Review Reports

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The aim of the study is to evaluate the environmental impacts of various consumer behaviors, particularly in the context of barbecuing activities. The study uses an analytical approach to provide suggestions and guidelines for minimizing the environmental footprint of these activities. It aims to help in making decisions that promote sensible and responsible behaviors. Author need major revision; some comments are given below:

1. While charcoal, gas, and electric grills were studied, other types, like wood-burning, pellet, or solar grills, could be evaluated to provide a wider perspective.

2. Besides GWP, AP, EP, ADP, and LU, it would be beneficial to consider other impact categories like human toxicity and water scarcity.

3. Rather than saying that ingredients are significant contributors to environmental impact, the analysis could provide a more detailed breakdown of different foods' impact to allow more targeted recommendations for consumers.

4. The environmental impact of grilling is likely to be dependent on the country's specific features, including climate, barbecue frequency, and preferred types of grills or food. Recommendations could be more effective if tailored to those features.

5. To understand how effective the recommendations could be, a quantitative evaluation, possibly using scenario analysis, could be included to estimate potential reductions in environmental impacts from changes in consumer behavior.

6. A survey or some form of primary research could help understand the behaviors and trends that lead to certain choices around barbecuing, thus strengthening the recommendations made.

 

 

Author Response

Dear Reviewer 1,

Thank you very much for taking the time to review our manuscript. We greatly appreciate your valuable input as it helped refine our manuscript further in order to proceed with the publication.

Please find the detailed responses to your comments and suggestions in the table below. The corresponding revisions/corrections are highlighted/in track changes in the re-submitted file.

We hope all our comments are comprehensible. Please let us know, if we should provide further information or clarification.

On behalf of all authors,

Many thanks and best regards from Stuttgart

Kevin Christopher Dorling

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

I read the article under review with great interest. It is compelling, catering not just to scientists and specialists in sustainable development but also to producers of durable goods, food products, and even everyday consumers and households. The article delves into the environmental repercussions of different grilling techniques, specifically honing in on coal, gas, and electric methods. This pioneering study addresses a void in the existing literature by integrating a detailed methodology and encompassing diverse impact categories. The subjects chosen for research by the authors, along with the analytical results procured, certainly warrant attention from a broader readership.

Given that earlier studies primarily revolved around greenhouse gas emissions, the originality of this research is commendable. The authors widen the analytical lens to envelop the complete life cycle of grills as well as the varied ingredients employed during the grilling process. This nuanced approach significantly augments the existing body of scientific knowledge, furnishing readers with pivotal data and insightful recommendations.

The article is organized with clarity and follows a logical trajectory. Arguments are lucidly articulated by the authors, neatly segmented into pertinent sections and subsections. The article's abstract is comprehensive, encapsulating the salient features of the study adeptly.

One potential area of enhancement for the article is the inclusion of research hypotheses within its methodology. While the authors delineate the study's objective, there is a conspicuous absence of posed or validated research hypotheses. I would advocate for an augmentation of the article in this specific domain.

Author Response

Dear Reviewer 2,

Thank you very much for taking the time to review our manuscript. We greatly appreciate your valuable input as it helped refine our manuscript further in order to proceed with the publication.

Please find the detailed responses to your comments and suggestions in the table below. The corresponding revisions/corrections are highlighted/in track changes in the re-submitted file.

We hope all our comments are comprehensible. Please let us know, if we should provide further information or clarification.

On behalf of all authors,

Many thanks and best regards from Stuttgart

Kevin Christopher Dorling

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

#SUMMARY:

The main objective of the study is to extend the existing information on the LCA of the barbecuing activity. Specifically, it seeks to expand the indicators evaluated in these types of assessments by presenting a case study based on the German context. To this end, the authors select the most common types of grills, their corresponding energy sources, and the most common ingredients used in these events. In this way, they aim to evaluate the contribution of each of these inputs and derive recommendations to be taken into account by users of this type of activity.

