Impacts of Land Urbanization on CO₂ Emissions: Policy Implications Based on Developmental Stages

Round 1

Reviewer 1 Report

General concept comments

Article: In subsection 2.1.4. Panel regression model construction, the authors of the article should give a more detailed explanation of the use of Environmental Kuznets Curve, it is not clear what from this hypothetical theory was taken for research, except for “...quadratic term of land urbanization” and why did the researchers choose it?

Specific comments

1.      Line 94. Present the first EKC transcript on line 94 rather than in Section 4. Conclusion and Discussion and line 401.

2.      In general, according to the context of the article. Isn't it obvious that if EKC is not used in research, the potential increase in urbanization will still be accompanied by increased carbon emissions and vice versa? Because large cities consume more energy resources compared to smaller cities, which is accompanied by a load on the ecosystem.

3. Urbanization is directly related to the structure of the country's economy, technological modernization of production and largely depends on government regulation. Could this only lead to a short-term decline in carbon emissions before carbon levels begin to rise again?

 

Comments for author File: Comments.pdf

Author Response

1. Response to Reviewer #1: In subsection 2.1.4. Panel regression model construction, the authors of the article should give a more detailed explanation of the use of Environmental Kuznets Curve, it is not clear what from this hypothetical theory was taken for research, except for “...quadratic term of land urbanization” and why did the researchers choose it? Response: Thank you very much for your remind. We refer to adopted the Environmental Kuznets Curve (EKC) theory to examine if there exists a nonlinear relationship between land urbanization and per capita CO2 emissions. The EKC theory posits that during the initial stages of economic development, environmental degradation is relatively low. Subsequently the country's economic development has been accompanied by an increase in its environmental pollution. A tipping point is reached at a certain level of economic development where environmental degradation starts to decline, leading to continuous improvements in environmental quality thereafter. This relationship between economic growth and environmental pollution forms an inverted "U" shape. The EKC theory holds significant value in green economy research. It suggests the potential for nonlinear relationships between variables, with differing correlations at various developmental stages. Inspired by EKC theory, we attempt to verify the nonlinear relationship between land urbanization and per capita CO2 emissions. Common practice in existing research when analyzing such nonlinear relationships is to introduce the quadratic term of the explanatory variable, an approach also adopted in this paper. Following your suggestion, we have added reasons for selecting the EKC in section 2.1.4 and provided a more detailed explanation. The relevant content is modified as follows. In addition, the Environmental Kuznets Curve (EKC) theory posits that the relationship between economic growth and environmental pollution is not linear but exhibits an "inverted U-shaped". The correlation between economic growth and pollution varies at different developmental stages. Inspired by the EKC theory [42], we suspect a nonlinear relationship between land urbanization and per capita CO2 emissions. It is essential to determine if their relationship is linear or nonlinear, enhancing our understanding of carbon emission effects from land urbanization. Hence, we also introduce the quadratic term of land urbanization. 1. Line 94. Present the first EKC transcript on line 94 rather than in Section 4. Conclusion and Discussion and line 401. Response: Thank you very much for your suggestion. We have added the full name of the EKC theory on line 94 and removed it in Section 4. 2. In general, according to the context of the article. Isn't it obvious that if EKC is not used in research, the potential increase in urbanization will still be accompanied by increased carbon emissions and vice versa? Because large cities consume more energy resources compared to smaller cities, which is accompanied by a load on the ecosystem. Response: We acknowledge your viewpoint that " the potential increase in urbanization will still be accompanied by increased carbon emissions". However, that's not the focus of this paper. We chose per capita CO₂ emissions instead of total CO₂ emissions as the explained variable precisely for this reason. Per capita emissions facilitate a horizontal comparison between cities of different sizes. As you mentioned, while large cities might consume more energy resources and emit more CO₂ compared to smaller cities, their per capita CO₂ emissions may not necessarily be higher. Urban expansion can introduce scale and agglomeration benefits, which might enhance regional energy efficiency and consequently dampen carbon emissions. The correlation between land urbanization and per capita CO₂ emissions is not intuitive and requires empirical study for quantification, which is the primary aim of this paper. We hope our response addresses your concerns and welcome any further suggestions. 3. Urbanization is directly related to the structure of the country's economy, technological modernization of production and largely depends on government regulation. Could this only lead to a short-term decline in carbon emissions before carbon levels begin to rise again? Response: We cannot provide a precise answer to this question as this paper doesn't distinguish between the short-term and long-term effects of land urbanization on per capita CO₂ emissions. This question, however, gives us a direction for future research: to delve deeper into the short and long-term impacts of land urbanization on per capita CO₂ emissions. We have highlighted this as a future research direction in the discussion section of the paper. Furthermore, it is necessary to further explore whether the carbon emission effect of urbanization is short-term or long-term, which is crucial for the government to formulate carbon reduction policies.

