Analysis of Climate-Related Risks for Chile’s Coastal Settlements in the ARClim Web Platform

Round 1

Reviewer 1 Report

The study aims to explore climate-change-related risks along the Chilean coasts, focusing on flooding and fisheries and operational shutdowns due to changes in climate.

 In brief, I think that this is an interesting paper with solid results. Thus, in my opinion, the ms. can be accepted for publication after major revision. My major problem was how sensitivity was calculated, as I explain below. Some grammar and style edits are necessary.

 Specific comments follow:

Abstract

The abstract is well written. However, it is difficult to grasp the goals of the study and the main results from just reading the abstract. I would recommend making sure that these are clearer. Also, the conclusions are not easy to grasp in the abstract.

 Introduction

The introduction is very interesting and nicely written. It contains good and interesting information regarding the actions taken my Chile to face climate Change-related risks. Coastal risk is associated with exposure, sensitivity and hazards. I wonder if the authors use sensitivity as a synonym of vulnerability? From my experience (what I have worked with, and the articles I have read), it is more common to use vulnerability instead of sensitivity (see for instance the work by Kron et al. 2019. Changes in risk of extreme weather events in Europe. Environmental Science and Policy 100: 74-83. Can you please explain this?

 In general, the introduction is well-explained and easy to follow. However, before the methos section, I think the authors should clearly state the goals of the study. These are not clear neither here, nor in the abstract.

 Methods.

In section on storm surge and astronomical tide: (Line 201) why did the authors use data from 2010 as representative of the historical period? This seemed odd to me.

 Section on sensitivity- Lines 289-293. It is not clear to me how this was calculated by the authors, since the units of the variables used are very different: type of settlement (binomial, urban or rural); exposed buildings (I guess it was number of buildings); housing and population density (number of houses or people per unit area); and fraction of inhabitants per housing (was this a percentage?). How were these variables pondered from 0 to 1? How can you add several variables with different units? The authors really need to explain this. Any scientific study should be replicable, and I could not replicate their calculations of sensitivity.

 Operational downtime risk.- Line 329. Is this sensitivity the same as in the equation for risk? This is not clear. Pleas explain.

 Sensitivity.- Lines 390-392. Again, it was not clear to me. How can you have similar variables in the equation with which you are calculating the index? I mean, Sensitivity = Operational sensitivity index (So) + structural sensitivity (Se). Also, the equations to estimate So and Se are additions of variables with different units… so it is a similar problem than that outlined before.

 Results

They are clear and interesting (except for sensitivity, because I did not understand how it was calculated.

 Figures 6 and 8.- I think it would be easier to see this figure if the authors used contrasting colors (maybe the same for each index), instead of different-sized circles. It could be red, the worst condition, and green the best.

 Discussion and conclusions

 The ideas in the discussion were very interesting. Perhaps the discussion could be shortened…

Author Response

REVIEWER 1

 

The study aims to explore climate-change-related risks along the Chilean coasts, focusing on flooding and fisheries and operational shutdowns due to changes in climate. In brief, I think that this is an interesting paper with solid results. Thus, in my opinion, the ms. can be accepted for publication after major revision. My major problem was how sensitivity was calculated, as I explain below. Some grammar and style edits are necessary.

 

Reply: Thanks.

 

Specific comments follow:

 

Abstract

 

The abstract is well written. However, it is difficult to grasp the goals of the study and the main results from just reading the abstract. I would recommend making sure that these are clearer. Also, the conclusions are not easy to grasp in the abstract.

 

Reply: The abstract is amended to better explain the goals and main results of the study.

 

Introduction

 

The introduction is very interesting and nicely written. It contains good and interesting information regarding the actions taken my Chile to face climate Change-related risks. Coastal risk is associated with exposure, sensitivity, and hazards. I wonder if the authors use sensitivity as a synonym of vulnerability. From my experience (what I have worked with, and the articles I have read), it is more common to use vulnerability instead of sensitivity (see for instance the work by Kron et al. 2019. Changes in risk of extreme weather events in Europe. Environmental Science and Policy 100: 74-83. Can you please explain this?

 

Reply: ARCLIM was envisioned to communicate the main components of risk, namely, hazard, exposure and vulnerability using a common framework across many different socio-economic sectors of systems to facilitate comparison and analysis. Vulnerability is defined as a combination of sensitivity and adaptive capacity. However, only few sectors have developed a conceptual framework to account for adaptive capacity in a (semi) quantitative manner. On the contrary, sensitivity data was frequently available or relatively easy to develop. Under these conditions, lead PI of the project decided for consistency to represent the vulnerability within the ARCLIM project focusing on the sensitivity component. Further work can refine this assessment developing specific sectors indicators of adaptive capacity allowing a better representation of vulnerability.

