PCLM-D-22-00169

Designing an acceptable and fair carbon tax: the role of mental accounting

PLOS Climate

Dear Dr. Mus,

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 version of the manuscript that addresses the points raised during the review process.

Both reviewers have provided itemized lists of changes that they believe would improve the manuscript. Please respond to each one, and either make the proposed change or explain why you believe it would not improve the manuscript (or would do so too trivially to be worth making).

Reviewer 1 also points to one potentially significant limitation of the manuscript. The overall conclusion is that the experiments demonstrate that "mental accounting" is the reason laypeople prefer that the revenues from taxes are earmarked for spending whose impacts are consistent with those of the tax. But do they? The reviewer suggests an alternative explanation​. Can you explain why this alternative explanation can be ruled out? Or, why the reviewer's understanding of your arguments is not correct? Convincingly addressing this reservation of Reviewer 1, in some way, is a firm condition for publication of the manuscript.

Please submit your revised manuscript by Mar 13 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 climate@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pclm/ 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 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'.

Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

We look forward to receiving your revised manuscript.

Kind regards,

Malcolm Fairbrother, Ph.D.

Academic Editor

PLOS Climate

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Additional Editor Comments (if provided):

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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: Partly

Reviewer #2: Partly

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

Reviewer #1: N/A

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: Dear authors,

first, I think this article has many qualities: it is concise, well written, and tackles an interesting research question. Now, although very enthusiastic as I read your abstract and introduction, I became more skeptical when I read your argumentation. You claim to show that if people prefer a carbon tax whose revenues are earmarked to green spending (rather than not earmarked), this is because of mental accounting, i.e. an intrinsic preference for a correspondence between the domain of revenues and spending. If the result were compelling, it would be a valuable contribution to the political economy of climate policies. However, the paper cannot rule out an alternative explanation: people prefer a green-earmarked carbon tax because green spending is complementary to the carbon tax (having only one of the two would only reach partial effectiveness).

Thus, I find the conclusions overstated, and the case for your policy recommendation weaker than what you claim.

A small additional survey (of the same sort that the 4 small studies that you conducted) would allow testing which hypothesis holds, between mental accounting and complementarity. For example, you could test which package receives higher support between a carbon tax + a tobacco tax + green spending + tobacco prevention vs. carbon tax funding green spending + tobacco tax funding tobacco prevention. You could also have an open-ended question and ask people why they prefer that a carbon tax funds green spending rather than something else (then read and synthesize the answers). You could also ask directly whether there should be a correspondence between the domain of revenues and that of spending.

I would really like the paper if you conduct an additional survey like sketched above and make the various corrections that I recommend below. If you only make the corrections (and not the additional survey), you need to tone down your conclusion and reckon that your mental-accounting hypothesis, though consistent with the data, is not fully proven. I am not sure yet whether the paper would be fitted for publication in that case without an additional survey.

Apart from collecting additional data to test the mental accounting vs. complementarity hypotheses, here are my recommendations and comments:

• l. 54: Remove the example of the Swiss referendum. This was not a carbon tax but an energy tax (exempting renewables). It seems to have been rejected because of the very large amount of the tax. Overall, this is a bad example. https://fr.wikipedia.org/wiki/Initiative_populaire_%C2%AB_Remplacer_la_taxe_sur_la_valeur_ajout%C3%A9e_par_une_taxe_sur_l%27%C3%A9nergie_%C2%BB

• l. 112, 184: It is not clear why you replicate your British study. You should explain it, or if there is no good explanation, why not merging the datasets of the original and replication surveys?

• l. 132: What is the "color test"? Please include a footnote.

• l. 179: Change to "the xx% of participants who ranked..."

• l. 211: You should display Supplementary Fig. 1 instead of Fig 3. There is not reason to bury the information it contains.

• l. 230-245: This reasoning –discarding the role of perceived effectiveness in the support– is flawed, because effectiveness is not binary. People may well think (and for good reasons) that a carbon tax alone is effective but a carbon tax + green investments is more effective, will achieve more emission reductions. I think what supports your mental accounting hypothesis is rather that compared to general budget expenses, green investments are more supported when complemented with a carbon tax. I think it is more compelling than the interaction with the preferred policy, as this interaction may be simply explained by the fact that people are happy as soon as their preferred policy is funded, whatever the tax is. And yet, this reasoning would still not be enough in favor of the mental accounting hypothesis, given that people may simply view the carbon tax and green investments as complementary. Your second study is more compelling in that regard. Anyway, unless you asked for the effectiveness of the carbon tax vs. carbon tax + green investments, I think you should discard this paragraph.

• l. 264: Fig 4 is unreadable (pixelized). And by the way, it is annoying to have the figures at the end rather than in the text.