Author Response File: Author Response.docx

Reviewer 2 Report

Here are my comments and suggestions for this manuscript:

1. In the title, since "land urbanization" is a technical term not known by non-specialists, I suggest it be placed in quotation marks.

2. The subtitle is not very informative of the authors' thesis. Therefore, I recommend a new subtitle that conveys the main finding and conclusion from the authors' data in the manuscript rather than mere "fresh evidences of countries globally" which is also awkwardly worded. It seems like it would be: "the need for countries to consider their "unique stage of development when devising greenhouse gas reduction policies."

3. Footnote 2 which is cited on line 31 is from 2014 publication date. I was surprised at the many citations that were more than 10 years old. I would respectfully suggest that the authors search for more recent analyses for their discussion that might even support their thesis about "state of development" even more clearly.

4. Good to give the technical meaning for "land urbanization" in line 36, but that reinforces my recommendation for putting the term in quotes in the title.

5. line 45, the word "progression" seems misplaced here. I think the authors mean: "urban progress" which is different in meaning than "progression."

6. line 38, refers to the "accelerating trajectory" of land urbanization" globally. It would be useful to suggest some reasons for this noted phenomenon to help the reader understand the subject being discussed.

7. lines 49-50, why is land urbanization desirable which is implied by these lines, but not explained.

8. lines 68-69, the claim is made that "the relationship between land urbanization and carbon emissions is paramount for the transition toward regionally focused low-carbon urbanization," but it is never explained why. The reasons for this alleged highly significant relationship should be given here.

9. line 79, "scale and agglomeration benefits" should be explained in case of non-specialist reader is unaware of these concepts.

10. line 77, should be new paragraph beginning with: "One one side of this argument . . . "

11. line 88, avoid contractions in such formal writings like "it's."

12. line 94, reference is made to "EKC theory" without clarification for the non-specialist reader. The acronym is OK to use AFTER the theory's name has been given and the acronym is attached to it.

13. line 99, why is panel data referred to as "parallel data?" Also, this name of the date should be put in quotes and explained.

14. line 102, why does the "panel regression model enhance the credibility and effectiveness of estimation results?" Should be explained to the non-specialist to be rationally persuasive as well.

15. line 112, the word "stationarity" seems to be a word usage error. Do the authors mean "stability?" Check word usage here.

16. line 114, again acronyms without explanation and clarification as to their meaning: LLC and ADF tests. Full names of these tests should be provided when first used, then acronyms may be used properly for convenience.

17. lines 116-117, discuss different tests for difference kinds of panels, either homogeneous or heterogeneous panels, but it is never explained why this allocation of tests is made.

18. lines 174-177; good to provide full names for these factors with their acronyms attached here, but "energy structure (ES)," is not immediately obvious to the non-specialist reader and probably should be explained to be clear to such a reader.

19. in my version of the paper, the last line of Table 1 appears on the next page and separated from the rest of the Table. I would suggest that the Table appear in its entirely on the page for the reader to more easily view the EI, Energy intensity factor.

20. Page 5, Figure 1, omits the year the data referred to. I think the year of the data should be indicated in the caption of Figure 1.

21. line 202, vague phrase is used: "notably elevated levels of LU." I think this should be more precise and quantities should be indicated of such increased levels of LU.

22. line 207, precise data are given here of LU during the study period, but no source is given for the data which is needed here.

23. lines 208- 209; seems like the major finding for the research and should be reflected in the subtitle of the paper.

24. line 223, "all situated in Africa" is incorrect since New Guinea is not located in Africa. Correct this error.

25. Page 7, Figures 3, categories of LU seem widely disparate; one category appears to be from 3% to 100% which seems not very useful or precise; while another category is very tiny: "4% to 8%." I would check the groupings for the data here. Also, not clear if O.O1% intended to be .01% or 1 %? If the latter, what is "1.61%?"

26. lines 236-246, evidence for the several claims made in these lines are needed to make these claims rationally persuasive.

27. lines 250-252. Need to explain and support the goal of the stated study; why are nonlinear relationships important? Should discuss.

28. line 260, the introduction of "rights" language is new in the discussion and worthy of clarification given the fraught nature of this concept; what is "right to emit" and the "right to development?"

29. line 272, "mostly high-income countries." Should name these countries and how "high income" is being defined here.

30. Figure 5, page 9, is difficult to comprehend. What do the pointalist images supposed to represent? Also, the rectangles with a line across them are not immediately clear as to their meaning either. Consider alternative visual representations here, or perhaps none at all.