 

In general, the introduction is well-explained and easy to follow. However, before the methods section, I think the authors should clearly state the goals of the study. These are not clear neither here, nor in the abstract.

 

Reply: The goals are more explicitly included in the abstract by stating: “This paper illustrates the implementation of ARClim of on two 27 coastal sectors, operational downtime in fishing coves and flooding in coastal settlements, aiming to provide a tool to visualize comparative estimates of risk, which may enable decision makers and stakeholders to prioritize adaptation measures”.

 

Methods

 

In section on storm surge and astronomical tide: (Line 201) why did the authors use data from 2010 as representative of the historical period? This seemed odd to me.

 

Reply: We coincide with the reviewer’s concern. Fortunately, astronomical tide is bounded, periodic and relatively constant, thus there are no big changes throughout different periods. Thus, using one particular year is a reasonable approximation to characterize this variable. Storm surge, however, is climate dependent. The reason to use data from 2010 for the historical period was based on the practical reason that it was readily available during the project. Though we coincide that the best solution would be to use data covering the period 1985-2005, it would have taken resources (time, workforce) largely exceeding those allotted to the project. Nevertheless, storm surge was the least important contribution to flood level; thus, we speculate that the limitations introduced by using 2010’s data instead of the historical value should not have a relevant impact in the results of flooding risk of coastal settlements. This is clarified ion the document.

 

Section on sensitivity- Lines 289-293. It is not clear to me how this was calculated by the authors, since the units of the variables used are very different: type of settlement (binomial, urban or rural); exposed buildings (I guess it was number of buildings); housing and population density (number of houses or people per unit area); and fraction of inhabitants per housing (was this a percentage?). How were these variables pondered from 0 to 1? How can you add several variables with different units? The authors really need to explain this. Any scientific study should be replicable, and I could not replicate their calculations of sensitivity.

 

Reply: We agree with the reviewer’s concern that we are comparing different types of variables. However, all variables are non-dimensional, similarly weighted and scaled between 0 and 1 to allow comparison. Indeed, some of these variables may adopt 2 values (B= 0 or 1), 4 values (C= 0, 0.25, 0.5 or 1) and values between 0 and 1 depending on the population density (P), housing density (H) and habitants per house (F). We include an additional sentence to clarify this.

 

Operational downtime risk.- Line 329. Is this sensitivity the same as in the equation for risk? This is not clear. Please explain.

 

Reply: We understand the confusion as we were not rigorous when defining variables for both systems. In the new version, we add superscript to discriminate between the flooding risk of coastal settlements (equation 4)

and the operational downtime risk of fishing coves (equation 5)

 

Sensitivity.- Lines 390-392. Again, it was not clear to me. How can you have similar variables in the equation with which you are calculating the index? I mean, Sensitivity = Operational sensitivity index (So) + structural sensitivity (Se). Also, the equations to estimate So and Se are additions of variables with different units… so it is a similar problem than that outlined before.

 

Reply: We agree with the reviewer’s concern that we are comparing different types of variables. However, all variables are non-dimensional, similarly weighted and scaled between 0 and 1 to allow comparison. We include an additional sentence to clarify this.

 

Results

 

They are clear and interesting (except for sensitivity, because I did not understand how it was calculated.

 

Reply: Thanks.

 

Figures 6 and 8.- I think it would be easier to see this figure if the authors used contrasting colors (maybe the same for each index), instead of different-sized circles. It could be red, the worst condition, and green the best.

 

Reply: Though we coincide with the reviewers (it was a hard work to choose colors which would enhance contrast for the different fields), we decided to preserve the colors used in the web-based ARClim, as one of the main points of the article is to promote is online use. Changing the colors in the manuscript would imply changing the color of the web site, which is at this point unfeasible (the project is finished). We hope the reviewers understand that.

 

 Discussion and conclusions

 

The ideas in the discussion were very interesting. Perhaps the discussion could be shortened.

 

Reply: The discussion is shortened and some parts included in the new section of conclusions.

Reviewer 2 Report

186-187 Actualize with results of AR6 of the IPCC. Give more details on the IPCC methodology.

188-189 Explain why only scenario RCP 8.5 is explored.

428-509 Why 3.2 Flooding risk of coastal settlements is lacated before 3.1 Operational downtime risk of fishing coves?

