Characterizing the Embodied Carbon Emissions Flows and Ecological Relationships among Four Chinese Megacities and Other Provinces
Round 1
Reviewer 1 Report
This paper studies the carbon emission flows between four Chinese megacities and other provinces. The results are interesting and helpful for future decision-making on carbon policies. The manuscript was well formatted with nice Figures. I have some comments and suggestions as follows.
1. It is better to revise the title of this manuscript because the relationships between these four cities and other regions in China were also investigated.
2. L13. “measured as the percentage of urban residents nationwide” can be moved to the introduction section
3. L35. “It is expected to increase to 70% by 2030.” Reference should be cited here.
4. L36. Why do cities perform better in decreasing carbon emission than rural area? Explanation?
5. L48. Add references here.
6. L56. At the same time, …
7. What is the embodied carbon emission? The authors should give definitions.
8. L87. Some studies have ….
9. L99. What do ecological relationships exactly mean in this study? I think ecological relationship between two cities is far more beyond the carbon flows.
10. L109. What does “total system” mean?
11. L110-112. More explanations between the questions in this study and the argument in Parshall’s research should be detailed.
12. L114. Models >>> model
13. L 115. The authors should clarify what to process, manufacture, and transport.
14. L116-120. It is better to put these literatures in the introduction part.
15. Significant revisions are needed to make the methodology section more understandable to authors. For example, definitions of some notations are missing. What is I. Does the summation of xij on j equal to xi? What are A and E?
It is better to have a flowchart to illustrate the relationship between these variables.
16. L144-169. The description of the methods in this part has the same problem with the above section. Especially, what does (dij) mean? Does the bracket indicate a function or an operator? In addition, the author should underscore the necessity and utility of utilizing the ENA indicator here.
17. L166 should be rephrased.
18. L170. The authors should give more details about the data collection and processing. A question here is why this study only considers the carbon embedded in these energy materials? Is it possible to consider the carbon carried by other goods?
19. L177. Add references here.
20. L179. I don’t think it is worthy to narrate the detailed features of carbon emission in these four cities, although the figures look great. One or two paragraphs with tables or graphs to highlight the most relevant characteristics will be sufficient.
21. L248. Figure5 looks nice, but it is not clearly presented. The legend is missing. The font size is too small. So do the other figures.
22. L297. Replace the numbers that indicate the regions with their names.
23. L299-306. Redundant definitions here. These definitions have been given in 3.3.
24. L311. What does “total relationships” mean?
25. L318. What are the principles of ENA?
26. L319. Shaanxi >>> Shanxi
27. L321-324. Rephrase these lines.
28. L341. Add references here.
29. L387. In my opinion, this paragraph is not so relevant to this study. In other words, it does not contribute much to your research questions.
30. L420. How were the responsibilities calculated in Figure 10?
31. L432. It is not a surprise that there are differences in the ECE between these cities in 2007 and 2013. The policy implications behind these changes are of more interest.
32. L443. The expression of “Secondly, regional economic integration has obtained a certain result” is obscure and needs to be revised.
I suggest the authors focus conclusion on more policy implications based on the results and analysis, which will make this research more valuable. Especially, the author should clearly demonstrate the methods used in this study.
Author Response
Response to reviewer:
Dear reviewer:
Thanks for your valuable comments and suggestions. We have modified the manuscript accordingly, and detailed corrections are listed below:
Point 1: It is better to revise the title of this manuscript because the relationships between these four cities and other regions in China were also investigated.
Thank you for your comments. Yes, this manuscript included the relationships between these four cities and other regions in China. So, in the revised version, we have rewritten a part of conclusion part, as follows:
“The Characters of Embodied Carbon Emissions Flows and Ecological Relationships among four Chinese Megacities and other provinces”
2. L13. “measured as the percentage of urban residents nationwide” can be moved to the introduction section
Thank you for your suggestions. In the revised version, we have moved this sentence to introduction section, as you suggested.