31. lines 276-286, "stationarity" is used multiple times here with much unclarity as to its meaning. Reconsider another word or explain further what the authors mean by this nonword.

32. line 336, "environmental consciousness in shaping the trajectory of PC02 emissions." Do the authors mean "environmental conditions" here rather than "consciousness?" How does such an alleged "consciousness" produce a "nuanced understanding of the evolving relationship between LU and carbon emissions?" This would seem to be a key point in the authors' argument and should be discussed and supported further.

33. line 357, uses the word "stabilizing." Is that what the authors mean by "stationarity?" If so, "stabilizing" would be a superior word to use instead.

34. lines 375-376, key phrase would seem to be "composition of the industrial sector," but the phrase is never clarified and defined. I think it needs to be elaborated upon given the importance of this idea to the authors' argument.

35. line 391, important phrase, "intricate interplay" of various factors, could be improved upon. Do the authors mean: "interaction? "interconnection?" "Association?" I think these words might be more precise than "Interplay" here.

36. line 401, "EKC" is spelled out as the "Environmental Kuznets Curve" here, but it should be spelled out at the beginning of the paper above. In addition, the EKC should be discussed and clarified, especially for the non-specialist reader who may not know about Kuznets curve.

37. line 426, new paragraph needed beginning with: "The growing asymmetry .  . . " etc.

38. line 433, "decoupling of socio-economic growth from PCO2?" Is that possible? need to discuss alleged decoupling, what it means, and its feasibility. What about the position of challenging the goal of endless economic growth instead of this dubious "decoupling" idea?

39. line 436, "the QUALITY of LU" is stated, but this concept of the "quality" of LU was not discussed previously in the paper and needs to be defined and clarified here at the end of the paper which is probably not a good placement for this concept; it needs to be discussed previously.

40. line 443, new paragraph beginning: "In conclusion, ".

41. line 443, LU is spoken as "aligns harmoniously" "with resource and environmental capacities." How is this alleged "alignment" achieved? Need to discuss and defend since critical to authors' argument.

42. lines 453-458. These lines discuss a whole new approach than the one discussed in the paper. It should not end the paper, but perhaps put in a footnote as an alternative approach than the one the authors chose to pursue in the paper. Do not put new subject at the end of the paper. Paper Conclusion sections should only summarize what has already been discussed and claimed with no new claims or evidence or approaches in the Conclusion section.

 

Author Response

2. Response to Reviewer #2:

Here are my comments and suggestions for this manuscript:

1. In the title, since "land urbanization" is a technical term not known by non-specialists, I suggest it be placed in quotation marks.

Response: Thank you very much for your remind. We have placed "land urbanization" in quotation marks in the title.

 

2. The subtitle is not very informative of the authors' thesis. Therefore, I recommend a new subtitle that conveys the main finding and conclusion from the authors' data in the manuscript rather than mere "fresh evidences of countries globally" which is also awkwardly worded. It seems like it would be: "the need for countries to consider their "unique stage of development when devising greenhouse gas reduction policies."

Response: Thank you very much for your suggestions. Based on your suggestions, we have decided to adopt a new subtitle to reflect the main findings of the paper. The title is modified as follows.

Impacts of "land urbanization" on CO₂ emissions: Policy implications based on developmental stages

 

3. Footnote 2 which is cited on line 31 is from 2014 publication date. I was surprised at the many citations that were more than 10 years old. I would respectfully suggest that the authors search for more recent analyses for their discussion that might even support their thesis about "state of development" even more clearly.

Response: Thank you very much for your reminder. Footnotes 2 and 4 in this paper describe the global urban development status, indeed requiring recent research support. Footnotes 2 and 4 cite literature published in 2014 and 2020, respectively. Clearly, footnote 2 requires updating. Following your remind, we have replaced the literature cited in footnote 2 as: "Oecd., Cities in the world: A New Perspective on Urbanization. OECD Urban Studies/European Union 2020". We have also updated the data in the introduction: "Presently, urban regions are home to 56% of the global population, and they are responsible for generating more than 75% of the world's wealth". Most other references in the article are from research within the last five years. Admittedly, we also cite some literature older than 10 years, primarily in the methodology section, which aids in a deeper understanding of the methodological mechanics. We hope our response can be accepted and welcome your further suggestions.

 

4. Good to give the technical meaning for "land urbanization" in line 36, but that reinforces my recommendation for putting the term in quotes in the title.

Response: Thank you once again for your reminder. We have placed "land urbanization" in quotation marks in the title.

 

5. line 45, the word "progression" seems misplaced here. I think the authors mean: "urban progress" which is different in meaning than "progression."

