Freight Transport Decarbonization: A Systematic Literature Review of System Dynamics Models

Round 1

Reviewer 1 Report

In reviewing the original version of the paper, I suggest to reject it because only a systematic review of the use of system dynamics models that address the problem of decarbonisation of freight transport is certainly not sufficient for a scientific work, especially if the review shows that the use of such a method is not appropriate for the topic under study.  For this reason, I asked the authors to present at least one case study addressed with system dynamics models.  The authors' response was that they are not able to present a case study and instead consider the literature provided literature review sufficient for publication.
I am sorry, but especially after this answer, I consider unjustified and don't have innovative methodological contribution the publication of this work.

Author Response

Dear Reviewer 1,

Thank you for your review.

With our study, we aimed to review the state of the art of system dynamics modeling and point forward to future researches. We provided it with a robust literature review which establishes the state of the art for the benefit of researchers who would like to go down this path. We obtained important conclusions and suggestions for future research, as demonstrated. We believe that these contributions are a significant resource for researchers on this field. A case study is meant for the next step of our research.

Reviewer 2 Report

The paper has been carefully reviewed according to reviews and editors suggestion. The paper is suitable for being published on this journal.

Author Response

Dear Reviewer 2,

Thank you for the time dedicated to this review.

Reviewer 3 Report

Dear Editor. I read the paper today. It seems that this paper was reviewed previously because of a lot of changes I saw in that. But, I strongly recommend publishing this paper. Because it has been written strongly and fruitful for next researchers.

Also, as there are many parts that mention CO2, I would like to recommend some articles published that can be cited.

 

1. Armin Razmjoo, A Technical analysis investigating energy sustainability utilizing reliable renewable energy sources to reduce CO2 emissions in a high potential area. Renewable Energy, 2020. https://doi.org/10.1016/j.renene.2020.09.042.

 

2. Armin Razmjoo, Development of smart energy systems for communities: Technologies, policies, and applications. Energy 2022. https://doi.org/10.1016/j.energy.2022.123540.

 

 

3. Armin Razmjoo, Implementation of energy sustainability using hybrid power systems, a case study. Energy Sources, Part A: Recovery, Utilization, and Environmental Effects 2019. https://doi.org/10.1080/15567036.2019.1687623.

 

4. Armin Razmjoo, Development of Sustainable Energy Use with Attention to Fruitful Policy. Sustainability 2021, 13(24), 13840; https://doi.org/10.3390/su132413840.

Author Response

Dear Reviewer 3, thank you for your feedback.

We have taken the literature suggested into consideration. Especially the remarkable attention to the challenges for renewable energy adoption, an important decarbonization strategy addressed in our literature review. It was added as highlighted (first paragraph of Section 3.5, page 20):

“Achieving deep carbon reductions will require a significant shift from fossil fuels to renewable energy. In this solution area, the focus is on reducing the carbon content of energy sources. The available options include using cleaner and lower-carbon fuels, such as biofuels, blended fuels, hydrogen, and electrification that ideally uses renewable energy, which adoption will have significant challenges related to politics, economics, collaboration, awareness of technologies and methods, investment in renewable energy, acceptance of new technologies by societies, and type of governance [81]. Table 7 summarizes the SD models' objectives, policy elements, contributions, and limitations for promoting alternative energy sources”.

Thank you again for your review.

Round 2

Reviewer 1 Report

I do not change my opinion.

Only reviewing the bibliography on the use of a specific method for a particular problem does not justify publication in a good scientific journal. No advancements and innovative contributions are present in the paper.
The paper is to be rejected

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

The authors left 50 studies for further analyses. Non-English materials were rejected, therefore they were not taken into account, despite the fact they contained the keywords: “decarboni*”,  “emission”, “freight transport*”, and “system dynamics”. 
What was the amount of the rejected publications? - this was not indicated clearly and at the same time it is the reason why the range of the literature review that was made is narrowed down. 
Please, discuss and explain this issue in more detail. 

Reviewer 2 Report

The literature review proposed by this paper is interesting. This review meets the topic and the standard of the journal. The methodology adopted for carrying out such literature review is consistent. However, some mayor issues are detected.

This reviewer suggests the form “Ref. [Number] etc” instead of “[Number] etc”

Avoid personal forms as “we”, prefer impersonal forms.

Avoid the use of acronyms in the abstract and conclusion section.

The paper is not well written, and it is very hard to read, some parts of the paper are unclear. Therefore, this reviewer suggests editing it with the help of a native English speaker person.

The conclusions section is very poor. This reviver suggests to better remark the novelty the main findings of this research.

The suggestions provided by table 8 should better discussed and analyzed in a separate paragraph of conclusions section.

Reviewer 3 Report

The authors present an overview of 50 papers using System Dynamics (SD) to see how this methodology deals with the problem of decarbonisation in freight transport. In their literature review, the authors focus on papers using SD, as they claim that SD is particularly suitable for representing the performance of complex systems over time and obtaining meaningful feedbacks. For this reason, the authors believe that SD is also particularly advised to make a valuable contribution to the problem of decarbonising freight transport.

The method conducted for the literature analysis and for the selection of the 50 articles under study is well done and very well explained. In particular, very interesting are Figures 2, 3 and 4, concerning the relationship between different factors under analysis, respectively, found in the examined papers.

However, the very critical point of this paper is that it is not at all clear what the objective is and what its innovative content is. In fact, after stating that, obviously, the added value in any research work carried out with SD is the ability to capture the dynamics and temporal evolution of the systems analysed, the authors state that in all the 50 papers analysed, the time component is very lacking, if not almost absent. Therefore, the authors highlight the need to fill this gap. In particular, the authors propose a study carried out with SD that succeeds in internalising pollutant emissions and other external costs in order to find suggestions to facilitate the decarbonisation process, possibly integrating SD models with other methodologies commonly used to represent the dynamics of systems. Unfortunately, this intention of the authors is postponed to a successive paper. What, then, is the motivation for this paper? The only result highlighted in this paper is precisely the observation that there is no research work in the literature that uses SD to rigorously address the problem of decarbonisation in freight transport.

I suggest that the authors synthesise the systematic literature review presented in this paper into one or two sections of a new paper and focus the rest of the paper on presenting a case study addressing the problem of decarbonisation of freight transport using an SD aapproch. Of course, the case study and the obtained results should be presented. Without these results the paper cannot be considered for publication at all.