PONE-D-22-23019Carbon opportunity cost increases carbon footprint advantage of grain-finished beefPLOS ONE

Dear Dr. Blaustein-Rejto,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

Please submit your revised manuscript by Oct 29 2022 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

Please include the following items when submitting your revised manuscript:

• A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.
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• An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols.

We look forward to receiving your revised manuscript.

Kind regards,

Juan Carlos Suárez Salazar

Academic Editor

PLOS ONE

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Additional Editor Comments :

In general, the manuscript presents an adequate structure with some typographical errors. It is necessary that you can add additional information and explain more extensively some techniques of statistical analysis which has been requested by the reviewers, this will strengthen the manuscript.

[Note: HTML markup is below. Please do not edit.]

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: Partly

Reviewer #3: Yes

**********

2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: No

Reviewer #3: Yes

**********

3. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: No

Reviewer #3: Yes

**********

4. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

**********

5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: 1. Check the title.

40-43. Cite this part.

47-49. Cite this part.

89-94. These results should not be there.

130, 154, 157. Is it possible to reference the equations?

281 & 312. Please place figure title below the Fig.

320. Please include all the definitions below the table. The table must be self explanatory.

Figure S1. There are no white circles, and the map has no color

Recommendation: you may consider placing different types of dots on figure 2. This can help colorblind (daltonic) people with their understanding.

Reviewer #2: The paper conducts a pairwise comparison of pasture-finished operations and grain-finished operations. Also, the authors show that land-use intensity and carbon footprint are positively correlated. Thus, the paper concerns a fundamental and interesting research problem.

However, I have some recommendations for the authors:

1. Materials and methods.

a. Pairwise comparison: How did you collect the data? Table S8 shows information about 20 studies included in the pairwise comparison; how were the studies selected? It is necessary to add this information.

b. Regression analysis: How many observations did you use? Are the units 72 operations or 24 studies? Is it a cross-section regression, or is it panel data? (In this case, which are the individuals, and which is the time?) Where are the results of the Hausman test? Is it possible to use the Hausman test in a cross-section model? It is important to explain which model was estimated and what type of data was used.

2. Results and discussion

a. Pairwise comparison: This section describes the main findings from the t-test, but it seems that the numbers in table S3 are different from the text. Why didn’t you compare the findings from the nonparametric test with the t-test? If your data was collected from studies, why didn’t you use meta-analysis inside the t-test? I suggest explaining how the studies were selected and considering making a meta-analysis.

b. Regression analysis. Were the assumptions of the model validated? Are the same results if the authors add other variables (control)? Are the number of observations enough to estimate this kind of model?

Reviewer #3: This paper presents a rather complete comparison of the carbon footprint of grain-finished and pasture-finished beef production Systems, taking into account production emissions, soil carbon sequestration and carbon opportunity cost. The study use global information from 16 countries and several model to estimate emissions are considered. It is generally well written, with very few typing errors. The statistical methods used are correct and the authors took into account assumptions that make them valid. I recommend publishing it once a few minor corrections have been done.

Minor corrections:

Line 36. Replace “ kg” by “ kilograms”

Lines 76-76 and 80. Replace “et al” by “et al.”

Line 107 . Replace “ kg” by “ kilograms”

Line 109 111 113 Replace “et al” by “et al.”

Line 117 Replace “&” by “and”

Line 121 Replace “ kg” by “ kilograms” and eliminate “(ha)”. Universal acronyms like “ha” should not be defined

Line 125 Replace “et al” by “et al.”

Line 135 Replace “0.28 Mg carbon (C) ha-1 yr-1 “ by “0.28 Mg C ha-1 yr-1 “

Line 156 Replace “Where” by “where”

Line 162 Replace “one kg” by “one kilogram” or by “1 kg”

Lines 164 and 167 Replace “et al” by “et al.”

Line 172 Replace “ kg” by “ kilograms”

In lines 70, 76, 80 and 81 among others you write the author’s name, year, and the number of citation between brackets, but in several lines like 176, 189, 239, 259 (and more) the number in brackets is absent.

Line 176 Replace “et al” by “et al.”