 

#GENERAL CONCEPT COMMENTS

From a formal point of view, the article is lacking in several respects. Firstly, the structure is redundant in some respects and omits information in others. For example, the authors repeatedly mention that they are evaluating the difference between different barbecues (Abstract, Introduction, Section 2.1, the first paragraph of Section 2.2.1, Section 2.2.1 under the heading 'Functional Unit'). Disposable grills are mentioned several times in these sections, but it is not until section 2.2.2 that a clear distinction is made between the appliances actually evaluated, including these disposable grills. This makes the text more difficult to understand and the manuscript would benefit from a clear definition of the elements to be assessed. 

The methodology needs more transparency and discussion. This is addressed in the specific comments below. Some examples: why two different impact calculation methods were chosen, why only five impact categories were chosen, more details on end-of-life scenarios (both for the materials used to assemble the grills and for food waste), how the data in Table 2 are calculated from reference 39, etc.

It is worth noting that only about 50% of the included references are from international indexed journals. Plenty of references are not possible to go through since are in German. 

Furthermore, the discussion of the results in most of the paragraphs is limited to a description of what is shown in the figures, without any substantial evaluation of the causes that led to the results obtained. 

 

#SPECIFIC COMMENTS

* Line 13: Only five impact categories are considered. What is the reason for choosing these categories specifically? Authors claim that one of the contributions of their work is to expand previous studies focusing on a limited number of environmental issues Lines 53-56). Did the authors consider a previous contribution analysis? How do they ensure no burden shifting if their recommendations are followed? 

*Line 15: What is the reason for indistinctly using two different calculation methodologies for impact assessment? Furthermore, why the egalitarian perspective of ReCiPe is preferred for the "Land Use" indicator (Line 227)? CO2 effects derived from the land use changes won't be consistent with the 100 years considered within the GWP indicator as accounted for by the CML2001 method.

*General appreciation: Do the authors consider that the four people attending the BBQ would eat anyway? Did they consider taking credits for the food that would be consumed even though? It might be beneficial to elaborate further on this since it might be arguable. Ingredients are responsible for most of the evaluated impacts, but eating shouldn't be 100% attributed to barbecuing. 

*Line 20: In Line 10, authors state that they want to compare three grilling techniques: charcoal, gas and electric. Here (L20), they say that the most impactful is the disposable one, which they did not mention before. This should be more clear.

*Line 32: EU abbreviation not defined before in the text.

*Line 45: This paragraph (from L45 to L50), is in the same line as the previous one. Placing them together would increase readability.

*Line 53: What does varying boundary conditions mean? The authors choose a system boundary and evaluate the system without expanding it if I understood correctly. All variations, like scenario analysis, are performed within the system boundaries implied, although it would be beneficial to separately describe them under the 2.2.1 Section. 

*Line 56 to line 58: The first sentence here ("there has been limited exploration into the contributions of different grill segments to environmental impacts") seems to point out the first topic they provide for the research gap assessment, and the third sentence "a detailed methodological approach for the LCA of grilling") the same as the second research gap. So I only see the point of mentioning the consumer behaviour and further extending this comment respective to what (type of grill/fuel/ingredients).

*References 13 and 14: Authors cite GaBi software and GaBi Database here. At least the database used for building the background system should be mentioned in the main text given its influence on the results. In Figure 1, the name should be updated (Managed LCA Content database).

*Line 79: Unless I missed it, the LPG abbreviation was not defined before in the text.

*Lines 82 to 85: So different functional units are selected? In the first part, 1 kg of each ingredient is selected as the Functional Unit and the ingredients are compared with each other. In the second part, the functional unit described in Section 2.2.1 is used. I have various considerations regarding this aspect: 1 kg of food should not be compared to 1L of beer. One can drink 1L of beer during a barbecue but is not probable that he or she eats 1 kg of food. Thus, the comparison shown in Figure 5a is not proportioned. Second, for the comparison of the different grill devices (Section 4.2), what is the functional unit then? 1 kg of the device? Or is it just the functional unit as defined in Section 2.2.1? Third, why do this first? Would not be more understandable to evaluate the system under analysis, and then further explore the main contributors to the overall impact categories? Fourth, this disaggregated comparison is performed for grilling devices and ingredients. Why not for the energy sources? Are energy sources already considered during the use phase of the grilling devices? This is not easy to understand from Figure 1, so I would suggest including an explanation at this point in the text. 