3. L35. “It is expected to increase to 70% by 2030.” Reference should be cited here.
Thank you for your suggestions. In the revised version, we have cited the reference, which is shown as follows:
6.Guan X , Wei H , Lu S , et al. Assessment on the urbanization strategy in China: Achievements, challenges and reflections[J]. Habitat International, 2018, 71:97-109.
4. L36. Why do cities perform better in decreasing carbon emission than rural area? Explanation?
Thank you for your comments. This judgment comes from other scholar’s studies. For example, Yao et al., (2018), studied whether China’s rapid urbanization could reduce carbon emissions. Based on the panel data of China's 30 provincial-level regions during 2001–2014, that paper uses the threshold regression model and the mediating effect model to investigate the effect and its mechanism of urbanization process on carbon emissions measured by three indicators: carbon emission scale, per capita carbon emissions, and carbon intensity. The results show that urbanization can contribute to declines in carbon emission scale, per capita carbon emissions, and carbon intensity. That is to say, urbanization can present an abatement effect on carbon emissions.
Similar results can be seen in Dong’s study, which shows that urbanization has positive effect on carbon emission reduction. The research of Fan et al., (2019) shows that urbanization in the top five carbon emissions provinces in China can effectively contribute to carbon emissions.
Yao X , Kou D , Shao S , et al. Can urbanization process and carbon emission abatement be harmonious? New evidence from China[J]. Environmental Impact Assessment Review, 2018, 71:70-83.
Dong F , Wang Y , Su B , et al. The process of peak CO2 emissions in developed economies: A perspective of industrialization and urbanization[J]. Resources, Conservation and Recycling, 2019, 141:61-75.
Fan J S , Zhou L . Impact of urbanization and real estate investment on carbon emissions: Evidence from China's provincial regions[J]. Journal of Cleaner Production, 2018.
5. L48. Add references here.
Thank you for your suggestions. In the revised version, we have added the we have cited the reference, which is shown as follows:
11. Kang Y Q, Zhao T, Yang Y Y. Environmental Kuznets curve for CO2 emissions in China: A spatial panel data approach[J]. Ecological Indicators, 2016, 63:231-239
6. L56. At the same time, …
Thank you for your suggestions. In the revised version, we have deleted this unsuitable expression.
7. What is the embodied carbon emission? The authors should give definitions.
Thank you for your comments. Embodied carbon refers to the carbon dioxide directly or indirectly emitted throughout the production chain in order to obtain a certain product. In the revised version, we have added this definition. We also draw a figure to show a more intuitive definition of embodied carbon emission, which is shown in appendix Figure.A1.
8. L87. Some studies have ….
Thank you for your suggestions. In the revised version, we have changed the unsuitable expression “some research has” into “Some studies have”.
9. L99. What do ecological relationships exactly mean in this study? I think ecological relationship between two cities is far more beyond the carbon flows.
Thank you for your comments. Yes, there are a lot of relationships between different cities, and is far more beyond the carbon flows. But in this paper, we only focus on carbon flows. And this carbon flows related ecological relationship is systematically simulate the flows and the resulting functional relationships among a system's components. In this paper, we applied “Network enviro analysis” to calculate and analyze these relationships. The definition of this approach is shown as follows:
Ecological network analysis is an effective method to study a system's structure and functions, making it possible to analyze the structural distribution and functional relationships within the system. Ecological network analysis developed from the input–output method, and was first proposed by Patten (1991). This method can simulate the flows of materials and energy in an ecosystem from a holistic perspective and can analyze the structure and function of the system. The ecological relationships revealed by this ecological network analysis can reveal the nature of the relationships between any two components of the system, which can then be classified into mutualism, competition, control, exploitation, and neutral relationships. This approach has been applied to analyses of both natural ecosystems and socioeconomic systems (Borrett etal.,2007), including studies of energy (Zhang et al., 2011), urban systems (Li etal.,2012), virtual water (Yang et al., 2012), and carbon (Chen andChen,2012).
Patten, B.C.,1991. Network ecology: indirect determination of the life-environment relationship in ecosystems. In: Higashi, M., Burns, T.(Eds.), Theoretical Studies of Ecosystems: The Network Perspective. Cambridge University Press, New York, pp. 288–351.