513-664 It is recommended to separate the sections "Discussion" and "Conclusions". This will help the reader to appreciate the most important conclusions.

General: Recommended to include the references of the annexed file.

 

Comments for author File: Comments.pdf

Author Response

REVIEWER 2

 

186-187 Actualize with results of AR6 of the IPCC.

 

Reply: Results of AR6 were not available when ARClim became operational in 2020. Therefore, the computation of risk was based on data from AR5. We believe it’s not consistent to cite results of AR6, not two references proposed by the reviewer, namely:

 

• IPCC (2021). Summary for Policy Makers. V. Masson-Delmotte, P. Zhai, Y. Chen, L. Goldfarb, M. I. Gomis, J. B. R. Matthews, et al. (eds.), Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change.

 

• IPCC (2022). Climate Change 2022: Impacts, Adaptation, and Vulnerability. H.-O. Pörtner, D. C. Roberts, M. Tignor, E. S. Poloczanska, K. Mintenbeck, A. Alegría, M. Craig, S. Langsdorf, S. Löschke, V. Möller, A. Okem, B. Rama (eds.), Climate Change 2022: Impacts, Adaptation, and Vulnerability. Contribution of Working Group II to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change.

 

186-187 Give more details on the IPCC methodology.

 

Reply: The computation of Sea Level Rise (which we believe is what the reviewer is asking for) was based on 21 GCM which include several contributions. This dataset was produced by Slangen et al. (2014), which was not cited in the first manuscript. We therefore cite the reference and slightly amend the text.

 

• Slangen, A.B.A.; Carson, M.; Katsman, C.A.; Van de Wal, R.S.W.; Köhl, A., Vermeersen, L.L.A., & Stammer, D. (2014). Project-ing twenty-first century regional sea-level changes. Climatic Change, 124(1), 317-332.

 

188-189 Explain why only scenario RCP 8.5 is explored.

 

Reply: The use of RCP 8.5 was considered as the worst-case scenario based on the best available information (i.e., CMIP5) we had at hand when developing ARClim. This comment is included in the manuscript.

 

428-509 Why 3.2 Flooding risk of coastal settlements is located before 3.1 Operational downtime risk of fishing coves?

 

Reply: The numbering is amended.

 

513-664 It is recommended to separate the sections "Discussion" and "Conclusions". This will help the reader to appreciate the most important conclusions.

 

Reply: We include a new section of conclusions, including text formerly used in the discussion.

 

General: Recommended to include the references of the annexed file.

 

Reply: We include the following references proposed by the reviewer.

 

• Marín-Monroy, E.A., Hernández-Trejo, V., Ojeda Ruiz de la Peña, M.A., Romero-Vadillo, E. and Ivanova-Boncheva, A. (2021). Perceptions and Consequences of Socioenvironmental Vulnerability Due to Tropical Cyclones in Los Cabos, Mexico, Sustainability, Volume 13(12), 678, https://doi.org/10.3390/su13126787

 

• Reguero BG, Griggs G. Editorial: Adaptation to Coastal Climate Change and Sea-Level Rise. Water. 2022; 14(7):996. https://doi.org/10.3390/w14070996

Round 2

Reviewer 1 Report

 

The authors have mostly addressed all the recommendations I made in the first revision. There are a few minor recommendations left.

 

1. I still think that sensitivity and adaptive capacity need a clearer definition. (Line 59).
2. Storm surge using data from 2010. I understand the reasons for doing so. But then, I think the authors should add a few lines in the discussion explaining this limitation of their study. The same arguments used in the response letter can be used for this.
3. Please make sure that the elements of each equation are clearly explained.

 

 

Author Response

I still think that sensitivity and adaptive capacity need a clearer definition. (Line 59).

 

Reply: Sensitivity and adaptative capacity are defined as in IPCC’s AR5, following the reference:

 

• IPCC, 2022: Annex II: Glossary [Möller, V., R. et al. (eds.)]. In: Climate Change 2022: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [H.-O. Pörtner et al. (eds.)]. Cambridge University Press, Cambridge, UK and New York, NY, USA, pp. 2897–2930, doi:10.1017/9781009325844.029.

 

Storm surge using data from 2010. I understand the reasons for doing so. But then, I think the authors should add a few lines in the discussion explaining this limitation of their study. The same arguments used in the response letter can be used for this.

 

Reply: We include a few lines in the discussion explaining this limitation.

 

Please make sure that the elements of each equation are clearly explained.

 

Reply: All the equations and components are now explained (there were some elements if the flooding hazard omitted in the earlier version of the manuscript).