Response: Thank you very much for your reminder. According to your reminder, we have replaced "progression" with " progress".

 

6. line 38, refers to the "accelerating trajectory" of land urbanization" globally. It would be useful to suggest some reasons for this noted phenomenon to help the reader understand the subject being discussed.

Response: Thank you very much for your suggestion. Land urbanization is influenced by various factors such as societal productivity, scientific and technological advancements, and industrial structure. It is a manifestation of the social transformation experienced by a nation during its industrialization and modernization process. Existing data indicate that in recent years, global urban land expansion has predominantly occurred in Asia, particularly in developing countries like China and India. To help the reader understand the subject being discussed, according to your suggestion, we have added the reasons for the phenomenon of the 'accelerated trajectory' of global land urbanization. The relevant content is modified as follows.

Benefitting from the contributions of developing countries, global urban expansion has been on an accelerating trajectory. Research has revealed that over the past two decades, the expansion of urban built-up land globally has been growing at an average annual rate of 9,000 to 10,000 km² [4].

 

7. lines 49-50, why is land urbanization desirable which is implied by these lines, but not explained.

Response: Thank you very much for your reminder. As mentioned earlier, land urbanization emerges as an essential pathway for urban progress primarily propelled by societal demands. Land urbanization, by converting non-built land into built-up areas, enables the provision of public facilities, infrastructure, commerce, housing, and other functions, effectively fostering socio-economic development. Consequently, governments craft urban development strategies that align with the principles of land urbanization. We have already explained the advantages of land urbanization in the paper.

 

8. lines 68-69, the claim is made that "the relationship between land urbanization and carbon emissions is paramount for the transition toward regionally focused low-carbon urbanization," but it is never explained why. The reasons for this alleged highly significant relationship should be given here.

Response: Thank you very much for your reminder. It has been confirmed that land use significantly influences carbon emissions from existing research. However, there is currently no consensus in the academic community regarding the specific impact of land urbanization on carbon emissions. Establishing a clear understanding of the relationship between land urbanization and carbon emissions is a prerequisite for formulating low-carbon policies, which are paramount for the transition toward regionally focused low-carbon urbanization. In line with your suggestion, we have added the reasons for this significant relationship. The relevant additions are as follows.

Unfortunately, there is currently no consensus in the academic community regarding the specific impact of land urbanization on carbon emissions. A nuanced comprehension of the relationship between land urbanization and carbon emissions is a prerequisite for formulating low-carbon policies, which are paramount for the transition towards regionally-focused, low-carbon ur-banization.

 

9. line 79, "scale and agglomeration benefits" should be explained in case of non-specialist reader is unaware of these concepts.

Response: Thank you very much for your suggestion. We have added an explanation of "scale and agglomeration benefits" to make it more accessible for non-specialist reader to understand. The relevant additions are as follows.

Conversely, some studies underscore that urban growth can introduce scale and agglomeration benefits, promoting the concentration of production factors and facilitating the sharing of resources and knowledge. As a result, urban growth might enhance regional energy efficiency and conse-quently dampen carbon emissions.

 

10. line 77, should be new paragraph beginning with: "One one side of this argument . . . "

Response: Thank you very much for your reminder. "On one side of this argument . . . " is an explanation of the first viewpoint regarding the relationship between elationship between urbanization and carbon emissions, closely tied to the preceding content. Creating a new paragraph might disrupt the overall coherence of the article. Consequently, we have decided not to incorporate the suggested paragraph.

 

11. line 88, avoid contractions in such formal writings like "it's."

Response: Thank you very much for your remind. We have replaced contractions such as "it's" and "there's".

 

12. line 94, reference is made to "EKC theory" without clarification for the non-specialist reader. The acronym is OK to use AFTER the theory's name has been given and the acronym is attached to it.s

Response: Thank you very much for your remind. We have added the full name of Environmental Kuznets Curve (EKC).

 

13. line 99, why is panel data referred to as "parallel data?" Also, this name of the date should be put in quotes and explained.

Response: Thank you very much for your remind. Panel data is referred to as "parallel data" because it is organized in a parallel manner, enabling researchers to simultaneously examine relationships between different time points and different individuals within a single dataset. "Parallel data" is merely our additional interpretation of panel data; removing it does not affect the content of the article. For the sake of reader comprehension, we have decided to omit the mention of parallel data. Furthermore, we have added an explanation of panel data.

Panel data is a dataset that encompasses multiple observation time points and multiple observed entities. introduces a cross-sectional dimension to time series analysis, selecting specific obser-vations within the cross-section.

