Beyond the Rising Tide: Towards Effective Climate Policy in Coastal Urban Centers

Round 1

Reviewer 1 Report (Previous Reviewer 2)

Comments and Suggestions for Authors

None.

Reviewer 2 Report (Previous Reviewer 3)

Comments and Suggestions for Authors

This paper is a study comparing worldwide coastal megacities. A paragraph has been added justifying studies with few variables. Anyhow the results are interesting and might be important to the cities quoted. 

I do not add more commentaries since mine were attended

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The paper, intitled “Beyond the Rising Tide: Towards Effective Climate Policy in Coastal Urban Centers”, addresses the extremely important topic how climate changes will affect large coastal cities in the future.

 

General comments:

In general, the paper reads like an essay, with a good review of the main issues to be considered seconded by references. This essay style reflects also on the fact that parts of the materials and methods, results and discussion, and even conclusion read as introduction passages.

The analysis itself is, in my opinion, superficial and insufficiently documented (from reading the paper it would be impossible to reproduce the results without extensive trial and error). Based on its results, the authors make inferences and claims that, while very likely true, can hardly be reached from their results.

I do not think the proposed methodology, simple and of global applicability, will be particularly useful to steer climate change action in large and mega cities even close to the level claimed by the authors. Such cities attract the attention and muster the resources necessary for custom climate change actions to be identified and planned (not necessarily implemented). I see the potential value of the current methodology in raising awareness.

As the paper includes significant literature review, I wonder why the authors did not attempt to make a review publication, without “new methodology” but focused on all the issues discussed in the text, instead of drafting the paper in its current form.

 

Detailed comments:

In the abstract, human mobility is used. I believe human migration would be more suitable given the contents of the paper.

The introduction is well written and clear. It outlines several perceived shortcomings in current research that should be addressed to fully understand the interplay between climate change, human migration, and biodiversity in large coastal cities. Only in the last paragraph do authors hint at what their aim is. I would prefer an introduction that already outlines, not only what the authors’ set out to accomplish, but also: 1) a hint of how they intend to do it and 2) a critical comment on similar earlier works/attempts.

In the methodology, it is not clear why SIDS are mentioned at the onset, only for the authors to mention they will not be looked at. This could be removed or included in the introduction.

How did the authors interact with the “online platform” used to retrieve simulations of sea level rise due to simulations? How is the sea level rise of 0.5 m related to SSP scenarios?

Figure 1 is not fully coherent with the remainder of the paper.

Figure 2 should focus on coastal cities.

The authors state that “Analyzing the complex interactions between coastal Megacities and the environment, key components emerge, such as: urbanization, energy consumption, transportation, industry, agriculture, water consumption, and tourism [41]. These interactions manifest as drives, pressures, states, and impacts, revealing obstacles to implementing global development policies in large coastal urban agglomerations.” In other words, the issue is complex. Yet, they propose a very simple classification system to address this problematic. They should explain why such an approach should work.

Finally, the proposed classification is troublesome for me. What strikes me the most is that socioeconomic features, very important to evaluate adaptation potential and resilience, are not directly factored in the analysis. As a close second, the classification is based on a set of binary rules of the affected/not affected type, leaving aside issues of magnitude of the impacts. Related to this, what are the thresholds associated with each criterion? For example, minor parts of a city may be vulnerable to sea level rise, without it being a major issue to the whole agglomeration. Another example is migration. Every mega city will attract people, what sets apart those classified as “migratory destinations”? I am also curious as to why, within the proposed classification system, a city that is vulnerable to sea level rise and a biodiversity hotspot, but not a migratory destination, is not considered. Finally, the labelling of the 4^th class “critical climate emergency” is – in my opinion – misleading.

 

Specific comments:

Please refer to the attached pdf file.

Comments for author File: Comments.pdf

Comments on the Quality of English Language

The paper is well written and clear. I identified only minor editing issues, highlighted in the attached pdf file.

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript is good.  The authors developed a vulnerability classification system for the world's large cities related to climate conditions and change.  They classified large cities based on several criteria, implicating potential future conditions.  The results and related conclusions are sound.  

I think that the study will interest many parties around the world.  However, I think that the study could be improved/expanded by offering a model that small cities/towns could use to perform self-assessments along similar lines of the study.  Such a model could be applicable globally and allow for planners to conceptualize current and future conditions in a new light.  

Figure 2, the map, needs to be edited.  For example, it locates Guangzhou in southern India, rather than China.  

Comments on the Quality of English Language

The English language could be improved moderately but it is good.  

Reviewer 3 Report

Comments and Suggestions for Authors

This paper proposes classifying climate emergency coastal megacities. The authors conclude that 43 megacities are categorized into four levels of vulnerability. They use it straightforwardly and logically, but the main problem with the exposure of the methods and results is that the authors must provide a map (or table) for each indicator. 

When mixing apples and pears, investigators must explain how and why they added the variables, especially whether the indicators are comparable. Have all the indicators used the same weight? If that is so, migration has a different impact than sea level rise or population growth. Depicting a map for each indicator could help to understand the adding experiment.

While the research is comprehensive, there is a need for more precision in some of the results. For instance, the use of the indicator 'megacity' for cities with no coastal importance could be further explained. This precision will enhance the credibility of the research and keep the readers interested. 

The resulting classification of megacities is repeated several times in Figure 3, as well as in the results and conclusion text.