Borrett, S.R., Fath, B.D., Patten, B.C.,2007. Functional integration of ecological networks through pathway proliferation. J. Theor. Biol . 245(1), 98–111.
Zhang Y , Li S , Fath B D , et al. Analysis of an urban energy metabolic system: Comparison of simple and complex model results[J]. Ecological Modelling, 2011, 223(1):14-19.
Li S , Zhang Y , Yang Z , et al. Ecological relationship analysis of the urban metabolic system of Beijing, China[J]. Environmental Pollution, 2012, 170(none):169-176.
Yang Z , Mao X , Zhao X , et al. Ecological Network Analysis on Global Virtual Water Trade[J]. ENVIRONMENTAL SCIENCE & TECHNOLOGY, 2012, 46(3):1796-1803.
Chen S , Chen B . Network Environ Perspective for Urban Metabolism and Carbon Emissions: A Case Study of Vienna, Austria[J]. Environmental Science & Technology, 2012, 46(8):4498-4506.
10. L109. What does “total system” mean?
Thank you for your comments. The total system means that the entire China, which in this paper we consider it as a system.
11. L110-112. More explanations between the questions in this study and the argument in Parshall’s research should be detailed.
Thank you for your comments. In the revised version, we have added the explanation between the questions in this study and the argument in Parshall’s research, which is shown as follows:
Although from energy consumption and direct carbon emissions perspective, the urbanization seems to environment friendly. For the four Chinese megacities, considering that they consumed a large amount of ECE, Parshall’s conclusion seems to cannot directly applied the four megacities. Therefore, the question is what its influence on ECE flows between four megacities with other Chinese regions.
12. L114. Models >>> model
Thank you for your comments. In the revised version, we have corrected it.
13. L 115. The authors should clarify what to process, manufacture, and transport.
Thank you for your comments. In the revised version, we added a paragraph to make a clear description about the method, which shows as follows:
In this paper, we used three kinds of models to figure out embodied carbon emissions flows and ecological relationships among four Chinese megacities. The first model is the embodied carbon emissions calculation model, based on input-output table, which is used to calculate the embodied carbon emissions in a sector. Secondly, the multi-regional input-output model is used to quantify embodied carbon emissions flows between different regions. Because the multi-regional input-output table contains the input and output relationships between different sectors in different provinces (megacities). Thirdly, Ecological network analysis (ENA) is evolved from input-output models, which could be used to determine the relationships among the nodes of the network based on material flows. ENA can visualize the import and export ECE among a system, which could broaden the research view of ECE flows.
14. L116-120. It is better to put these literatures in the introduction part.
Thank you for your suggestions. In the revised version, we have put these literatures in the introduction part.
15. Significant revisions are needed to make the methodology section more understandable to authors. For example, definitions of some notations are missing. What is I. Does the summation of xij on j equal to xi? What are A and E? It is better to have a flowchart to illustrate the relationship between these variables.
Thank you for your comments. In the revised version, we added detailed explanation about the definitions and draw a detailed figure about input output table to make the methodology more clearly. All the modification can be seen in the revised version.
16. L144-169. The description of the methods in this part has the same problem with the above section. Especially, what does (dij) mean? Does the bracket indicate a function or an operator? In addition, the author should underscore the necessity and utility of utilizing the ENA indicator here.
Thank you for your comments. In the revised version, we have also added detailed explanation about all definitions and a detailed figure about multi-regional input output table to make the methodology more clearly. All the modification can be seen in the revised version.
17. L166 should be rephrased.
Thank you for your comments. In the revised version, we have rephrased this sentence. And we draw a figure to simplified display the model of the ecological flows in the societal metabolic system.
18. L170. The authors should give more details about the data collection and processing. A question here is why this study only considers the carbon embedded in these energy materials? Is it possible to consider the carbon carried by other goods?
Thank you for your comments. In the revised version, we have added more details about data collection and processing in attached materials. The reason why we only consider the carbon embodied is that, firstly, carbon emissions matters, China have a huge pressure on reduce carbon emissions. Secondly, cities, especially for megacities, have to reduce carbon emissions, and need a method to quantity their carbon emissions reduction responsibility.