 

14. line 102, why does the "panel regression model enhance the credibility and effectiveness of estimation results?" Should be explained to the non-specialist to be rationally persuasive as well.

Response: Thank you very much for your remind. Time series regression model often suffer from issues of multicollinearity and endogeneity, leading to inaccurate estimation results. Panel regression model, which account for individual differences and time trends, effectively address issues of multicollinearity and endogeneity, thereby enhancing the credibility and effectiveness of estimation results. According to your recommendation, we have added an explanation of panel regression model. The relevant additions are as follows.

Panel regression model, by accounting for individual differences and time trends, effectively address the issues of multicollinearity and endogeneity commonly found in time series analysis, thereby enhancing the credibility and effectiveness of estimation results.

 

15. line 112, the word "stationarity" seems to be a word usage error. Do the authors mean "stability?" Check word usage here.

Response: Thank you for your input regarding the terminology for data stationarity. While "stability" is a valid term, in the context of regression analysis and panel data modeling, "stationarity" is a more commonly accepted term. It specifically describes the statistical properties of data remaining constant over time, which is a critical concept in our field. To ensure clarity and consistency within the field, it's advisable to use ''stationarity' in our work. sHowever, I'm open to further discussion if you have strong reasons for preferring ''stability'' in this specific context.

 

16. line 114, again acronyms without explanation and clarification as to their meaning: LLC and ADF tests. Full names of these tests should be provided when first used, then acronyms may be used properly for convenience.

Response: Thank you very much for your remind. The full names of LLC and ADF tests are Levin-Lin-Chu and Augmented Dickey-Fuller. We have provided full names of these tests. The relevant modifications are as follows.

the Levin-Lin-Chu (LLC) unit root test and the Augmented Dickey-Fuller (ADF) unit root test.

 

17. lines 116-117, discuss different tests for difference kinds of panels, either homogeneous or heterogeneous panels, but it is never explained why this allocation of tests is made.

Response: Thank you for your valuable feedback. The decision to employ both homogeneous and heterogeneous panel unit root tests is motivated by the need to comprehensively assess the stationarity properties of the panel data. By utilizing both methods, we aim to provide a more robust analysis. This approach is widely recognized in the field and helps reduce the risk of misjudging stationarity issues. According to your recommendation, we have added the explanation.

The LLC unit root test is primarily used for homogeneous panels, whereas the ADF unit root test is better suited for heterogeneous panels. By employing both homogeneous and heterogeneous panel unit root tests simultaneously, a comprehensive assessment of data stationarity is achieved, reducing estimation misjudgments.

 

18. lines 174-177; good to provide full names for these factors with their acronyms attached here, but "energy structure (ES)," is not immediately obvious to the non-specialist reader and probably should be explained to be clear to such a reader.

Response: Thank you for your suggestion. We have provided the definitions of factors in the table 1. We believe that the definitions provided in the table 1 are sufficiently clear to convey the meaning of the variables for non-specialist reader. We have aimed for clarity and conciseness in our presentation. However, we appreciate your attention to detail.

 

19. in my version of the paper, the last line of Table 1 appears on the next page and separated from the rest of the Table. I would suggest that the Table appear in its entirely on the page for the reader to more easily view the EI, Energy intensity factor.

Response: Thank you very much for your reminder. We have reformatted Table 1 to fit entirely on one page, making it more convenient for readers to view the table content.

 

20. Page 5, Figure 1, omits the year the data referred to. I think the year of the data should be indicated in the caption of Figure 1.

Response: Thank you very much for your reminder. We have added the year of the data, 2015, to the caption of Figure 1.

 

21. line 202, vague phrase is used: "notably elevated levels of LU." I think this should be more precise and quantities should be indicated of such increased levels of LU.

Response: Thank you for your suggestion. We have provided LU levels to increase the accuracy of the presentation, using 2020 as an example. The relevant modifications are as follows.

For instance, in 2020, high-income nations exhibit notably elevated levels of land urbanization in contrast to their lower income counterparts, with 5.74% for high-income nations and 1.47% for low-income nations.

 

22. line 207, precise data are given here of LU during the study period, but no source is given for the data which is needed here.

Response: Thank you very much for your reminder. We have provided the data source in Section 2.2. The Land Urbanization (LU) in this study is calculated as the ratio of urban built-up land area to total land area, with the primary data sourced from the the World Bank's Development Indicators database.

 

23. lines 208- 209; seems like the major finding for the research and should be reflected in the subtitle of the paper.

Response: Thank you for your suggestion. Based on your suggestions, we have updated the subtitle of this paper. The title is modified as follows.

