PCLM-D-26-00028

Limits to trade’s buffering of compounding climatic and non-climatic shocks to global grain supplies

PLOS Climate

Dear Dr. Jasper Verschuur,

Thank you for submitting your manuscript to PLOS Climate. After careful consideration, we feel that it has merit but does not fully meet PLOS Climate’s publication criteria as it currently stands. Therefore, we invite you to submit a revised manuscript that addresses the reviewer's points. Pay particular attention to the quality of writing to suit the journal. A lot of clarity has been sought by one of the reviewers. Pay careful attention while addressing all the queries raised by the reviewers.

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Sejian Veerasamy, MVSc & PhD

Academic Editor

PLOS Climate

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Reviewers' comments:

Reviewer's Responses to Questions

-->Comments to the Author

1. Does this manuscript meet PLOS Climate’s publication criteria? Is the manuscript technically sound, and do the data support the conclusions? The manuscript must describe methodologically and ethically rigorous research with conclusions that are appropriately drawn based on the data presented.-->

Reviewer #1: Yes

Reviewer #2: Yes

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

Reviewer #1: Yes

Reviewer #2: Yes

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-->3. Have the authors made all data underlying the findings in their manuscript fully available (please refer to the Data Availability Statement at the start of the manuscript PDF file)?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception. 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

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

PLOS Climate 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

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-->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: The manuscript presents a comprehensive and methodologically robust analysis of the role of bilateral trade in buffering compounding climatic and non-climatic shocks to global grain supplies. The topic is timely, policy-relevant, and well aligned with current debates on food system resilience. The modelling framework is sophisticated and the dataset is extensive. However, despite its strong scientific contribution, the manuscript would benefit from substantial revisions in academic writing quality, stylistic consistency, clarity of exposition.

Reviewer #2: This manuscript presents a global bilateral trade model for four major staple crops (maize, wheat, rice, soybean) across 177 countries to examine the extent to which international trade can buffer, or sometimes amplify, compounding climatic and non‑climatic shocks to food supplies and prices. The topic is timely, important, and clearly within the scope of PLOS Climate. Overall, I find the work methodologically sound, policy‑relevant, and suitable for publication after addressing a number of clarifications and extensions noted below.

Overall assessment and contribution

The paper makes a valuable contribution by bringing together:

A global, bilateral, multi‑commodity trade framework.

Multiple classes of shocks (climate‑induced yield variability, conflict‑related disruptions inspired by the Ukraine war, energy price shocks, and trade bans).

An explicit focus on compound shocks and their implications for consumer surplus, prices, and trade patterns.

The study shows that:

Non‑climatic shocks, particularly energy price shocks, can dominate climate‑related yield shocks in terms of global impacts on prices and welfare.

Trade adjustments often help buffer shocks but with clear limits and heterogeneity across countries and crops.

Under unfavorable global weather conditions combined with a compound shock, global losses in consumer surplus can exceed USD 600 billion and affect a large number of countries.

This is an important result, and the paper advances the discussion about food system resilience by explicitly quantifying how shocks of different types, and in combination, propagate through trade networks.

Methods and statistical / quantitative rigor

The study is framed as a global partial‑equilibrium trade model rather than a classical statistical analysis, which is appropriate for the questions addressed. Within that paradigm:

The model structure (countries × crops × bilateral trade flows) and the representation of supply, demand, and trade are in line with current practice in the food and climate risk modeling literature.

Parameter choices (elasticity, baseline trade and production, etc.) appear to come from recognized data sources and the existing literature.

The shock formulations (climatic yield variability, conflict‑related shocks, energy price shocks, trade bans, and their compound combination) are plausible, scenario‑based constructions.

On balance, I consider the analysis to be:

Appropriate for the research question.

Implemented with a reasonable level of rigor.

Transparent enough (given the text) that another group could conceptually replicate or extend it, especially if code and processed data are made available as indicated.

That said, there are several areas where additional explanation or robustness analysis would considerably strengthen the paper.