*Line 87: What is the meaning of grill sectors? Are the different material inputs to the grilling devices? It seems a confusing expression.

*Line 91: The scenarios are built a priori (before seeing the results of their application). Thus, defining them as environmentally friendly/unfriendly diminishes the meaning of carrying them out. I would redefine them as something like less consuming and more consuming scenarios, something less straightforward.

*Figure 1, comment 1 (top box): Authors did not mention grilling frequency before. Is this referred to the functional unit (Lines 73-74)?  If so, it would be beneficial to explain it.

*Figure 1, comment 2 (grilling devices box): From this, it is still not very clear the difference between grilling devices and energy sources. This should be clearly addressed before. I understand that different devices consume different fuels, but this is confusingly written.

*Figure 1, comment 3 (environmental impacts, energy sources box): I understand charcoal, electricity and LPG as energy sources for comparison, but I don't understand "consumption" in this context.

*Figure 1, comment 4 (data collection box): This is the first time that the abbreviation BOM appears in the text.

*Figure 1, comment 5 (environmental impacts, grilling ingredients box): explain "mean", before Figure or as a caption.

*Figure 1, comment 6 (environmental impacts, grilling devices box): the arrow from "use phase" to this box gives the impression that the grilling devices are only considered during the use phase. I understand that it is only the energy sources that are considered during the use phase of the grilling devices, but it should be drawn differently (at least the other way around). 

*Figure 1, comment 7 (last two boxes): as far as I understand, the scenarios are defined independently from the interpretation, so I do not fully understand the connection with the previous box. Furthermore, these scenarios are built varying the parameters shown in the consumer behaviour box, so I do not see these two boxes as separate entities (might be considered as one single box joining them with an e.g. a dotted line?). Finally, the outcome of these boxes as an input to the top of the hierarchy are not suggestions as far as I understand. Conversely, the input modification is used to rerun the analysis for the different scenarios defined, and after all the iterations some suggestions are brought. So I would suggest to modify the scheme in accordance. 

*Figure 1, comment 8: Why EoL of grills and food waste is not shown here as a part of the analysis?

*Lines 117 to 118: I cannot check reference 25 for language reasons, but does this reference not mention any vegetables that can be properly grilled (maize, potatoes, onions...)? The authors mention lettuce and bell pepper, but as I understand from Table B2 only the first is considered (if I am not mistaken and this is the case, that should be changed in the main text). 

*Lines 164 to 167: From this sentence looks like materials are extracted in the same country in which the manufacturing process takes place, but that looks rather odd. Where do these materials come from in the Managed LCA Content (GaBi) database? Even if the transport is not data is not included (for reasons such as scattered production of each material), this information is usually available and should be included to get an idea of the potential implications. Still, my recommendation would be to provide an estimate for the transport, since metals might be extracted in remote regions. Besides, I think the exclusion of the manufacturing/ensembling process is an important limitation that should be clearly stated. 

*Line 175: Reference 36 is in German so I could not check these emissions. Thus, it would be a good inclusion to cite them at least as an Anex so this inventory is easily accessible for all readers. Only GWP, AP and EP indicators are evaluated (L178), is there any justification in the provided reference for only including these three?

*Line 181: I quote --> "In the End-of-Life (EoL) phase, the recycling of metal materials accounted only for 181 the credit associated with the metal, disregarding the electricity consumed in this process". This approach implies allocating all the impact to the recycled metal post-consumer, which is in disagreement with the GaBi database modelling principles and thus inconsistent with the background data in the study if I am understanding correctly. Still, in Figure 2 there is an arrow joining electricity with the EoL block. Implications of the recycling process should be considered if EoL phase is under system boundaries. Also, the authors show other options that are not mentioned in the text (landfilling, energy valorization...).  I miss a more elaborated comment in this section since I am not very sure how is this part modelled. A last question here is: why are gas bottles not considered at this point?

*Line 186: I am curious about how the authors implement this information in their SimaPro model. Do they input the data as elementary flows as reported in this literature? 

*Line 202: What is the justification for assuming the equivalence of 2 disposable grills = 1/75 large grills? 

