An Analysis of Disparities and Driving Factors of Carbon Emissions in the Yangtze River Economic Belt

Round 1

Reviewer 1 Report

This paper analyses driving factors of carbon emissions based on energy  consumption and related economic development data in the Yangtze River Economic Belt (YREB) over the 2005-2016 eleven-year period using the STIRPAT model. A descriptive analysis on the spatio-temporal evolution of carbon emissions in the YREB is also provided. In the current state, the paper has various deficiencies and needs further editing, before it is ready for publication in Sustainability.

Main points

1)     The Introduction should state the objectives of the work and provide an adequate background, avoiding a detailed literature survey. Therefore the Authors should reduce the Introduction by creating a new section where a detailed literature review is provided.

2)     Literature review section. In fact, although the authors state that “Referencing domestic and foreign literature, this paper takes the YREB as an example and uses 122 the extended STIRPT model to conduct an in-depth analysis…” there are only few foreign papers using STIRPAT cited in the text. Therefore, I believe that foreign literature should be expanded by including previous studies that have used STIRPAT model for estimating the impact of population, affluence and technology on pollutant emissions. More specifically, the authors should mentioned those paper that analysed driving forces of carbon emissions by considering countries, provinces and municipalities.

For example at national level, Liddle, B., (2013) Population, affluence, and environmental impact across development: Evidencefrom panel cointegration modeling, Environmental Modelling & Software 40 (2013) 255e266, Castellano, R., Laureti, T., & Regoli, A. (2010). Estimating The Effects Of Road Transportation On Environmental Quality. Environmental Engineering & Management Journal (EEMJ), 9(9); Liddle, B. (2013).Impact of population, age structure, and urbanization on carbon emissions/energy consumption: evidence from macro-level, cross-country analyses. Popul.Environ. http://dx.doi.org/10.1007/s11111-013-0198-4.

At county or provincial levels, for example Roberts,T.,2011.Applying the STIRPAT modeling a post-Fordist landscape: can a traditional econometric model work at the local level? Appl.Geogr.31, 731–739 and  T Laureti, JM Montero, G Fernández-Avilés  (2014) Energy Policy, 74, 557–568 and  the papers cited there.

Moreover a more detailed literature review could help in writing section 5.2 and when the author/s compare their results with previous findings. 

·       METHOD. Section 2.2.2. The STIRPAT model should be expressed in a more formal way for panel data. Formulae 1,2 and 3 are rather generic and do not refer to the specific data used in the paper. Moreover, model specification cannot be limited to Table 1 and a more detailed discussion should justify the consideration of the variables as indicators of Population, Technology and Affluence.

·      DATA. Data used in this paper need clarification and deserves a detailed description. Section 3.1 contains some interesting detail about the evolution of the dependent and one of the independent variables used in model specification. However,  summary statistics of variables used are needed to help the readers to understand spatial and temporal differences as well as to interpret the effects found. Figure 3 should be integrated by a Table indicating which provinces are downstream, upstream and midstream. Moreover, how many municipalities are considered?

·      RESULTS. This section needs clarification. Why the authors decide for a fixed effect model? Why the spatial correlation among provinces in carbon emissions in the YREB is not considered when selecting the STIRPAT model? In fact, the authors do not use a spatial model or a spatio-temporal specification but a generic panel data model is applied.

·      TITLE. Since the spatial analysis is only explorative and limited to the dependent variable (Figure 4) I believe that the title of the paper should be changed accordingly by deleting spatio-temporal analysis.

·       Finally, the paper needs a careful round of editing since it contains several typos.

Author Response

This paper analyses driving factors of carbon emissions based on energy consumption and related economic development data in the Yangtze River Economic Belt (YREB) over the 2005-2016 eleven-year period using the STIRPAT model. A descriptive analysis on the spatio-temporal evolution of carbon emissions in the YREB is also provided. In the current state, the paper has various deficiencies and needs further editing, before it is ready for publication in Sustainability.

Dear reviewers, thank you very much for your valuable advice. According to your proposal, we have made a substantial revision of the paper from several aspects, such as the title, the introduction, the literature review, the model formulation, and the final results, so as to get your approval.