Major comments

1. Clarify model structure and key elasticity

The description of the trade model is central to the paper’s credibility, and it would help to provide a slightly more explicit, self‑contained treatment. In particular:

Please clarify:

The exact functional forms used for supply, demand, and trade (e.g., Armington, CES, log‑linear, etc.), and how price pass‑through is modeled.

The sources and ranges for key elasticity (demand, supply, trade substitution), and whether they vary by country and crop.

How domestic consumption is linked to world prices versus local prices, and how any trade or transaction costs are treated.

I recommend adding either a schematic or a concise mathematical formulation in the main text, and moving fuller derivations and parameter tables to the Supplementary Information if space is a concern. This will help readers assess the strength of your conclusions about buffering limits.

2. Treatment of uncertainty and robustness

The paper currently relies on a set of well‑motivated scenarios but would benefit from a clearer treatment of uncertainty:

It would be helpful to:

Perform and report at least a simple sensitivity analysis on key elasticity and key shock magnitudes (e.g., how do results change under high vs low price elasticity, or under somewhat weaker/stronger energy price shocks?).

Clarify whether the climatic yield variability shocks are derived from a probabilistic distribution (e.g., historical inter-annual variability, climate model ensembles) and how many realizations are used, or whether these are stylized scenarios.

If computational constraints prevent extensive sensitivity analysis, a smaller number of carefully chosen variants with clear plotting of differences (e.g., changes in global consumer surplus, number of countries with severe supply losses) would substantially increase confidence in the robustness of the conclusions.

3. Distinguishing model “shock stories” from empirical events

The manuscript uses exemplar shocks motivated by the Ukraine war, energy price spikes, and observed trade bans. This is a powerful way to make the results policy‑relevant, but it is important that readers clearly understand:

Which aspects are stylized, scenario‑based abstractions versus empirical reconstructions.

To what extent the “Ukraine‑like” or “energy price–like” shocks match observed magnitudes and patterns, and where you intentionally deviate for stress‑testing purposes.

I suggest being explicit in the text and/or a table about:

The calibration of each shock (e.g., percentage reduction in exports from a specific region, energy cost pass‑through to production costs, scale of trade bans).

Whether each scenario is intended as a plausible historical analogue, an upper‑bound stress test, or something in between.

This will prevent readers from over‑interpreting the scenarios as exact reproductions of recent events.

4. Interpretation of trade’s “buffering” vs “amplifying” role

One of the key conceptual contributions is the assessment of trade as a buffer or amplifier. To make this more transparent:

Please clarify:

How you define and measure “buffering” and “amplifying” outcomes in quantitative terms (e.g., comparison to an autarky baseline, or to a scenario with restricted trade flows).

Whether buffering is evaluated globally, regionally, and/or for specific vulnerable country groups, and over what time horizon (single‑year shock vs multi‑year sequences if relevant).

It could be particularly illuminating to show:

A comparison between the actual trade network and a counterfactual with more restricted trade, for at least one or two key scenarios, to highlight when and where openness helps or hurts.

Simple metrics (for example, changes in variance of consumption or prices across countries) with and without trade adjustment.

These additions would make the “limits to buffering” conceptually sharper.

5. Country‑level heterogeneity and equity implications

The paper emphasizes variation in impacts across regions and countries, which is crucial from a food security standpoint. I encourage you to:

More explicitly identify which types of countries are most exposed (e.g., net food‑importing low‑income countries, conflict‑affected states, high‑import‑dependence small economies) and why, in terms of the model structure.

Where possible, relate these groups to existing vulnerability classifications (e.g., LIFDCs, SIDS, etc.), even if just qualitatively.

Some additional maps or summary plots that highlight:

Top decile of countries by loss in calories or consumer surplus.

Shifts in trade dependence for these countries under different shocks.

would make the equity and justice implications of the findings more tangible.

Data availability and reproducibility

The Data Availability Statement indicates that the underlying data used to build the baseline (e.g., FAO/other public databases) and the model outputs will be fully available, consistent with PLOS policy. This is essential for a modeling paper of this kind.

To strengthen reproducibility further, I recommend:

Depositing the core model code (or at least a reduced, documented version that reproduces key figures and tables) in a public repository with a DOI.

