International Climate Migrant Policy and Estimates of Climate Migration

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

 

1、The paper presents a significant amount of information on climate migration estimates and the roles of different organizations. However, the central arguments could benefit from clearer organization. For instance, the distinction between "sudden-onset" and "slow-onset" migration drivers is critical yet not introduced systematically.

2、While the author references key reports like the Groundswell and IDMC data, more explicit details on data limitations and assumptions (e.g., the 10% underestimation by IDMC) would strengthen the paper. Discussing potential biases and their implications would add to the credibility and transparency of the arguments.

3、The policy recommendation to separate climate migration from existing adaptation and mitigation categories under UNFCCC is an interesting proposal. However, it could benefit from a more in-depth exploration of the feasibility of creating new structures and the political challenges this might entail. Please providing comparative examples or case studies on similar institutional restructurings.

4、The paper provides a rough cost estimate of $7,000 per climate migrant. However, this figure might benefit from additional context. For example, explaining the expected economic conditions under which this estimate holds, or the potential cost variations across different regions, would make this estimate more robust. A comparative analysis of current costs for other categories of migrants would also provide a useful benchmark.

5、Current climate migration predictions often rely on statistical data and trend analysis, which may struggle to capture the complex, nonlinear relationships between climate factors and migration patterns. Deep learning could potentially model these complex relationships by incorporating historical climate data, demographic information, and socioeconomic variables. Moreover, they could identify regions at higher risk of climate-induced migration, thus assisting policymakers in proactive planning and resource allocation. The author could provide a brief review of this aspect, which can refer to DOI: 10.1016/j.rse.2023.113884, DOI: 10.1080/15481603.2022.2142727.

6、Some sections use specialized terms (e.g., "IDPs," "anthropogenic climate change") that may not be familiar to all readers. Providing brief explanations or a glossary of terms could improve accessibility. Additionally, certain sentences are lengthy and complex, potentially hindering readability. Breaking these down into shorter, more direct statements may enhance comprehension.

 

 

Author Response

Response to Reviewer 1 comments

Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding revisions/corrections highlighted/in track changes in the re-submitted file.

1. The paper presents a significant amount of information on climate migration estimates and the roles of different organizations. However, the central arguments could benefit from clearer organization. For instance, the distinction between "sudden-onset" and "slow-onset" migration drivers is critical yet not introduced systematically.

Thanks for this suggestion. I have added an outline in the Introduction to clarify the organization for the reader and I have added definitions of slow- and sudden-onset climate change events. (Page 4, lines 157-169.)

2. While the author references key reports like the Groundswell and IDMC data, more explicit details on data limitations and assumptions (e.g., the 10% underestimation by IDMC) would strengthen the paper. Discussing potential biases and their implications would add to the credibility and transparency of the arguments.

Thanks for this suggestion. I have added substantial information and discussion of data limitations and assumptions in IDMC data including more information on how they tend to underestimate migration driven by sudden-onset climate change events. (Pages 5-6, lines 246-275.) The paper already includes extensive discussion of data limitations and assumptions in Groundswell.

3. The policy recommendation to separate climate migration from existing adaptation and mitigation categories under UNFCCC is an interesting proposal. However, it could benefit from a more in-depth exploration of the feasibility of creating new structures and the political challenges this might entail. Please providing comparative examples or case studies on similar institutional restructurings.

Thanks for this suggestion. I have added comparisons with the establishment of other new development agencies—the Global Environment Facility and the President’s Emergency Plan for AIDS Relief (PEPFAR)—when new functions (such as functions for helping climate migrants to rebuild their lives) do not fit previously established agencies’ forms. (Pages 14-15, lines 724-734.)

4. The paper provides a rough cost estimate of $7,000 per climate migrant. However, this figure might benefit from additional context. For example, explaining the expected economic conditions under which this estimate holds, or the potential cost variations across different regions, would make this estimate more robust. A comparative analysis of current costs for other categories of migrants would also provide a useful benchmark.

Thanks for this suggestion. While the paper already justifies the rough estimate of $7000 based on comparative analysis of the three current categories of migrants supported by humanitarian aid, I have added a number of additional cost-points of expenses for climate migrants that also support this estimate. (Page 13, lines 652-667.)