Line 206 “where” without capital letter

Line 237 Replace “MgC” by “Mg C”

Line 239 Replace “et al” by “et al.”

Line 254 and 261. Replace “kg CO2e/kg” by “kg CO2e kg-1”

Line 259 Replace “et al” by “et al.”

Line 264 Table 1. Eliminate the dot at the end of table title

Line 265 Replace “ kg” by “ kilograms”

Line 320 Table 2. explain what the numbers in parentheses are

Line 353 Replace “et al” by “et al.”

Line 362 Replace “et al” by “et al.”

Line 482-483 Replace Agricultural Systems by the abbreviation Agric. Syst.

Table S4: Replace “kgCO2e kg-1” by “kg CO2e kg-1”

**********

6. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: Yes: Vinicio Barquero

Reviewer #2: No

Reviewer #3: No

**********

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step.

PONE-D-22-23019R1Carbon opportunity cost increases carbon footprint advantage of grain-finished beefPLOS ONE

Dear Dr. Blaustein-Rejto,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

Please submit your revised manuscript by Jun 29 2023 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

Please include the following items when submitting your revised manuscript:

• A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.
• A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.
• An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols.

We look forward to receiving your revised manuscript.

Kind regards,

Malik Muhammad Akhtar, PhD, Postdoc

Academic Editor

PLOS ONE

Review Comments to the Author

Reviewer #1

Check the title.

40-43. Cite this part.

47-49. Cite this part.

89-94. These results should not be there.

130, 154, 157. Is it possible to reference the equations?

281 & 312. Please place figure title below the Fig.

320. Please include all the definitions below the table. The table must be self explanatory.

Figure S1. There are no white circles, and the map has no color

Recommendation: you may consider placing different types of dots on figure 2. This can help colorblind (daltonic) people with their understanding.

Reviewer #2

The paper conducts a pairwise comparison of pasture-finished operations and grain-finished operations. Also, the authors show that land-use intensity and carbon footprint are positively correlated. Thus, the paper concerns a fundamental and interesting research problem.

However, I have some recommendations for the authors:

1. Materials and methods.

a. Pairwise comparison: How did you collect the data? Table S8 shows information about 20 studies included in the pairwise comparison; how were the studies selected? It is necessary to add this information.

b. Regression analysis: How many observations did you use? Are the units 72 operations or 24 studies? Is it a cross-section regression, or is it panel data? (In this case, which are the individuals, and which is the time?) Where are the results of the Hausman test? Is it possible to use the Hausman test in a cross-section model? It is important to explain which model was estimated and what type of data was used.

2. Results and discussion

a. Pairwise comparison: This section describes the main findings from the t-test, but it seems that the numbers in table S3 are different from the text. Why didn’t you compare the findings from the nonparametric test with the t-test? If your data was collected from studies, why didn’t you use meta-analysis inside the t-test? I suggest explaining how the studies were selected and considering making a meta-analysis.

b. Regression analysis. Were the assumptions of the model validated? Are the same results if the authors add other variables (control)? Are the number of observations enough to estimate this kind of model?

Reviewer #3

This paper presents a rather complete comparison of the carbon footprint of grain-finished and pasture-finished beef production Systems, taking into account production emissions, soil carbon sequestration and carbon opportunity cost. The study use global information from 16 countries and several model to estimate emissions are considered. It is generally well written, with very few typing errors. The statistical methods used are correct and the authors took into account assumptions that make them valid. I recommend publishing it once a few minor corrections have been done.

Minor corrections:

Line 36. Replace “ kg” by “ kilograms”

Lines 76-76 and 80. Replace “et al” by “et al.”

Line 107 . Replace “ kg” by “ kilograms”

Line 109 111 113 Replace “et al” by “et al.”

Line 117 Repace “&” by “and”

Line 121 Replace “ kg” by “ kilograms” and eliminate “(ha)”. Universal acronyms like “ha” should not be defined

Line 125 Replace “et al” by “et al.”