Impacts of land urbanization on CO₂ emissions: Policy implications based on developmental stages

 

24. line 223, "all situated in Africa" is incorrect since New Guinea is not located in Africa. Correct this error.

Response: Thank you for your careful review and feedback. We appreciate your keen attention to detail. You are correct that Papua New Guinea is not located in Africa; it is situated in the southwestern Pacific Ocean. We apologize for the error in our previous text, and we will make the necessary correction. We appreciate your assistance in ensuring the accuracy of our paper. The relevant modifications are as follows.

Remarkably, the five countries showcasing the lowest land urbanization level in 2020 were Mauritania, South Africa, Morocco, Botswana, and Papua New Guinea — all situated in Africa except Papua New Guinea, with their land urbanization figures resting below the 0.01% threshold.

 

25. Page 7, Figures 3, categories of LU seem widely disparate; one category appears to be from 3% to 100% which seems not very useful or precise; while another category is very tiny: "4% to 8%." I would check the groupings for the data here. Also, not clear if O.O1% intended to be .01% or 1 %? If the latter, what is "1.61%?"

Response: Thank you for your feedback and attention to the classification of countries based on LU levels in Figures 3. Our classification, which divides countries into groups of 0.01%-0.40%, 0.41%-0.80%, 0.81%-1.60%, 1.61%-3.20%, and 3.21%-100%, was designed with the intention to ensure that each category contains approximately an equal number of countries. We believe that our approach offers a balanced way to represent the distribution of LU levels while maintaining a practical and manageable number of categories. We are open to discussing alternative approaches if you have any specific suggestions.

To avoid ambiguity, we have decided to replace the category ''3.21%-100%'' with ''>3.21%''. The unit for LU levels in the figure is percentage (%), representing ''0.01%'', ''0.40%'', ''0.80%'', ''1.60%'', and ''3.20%''.

 

26. lines 236-246, evidence for the several claims made in these lines are needed to make these claims rationally persuasive.

Response: Thank you for the valuable suggestion. We appreciate the importance of substantiating our claims with robust evidence to enhance the persuasiveness of our research. We highly value your feedback, which is instrumental in our work. According to your suggestion, we have cited following literature to explicitly and firmly support our points.

With reference to existing research [43-45], we infer the following reasons for the emergence of each pattern.

43. Liu, Q.; Wang, S.; Zhang, W.; Li, J.;Kong, Y., Examining the effects of income inequality on CO2 emissions: Evidence from non-spatial and spatial perspectives. Applied Energy 2019, 236, 163-171.
44. Wang, J.; Wang, S.; Zhou, C.; Feng, K., Consumption-based carbon intensity of human well-being and its socioeconomic drivers in countries globally. Journal of Cleaner Production 2022, 366, 132886.
45. Hao, Y., Effect of economic indicators, renewable energy consumption and human development on climate change: An empirical analysis based on panel data of selected countries. Frontiers in Energy Research 2022, 10, 841497.

 

27. lines 250-252. Need to explain and support the goal of the stated study; why are nonlinear relationships important? Should discuss.

Response: Thank you for your suggestion. Comparing Figure 2 and Figure 4 reveals that the evolutionary trajectories of land urbanization and per capita CO2 emissions exhibit nuanced disparities. However, the incongruence between these trends does not necessarily imply a lack of relationship between land urbanization and per capita CO2 emissions. Inspired by the EKC theory, we suspect a nonlinear relationship between land urbanization and per capita CO2 emissions. It is essential to determine if their relationship is linear or nonlinear, enhancing our under-standing of carbon emission effects from land urbanization. According to your suggestion, we have added a discussion on non-linear relationships in the section 2. The relevant additions are as follows.

In addition, the Environmental Kuznets Curve (EKC) theory posits that the relationship between economic growth and environmental pollution is not linear but exhibits an "inverted U-shaped". The correlation between economic growth and pollution varies at different developmental stages. Inspired by the EKC theory [42], we suspect a nonlinear relationship between land urbanization and per capita CO₂ emissions. It is essential to determine if their relationship is linear or nonlinear, enhancing our understanding of carbon emission effects from land urbanization. Hence, we also introduce the quadratic term of land urbanization.

 

28. line 260, the introduction of "rights" language is new in the discussion and worthy of clarification given the fraught nature of this concept; what is "right to emit" and the "right to development?"

Response: Thank you for your feedback and for emphasizing the complexity of the concept of "rights". While we appreciate the importance of clarity and precision in our research, we also recognize that the detailed explanation of the concept of "rights" might not align with the primary focus of our study. In light of this consideration, we have decided to remove the relevant statements related to this concept. We appreciate your understanding of our decision and value your input.

 

29. line 272, "mostly high-income countries." Should name these countries and how "high income" is being defined here.

