Spatial-Temporal Evolution and Influencing Factors of Animal Husbandry Carbon Emissions: A Case Study of Shandong Province, China

Round 1

Reviewer 1 Report (Previous Reviewer 1)

The manuscript has been significantly enhanced after adapting to review comments. The paper has input in research area for sure.   I recommend to publish this manuscript.

Author Response

Based on the opinions of the editor-in-chief and the reviewer, we have made extensive changes to the manuscript to make the results convincing. Thank you again for your positive comments and valuable suggestions to improve the quality of our manuscripts.

Author Response File: Author Response.pdf

Reviewer 2 Report (New Reviewer)

This manuscript aims to study the spatial distribution and dynamic evolution of livestock carbon emissions in Shandong Province, China. In my opinion, it is an important case study, particularly for Chinese livestock breeders and producers. This paper is well improved by the authors (Round 1). The high similarity percentage of this MS may be due to the existence of a copy on "preprints.org". Anyway, please avoid writing "livestock and poultry" because poultry are livestock animals. Additionally, add the reference number beside the author's surname in the text (e.g., L.122 Dai et al. [13]). Provide the missed statistical analysis section.  L.433: "policy recommendations". References: Follow the journal format.

Acceptable.

Author Response

Based on the opinions of the editor-in-chief and the reviewer, we have made extensive changes to the manuscript to make the results convincing. Thank you again for your positive comments and valuable suggestions to improve the quality of our manuscripts.

Author Response File: Author Response.pdf

Reviewer 3 Report (New Reviewer)

Dear authors, 

here is my review for the paper: Spatial differentiation and dynamic evolution of carbon emissions from animal husbandry: A Case Study of Shandong Province, China

Introduction paragraph provides information about the challenges generated by greenhouse gas emissions that appear in the sphere of animal husbandry, with all mitigation attempts not only from China but all over the planet. References were made both to the current estimate of emissions and to the political initiatives that try to limit them.

However, there are few shortcomings concerning the theoretical background on the topic (see the comments in text).

The research results and analyzes are original and contribute to the scientific knowledge of GHG in animal and poultry farming.

Overall, the text contributes with the results obtained and their interpretation to the understanding of GHG from agriculture and provides guidance for future research and political initiatives in the field.

The aim of the research is not very clearly stated in the last paragraph of the introduction.

In the research, calculations and statistical analyzes were used for carbon emissions from animals and birds in China, Shandong province.

The research hypotheses are not clearly explained, but the research aims to investigate the factors that contribute to GHG from animal husbandry.

Material and Methods shortcomings:

1. There is no detailed description of the methods used for data sampling for GHG emission, based mainly on references and secondary sources, without explanations on how to determine GHG emission.

2. The methodology does not take into account the variation of carbon emissions depending on area, climate or husbandry management, which could influence the results.

3. The difference between direct and indirect emissions from animals and birds is not clear in order to understand their impact on animals and environment.

4. The technical details to accurately measure the emissions resulting from manure management and gastrointestinal fermentation are missing.

5. The impact on the environment and human and animal health that can be associated with animal husbandry is not addressed (e.g. heating sources, waste water, etc.).

More details in the methodology section could provide greater clarity on the statistical analysis used.

Results

It is advisable to discuss the factors that contribute to changes in the animal population, agricultural practices or technological advances, respectively political interventions, agriculture prctices  and climate variability.

Descriptive statistics are presented for total carbon emissions and their intensity over time, but without clear statistical analyzes for the observed trends; what are the factors behind these trends?

References are made to previous studies, but no detailed comparisons were made between the research findings and the existing ones.

Discussions regarding the potential political implications of the research findings, which could influence political decisions leading to carbon emission mitigation resulting from animal and poultry farming in Shandong province.

Replace „term density curve” with the standard term „kernel density curve” or „density estimation curve”

 „polarization” and „differentiation” terms for carbon emission exchage is not scientifical clear

The results obtained are characteristic of Shandong province, as a result the limits of generalization for wider contexts should be specified.

It is essential to discuss the accuracy and reliability of the data used in the data analysis and validation.

Conclusions

The paper brings valuable results regarding carbon emissions from animal and poultry husbandry, with practical policy recommendations. However, the authors acknowledge that the calculation of carbon emissions is limited by the available data, which may influence the accuracy of the results. At the same time, the omission of some factors that contribute to carbon emissions is recognized, which requires further investigation into the omitted factors and the generalization for wider areas.

Please see also the comments in text.