Point 1: The Introduction should state the objectives of the work and provide an adequate background, avoiding a detailed literature survey. Therefore the Authors should reduce the Introduction by creating a new section where a detailed literature review is provided.

Response 1: The objectives of the work have been added to the line 50-51. The introduction has been reduced and a new section “2. Research Status” has been added to provide detailed literature review.

Point 2: Literature review section. In fact, although the authors state that “Referencing domestic and foreign literature, this paper takes the YREB as an example and uses 122 the extended STIRPT model to conduct an in-depth analysis…” there are only few foreign papers using STIRPAT cited in the text. Therefore, I believe that foreign literature should be expanded by including previous studies that have used STIRPAT model for estimating the impact of population, affluence and technology on pollutant emissions. More specifically, the authors should mentioned those paper that analysed driving forces of carbon emissions by considering countries, provinces and municipalities.

For example at national level, Liddle, B., (2013) Population, affluence, and environmental impact across development: Evidencefrom panel cointegration modeling, Environmental Modelling & Software 40 (2013) 255e266, Castellano, R., Laureti, T., & Regoli, A. (2010). Estimating The Effects Of Road Transportation On Environmental Quality. Environmental Engineering & Management Journal (EEMJ), 9(9); Liddle, B. (2013).Impact of population, age structure, and urbanization on carbon emissions/energy consumption: evidence from macro-level, cross-country analyses. Popul.Environ. http://dx.doi.org/10.1007/s11111-013-0198-4.

At county or provincial levels, for example Roberts,T.,2011.Applying the STIRPAT modeling a post-Fordist landscape: can a traditional econometric model work at the local level? Appl.Geogr.31, 731–739 and  T Laureti, JM Montero, G Fernández-Avilés  (2014) Energy Policy, 74, 557–568 and  the papers cited there.

Moreover a more detailed literature review could help in writing section 5.2 and when the author/s compare their results with previous findings.

Response 2: Since the analysis of the literature by the study area classification is highly repetitive, this paper makes a statement from the LMDI decomposition and STIRPAT model research methods, and added studies that analyzed driving factors of carbon emissions by STIRPAT model in the line 73-87.

Point 3:  METHOD. Section 2.2.2. The STIRPAT model should be expressed in a more formal way for panel data. Formulae 1, 2 and 3 are rather generic and do not refer to the specific data used in the paper. Moreover, model specification cannot be limited to Table 1 and a more detailed discussion should justify the consideration of the variables as indicators of Population, Technology and Affluence.

Response 3: The STIRPAT model has been expressed in a more formal way for panel data in line 127,131,136. The supporting references of variable selection have been added to Table 1.

Point 4: DATA. Data used in this paper need clarification and deserves a detailed description. Section 3.1 contains some interesting detail about the evolution of the dependent and one of the independent variables used in model specification. However, summary statistics of variables used are needed to help the readers to understand spatial and temporal differences as well as to interpret the effects found. Figure 3 should be integrated by a Table indicating which provinces are downstream, upstream and midstream. Moreover, how many municipalities are considered?

Response 4: A new section “3.3 Data” has been added to describe the source of data used in this paper. The descriptive statistics of the variables in Eq. (4) are reported in Table 7 in Appendix. The Table 2 has been added to describe the regions included in the upstream, midstream, and downstream.

Point 5: RESULTS. This section needs clarification. Why the authors decide for a fixed effect model? Why the spatial correlation among provinces in carbon emissions in the YREB is not considered when selecting the STIRPAT model? In fact, the authors do not use a spatial model or a spatio-temporal specification but a generic panel data model is applied.

Response 5: The results of model setting test for building a fixed effect model have been added to Table 4. The spatial-temporal analysis of this paper is based on the differences in current status of carbon emissions in the YREB, so we didn’t consider a spatial correlation among provinces. And we deleted the correlation analysis of carbon emissions and key driving factors among provinces, because the results of the correlation analysis are repetitive with the model regression results.