5. Current climate migration predictions often rely on statistical data and trend analysis, which may struggle to capture the complex, nonlinear relationships between climate factors and migration patterns. Deep learning could potentially model these complex relationships by incorporating historical climate data, demographic information, and socioeconomic variables. Moreover, they could identify regions at higher risk of climate-induced migration, thus assisting policymakers in proactive planning and resource allocation. The author could provide a brief review of this aspect, which can refer to DOI: 10.1016/j.rse.2023.113884, DOI: 10.1080/15481603.2022.2142727.

Thanks for this suggestion. After looking through the two indicated papers that discuss deep learning, I am not convinced that this methodology would significantly improve the foundation for climate migrant policy. My central arguments are that the policy community has greatly underestimated total potential climate migration and that the climate change policy community for the most part ignores the many millions of current climate migrants and is failing to prepare for larger numbers in the future. Should the policy community take on climate migration as a central concern alongside mitigation and adaptation, I don’t think it would be difficult to identify regions and populations at higher risk. The paper already points out that further research could significantly improve estimates of individual forms of climate migration.

6. Some sections use specialized terms (e.g., "IDPs," "anthropogenic climate change") that may not be familiar to all readers. Providing brief explanations or a glossary of terms could improve accessibility. Additionally, certain sentences are lengthy and complex, potentially hindering readability. Breaking these down into shorter, more direct statements may enhance comprehension.

Thanks for this suggestion. I have added clarification of the terms “IDPs” and “anthropogenic climate change.” (Page 4, lines 182-187 and 194-195.) Several sentences have also been shortened. (Page 7, lines 346-350; page 10, lines 483-486; page 12, lines 605-606.)

Thanks again for the helpful suggestions.

 

Reviewer 2 Report

Comments and Suggestions for Authors

1. "The paper argues that the costs of supporting climate migrants are projected to increase significantly, from approximately $49 billion annually in the 2020s to around $175 billion annually by the 2040s. However, this estimate requires further elaboration, including detailed justification and reliable data sources, to ensure clarity and prevent potential misinterpretation by readers.

2. "The author opens with compelling arguments in the introduction, effectively engaging the reader. However, some of these initial points lack proper citations, which weakens the foundation of the claims made. Adding references to support these statements would enhance credibility and give due credit to previous research."

3. In this paper, the author presented several estimates for climate migration. However, not academically justified why such figures/models are chosen in comparison with others. This would lead to challenges in validating accurate projections

4. In this paper, the author didn’t define few important concepts (e.g., climate migrants or "displacement). This will bring more confucion to the readers. Better to define these terms first and then logically link it with the core concept of the paper

5. I have seen in this paper that the author mainly relied on different reports such as “the Groundswell report by the World Bank”. However failed to engage critically with or comparing other studies that might offer different projections or methodologies

6. One major flaw I have noticed while going through the whole manuscript especially the organization of the manuscript as the transitions between different sections are more often abrupt and in some sections, the core arguments are repetitive. This makes hard to follow the main thesis of the manuscript

 

Comments on the Quality of English Language

The English could be improved to more clearly express the research.

Author Response

Response to Reviewer 2 comments

Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding revisions/corrections highlighted/in track changes in the re-submitted file.

1. The paper argues that the costs of supporting climate migrants are projected to increase significantly, from approximately $49 billion annually in the 2020s to around $175 billion annually by the 2040s. However, this estimate requires further elaboration, including detailed justification and reliable data sources, to ensure clarity and prevent potential misinterpretation by readers.

Thanks for this suggestion. I have added additional information on costs related to climate migrants that help to substantiate these estimates. (Page 13, lines 652-667.) Your quote of $49 to $175 billion is taken from the Introduction, where I am introducing arguments that are elaborated later in the paper, specifically in Section 7: What Would It Cost to Support Climate Migrants? Also, the paper makes clear that these are only rough estimates, to give an idea of the overall scale of costs, particularly compared to overall resources devoted to mitigation and adaptation and future needs in these areas. The paper makes clear that stronger mitigation and adaptation would probably reduce these costs.

2. The author opens with compelling arguments in the introduction, effectively engaging the reader. However, some of these initial points lack proper citations, which weakens the foundation of the claims made. Adding references to support these statements would enhance credibility and give due credit to previous research.

Thanks. I have added citations to the Introduction, as suggested. (Page 1, lines 33 and 37.)

