LAYERS: A Decision-Support Tool to Illustrate and Assess the Supply and Value Chain for the Energy Transition

Round 1

Reviewer 1 Report

The figure 1 and figure 2 are unfocused. The resolution must to be improved.

It must be included in the paper a list of abbreviations. There are used a lot of abbreviations, some common, some not, being very difficult to follow and understand the paper.

In the conclusions chapter it should be made a comparison between the LAYERS method and other similar methods, used for this type of study.

Author Response

thank you for your comments. We have addressed all the 31 comments, including the editorial issues that have been raised, and have considered the 26 minor comments made by R#1, R#2 and R#3. Subsequently, we revised the manuscript and the Supporting Information, and all the specific changes or rebuttals are described in the Comment and Response table in our response letter- see the attached file. 

Author Response File: Author Response.pdf

Reviewer 2 Report

Shall congratulate authors of developing very interesting and useful analysis tool and presentation aid. Think that Figure 8 in manuscript is key contribution of this approach, and brings numerous interesting development directions. Due to these, I am seeking reasons and route to accept this paper and get is published. Layers application will without a doubt create better awareness in the EV sector.

Have worked for decades with export and import flows, and analyzing these for own research, teaching and projects. Therefore, I am rather doubtful about the information quality of world trade in Comtrade. Of course, this is not Comtrade database issue or problem, but many trade statistics are completely rubbish, if you e.g., use data from African countries. Many countries report exports as significantly lower what they appear in import side of the equation. Or African country reports exports to totally different countries, if you check import countries arguing business activity with this country in their own statistics. Let me illustrate this issue little bit further. Took commodity code of this research (Table 2), nr. 260500 and went to Comtrade database. Took year 2019 and searched all countries, where Congo (dem. rep.) exported this raw material. In total Congo's data said that they exported cobalt worth of 22,44 mill. USD, and China being the most important destination with 12,8 mill. USD exports value. Other countries, where Congo reports to export are UAE and South Africa. However, if will use exactly same year 2019, and search from Comtrade imports of Cobalt from Congo, shall have China as largest importer with value of 172,6 mill. USD, which is followed by Morocco having trade value of 28.7 mill. USD. Other import countries are Korea and South Africa (with low trade value). Maybe you can catch the lesson in here - import of cobalt in world countries is ten times higher from Congo, what Congo itself argues it to be (as exports). In addition, Morocco is not having any export activity from Congo, but Morocco itself reports to import cobalt out of this country. Due to these inaccuracies, would suggest authors to report, how they are building entire network of trade between mining, refining, manufacturing and use. And could we trust this?

Can say that even from European countries you may find strange statistics, if you follow raw material trade and import-export values. One reason could be avoiding taxes in importing country side or alternatively, raw materials are sold one or more times during its transportation process out of raw material source to final import country. It would be worthwhile to check this from your data, especially from most important regions. Currently, you argue that "data quality is generally good". I doubt this.

MDPI and Sustainability recommends that all proposed articles should have abstract length around 200 words. Currently, this article is having nearly 250 words. Please make it shorter and more concise.

Article would benefit a lot from research problem statement through research question(s) in the early part of the main text. These should be answered in the end of the manuscript.

Conclusions sections is somehow limited in this research. Please bring back earlier research and their argumentation, and try to show, what is your contribution to the field (this will possibly answer your research question too). Do also try to propose future research directions in the end of the manuscript.

In conclusions section, please check first sentence (decision is unnecessarily twice in the very beginning). Also in same paragraph these is part of "...and to presents...", think that you should use singular form. Do also remember that in lists you need to use word "and" between second last and last item.

This proposed manuscript uses word "Chapter" to talk about Sections of manuscript. Do note that in scientific article we do not have any chapter, there are just sections.

Second section would benefit from other research works and their recognition.

Author Response

thank you for your comments. We have addressed all the 31 comments, including the editorial issues that have been raised, and have considered the 26 minor comments made by R#1, R#2 and R#3. Subsequently, we revised the manuscript and the Supporting Information, and all the specific changes or rebuttals are described in the Comment and Response table in our response letter- see the attached file. 

Author Response File: Author Response.pdf

Reviewer 3 Report

Introduction

• Write full form when it appears first, e.g., GIS and so on.
• Lines 50-51; add a reference.
• Line 246-247, 485-486; instead, Chapter use Section, correct for the whole paper.
• See SI Figure S1, Check line 83.
• Research design is missing; the problem statement and significance of the work need to be refined and can be better presented. Write the intended contribution of the study and objectives. Define research questions.

Materials and Methods

• This Section is well presented. However, the quality of Figure 1 and Figure 2 can be enhanced more.

Results and Discussion

• Validation of the prosed model is missing. 3D visualization and presentation are good. What is the link with the stated objectives?
• What are the limitations of the model? Write down managerial implications.
• Add more discussion on how the implementation of the model benefits society.
• What would be the consequences of changing the observed situation in the real world, and what would be the ways to change/improve the observed condition.

Conclusions

• Conclusions must be supported with quantitative results.
• Discussion and conclusions do not establish a strong correlation with cleaner production/sustainability/environmental concerns. Please link your empirical results with a broader and deeper literature review in your discussion section.
• In your conclusions, please discuss the implications of your research. Although discussions and findings must go deeper, it would be more interesting if the authors focused more on the significance of their findings.

Author Response

thank you for your comments. We have addressed all the 31 comments, including the editorial issues that have been raised, and have considered the 26 minor comments made by R#1, R#2 and R#3. Subsequently, we revised the manuscript and the Supporting Information, and all the specific changes or rebuttals are described in the Comment and Response table in our response letter- see the attached file. 

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

Authors revised the paper as per comments, from my side it is fine to accept.