Point 6: TITLE. Since the spatial analysis is only explorative and limited to the dependent variable (Figure 4) I believe that the title of the paper should be changed accordingly by deleting spatio-temporal analysis.

Response 6: The title has changed to “An Analysis of Spatiotemporal Disparities and Driving Factors of Carbon Emissions in the Yangtze River Economic Belt”.

Author Response File: Author Response.docx

Reviewer 2 Report

The contents of the paper is quite all right. There are a few issues, which need to be taken care of: see the reviewer's report.

Comments for author File: Comments.pdf

Author Response

This paper was submitted for possible publication in the in the MDPI journal Sustainability.

Dear reviewers, thank you very much for your valuable advice. According to your proposal, we have made a substantial revision of the paper, so as to get your approval.

Point 1: Page 1 lines 22, 24. Nowadays people often write “First,” instead of “Firstly,”, and “Second,” instead of “Secondly,”.

Response 1: Sorry, we have made a change.

Point 2: Page 1 line 19. The authors should mention, somewhere in the beginning of the paper, that the acronym “STIRPAT” stands for “Stochastic Impacts by Regression on Population, Affluence and Technology”.

Response 2: Sorry, we have made a change.

Point 3: Page 1 line 27. Do the authors mean “is higher than the correlation between carbon emissions and energy intensity”? If yes, then the authors should make this clear.

Response 3: Referring to the opinions from other reviewers, we deleted the correlation analysis of carbon emissions and key driving factors among provinces, because the results of the correlation analysis are repetitive with the model regression results.

Point 4: Page 2 line 54. Perhaps it is useful to recall that “LMDI” stands for “Logarithmic Mean Divisia Index”.

Response 4: Sorry, we have made a change.

Point 5: Page 2 line 77. There should be more space between “China[1].” And “Lee”. A similar remark applies at several more instances, like page 2 line 88 (between “sector[15].” and “Shi”, page 2 line 92 and page 3 line 102 (between “emissions[16].” and “Wang”), page 3 line 108 (between “level[21].” and “Specifically”, page 7 line 236 (between “by 2.” And “Through”

Response 5: Sorry, we have made a change.

Point 6-7: Page 2 line 77: “adopted multi-level” should read “adopted the multilevel”;

Page 2 line 78: “urban form path” should read “the urbanization pattern”. That is what the authors mean in the opinion of this reviewer.

Response 6-7: Sorry, we have replaced this literature with a more appropriate one.

Point 8: Page 2 line 80: ‘used STIRPAT” should read “used the STIRPAT”.

Response 8: Sorry, we have made a change.

Point 9: Page 2 line 87: “on Kaya” should read “on the Kaya”.

Response 9: Sorry, we have replaced this literature with a more appropriate one.

Point 10-11: Page 2 line 93: “a set of complete evaluation index system of urban” should read “a complete system of evaluation indices related to the urban”. Anyway, this what this reviewer believes; Page 2 line 95: insert “the” two times; in front of “urban”, and just after “and”.

Response 10-11: Sorry, we have replaced this literature with a more appropriate one.

Point 12: Page 3 line 123: “of factors” should read “of those factors”.

Response 12: Sorry, we have made a change.

Point 13: Page 4 line 166–167. Whereas the parameters in formula (1) are written in italic, that is not the case for the ones in formula (2). In addition, when taking logarithms one should also take logarithms of the multiplicative factors. So formula (2) should read

ln(I) = ln(a) + b ln(P ) + c ln(A) + d ln(T ) + ln(ε). (2) A similar remark applies to formula (3)

Response 13: Sorry, we have made a change.

Point 14: Page 5 line 188: “than other” should read “than in other”.

Response 14: Sorry, we have made a change.

Point 15: Page 6 lines 201, 202; page 7 line 222; page 10 lines 303, 313; page 12 lines 391, 395, 418, 419. This reviewer believes that it better to write “regions” instead of “reaches”.

Response 15: Sorry, we have made a change.