Response: Thank you for your comment. We have already defined the concept of "high income" in section 2.2. We appreciate your suggestion; however, we believe that the definition provided in the paper is sufficient for the context of our study.

In light of your 30th feedback, we have decided to remove Figure 5, and the associated statement will be deleted accordingly. Therefore, no further modifications will be made regarding this specific suggestion.

 

30. Figure 5, page 9, is difficult to comprehend. What do the pointalist images supposed to represent? Also, the rectangles with a line across them are not immediately clear as to their meaning either. Consider alternative visual representations here, or perhaps none at all.

Response: Thank you for your feedback regarding the box plots (Figure 5) in our paper. We appreciate your perspective and understand your concerns about its clarity. After careful consideration, we have decided to remove the box plot from the paper. We appreciate your guidance in this matter.

 

31. lines 276-286, "stationarity" is used multiple times here with much unclarity as to its meaning. Reconsider another word or explain further what the authors mean by this nonword.

Response: Thank you for your continued attention to the usage of the term "stationarity" in our paper. We want to reiterate that, upon reevaluation, we are confident that the term "stationarity" is appropriately used in the context of panel data, and this point has been addressed in detail in our response to Comment 15. We appreciate your diligence and feedback, which have contributed to the clarification of this matter.

 

32. line 336, "environmental consciousness in shaping the trajectory of PCO2 emissions." Do the authors mean "environmental conditions" here rather than "consciousness?" How does such an alleged "consciousness" produce a "nuanced understanding of the evolving relationship between LU and carbon emissions?" This would seem to be a key point in the authors' argument and should be discussed and supported further.

Response: Thank you for your valuable suggestion regarding the use of "environmental consciousness". We appreciate your input and agree that "environmental conditions" would be a more appropriate choice of phrasing. We will make the necessary adjustment to the text in accordance with your recommendation.

In addition, Thank you for your insightful observation regarding a specific statement in our paper. While we understand the significance of this point, it is not the key point of our research. In order to avoid any potential ambiguity and maintain the clarity of our main message, we have decided to remove this particular content.

 

33. line 357, uses the word "stabilizing." Is that what the authors mean by "stationarity?" If so, "stabilizing" would be a superior word to use instead.

Response: Thank you for your question regarding the term 'stabilizing' in our paper. We appreciate your attention to detail. In this context, "stabilizing" does not carry the same meaning as "stationarity". "Stabilizing" is used to indicate a trend of becoming more stable or steady over time, whereas "stationarity" is a term we have specifically used to refer to the stationarity of panel data. We apologize for any potential confusion and appreciate the opportunity to clarify the distinction between the two terms in our paper.

 

34. lines 375-376, key phrase would seem to be "composition of the industrial sector," but the phrase is never clarified and defined. I think it needs to be elaborated upon given the importance of this idea to the authors' argument.

Response: Thank you for pointing out the issue with the phrase "composition of the industrial sector". We appreciate your observation. In fact, this phrase is synonymous with "industrial structure", and we acknowledge that using a consistent terminology is essential for clarity. Therefore, we will adopt your suggestion and uniformly use 'industrial structural' throughout the paper to prevent any confusion. We have provided the definition of 'industrial structure' in Table 1. Your feedback is valuable in refining the precision of our terminology.

 

35. line 391, important phrase, "intricate interplay" of various factors, could be improved upon. Do the authors mean: "interaction? "interconnection?" "Association?" I think these words might be more precise than "Interplay" here.

Response: Thank you for your suggestion to improve the phrase 'intricate interplay.' We appreciate your feedback and agree that 'intricate interaction' is a more precise choice of wording. We will make the adjustment to use 'intricate interaction' in the paper to enhance clarity and precision. Your valuable input is important in refining the language and expression in our research.

 

36. line 401, "EKC" is spelled out as the "Environmental Kuznets Curve" here, but it should be spelled out at the beginning of the paper above. In addition, the EKC should be discussed and clarified, especially for the non-specialist reader who may not know about Kuznets curve.

Response: Thank you very much for your remind. We have spelled out "EKC" as the "Environmental Kuznets Curve" at the beginning of the paper above.

We refer to adopted the Environmental Kuznets Curve (EKC) theory to examine if there exists a nonlinear relationship between land urbanization and per capita CO₂ emissions. The EKC theory posits that during the initial stages of economic development, environmental degradsation is relatively low. Subsequently the country's economic development has been accompanied by an increase in its environmental pollution. A tipping point is reached at a certain level of economic development where environmental degradation starts to decline, leading to continuous improvements in environmental quality thereafter. This relationship between economic growth and environmental pollution forms an inverted "U" shape. The EKC theory holds significant value in green economy research. It suggests the potential for nonlinear relationships between variables, with differing correlations at various developmental stages. Inspired by EKC theory, we attempt to verify the nonlinear relationship between land urbanization and per capita CO₂ emissions. Following your suggestion, we have added reasons for selecting the EKC in section 2.1.4 and provided a more detailed explanation. The relevant content is modified as follows.

