context of the study? What are the key messages? What is the novelty of the approach, what are the advantages and disadvantages, and why was this specific approach chosen? What are the limitations? Also, a typical reader might not understand how the specific approach adopted in this study tackled some of the issues mentioned in the chapter. For example, how did it address the transparency? How did it help the stakeholders in decision-making? Explicitly exploring and answering these questions would lead to a much stronger paper with a more broadly applicable impact and will allow for broadening the readership of the manuscript beyond subject area experts.

The conclusions section (Section 6) would benefit from a synthesis of the main points of the study, highlighting the advantages of the adopted approach and the importance of the paper more briefly. This would help the reader understand why the study should matter to them after having finished reading the paper.

Finally, as a suggestion and according to the GC guidance, the ethical statement should be more comprehensive, and a description of the process should be included in the methodology section of the paper.