Point 16: Page 6 lines 201–203. The sentence beginning with “Generally, carbon” should be changed. A suggestion is “Generally, over the 2005-2016 period the carbon emissions in the downstream areas are larger than in those which lie upstream, while over the same time period, upstream carbon emissions are higher than midstream emissions”.

Response 16: Sorry, we have made a change.

Point 17: Page 6 line 201: “uneven” should (probably) read “disproportionate”.

Response 17: Sorry, we have replaced this word with a more appropriate one.

Point 18: Page 6 line 212: “Strongly contrasting” could also read “In strong contrast to”.

Response 18: Sorry, we have made a change.

Point 19: Page 6 lines 214–220. The sentence starting with “Although” seems to be grammatically correct, but is very long. A suggestion is to split it just after “2010-2016 period”. The second half of the sentence could be changed to “This trend is hypothesized to be related to those regions shifting from initial industrial stages to more advanced ones, and gradually placing greater importance on green industrial development and reasonable sage of ecological factors to develop tourism and a local pharmaceutical industry.”

Response 19: Sorry, we have made a change.

Point 20: Page 7 lines 225, 226, 229, 234. Perhaps it is nicer to write “excessive” instead of “excess”.

Response 20: Sorry, we have made a change.

Point 21: Page 9 line 266: “to carbon” should “to the carbon”.

Response 21: Sorry, we have made a change.

Point 22: Page 9 line 270: “Population” should read “The population size” or “The size of the population”; “determining” should read “in determining the”

Response 22: Sorry, we have made a change.

Point 23: Page 9 line 276: “urbanization rate and carbon emission” should read “the urbanization rate and the carbon emission”. CARBON EMISSIONS IN THE YANGTZE RIVER 3

Response 23: Sorry, we have made a change.

Point 24: Page 9 line 277: “urbanization” should read “the urbanization”.

Response 24: Sorry, we have made a change.

Point 25: Page 10 line 302: “is generally” should read “are generally” or “are in general”.

Response 25: Sorry, we have made a change.

Point 26: Page 10 line 309: “equal to” should read “are equal to”.

Response 26: Sorry, we have made a change.

Point 27: Page 10 line 310: “for every 1 % increases” should read “then for every “1 % increase”.

Response 27: Sorry, we have made a change.

Point 28-30: Page 11 line 363: “Jiangsu, Anhui and Jiangxi are slightly higher than other provinces” should read “In Jiangsu, Anhui and Jiangxi this correlation is slightly higher than in the other provinces”; Page 11 line 364: “the three” should read “these three”; Page 11 lines 369–370: “greatly” should read “strongly”; “the technical update” should read “technical updates”.

Response 28-30: Sorry, we have deleted the correlation analysis of carbon emissions and key driving factors among provinces, because the results of the correlation analysis are repetitive with the model regression results.

Point 31: Page 12 line 393: “industrial structure” should read “the industrial structure”.

Response 31: Sorry, we have made a change.

Point 32: Page 12 line 396: “YRD cities” should read “the YRD cities”.

Response 32: Sorry, we have made a change.

Point 33: Page 12 line 408: “In the short term” should read “In short-term”.

Response 33: Sorry, we have made a change.

Point 34: Page 12 line 409: “formulate” should read “to formulate”.

Response 34: Sorry, we have made a change.

Point 35: Page 13 line 441: “technology [J]” should read “technology [J]”. In fact, in the list of bibliographical references there several “[J]’s” which are too close to the text: page 13 lines 443, 459, 466, 469, 472; page 14, lines 479, 482, 486, 498, 503.

Response 35: Sorry, we have made a change.

Author Response File: Author Response.docx

Reviewer 3 Report

COMMENTS:

The subject of the publication is very interesting but there are some weak points that require adjustment:

L32-L133:      The Introduction section is too long. The introduction should be synthetic      and reflect the main research problem. At the end of this section, the      purpose of the work should be emphasized.

L136-L144:      Please indicate specific sources of data used and describe their meaning      in research in detail.

L151: Please      indicate and justify why specific energy sources have been selected for      evaluation.

L152: Please      adapt the principle of recording equations according to the requirements      of the journal. No equation number.