Comments for author File: Comments.pdf

Author Response

Based on the opinions of the editor-in-chief and the reviewer, we have made extensive changes to the manuscript to make the results convincing. Thank you again for your positive comments and valuable suggestions to improve the quality of our manuscripts.

Author Response File: Author Response.pdf

Reviewer 4 Report (New Reviewer)

1.     This paper has many highlighted (shaded) paragraphs.  Usually these highlights or shades are done at revision and re-submission.  If this paper is submitted first time to this journal, then a clean manuscript should be provided.  If this paper is a revised resubmission, then a point-to-point reply letter should be provided.

2.     This paper mainly computes the distribution of animal husbandry carbon emissions and turns the numerical results into diagrams.  However, it is not clear what academic propositions that these numerical results and diagrams convey to the readers.  Take Figure 1 as an example.  The darker regions imply that they have higher carbon emissions.  However, there is no further associate models such as regressions to explain why they have higher carbon emissions.

3.     Similarly, Figure 3 reports the densities.  However, there is no explanatory variable included in any formal analysis to further explain why this kind of distribution is formed and how these distributions can be used for policy formation.

4.     That is, this paper simply did the computation of numbers by using Eqs. (1) to (8) but has no further statistical analysis with explanatory variables.  There are only numbers of dependent variables waiting to be explained but there is no independent variable to explain these numbers.

5.     The conclusion now is a pure summarization of the computed numerical numbers.  Even though in the second part of conclusion there are policy suggestions, these policy instruments were not in any model of this paper.  Therefore, these policy suggestions are pure conjectures without statistical evidence.

6.     It is strongly suggested that the related academic propositions should be included.  It will be helpful to indicate what academic propositions are supported or not supported by the empirical findings in this paper.

This shaded manuscript is difficult to read.  There are a lot of gammar and spelling corrections marked on this manuscript.

Author Response

Based on the opinions of the editor-in-chief and the reviewer, we have made extensive changes to the manuscript to make the results convincing. Thank you again for your positive comments and valuable suggestions to improve the quality of our manuscripts.

Author Response File: Author Response.pdf

Reviewer 5 Report (New Reviewer)

The submitted article entitled: "Spatial differentiation and dynamic evolution of carbon emissions from animal husbandry: A Case Study of Shandong Province, China" is an original research paper on the topic of Carbon emissions in agriculture associated with livestock farming. Using panels and statistical methods, the authors examine the level and dispersion of carbon emissions in selected regions in China, from the time series of data for the years 2001 - 2022. With its focus, this work could be classified in the Environmental policy category and corresponds to the publication focus of the journal Sustainability.

It can be stated that the research has a rather local significance, without significant foreign overlap, it is carried out in local conditions and specifics of Chinese industrial production. It is also a relatively frequently researched issue, on which there are enough publications in representative databases.

Unfortunately, the presented research contains a number of shortcomings, especially in the area of presentation.

- The abstract is rather unintelligibly worded and I lack a clear, concise qualification of the specific results achieved in numbers and percentages. Emissions decreased, increased - but by how much? There is also a lack of better specifications of the research methods used. It should be remembered that the Abstract is a summary of the work, where the research is to be briefly presented.

- The Introduction section lacks a clear delineation of the research objective and the research questions that lead to it. This is how the Conclusion of the work should be subsequently organized. In the Introduction, I also completely lack a description and specification of the examined economic regions and the examined time period. The authors also did not specify well what emissions they are actually looking at - the CO2 equivalent associated with agricultural production, including the carbon footprint, or just the direct emissions produced by animals? It's quite confusing this way. From the conclusion, it can be understood that these are total emissions, however, this needs to be clearly qualified and allocated already in the Introduction, including the subsequent methodology.

- The best part of the work is the analysis itself in the Results section. I can state that the methodology is suitable and the time series is long enough. On the contrary, there is a lack of a better description of it - crisis, slowdown in production, etc. All this has an effect on the result at the end of the analysis.

- Maps of the regions are used in the Results section - here it is necessary to indicate the source from which the maps are taken and if it is a software application, it is advisable to indicate the program used.

- I perceive the Conclusion section as downright weak. Names of provinces that have not been specified before and are unknown to the reader are listed here.

- Here, the authors completely renounced the clear qualification of the specific results achieved - in percentages, units of measurement, tons, etc. An evaluation of the chosen research goal and research questions would be ideal here. And again, emissions increased, decreased, yes, but by how much??

- Within the discussion, I completely miss comparison with other works on the same topic. This would help expand the poor literary sources - which is another problem.