In addition, the Environmental Kuznets Curve (EKC) theory posits that the relationship between economic growth and environmental pollution is not linear but exhibits an "inverted U-shaped". The correlation between economic growth and pollution varies at different developmental stages. Inspired by the EKC theory [42], we suspect a nonlinear relationship between land urbanization and per capita CO₂ emissions. It is essential to determine if their relationship is linear or nonlinear, enhancing our understanding of carbon emission effects from land urbanization. Hence, we also introduce the quadratic term of land urbanization.

 

37. line 426, new paragraph needed beginning with: "The growing asymmetry . . . " etc.

Response: Thank you for your suggestion to create a new paragraph at the specified location. We appreciate your attention to the organization and structure of our paper. We will implement the addition of a new paragraph as you recommended to enhance the flow and clarity of the text.

 

38. line 433, "decoupling of socio-economic growth from PCO2?" Is that possible? need to discuss alleged decoupling, what it means, and its feasibility. What about the position of challenging the goal of endless economic growth instead of this dubious "decoupling" idea?

Response: Thank you for your feedback regarding the concept of "decoupling" in our paper. We appreciate your insights. In light of your suggestion, we have decided to remove the related references to "decoupling" in our paper and will replace the expression to better align with your recommendations. The relevant modifications are as follows.

This entails a concerted focus on reshaping industrial and energy structures, without the sole focus on endless economic growth, in order to reduce per capita carbon emissions.

 

39. line 436, "the QUALITY of LU" is stated, but this concept of the "quality" of LU was not discussed previously in the paper and needs to be defined and clarified here at the end of the paper which is probably not a good placement for this concept; it needs to be discussed previously.

Response: Thank you for your observation regarding the introduction of the concept of the "quality" of LU in our discussion section. We appreciate your attention to detail. We appreciate your attention to detail. While the concept of "quality" of LU was not explicitly discussed earlier in the paper, we believe it is a relevant concept in the context of our research. In response to your suggestion, we plan to enhance our discussion on the "quality" of LU to provide a more comprehensive understanding of the subject. This will help to clarify the concept and its relevance to our study. The relevant modifications are as follows.

Drawing insights from the expansion patterns of high-income countries, emphasis should be placed on the quality of land urbanization. Specifically, the focus is on preserving urban environments, promoting sustainable urban development, and increasing urban land efficiency. This entails mitigating ecological pressures resulting from urban expansion and aligning such expansion with the ca-pacity of local resources and the environment.

 

40. line 443, new paragraph beginning: "In conclusion, ".

Response: Thank you for your suggestion to create a new paragraph at the specified location. We appreciate your attention to the organization and structure of our paper. We will implement the addition of a new paragraph as you recommended to enhance the flow and clarity of the text.

 

41. line 443, LU is spoken as "aligns harmoniously" "with resource and environmental capacities." How is this alleged "alignment" achieved? Need to discuss and defend since critical to authors' argument.

Response: Thank you for your feedback on our manuscript. Based on the findings of the study, this paper provides policy recommendations for land urbanization strategies in various countries. We have provided a comprehensive framework for our policy recommendation, though we acknowledge the absence of specific measures. For example, we propose that urban expansion should respect ecological thresholds to aligns harmoniously with resource and environmental capacities. We suggest that policymakers should take ecological thresholds into account when determining land urbanization strategies. Given the policy's context-dependent nature, we're hesitant to prescribe universal measures. After careful consideration, we have decided not to provide more detailed implementation measures. We hope our response can be accepted and welcome your further suggestions.

 

42. lines 453-458. These lines discuss a whole new approach than the one discussed in the paper. It should not end the paper, but perhaps put in a footnote as an alternative approach than the one the authors chose to pursue in the paper. Do not put new subject at the end of the paper. Paper Conclusion sections should only summarize what has already been discussed and claimed with no new claims or evidence or approaches in the Conclusion section.

Response: Thank you for your feedback. We appreciate your guidance. While we understand the standard practice of not introducing new topics in the conclusion, we believe that mentioning the limitations of our current study and suggesting future research directions is pertinent. This helps provide context and guidance for future investigations in the field. We will, however, ensure that our conclusion remains concise and aligned with your recommendations

Author Response File: Author Response.docx