Long-Term Projection of Transport-Related Social Cost of Greenhouse Gas Emissions in Qatar

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

No baseline data - from 2023 or earlier. It is therefore difficult to assess the feasibility of the baseline scenario and the expected progress. Moreover, the second scenario is unclear - on what basis is the improvement in efficiency assumed? This should be supplemented and made credible so that these are not wishes but probable changes.

Author Response

Dear Expert,

Thank you very much for your time and valuable feedback which substantially improved our manuscript.

Attached are our replies.

Much appreciated.

 

 

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

The paper is an interesting case study for the assessment of external cost of transport. However, it is needed to consider the following comments for the improvement of the paper's impact:

In the introduction (lines 61-62), some information on the increase (rate) of population and the economy recently would better explain the "remarkable advancements" mentioned above in the text. If available, some data on the increase of vehicle ownership (lines 64-65) and use, maybe in comparison to global, regional or other countries’ data, would be informative and supportive of the paper’s scope. This more detailed description would offer data and trends which could help the reader understand the development of the baseline and the rest of scenarios. In this context, you may consider adding a section for the description of the study area, i.e. the recent developments and current situation of transport development in Qatar in relation to both reasons and (environmental) impacts.

A minor comment refers to the use of the term "nation". While "national" may refer to the country, the term "nation" refer to the people of a specific nationality, within or outside the boundaries of the corresponding country. E.g., in line 81 I believe that you do not mean “within the nation” but “within the country”.

In Methods, namely referring to lines 95-97, it would be helpful to the reader in order to better understand the LEAP tool, to briefly mention some other cases from the international literature where the specific tool was applied, in what context and to what purpose. Furthermore, here and later on in the text, you mention the use of the specific methodology in sectors other than transport. However, there are several recent and older published research papers discussing the assessment of the external costs from transport (using LEAP or the Handbook on the external costs of transport etc.). There should be a synthetic review and discussion of such research in your paper. If your paper adds something new in this literature, methodologically or regarding the area of implementation or in any other aspect, it should be highlighted. 

In the same section (i.e., Methods), you provide general information about the concept of the methodology and its origins and use. However, a more elaborated description of the step-by-step methodological process and more details about the source and use of data, equations, unit values, assumptions, setting up of scenarios, etc. Part of this information is provided in the section of results but should be moved to the methodological part. The rest of the information is missing. The components of each scenario should be described in more detail.

In conclusions, a clear distinction between the contribution of the specific case study for the policy makers of Qatar and the added value for research and policy making in general could increase the impact of the paper.

 

Author Response

Dear Expert,

Thank you very much for your time and valuable feedback which substantially improved our manuscript.

Attached are our replies.

Much appreciated.

Author Response File: Author Response.docx

Reviewer 3 Report

Comments and Suggestions for Authors

This manuscript uesed LEAP tool to analyze the greenhouse gas imissions in different scenarios. The research content has certain practical significance for green and sustainable transportation.There are several suggestions for further improvement: 

1. The analysis of literature review in the Introduction is insufficient. It is recommended to summarize the achievements and shortcomings of existing research and introduce the content of this study. Highlight the innovative points and research significance of this study.

2.Suggest adding the interface or link of LEAP tool.

3.Is Public Transport Scenario only a 1% increase in public transportation? Is there a linear relationship between the growth of public transportation and the reduction of emissions? If it is not a linear relationship, it is not sufficient to only consider a 1% increase in public transportation. Suggest explaining the relationship between bus growth and emission reduction. Suggestions for discussing the total amount and structure of future travel. The future travel demand needs to be predicted, rather than fixed and unchanging.

4.Has Fuel economy improved scenario considered the increasing growth of new energy vehicles and electric vehicles? How should we consider it in this context?

5. It is recommended to provide the shortcomings and limitations of the research in section 5,so as to indicate the content that needs further research.

6. The paper is more like a project report, it is recommended to increase the theoretical depth of the paper. Especially for the emission calculation basis in different scenarios, it is recommended to provide explanations.

It is recommentd to resubmit the paper after major revisions.

Author Response

Dear Expert,

Thank you very much for your time and valuable feedback which substantially improved our manuscript.

Attached are our replies.

Much appreciated.

Author Response File: Author Response.pdf

Reviewer 4 Report

Comments and Suggestions for Authors

(1) Consider adding more recent studies on traffic emissions and social cost analysis to enrich the theoretical background and practical significance of the article.

(2) The description of the specific parameters and assumptions used in the LEAP model seems insufficiently detailed. It is recommended that the authors provide more information about the model settings and input parameters to help readers better understand the research method.

(3) The conclusion section of the article needs more data support. The authors are advised to further analyze the data to provide more robust evidence for the conclusions.

(4) The writing format of the article should be further standardized. For example, references should not be cited in the conclusion. Each paragraph should have a first-line indent.

Comments on the Quality of English Language

Some small issues have been addressed.

Author Response

Dear Expert,

Thank you very much for your time and valuable feedback which substantially improved our manuscript.

Attached are our replies.

Much appreciated.

Author Response File: Author Response.docx

Round 2

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript has improved a lot.  The authors should do a thorough proofreading of the entire manuscript before publication. 

 

Author Response

Dear Expert REviewer,

Thank you very much again for your time and effort.

Attached is our revised manuscript. It was read word by word for proofreading and better connectivity.

The changes highlighted in green indicate better and clearer context as requested.

Thank you very much.

Author Response File: Author Response.pdf