19. L177. Add references here.
Thank you for your suggestion. In the revised version, we have added the reference.
46. Zhang Y, Zheng H, Fath B D, et al. Ecological network analysis of an urban metabolic system based on input–output tables: Model development and case study for Beijing[J]. Science of the Total Environment, 2014, 468-469(468-469C):642.
20. L179. I don’t think it is worthy to narrate the detailed features of carbon emission in these four cities, although the figures look great. One or two paragraphs with tables or graphs to highlight the most relevant characteristics will be sufficient.
Thank you for your comments. Yes, in revised version, we redrawn the figure and put the figure 5-8 together. At the same time, we put the data of these figures in a table in supplemental materials Table2.
21. L248. Figure5 looks nice, but it is not clearly presented. The legend is missing. The font size is too small. So do the other figures.
Thank you for your comments. In revised version, we redrawn these figures.
22. L297. Replace the numbers that indicate the regions with their names.
Thank you for your comments. In revised version, we have added a map that show which region the number code represents and where they are. We also added a table to show which region the number code represents. They are shown in Appendix Figure.A2 and TableA1, respectively.
23. L299-306. Redundant definitions here. These definitions have been given in 3.3.
Thank you for your comments. In revised version, we have deleted these redundant definitions.
24. L311. What does “total relationships” mean?
Thank you for your comments. Yes, this expression of total relations is little misleading. In revised version, we have rewritten this expression to “sum number of other four ecological relationships”.
25. L318. What are the principles of ENA?
Thank you for your comments. The principles of ENA is that “there are four types of relationships: Exploitation, in which one component receives more benefits than it transfers to the other component; Control, in which one component's outputs are controlled by the other component; Competition, in which both components are harmed by the relationship; neutralism, in which there is no net effect on either component; and Mutualism, in which both components benefit from the relationship. Because control and exploitation are reciprocal relationships (i.e., they differ only in the direction of the utility flow. The earliest literature, which applied these principles, is hard to find. But there are plenty of studies have used these principles. Here are some part of them:
Zhang Y , Zheng H , Fath B D , et al. Ecological network analysis of an urban metabolic system based on input–output tables: Model development and case study for Beijing[J]. Science of The Total Environment, 2014, 468-469:642-653.
Yan Z, Zheng H, Yang Z, et al. Urban energy flow processes in the Beijing–Tianjin–Hebei (Jing-Jin-Ji) urban agglomeration: combining multi-regional input–output tables with ecological network analysis[J]. Journal of Cleaner Production, 2016, 114:243-256.
Li Y, Yan Z, Yang N. Ecological network model analysis of China's endosomatic and exosomatic societal metabolism[J]. Procedia Environmental Sciences, 2010, 2:1400-1406.
26. L319. Shaanxi >>> Shanxi
Thank you for your comments. Because there two provinces (number code 4 and number code 26) have the same phonetic transcription (Shanxi) in China. So, in order to distinguish them, we used Shaanxi to present number code 26. In the revised version, we have drawn a map that shows the China’s provinces location and their number code. This map is shown in Appendix Figure.A2 and TableA1.
27. L321-324. Rephrase these lines.
Thank you for your comments. In the revised version, we have rewritten this part, which is shown as follows:
Taking Beijing as an example, exploitation is the main relationships between Beijing and the other 29 regions, accounting for 69% of sum number of other four ecological relationships. The percentages of control and competition were 17% and 10%, respectively. There are two types of regions, which have exploitative relationships with Beijing.
28. L341. Add references here.
Thank you for your comments. In the revised version, we have added reference here.
49. Wang X, Tang X, Zhang B, et al. Provincial Carbon Emissions Reduction Allocation Plan in China Based on Consumption Perspective[J]. Sustainability, 2018, 10(5):1342.
29. L387. In my opinion, this paragraph is not so relevant to this study. In other words, it does not contribute much to your research questions.
Thank you for your comments. In the revised version, we have deleted those paragraphs.