L172: Table      signatures should be adapted to the requirements of the journal.

The      article should be arranged in the convention of the journal, ie      Introduction, Methodology, Results and Discussion, Conclusions, and References.      

L173-L370:      Sections 3 and 4 should be shortened and the results of the tests should      be presented in a systematic manner. In the current form, the article is      overloaded with an irrelevant description. The obtained test results      should be described in a consistent and transparent manner with the      discussion of the results obtained.

L354: Title      with a capital letter

L371-436:      The Conclusions section should be shortened. Please, focus on the main      conclusions from the conducted tests.

In the article before the summary, the 'Discussion' section      should be found. It is necessary to refer to the data in the subject      literature and compare the results from the tests with data obtained in      other similar studies. It is necessary to add a discussion part to the      article, which is indispensable and constitutes a valuable element of      scientific work. However, it should be emphasized that partly the authors      have discussed the results, but in my opinion it should be more extensive.

L407: Reference: Please review references list following      Journal guidelines. I suggest expanding the bibliography with new items.      Currently, it is a weak part of the job.

Author Response

The subject of the publication is very interesting but there are some weak points that require adjustment.

Dear reviewers, thank you very much for your valuable advice. According to your proposal, we have made a substantial revision of the paper, so as to get your approval.

Point 1: L32-L133: The Introduction section is too long. The introduction should be synthetic and reflect the main research problem. At the end of this section, the purpose of the work should be emphasized.

Response 1: The introduction section has been refined, and the objectives of the work have been added to the 50-51 line.

Point 2: L136-L144: Please indicate specific sources of data used and describe their meaning in research in detail.

Response 2: A new section “3.3 Data” has been added to describe the source of data used in this paper. The descriptive statistics of the variables in Eq. (4) are reported in Table 7 in Appendix. The introduction has been reduced and a new section “2.Research Status” has been added to provide detailed literature review.

Point 3: Please indicate and justify why specific energy sources have been selected for evaluation.

Response 3: The instructions for selecting a specific energy source have been added to the line 119-123.

Point 4: L152: Pleas adapt the principle of recording equations according to the requirements of the journal. No equation number.

Response 4: Sorry, we have made a change.

Point 5: L172: Table signatures should be adapted to the requirements of the journal.

The article should be arranged in the convention of the journal, ie Introduction, Methodology, Results and Discussion, Conclusions, and References.

Response 5: Sorry, we have made a change.

Point 6: L173-L370: Sections 3 and 4 should be shortened and the results of the tests should be presented in a systematic manner. In the current form, the article is overloaded with an irrelevant description. The obtained test results should be described in a consistent and transparent manner with the discussion of the results obtained.

Response 6: The sections 3 and 4 have been refined, and all the test results are shown in Table 4. We deleted the correlation analysis of carbon emissions and key driving factors among provinces, because the results of the correlation analysis are repetitive with the model regression results. The discussion of the results obtained has been added to the line 247-322.

Point 7: L354: Title with a capital letter

Response 7: Sorry, we have made a change.

Point 8: L371-436: The Conclusions section should be shortened. Please, focus on the main conclusions from the conducted tests. In the article before the summary, the 'Discussion' section should be found. It is necessary to refer to the data in the subject literature and compare the results from the tests with data obtained in other similar studies. It is necessary to add a discussion part to the article, which is indispensable and constitutes a valuable element of scientific work. However, it should be emphasized that partly the authors have discussed the results, but in my opinion it should be more extensive.

Response 8: The Conclusions section has been refined. We have added a new section “5.2 Discussion” to compare the results from the tests with data obtained in other similar studies.

Point 9: L407: Reference: Please review references list following Journal guidelines. I suggest expanding the bibliography with new items. Currently, it is a weak part of the job.

Response 9: Sorry, we have made a change.

Author Response File: Author Response.docx

Round 2

Reviewer 3 Report

The article after the corrections made by the Authors can be accepted for printing after adapted to Journal requirements:

The font size should be adapted to Journal requirements (i.e. L248, L265)

L273: should be 'China'.