3. In this paper, the author presented several estimates for climate migration. However, not academically justified why such figures/models are chosen in comparison with others. This would lead to challenges in validating accurate projections

The paper only aims to make rough estimates. I make clear that the current state of knowledge does not permit accurate projections. While the policy community is currently estimating potential climate migration by 2050 at around 200 million, I argue that 500 million is a more realistic estimate. The evidence I offer is sufficient to support this overall rough estimate, and I explain factors that could lead to significantly higher or lower numbers.

4. In this paper, the author didn’t define few important concepts (e.g., climate migrants or "displacement). This will bring more confucion to the readers. Better to define these terms first and then logically link it with the core concept of the paper.

Thanks for this suggestion. I have added further elaboration to Section 3, on Categories and Available Data Related to Climate Migration, which lays out meanings of “climate migrants” and “displacements.” (Page 4, lines 156-169.) I believe they are logically linked with the core concept of the paper. I have also added definitions and further explanation for other important concepts.

5. I have seen in this paper that the author mainly relied on different reports such as “the Groundswell report by the World Bank”. However failed to engage critically with or comparing other studies that might offer different projections or methodologies.

As the paper makes clear, the World Bank’s Groundswell is the unique report used as a standard reference for estimates of potential climate migration by the climate change policy community and the media since 2018, and unlike earlier analyses it employs sophisticated statistical methods. Since the paper argues that climate change policy should be changed to address the needs of climate migrants, it is this estimate normally used by the policy community that is relevant.

6. One major flaw I have noticed while going through the whole manuscript especially the organization of the manuscript as the transitions between different sections are more often abrupt and in some sections, the core arguments are repetitive. This makes hard to follow the main thesis of the manuscript.

Thanks for these suggestions. As noted above, the outline of the paper that I have added to the Introduction should make the manuscript’s organization clearer and help with its flow. I have checked all the transitions between sections and I believe they are all clear.

Regarding repetition, as this paper is submitted for a special edition of Sustainability on Climate Adaptation, Sustainability, Ethics, and Well-Being, conventions and styles in the Ethics literature are appropriate here. As a Perspectives paper making an ethical argument, as I develop the arguments I repeat some central claims in new contexts that bring new implications to light or where the claim is strengthened by new material. I believe that readers in the climate change policy community will have no trouble following the manuscript’s main thesis.

Thanks again for your suggestions.

Reviewer 3 Report

Comments and Suggestions for Authors

Please see attached report.

Comments for author File: Comments.pdf

Author Response

Response to Reviewer 3 comments

Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding revisions/corrections highlighted/in track changes in the re-submitted file.

1. Abstract   The abstract is overly lengthy and can benefit from a more concise summary. Aim to clearly convey the study's purpose, methodology, and main findings without delving into excessive detail.

It appears that your suggestions are informed by conventions in the scientific literature, but this paper is submitted to a special edition of Sustainability on Climate Adaptation, Sustainability, Ethics, and Well-Being. It speaks to the climate change policy community bringing ethical as well as scientific arguments to bear. I have published extensively in the ethics and policy literatures, where stylistic conventions are quite different. I believe that the Abstract as written is clear and helpful for readers in the policy community and conforms to appropriate stylistic conventions for this paper.

2. Introduction  The introduction should be rewritten to establish a compelling case for the study. Consider addressing the following:

• Why should readers and stakeholders care about this research?
• What is the novelty of your approach or findings?
• How does this work contribute to or challenge existing theories, and how does it build upon prior research?
• What makes this paper distinct within its field?

Additionally, include a paragraph at the end of the introduction that outlines the manuscript structure, guiding the reader on what to expect in the forthcoming section.

Thanks for the suggestion for an outline in the Introduction. As suggested, I have added an outline. (Page 1, lines 58-67.) Regarding the other suggestions, I believe the Introduction makes the novelty, importance, and contribution of the paper clear to the policy community which is its main intended audience and that the style and organization are consistent with relevant conventions (in ethics and policy literatures).

3. Section Titles The section titles currently resemble questions. Renaming them to reflect their content would improve clarity and professionalism.

It is normal in the ethics and policy literatures to frame headings as questions. I believe the current heading indicate the subsequent content clearly and that this form of heading is appropriate for this paper.

4. Literature Recommendations For the discussion on global emissions, referencing the work by Wojewodzki et al. (2023) would provide valuable context. Similarly, Shahrour et al. (2023) offers insights into greenhouse gas emissions and climate change, which could strengthen your arguments in this area, especially in the discussion on page 8.