30. L420. How were the responsibilities calculated in Figure 10?
Thank you for your comments. If relationships between the two regions are control and exploitation relationship, they should take responsibility for one another. The specific data is calculated by the ECE flows data divided by their total ECE consumption. In the revised version, we have added this explanation to make it more understandable.
31. L432. It is not a surprise that there are differences in the ECE between these cities in 2007 and 2013. The policy implications behind these changes are of more interest.
Thank you for your comments. In the revised version, we have added a paragraph to analyze the reason behind this phenomenon, which is shown as follows: “The reason why this phenomenon happened is that, on one hand, the economy of four megacities increased steadily [5], which increased the trade demand. On the other hand, these four megacities, especially for Beijing and Shanghai, have continued to promote industrial transformation and upgrading. Their tertiary industry’s scale grew faster than other industries, which means that they required more resource input.”
32. L443. The expression of “Secondly, regional economic integration has obtained a certain result” is obscure and needs to be revised.
Thank you for your comments. In the revised version, we have rewritten this sentence into “in the past decade, the Chinese government has promoted inter-regional coordinated development strategy, which is increase the economic cooperation among specific regions, such as Beijing-Tianjin-Hebei (abbreviated to Jing-Jin-Ji) integration and Integration of Yangtze River Delta. This strategy has obtained certain results.”
I suggest the authors focus conclusion on more policy implications based on the results and analysis, which will make this research more valuable. Especially, the author should clearly demonstrate the methods used in this study.
Thank you for your suggestions. In the revised version, we have rewritten and drew some figures to demonstrate the methods more clearly. And we also rewritten part of conclusion section.
Thank you for your useful comments and suggestions again!
Best Regards,
Xuecheng Wang
Author Response File: 
Author Response.docx
Reviewer 2 Report
The question posed in the paper is relevant for the special issue of the Journal. It approaches the measuring of city-level carbon emissions, using an adequate methodology (IO).
The introduction presents the rationale for the study – China as a country with vast cities and growing carbon emissions.
The literature review seems to cover the most relevant studies in the field.
The ECE and ENA models seem well specified.
The results are of interest, and the included graphics clearly show most important outputs. Figures 5-8 shows the ECE flows originally (although the resolution could be increased). Fig 11 seems to repeat a sum of figures 5-8 (?) I believe Figure 11 is enough, and there is no need to include all four others if provided with good resolution.
The conclusions section requires some work. It only repeats a summary of the results that have just been presented in the previous section. Conclusions should provide a synthesis of arguments presented in the paper to show how these converge to address the research problem and the overall objectives of your study. They should also indicate opportunities for future research.
The overall English language is good. Minor language issues:
- I would change the acronym CER, for in ‘carbon language’ means Certified Emission Reduction, corresponding to the reductions from the Clean Development Mechanism (CDM) projects.
- Review titles of 5.1, 5.2 and 5.3.
Author Response
Response to reviewer:
Dear reviewer:
Thanks for your valuable comments and suggestions. We have modified the manuscript accordingly, and detailed corrections are listed below:
Point 1: The results are of interest, and the included graphics clearly show most important outputs. Figures 5-8 shows the ECE flows originally (although the resolution could be increased). Fig 11 seems to repeat a sum of figures 5-8 (?) I believe Figure 11 is enough, and there is no need to include all four others if provided with good resolution.
Thank you for your comments. Yes, the fig 11 is kind of a sum of figures 5-8. But figure 11 is the data of 2007, while figures 5-8 is the data of 2012. So, in the revised version, we redrawn the picture and put the figure 5-8 together.
Point 2:The conclusions section requires some work. It only repeats a summary of the results that have just been presented in the previous section. Conclusions should provide a synthesis of arguments presented in the paper to show how these converge to address the research problem and the overall objectives of your study. They should also indicate opportunities for future research.