Providing a short “how‑to‑reproduce” section (e.g., which scripts to run and in what order to regenerate main results) in the Supplementary Information or repository README.

This will greatly enhance the utility of your work to other researchers and to policy analysts.

Presentation and clarity

The manuscript is generally well written and logically structured, but a few improvements could help:

Consider tightening some sections of the Results by focusing more on a small number of “headline” findings and using figures or tables to summarize finer detail.

Ensure that all acronyms are defined on first use, especially for readers coming from climate science or policy backgrounds rather than trade economics.

Where you report large aggregate monetary figures (e.g., USD 600 billion), briefly remind the reader what these represent (consumer surplus loss in a given year, under which compound shock configuration) and, if possible, provide context (e.g., relative to global agricultural GDP).

These changes would make the paper more accessible to an interdisciplinary readership.

Ethics and dual publication

I did not identify any concerns regarding research ethics, dual publication, or publication ethics based on the manuscript text. The work is based on secondary data and modeling, and there is no apparent human‑subjects or animal‑related component.

In summary, this is a strong and timely manuscript that addresses an important question at the intersection of climate risk, trade, and food security. The modeling approach is appropriate and, as described, technically sound. The main conclusions about the limits of trade’s buffering role under compounding climatic and non‑climatic shocks are well motivated and of high policy relevance.

I recommend publication after the authors:

Provide clearer detail on model structure and parameterization.

Add or better document sensitivity/uncertainty analysis.

Clarify the status of exemplar shocks as stylized scenarios.

Sharpen the definitions and metrics of trade “buffering” vs “amplifying.”

Strengthen the discussion of heterogeneous and equity‑relevant impacts.

These revisions will significantly enhance the clarity, robustness, and impact of the study.

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Reviewer #1: No

Reviewer #2: No

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Attachments

Attachment

Submitted filename: The comments.pdf

Assessing the Resilience of Global Grain Supplies to Compound Climatic and Non-Climatic Shocks

PCLM-D-26-00028R1

Dear Dr.Jasper Verschuur,

We are pleased to inform you that your manuscript 'Assessing the Resilience of Global Grain Supplies to Compound Climatic and Non-Climatic Shocks' has been provisionally accepted for publication in PLOS Climate.

Before your manuscript can be formally accepted you will need to complete some formatting changes, which you will receive in a follow-up email from a member of our team.

Please note that your manuscript will not be scheduled for publication until you have made the required changes, so a swift response is appreciated.

IMPORTANT: The editorial review process is now complete. PLOS will only permit corrections to spelling, formatting or significant scientific errors from this point onwards. Requests for major changes, or any which affect the scientific understanding of your work, will cause delays to the publication date of your manuscript.

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Thank you again for supporting Open Access publishing; we are looking forward to publishing your work in PLOS Climate.

Best regards,

Sejian Veerasamy, MVSc & PhD

Academic Editor

PLOS Climate

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Additional Editor Comments (if provided):

Reviewer Comments (if any, and for reference):

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: (No Response)

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-->2. Does this manuscript meet PLOS Climate’s publication criteria? Is the manuscript technically sound, and do the data support the conclusions? The manuscript must describe methodologically and ethically rigorous research with conclusions that are appropriately drawn based on the data presented.-->

Reviewer #1: Yes

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

Reviewer #1: Yes

**********

-->4. Have the authors made all data underlying the findings in their manuscript fully available (please refer to the Data Availability Statement at the start of the manuscript PDF file)?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception. 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

**********

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

PLOS Climate 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

**********

-->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: This research provides a comprehensive analysis of optimizing sugarcane irrigation, emphasizing the need for goal-specific, climate-adapted, and crop-stage-sensitive strategies. It effectively integrates simulation results with practical considerations, offering valuable insights for improving water use efficiency and profitability in sugarcane production, particularly in regions facing climate variability.

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-->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.

Do you want your identity to be public for this peer review? If you choose “no”, your identity will remain anonymous but your review may still be made public.

For information about this choice, including consent withdrawal, please see our Privacy Policy.-->

Reviewer #1: No

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