While Wojewodzki et al. (2023) analyze carbon pollution policies in the private corporate sector, my paper addresses intergovernmental policies of the UNFCCC particularly in relation to support for climate migrants. I do not believe that this reference is directly relevant and I disagree with this suggestion.

While Shahrour et al. (2023) analyze the literature on the exposure of private corporations to climate risk, the dynamics of this exposure are very different from the dynamics of the risk people in developing countries face to displacement from their homes due to climate change. I do not believe that this reference is directly relevant and I disagree with this suggestion.

5. Clarification on James Hansen James Hansen’s name is cited, yet not all readers may be familiar with his work.

I believe it is clear from the context that James Hansen is a climate scientist.

6. Copy Editing Suggestions The manuscript would benefit from professional copy editing. Issues include inconsistent capitalization, such as "[a]pproximately one billion..." and "[o]ver one billion..." Avoid capitalizing unnecessary words like "Key Findings," which disrupts readability.

Thanks for these suggestions. I have adjusted for consistent capitalization and replaced the capitals in “Key Findings” with lower case letters. (Page 12, lines 580-582.)

7. Supportive Evidence The last paragraph before the discussion section on page 12 lacks sufficient evidence to back up the statements made. Strengthen this section by incorporating relevant data or citations.

Thanks for this suggestion. I have deleted the sentence, “When climate migrants leave their home countries, economic costs, cultural disruptions to migrants’ lives, and political disruptions are all likely to increase,” for which sufficient evidence is not offered. I believe that the other estimates in the paragraph are reasonable for their purposes, as rough estimates to inform current policy, and adequately supported by the paper’s wider arguments.

8. Tone in Discussion Section In Section 8, the tone becomes overly assertive. Avoid unsubstantiated claims, as they can detract from the scientific rigor of the discussion. For example, phrases like, "We can speculate that the UNFCCC has categorized climate migrants under adaptation and largely ignored them partly due to the political sensitivity of immigration in advanced countries," should be softened and supported by evidence. Scientific writing should convey hypotheses and analyses, avoiding speculation without basis.

I disagree with this suggestion. In the ethics and policy literatures it is considered appropriate to employ widely accepted premises that aid in interpreting a paper’s substantive contributions. In ethical writing it is appropriate to make ethical arguments that take the wider social context into account.

9. Conclusion and Conflict of Interest In the conclusion, similarly, avoid assertive language and speculative claims without support. Additionally, the mention of research findings and potential conflicts of interest should be in a separate section rather than in the introduction.

While I have added examples of other cases where the development community has created new organizations to address matters that established organizations have not adequately addressed, as a Perspectives paper focused on an area of Ethics I believe the language and claims in the Conclusion are appropriate and adequately supported by the paper’s analysis. The Introduction does not address potential conflicts of interest.

Thank you again for your suggestions.

 

 

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

I have no more questions.

Reviewer 2 Report

Comments and Suggestions for Authors

Thank you for addressing the comments. I have checked the revised manuscript carefully and found that the author addressed all the comments carefully. Thus i accept this manucript in its present form

Reviewer 3 Report

Comments and Suggestions for Authors

Thank you for submitting the revised manuscript, which remains almost unchanged.

The manuscript falls short of meeting the journal's standards for scientific rigor, interdisciplinary integration, and evidentiary support. Please refer to my previous report in this regard.

The tone in some sections, such as the discussion and conclusion, remains assertive and speculative. Ethical writing can accommodate nuanced arguments without overreaching claims, especially when addressing topics with significant policy implications.

Many responses to reviewer comments rely on disciplinary conventions as a rationale for retaining the manuscript's structure and content. While such conventions are respected, this journal serves a broader interdisciplinary audience that expects adherence to rigorous academic standards and engagement with diverse perspectives. For instance, in the comment regarding James Hansen, your response suggests that you believe it is clear from the context who he is. I must emphasize that personal beliefs are not a substitute for the clarity and precision required in rigorous scientific writing.

Considering these concerns, beyond others, the manuscript does not currently meet the expectations of the journal for publication. I encourage you to revisit these areas and consider a more comprehensive revision for future submissions, potentially targeting a journal more closely aligned with the stylistic and thematic conventions of ethics and policy.

Therefore, I regret to inform you of my decision to reject your paper.

Comments on the Quality of English Language

Requires copy-editing.