Thank you for your comments. Yes, we did not clearly represent conclusions. So, in the revised version, we have rewritten a part of conclusion part, as follows:
(1) There are some similarities between the four Chinese megacities. Firstly, both the DCE per GDP and DEC per capita of these four megacities were lower than average for all of China. The ECE per GDP and ECE per capita, however, were much larger than average for all of China, which means that these four megacities have relatively advanced energy and emission technology. Secondly, Exploitation is the main relationship that exists between these four megacities and the other regions of China. As a result, these four megacities should take the responsibility of reducing the ECE for the regions on which they depend for resources, which have an exploitative relationship with them. These results provide a quantitative data for policy makers, to formulate megacities’ emission reduction policies from the perspective of China as a whole. However, further studies should be focus on how these megacities take the carbon emissions reduction responsibility. For example, whether Beijing should apply carbon emissions reduction technology to take carbon emissions reduction responsibility or providing complete carbon emissions reduction design plans and providing corresponding financial support to other provinces, which have ECE flows with Beijing.
(2) The four megacities had their own characteristics and were significantly different in industrial structure, ECE flows, and in their relationships with other regions of China. For example, all four megacities were net ECE importers, with Shanghai being the largest net ECE importer. Even though these four megacities have ECE flows with all other regions of China, the main ECE sources of these four megacities flowed from locations in their immediate geographic vicinities. These results provide policy makers a comprehensive understanding of the four megacities’ embodied carbon emissions consumption situation, which will help them to formulating industrial policies. For example, from low carbon development perspective, Shanghai should give priority to the development of an industry, which not only produce less direct carbon emissions, but also consume less ECE that import from nearby provinces.
Point 3: I would change the acronym CER, for in ‘carbon language’ means Certified Emission Reduction, corresponding to the reductions from the Clean Development Mechanism (CDM) projects.
Thank you for your suggestions. In the revised version, we have change the acronym CER.
Point 4:Review titles of 5.1, 5.2 and 5.3.
Thank you for your suggestions. In the revised version, we have change the titles as follows:
5.1” The similarities between the four megacities”
5.2” The differences between the four megacities”
5.3” The carbon emission reduction duty of four megacities”
Thank you for your useful comments and suggestions again!
Best Regards,
Xuecheng Wang
Author Response File: Author Response.docx
Reviewer 3 Report
In this manuscript, X. Wang et al. analyzed the four Chinese municipalities and their embodied carbon emissions and pointed out that exploitation is the main ecological relationship between these cities and other regions. The literature survey was well done and the method applied to the survey was appropriate and well analyzed.
Author Response
Response to reviewer:
Dear reviewer:
In this manuscript, X. Wang et al. analyzed the four Chinese municipalities and their embodied carbon emissions and pointed out that exploitation is the main ecological relationship between these cities and other regions. The literature survey was well done and the method applied to the survey was appropriate and well analyzed. Therefore, I recommend publishing this work in Sustainability as it is.
Thank you so much for your support.
Best Regards,
Xuecheng Wang
Round 2
Reviewer 1 Report
I think the authors addressed most of my comments last round. But I still have some comments as below.
1. The title needs to be tweaked. For example, “Characterizing the Embodied Carbon Emissions Flows and Ecological Relationships among four Chinese Megacities and other provinces”?
2. Line 122: from the perspective of energy consumption and direct carbon emissions, the urbanization seems to be environment friendly.
3. Line 124-125: “Parshall’s conclusion seems to cannot directly applied the four megacities. Therefore, the question is what its influence on ECE flows between four megacities with other Chinese regions.” This needs to be rephrased.
4. Line 131: ‘Secondly, the multi-regional input-output model is used to quantify embodied carbon emissions flows between different regions. Because the multi-regional input-output table contains the input and output relationships between different sectors in different provinces (megacities).’ Is there any causal relationship between these two sentences?
5. Polish the figures to make them clear, especially figure 8 and 11.
6. I cannot point out all the problems regarding the English language. The authors should go through the manuscript and make revisions very carefully to further improve the language. Help from native English speakers is strongly suggested.
Author Response
Response to reviewer:
Dear reviewer:
Thanks for your valuable comments and suggestions. We have modified the manuscript accordingly, and detailed corrections are listed below:
Point 1: The title needs to be tweaked. For example, “Characterizing the Embodied Carbon Emissions Flows and Ecological Relationships among four Chinese Megacities and other provinces”?.
Thank you for your suggestions. Yes, we think the title that you named is more appropriate. So, in the revised version, we use this title, as you suggested.