• 3.2 l. 293: You should expend on this section, as this is the one that is most compelling for your mental accounting hypothesis. In particular, Fig 5 lacks information. Instead, please plot a Figure similar to Supplementary Fig 1.Still with this study, there remains an untested hypothesis: do people prefer to have same-domain measures on both revenue and spending side (concomitancy) or do they want that the revenue funds the spending (earmarking)? To test that, you should have compared pe.g. rograms with a carbon tax + a tobacco tax + green spending + tobacco prevention vs. carbon tax funding green spending + tobacco tax funding tobacco prevention.If your results can be explained by concomitancy, it has policy implications: it means a carbon tax could fully fund cash transfers and be complemented with (say debt-funded) green investments.

• l. 327: You cannot bury the results like that, you should add the results with 0 earmarking to Fig 6, and comment on these. In particular, you should provide hypotheses as to why in the UK support decreases with low earmarking compared to no earmkaring.

• l. 361: I think you should write "attenuated" rather than "countered". If the transfers only goes to the three first deciles, then the tax is likely regressive on the fourth vs. tenth deciles.

• l. 383: If you don't count subsidies/investments into insulation, heating system and transportation as "environmental protection", then what remains in there? “Environmental protection” makes one think about biodiversity conservation, programs to clean areas from pollution, etc., not climate mitigation measures. I see that it is not defined in the questionnaire. Also, when I read “sustainable goods and services”, I think about organic food and theater plays, not a heat pump or an electric bicycle. Thus, I am wary that your respondents did not understand your measure the same way you thought about them (I don't even understand what measures you have in mind under “environmental protection”), and think you should then interpret the results with caution.

• Supplementary Table 1: You should add columns on actual frequencies of the different categories in the population. You should clearly state in the paper that your surveys are not representative along education, age, and political leaning (and that you cannot test for representativity along income as you don't ask for income). Fig 4 seems to show that there is no heterogeneous effects, so that the lack of representativity is less of an issue. You can also check if socio-demographics explain a little share of the variance of the support, which would further validate your choice not to get a representative sample.

• 5.2 l. ~415: Environmental cash transfer is the preferred option only for one third of the samples, so you should tone down, the preference for this scheme is not as strong as you state.

• l. 423: You did not test all option,s so it seems unjustified to say that the policy you present is “the most acceptable policy options for citizens”. For example, a carbon tax + green investments + cash transfers + higher deficit or wealth tax could perhaps be preferred.

• Figure 7 should rather be stacked bars rather than separate bars.

• l. 476: "likely" seems weird as the literature is clear that a carbon tax alone is regressive. You could rather say, "of the carbon tax alone".

• l. 500: The non-assignment rule is a myth (at least in France, I don't know for the UK). There are plenty of examples of earmarked taxes (taxes affectées) and various legal ways to implement them. I would remove these last sentences on the juridic issue, which is both wrong and irrelevant for this study. The beginning of the last paragraph is also not informative and could be dropped.

Best of luck with the revision.

Reviewer #2: The paper presents a rich amount of empirical evidence, gathered through a range of separate but related survey experiments. It is a strength that all experiments were pre-registered and that all data is publicly available. The topic is highly policy-relevant. I have some comments and concerns detailed below.

Abstract: “Across six experiments conducted in the United Kingdom and in France…”. A more precise statement should be given. The paper reports studies 1-4 each with version. Mostly there is version A in the UK and B in France, but 2A and 2B are both in the UK. This is a bit confusing, so a clear statement is needed. In the main text, the structure with many studies should be clearly justified.

Introduction: The paper by Klenert et al (already cited) should be devoted some more discussion, given that it assesses different earmarking purposes and finds that the optimal earmarking purpose is context-dependent. Might also be relevant to include in the conclusion.

Introduction: A recent paper on earmarking of fuel taxes in Norway (Tatham & Peters 2022) find that earmarking preferences vary strongly across different socioeconomic groups, in contrast to the current paper’s findings. Low-education and rural residence implies a preference for redistribution, while high education and urban residence implies a preference for environmental spending. This paper would also be worth discussing in the introduction and perhaps conclusions.

Line 111: “representative samples of the adult population stratified according to age, gender and ethnicity.” The statement is a bit unclear. Does it mean that a stratified sampling method was used, based on these variables, and that the resulting sample is representative wrt to the same variables?

Line 112: What was the rationale for conducting two replications of the experiment in the UK?

Line 126: The table referred to should also contain population means where available. If space permits, I suggest to move the table to the main manuscript. The representativity of the samples wrt to other variables (than age, gender, and ethnicity) should be briefly discussed, covering all studies. Especially wrt education.

Results (all studies): statistical test parameters should be explained at first use. Also, some more verbal explanation of results would be useful.

Line 170: not good syntax in this sentence

Study 1: For the interaction effect, it would be useful with an indication of the magnitude of this effect, in addition to the ANOVA test results. Additionally, the results section refers to Supplementary Note 2 for complete results. However, the main results are reported only in the main text, while the supplement reports additional results. This makes it a bit confusing to read the supplement, which should contain complete results even if that duplicates some reported in the main text.