Line 135 Replace “0.28 Mg carbon (C) ha-1 yr-1 “ by “0.28 Mg C ha-1 yr-1 “

Line 156 Replace “Where” by “where”

Line 162 Replace “one kg” by “one kilogram” or by “1 kg”

Lines 164 and 167 Replace “et al” by “et al.”

Line 172 Replace “ kg” by “ kilograms”

In lines 70, 76, 80 and 81 among others you write the author’s name, year, and the number of citation between brackets, but in several lines like 176, 189, 239, 259 (and more) the number in brackets is absent.

Line 176 Replace “et al” by “et al.”

Line 206 “where” without capital letter

Line 237 Replace “MgC” by “Mg C”

Line 239 Replace “et al” by “et al.”

Line 254 and 261. Replace “kg CO2e/kg” by “kg CO2e kg-1”

Line 259 Replace “et al” by “et al.”

Line 264 Table 1. Eliminate the dot at the end of table title

Line 265 Replace “ kg” by “ kilograms”

Line 320 Table 2. explain what the numbers in parentheses are

Line 353 Replace “et al” by “et al.”

Line 362 Replace “et al” by “et al.”

Line 482-483 Replace Agricultural Systems by the abbreviation Agric. Syst.

Table S4: Replace “kgCO2e kg-1” by “kg CO2e kg-1”

[Note: HTML markup is below. Please do not edit.]

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: All comments have been addressed

Reviewer #2: All comments have been addressed

**********

2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: Yes

**********

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

**********

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: I have reviewed the paper and I am satisfied with the changes made, please replace the figure to avoid copyright issues.

Reviewer #2: Thank you for your efforts to improve the quality of a paper that shows that land-use intensity and carbon footprint are positively correlated. The authors attended to my suggestions, so I feel this manuscript is now acceptable for publication.

**********

7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: Yes: Vinicio Barquero

Reviewer #2: No

**********

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step.

PONE-D-22-23019R2Carbon opportunity cost increases carbon footprint advantage of grain-finished beefPLOS ONE

Dear Dr. Daniel Blaustein-Rejto,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

Please submit your revised manuscript by Oct 08 2023 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

Please include the following items when submitting your revised manuscript:

• A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.
• A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.
• An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols.

We look forward to receiving your revised manuscript.

Kind regards,

Malik Muhammad Akhtar, PhD, Postdoc

Academic Editor

PLOS ONE

Journal Requirements:

Please review your reference list to ensure that it is complete and correct. If you have cited papers that have been retracted, please include the rationale for doing so in the manuscript text, or remove these references and replace them with relevant current references. Any changes to the reference list should be mentioned in the rebuttal letter that accompanies your revised manuscript. If you need to cite a retracted article, indicate the article’s retracted status in the References list and also include a citation and full reference for the retraction notice.

[Note: HTML markup is below. Please do not edit.]

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #4: (No Response)

Reviewer #5: All comments have been addressed

Reviewer #6: All comments have been addressed

**********

2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #4: Yes

Reviewer #5: Yes

Reviewer #6: Yes

**********

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #4: Yes

Reviewer #5: Yes

Reviewer #6: Yes

**********

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #4: Yes

Reviewer #5: Yes

Reviewer #6: Yes

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #4: Yes

Reviewer #5: Yes

Reviewer #6: Yes

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #4: Dear Authors,

The manuscript is extremely interesting and brings a great discussion to the world stage. Some suggestions and adaptations, before final acceptance.

Reviewer #5: Acceptable as revised Acceptable as revised Acceptable as revised Acceptable as revised Acceptable as revised Acceptable as revised Acceptable as revised Acceptable as revised Acceptable as revised Acceptable as revised Acceptable as revised

Reviewer #6: I was not participating in the previous rounds of review, so I am not familiar with all discussions done so far. I apologise to the authors if some of the points below were raised before.

The paper presents and comprehensive analysis by incorporating not only production emissions but also soil carbon sequestration and carbon opportunity cost, providing a more holistic view of beef production's environmental impact.

The calculation of soil carbon sequestration (SCS) based on the mean carbon sequestration rate of 0.28 Mg C ha-1 yr-1 raises some questions. Given the considerable variation in sequestration rates due to different environmental and management factors, the paper could discuss potential implications of using a single mean rate for diverse locations. Additionally, the choice of a 100-year time frame for carbon sequestration should be justified, particularly in relation to the potential differences in sequestration rates over shorter and longer periods.