- The Policy Proposal subsection contains rather naive and flat advice that is not entirely based on the research carried out. Ideas like: Low-emission cities are role models and will lead others to the goal of reducing carbon emissions are insufficient! And what if these cities simply have low industrial production and low agricultural production??

The research presented has obviously been edited repeatedly and there are red and shaded passages. Even so, I have to state that in this state the submitted article does not reach the quality required for publication in the impact journal Sustainability.

Moderate editing of English language required

Author Response

Based on the opinions of the editor-in-chief and the reviewer, we have made extensive changes to the manuscript to make the results convincing. Thank you again for your positive comments and valuable suggestions to improve the quality of our manuscripts.

Author Response File: Author Response.pdf

Round 2

Reviewer 4 Report (New Reviewer)

1.     As the revised manuscript indicates, the authors have made a lot of changes in this paper.  Almost 80% of this paper has been revised.  Even though the current manuscript still needs improvements, the efforts of authors should be positively affirmed.  However, some minor points still remain to improve.

2.     If possible, try to construct at least two research hypotheses from theories.  Statistical evidence should be provided to show if these research hypotheses are supported.

3.     Reference 16 is incomplete and starts with a period (.).  These incomplete items and broken sentences should be carefully checked and corrected.

4.     There are only 39 references in the current form, among which half of the references comes from local Chinese journals and books.  This implies insufficient references from major international journal articles.  Please cite at least 30 more references from major international journals.  Moreover, many of the local Chinese references should be replaced by international journal articles with similar findings.

Reference 16 is incomplete and starts with a period (.).  These incomplete items and broken sentences should be carefully checked and corrected.

Author Response

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Author Response File: Author Response.pdf

Reviewer 5 Report (New Reviewer)

The manuscript is improved on the level asked by publishing policy of the journal, after made correction.

Minor editing of English language required

Author Response

Please see attachment.

Author Response File: Author Response.pdf

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

A very important and topical issue. The article is well prepared from the methodological point of view. I have three comments:

1.       Data on global greenhouse gas emissions should be updated, quoted in lines 42-44 are from 2013-2015.

2.       Why are seeds not included in the emissions calculation for crop production?

3.       The following sentence is too general „ The root cause of these disparities can be attributed largely to the uneven development of different regions” (612-613), does not explain this variation.

Taking into account these minor comments, the article deserves publication.

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 2 Report

The manuscript is about spatial-temporal characteristics and dynamic evolution of greenhouse gas emissions from animal husbandry based on Life Cycle. The scope of this article is consistent with the requirements of the Sustainability, but it requires major revision in accordance with the comments below:

1.     Abstract is too long. According Instruction for Authors should be a total of about 200 words maximum. The abstract should be a single paragraph and should follow the style of structured abstracts, but without headings: 1) Background: Place the question addressed in a broad context and highlight the purpose of the study; 2) Methods: Describe briefly the main methods or treatments applied. Include any relevant preregistration numbers, and species and strains of any animals used. 3) Results: Summarize the article's main findings; and 4) Conclusion: Indicate the main conclusions or interpretations. 

2.     I believe that the costs presented in table 2, i.e. Unit price of coal and Breeding electricity unit price, should be in USD, not CNY. Many readers are from outside China and these values should be universal.

3.     In the rest of the work, costs should also be counted in USD.

4.     The quality of Figure 2 is very poor. 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

In this work, Wei et al. estimated life-cycle GHG emissions from animal husbandry in Shandong province in China between 2001 and 2021. Their estimates were based on static emission factors that did not reflect practice and technology changes, which are important for their trend analysis. For example, different fertilization practices could yield different nitrogen use efficiency and GHG emissions. This typically changes with income level and local policies. For power generation, the average thermal efficiency of coal power plants in China has improved dramatically, and the contribution of renewable energy has also increased rapidly. Together, they lowered GHG emissions in China. The use of the NRDC 2011 guideline does not represent this trend. Therefore, the temporal analysis in this study has severe limitations and contributes little to the field. Their dynamic analysis that showed multipolar development in GHG emissions in the region is interesting, which may indicate the intensification of the livestock industry. However, given the limitations of the method discussed above, it provides little insight. Because of these concerns, I do not recommend publishing the study in sustainability.

Moderate English editing is needed. For example, the three sentences in the abstract between lines 20 and 26 are in three different tenses. They should all be in the past tense since they describe the period between 2001 - 2021. 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

 Accept in present form.