Line 228: “it is important to demonstrate that this alternative hypothesis does fully account for our results.” Should it be “does not”?

Line 241: “Together, these results suggest that, at least in the British sample, the perceived ineffectiveness of the carbon tax does not fully account for people’s preference towards environmental earmarking.” This statement seems to provide only weak support to the overall message of the paper. It implies that perceived effectiveness might fully account for the preference for environmental earmarking in France. However, I believe the data might provide more support than this sentence indicates. On supplementary Figure 4, the earmarking effect is quite clear. It would be helpful to a) compare the size of the effect to that found in the overall sample b) disaggregate the figure between UK and France c) note the no. of observations in each country, as low numbers means that even sizeable effects can be non-significant. The effectiveness explanation could also be discussed in light of the results from study 2. As inheritance taxes do not aim for behavioral change, the effectiveness argument could not explain preference for matched earmarking in this case. On the other hand, if the effectiveness explanation cannot be dismissed, this should also be reflected in the abstract and conclusion, which currently highlight only the mental accounting explanation.

Study 2: Figures showing the change in mean support should be included (equivalent to Figure 2). Any substantial difference across the three tax domains should be discussed.

Study 3: The support level when earmarking is 0 should be included in Figure 6. It is strange that this information is provided in the supplementary material and not simply plotted in the figure. From what I understand, in the UK, mean support is higher with zero earmarking than with 25% or 50%. If that is the case, possible explanations should be discussed.

Study 3: The results should be compared with those from Study 1. Are the mean support levels consistent across studies?

Study 4, results: the ranking of no cash transfer vs and unconditional cash transfer should also be provided.

Line 456: “Relative to tax designs where earmarking is neither matched nor mismatched with the revenue source” Cumbersome formulation.

Line 499-502. If space permits, it would be interesting to discuss the legality of earmarking a bit more. E.g., How common are exceptions to the rule?

Visual aspects of figures:

I think it would be better to remove the dotted lines in Figure 3 and all similar figures, but keep the color coding of markers.

In a revised version, please ensure Figure 4 has higher resolution. Even after downloading the tif-file, the sub-titles are difficult to read.

In figure 7, the overall ranking between the three schemes is not so immediately clear to see (especially between no cash transfer and unconditional cash transfer). Please consider alternative ways of presenting.

Reference:

Tatham, M. & Peters, Y. (2022). Fueling opposition? Yellow vests, urban elites, and fuel taxation, Journal of European Public Policy, 1-25.

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Reviewer #1: Yes: Adrien Fabre

Reviewer #2: Yes: Håkon Grøn Sælen

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PCLM-D-22-00169R1

Designing an acceptable and fair carbon tax: the role of mental accounting

PLOS Climate

Dear Dr. Mus,

Thank you for submitting your manuscript to PLOS Climate. After careful consideration, we feel that it has significant merit, and is almost ready for publication. But before selecting the manuscript for publication, however, we would like you to consider further revising it, in light of the latest peer reviews.

One reviewer, in particular, remains unconvinced by key parts of the manuscript, and by how you addressed the previous feedback. If you see a way to address their latest comments, it seems that might further improve the paper. However, if at this point you believe the review comments are entirely unjustified, you may simply say so, and briefly explain why, and we will not require any more changes for publication.

Please submit your revised manuscript by Aug 18 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 climate@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pclm/ 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 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'.

Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

We look forward to receiving your revised manuscript.

Kind regards,

Malcolm Fairbrother, Ph.D.

Academic Editor

PLOS Climate

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.

Additional Editor Comments (if provided):

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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: (No Response)

Reviewer #2: (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

Reviewer #2: Yes

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

Reviewer #1: Yes

Reviewer #2: Yes

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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

Reviewer #2: Yes

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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

Reviewer #2: Yes

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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: Dear authors,

you addressed my minor comments, but you didn't successfully address the major one.

I appreciate that you toned down your results. The only paragraph where they are still overstated is the last one, as you write that the "complementarity hypothesis" I pointed out "could not account for other documented cases of preferences for specific earmarking outside consumption taxes (e.g., the preference for social spending earmarking of the inheritance tax [30,31])". The issue here is that the references you cite do not prove your claim, they merely show a preference for earmarking (not "specific" earmarking corresponding to the tax).

Indeed, what these papers show is that inheritance tax funding social programs is preferred to inheritance tax without specifying the revenue use. They do not show that there is an interaction between the domain of the tax and its revenue use. Ref 30 considers only one type of tax, so cannot study the interaction effect. Ref 31 could perhaps support your hypothesis as the interaction term seems positive (based on their descriptive statistics Table IV) but they do not study the interaction and thus do not report the statistical significance. Therefore, I don't find sufficient evidence to conclusively confirm your mental accounting hypothesis.