The range of total carbon footprints is wide, as indicated by the reported values ranging from -68.3 to 2169.3 kg CO2e kg-1 retail weight. While this variability highlights the diversity of beef production systems, it would be valuable to provide context and discuss potential reasons for such extreme values. Addressing potential outliers or anomalies that might significantly influence the results would enhance the credibility of the overall analysis.

While the discussion is comprehensive, some areas could benefit from further elaboration. These include the contributions of the additional components (soil carbon sequestration, carbon opportunity cost) to the overall assessment of sustainability and potential trade-offs within the components.

The paper acknowledges limitations in global representativeness due to the dataset's scope. To enhance the discussion, a more detailed exploration of how the findings might apply or differ in diverse regional contexts could be valuable. While the authors discuss limitations, further exploration of the implications of these limitations for policy and decision-making, particularly in scenarios where assumptions do not hold, could strengthen the discussion.

A question to the authors is what would happen in your analysis with countries that already have a very high carbon content in the soil (such as New Zealand due to the young soils from volcanic formation). There is limited opportunity to New Zealand to increase its soils carbon content. This is very different from countries like the USA that completed depleted soils due to crop production and are now claiming an “increase in soil carbon” due to pasture/regenerative practices. Can the USA (that depleted their soils before) get credits for soil carbon sequestration and New Zealand (that kept its soil with a high carbon content) don’t get credits? Is that a fair analysis?

Your” carbon footprint” definition does not match a Life Cycle Assessment (LCA) definition. You should be careful because readers thar don’t have an LCA background will think it does. You can’t say it is a “total” carbon footprint because soil carbon sequestration and carbon opportunity cost are included. For example, you are missing carbon sequestration from tress on beef and sheep farms – so is you carbon footprint “full”? I think it is not. You have an LCA with sensitivity analysis considering SOIL (only) carbon sequestration and carbon opportunity costs.

A better LCA term for you analysis around “land use intensity” is land occupation.

What is “retail weight beef”? Keep it simple and say it is per kg of beef. Your analysis is up to the farm-gate – you (or the authors you cite) converted the data from live weight to beef?

There is no discussion about the footprint breakdown. Grain-finished operations have a significant part of their footprint represented by carbon dioxide (a long lived GHG) due to the production of the grain. Pasture-based operation have most of its footprint represented by methane (a short-lived GHG). The authors do not address this difference in their analysis – as demonstrated by many papers published recently around the GP* metric, the emissions of methane do not corelate directly with warming if emissions are kept constant over the period of 20 years – i.e., there is no extra warming added to the atmosphere in this situation. This contrasts with the carbon dioxide that will warm the atmosphere for millennia. So this is an important difference between grain-finished and pasture finished systems that is not addressed in this paper and may affect the final results.

The authors also do not consider that, if the demand for meat stays the same, we would need to increase production in other areas -what is the full impact? Does the carbon opportunity costs are overweighed by the increase in meat production in other areas that might be less efficient (so there is a “carbon leakage”)?

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Reviewer #4: No

Reviewer #5: No

Reviewer #6: No

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Attachments

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Submitted filename: PONE-D-22-23019_R2_reviewer.pdf

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Submitted filename: Comments.docx

Carbon opportunity cost increases carbon footprint advantage of grain-finished beef

PONE-D-22-23019R3

Dear Dr. Daniel Blaustein-Rejto,

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

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PLOS ONE

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Reviewer #4: All comments have been addressed

Reviewer #5: All comments have been addressed

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Reviewer #4: Yes

Reviewer #5: Yes

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Reviewer #4: Yes

Reviewer #5: Yes

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Reviewer #4: Yes

Reviewer #5: Yes

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Reviewer #4: Yes

Reviewer #5: Yes

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All corrections, questions and considerations were duly answered. I congratulate you on accepting the manuscript.

Reviewer #5: revision ok .

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Reviewer #4: No

Reviewer #5: No

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