Point 2: Line 122: from the perspective of energy consumption and direct carbon emissions, the urbanization seems to be environment friendly.
Thank you for your comments. Yes, this sentence is a little confused. And, there is a repetition of this sentence and the previous argument (Parshall’s study found increased energy consumption and direct carbon emissions, caused by the urban expansion, could be offset by an improvement in energy efficiency and emission intensity). So, in the revised version, we decided to delete this sentence.
Point 3. Line 124-125: “Parshall’s conclusion seems to cannot directly applied the four megacities. Therefore, the question is what its influence on ECE flows between four megacities with other Chinese regions.” This needs to be rephrased.
Thank you for your comments. In the revised version, we have changed this sentence, which is shown as follows:
“Their direct energy consumption and carbon emissions could not indicate those megacities are higher energy efficiency and low emissions.”
Point 4. Line 131: ‘Secondly, the multi-regional input-output model is used to quantify embodied carbon emissions flows between different regions. Because the multi-regional input-output table contains the input and output relationships between different sectors in different provinces (megacities).’ Is there any causal relationship between these two sentences?
Thank you for your comments. Yes, these two sentences have no consequence. In the revised version, we have changed this sentence, which is shown as follows:
“Considering that the multi-regional input-output table contains the input and output relationships between different sectors in different provinces (megacities). So, we introduced the multi-regional input-output model, which is based on multi-regional input-output table, to quantify embodied carbon emissions flows between different regions.”
Point 5. Polish the figures to make them clear, especially figure 8 and 11.
Thank you for your suggestions. we think the reason that these figures are not clear is that the sharpness maybe limited by the word itself. In the revised version, we sent the original figures editors and make these figures clear.
Point 6. I cannot point out all the problems regarding the English language. The authors should go through the manuscript and make revisions very carefully to further improve the language. Help from native English speakers is strongly suggested.
Thank you for your suggestions. In the revised version, we have asked Mrs. Rebeca, who is a native English speaker, to help us go through the manuscript. All the modifications can be seen in revised manuscript.
Thank you so much for your useful comments and suggestions again!
Best Regards,
Xuecheng Wang
Author Response File: Author Response.docx
Round 3
Reviewer 1 Report
The authors addressed my previous comments. Below are some minor suggestions.
1. Chinese megacity is not an appropriate keyword. Also, more keywords are needed.
2. The title of section 5.1 should be Similarities in ECE between the four megacities? And, the title of section 5.2 should be Differences in ECE between the four megacities.
3. Label of the scale bar in Figure A2 to 0-1000 seems incorrect. In the middle is 480, then the entire is 900? Why not just use 0-1000?
4. Line 20. Exploitative is an adjective, weird to be used as a noun.
Author Response
Response to reviewer:
Dear reviewer:
Thanks for your valuable comments and suggestions. We have modified the manuscript accordingly, and detailed corrections are listed below:
Point 1: Chinese megacity is not an appropriate keyword. Also, more keywords are needed.
Thank you for your suggestions. Yes, Chinese megacity seems inappropriate. So, in the revised version, we have deleted this key word and added “City-level embodied carbon emission; Ecological relationship”, as you suggested.
Point 2. The title of section 5.1 should be Similarities in ECE between the four megacities? And, the title of section 5.2 should be Differences in ECE between the four megacities.
Thank you for your suggestions. Yes, the title of section 5.1 and section 5.2 should be named as you suggested. So, in the revised version, we have changed that.
Point 3. Label of the scale bar in Figure A2 to 0-1000 seems incorrect. In the middle is 480, then the entire is 900? Why not just use 0-1000?
Thank you for your suggestions. Yes, we need to adjust this figure. In the revised version, we have change this figure and use the 0-1000.
Point 4. Line 20. Exploitative is an adjective, weird to be used as a noun.
Thank you for your suggestions. Yes, we should use exploitation here. So, in the revised version, we have change this word, as you suggested.
We really appreciate your time. Thank you so much for your useful comments and suggestions again!
Best Regards,
Xuecheng Wang
Author Response File: Author Response.docx