Also, it is exaggerated to write that "This alternative hypothesis, however, has not yet been supported by theoretical or empirical works": the hypothesis is actually very close to the one that related to effectiveness that you (unconvincingly) test. Indeed, complementary policies are more effective than non-complementary ones. Also, it is common among economists to state that both price signals and green investments are needed and that they complement each other (e.g. Stiglitz, 2019).

I appreciate that you ran a complementary survey, but it is a pity that you dismissed all proposals I made for this survey.

- I agree that to "test which package receives higher support between a carbon tax + a tobacco tax + green spending + tobacco prevention vs. carbon tax funding green spending + tobacco tax funding tobacco prevention" would test a strong version of your hypothesis. But this would be very compelling if the test passes, and would not destroy your results if it doesn't. I like the thing you test in your complementary survey, which is in the same spirit of what I proposed, and it is a pity that you do not report these results.

- Also, asking open questions helps understanding how people reason. You cite a paper to show that "very often people are not aware of the heuristics they use to make decisions or judgments". But 1. "very often" isn't "always", 2. the kinds of judgments studied in that paper do not correspond to political judgment, so the external validity is unclear, 3. this would be a way to test the "complementarity hypothesis" (if t is never mentioned by the respondents, it gives more credit to mental accounting).

Reviewing your new version, I thought of another way to test the "complementarity hypothesis" without testing a strong version of mental accounting. We could use two taxes that are not behavioral with matched and unmatched earmarking. For example, property tax or inheritance funding either social housing or an endowment for everyone turning 18. If both matched tax-spending have a higher support than both unmatched ones, there would be clear evidence in favor of your hypothesis. It is important to taxes that do not aim at changing behaviors to rule out the complementarity hypothesis.

I disagree that your data dismiss a ceiling effect: you took my wording too literally. What I was getting at is that there is no reason for the support score to be linear in the support score of each of its components, even absent mental accounting or complementarity. This is why showing a positive interaction, even for a non-behavioral tax, would not be enough to prove mental accounting. What would be needed is the last idea I sketched, where the test would be that the support is higher for matched pairs, conditional on the types of tax and spending.

I hope this can give you ideas for future research.

Other comments:

- on Figure 5, you should display the support in the case with no earmarking. You comment on this result in the conclusion, but never present it.

- the abstract could more clearly present your contribution by stating that you find a positive interaction in the support of a green tax and green spending.

- your introduction should mention a third hypothesis (the complementarity hypothesis), at least in a footnote.

- a revenue use of the carbon tax that would make it both progressive and earmarked would be to distribute it entirely as an equal "environmental cash transfer" (an issue though is that the transfer would probably be too low to finance changes in equipment).

Reviewer #2: The authors have done a good effort in addressing the comments in the first round. The paper is now much more convincing. I nevertheless have a few question marks to the presentation of the results, and some minor suggestions.

Section 2.1.1. I suggest making it explicit that the sampling is non-probabilistic, and discussing the implications this has for the interpretation of the statistical tests presented.

311-312: The differences in absolute levels of support are not relevant in this context, so this sentence can be deleted.

312-317: This point is hard to follow. How is the interaction pattern different for the inheritance tax?

324-329: It should be justified why a meta-study is the appropriate type of analysis here.

Section 4.2: Please provide the tests for difference between 100% vs 0% and 75% vs 0%. From the figure, it seems that for the UK, support level for 75% is closer to for 0% than for 100%. If the support level for 75% is not significantly different than for 0% in both countries, the following statement is not supported by the data: “a highly matched earmarking scheme (75%) garners a strong level of support, close to that of a full earmarking scheme”, which is one of the main findings of the paper. In general, the support functions look very different across the two countries, which warrants some comment/discussion.

386-388: After the authors revised the statement in response to a comment by reviewer 1, it no longer makes sense. Presumably, earmarking any % of the revenue would attenuate the regressive effects, not only “at least 18%”. The statement should be revised to reflect the actual findings of the cited studies.

Supplementary Figure 1: I suggested including population distributions here, but the authors responded that those are not available for all the variables. I would nevertheless suggest including those population values that are available. I.e., gender, age, education, and maybe living area.

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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: Yes: Adrien Fabre

Reviewer #2: Yes: Håkon Grøn Sælen

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[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.

Designing an acceptable and fair carbon tax: the role of mental accounting

PCLM-D-22-00169R2

Dear Ms Mus,

We are pleased to inform you that your manuscript 'Designing an acceptable and fair carbon tax: the role of mental accounting' 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.

If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they'll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact climate@plos.org.

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

Best regards,

Malcolm Fairbrother, Ph.D.

Academic Editor

PLOS Climate

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Reviewer Comments (if any, and for reference):