*Line 207 to Line 210: Further assumptions are missing. Reference 39 reports a functional unit of "1.41 GJ/yr, as transferred to the cooking pot after the combustion of each fuel in the cookstove". How do the authors make the back calculations to 1 kg of charcoal? Additionally, the authors on Ref. 39 rely on the Ecoinvent database to assess the impacts of the charcoal, although they do not state the system model employed (cutoff, APOS, other). Since charcoal may rely on residual wood, this might have a significant impact that should be acknowledged by the authors.

*Table 2: The third column shows the impacts of charcoal for the reference scenario. Depending on the grill type, I assume that the consumption of charcoal would differ (I might have missed this data, but I did not see it). Despite this, the table caption says that these impacts are provided for 1 kg of charcoal. Which of both is correct? 

*Line 229: Please provide the references for justifying this choice. I understand that the provided indicators have been evaluated with CML2001 and ReCiPe (E) in previous studies, but I do not understand so easily why using both in the same study and why limiting the study to only five indicators if the aim is going further than the previous assessments.

 *Line 232: usually, LCA results are greatly affected by the methodological choices. Consequently, I would suggest to remove this sentence.

*Section 2.3.1: All the information presented in this paragraph has already been shown. Only the information about food waste (last sentence) was not mentioned in previous sections. So I would avoid redundancies by removing this paragraph (given that the reference scenario has already been defined) and including the information about the food waste in a previous section. Continuing on this, which EoL routes were considered for food waste?

*Line 256: Update the number of the section (2.3.2). The future scenarios seem to be a bit arbitrarily selected. Although logically speaking it makes sense to perceive them as they are arranged by the authors (environmentally friendly or unfriendly behaviours), the influence of the varied parameters is not easily captured by varying all the inputs at the same time. The scenario analysis should also answer what input influences the outcomes the most, by separately studying e.g.: lifespan and recycling percentage. If I look at S2 in Figure 10, I cannot understand if the 29% increase in ADP relates to the reduced lifespan, the material's weight or the recyclability percentage. Last consideration here: when grills are not recycled, what happens with the materials? They can undergo landfilling or energetic valorization according to Figure 2, but I don't know how they are specifically addressed. 

*Table 3, comment 1: In the reference scenario, the grilling ingredients have varied with respect to what is described in the text. What happens with the vegetables, bread and beer? 

*Table 3, comment 2: In the S5, the materials recovery rato goes up to 98%. Is that substantiated in any reference? It is quite high.

*Line 282: As far as I understand, manufacturing is not studied. Instead, materials are used as inputs separately. This seems confusing.

*Line 285: I don't understand the reasoning behind this. In Line 167 authors say: "During the use phase, neither the gaseous emissions resulting from meat grilling (emissions from fuel combustion are considered) nor the maintenance of the devices were incorporated into the evaluation process". This seems contradictory with the argument "This suggests that the use phase (charcoal combustion) had a significant impact on these two environmental aspects". Disaggregated results should be provided to clearly argue this point.

*Section 3.1: By the title, I would expect a comparison between all the devices under study, but instead only a comparison for the charcoal devices is shown. Why electrical and gas grills are excluded here?

*Section 3.2: Results for the grilling ingredients are based on a literature review. Thus a bit more of an elaborated comment on the implications of these datasets is expected: % of small and big bakeries, % intensive and extensive farm practices, etc. Also, Table B3 shows the impacts on the production of beer. 4 out of five categories based on two studies or less. This is way less compared with the rest of the ingredients, so its implications should be at least pointed out. Nothing of this is mentioned in the main text.

*Section 3: Authors present the results of ingredients and part of the devices (excluding LPG devices and electrical devices). Still, they do not include the raw results of the energy sources. What are the criteria? Excluding the use phase at this point of the analysis?

*Figure 5a: The information in Figure 5a has already been presented in Figure 4 in a more accurate way. This figure is thus redundant and is more complicated to see the information so I would suggest removing it.

*Section 4: Throughout the whole discussion I find a persisting issue. Authors display a comment on what is shown in the figures rather than an actual discussion. As an example, the authors comment on Figure 5b by pointing out the high scores of beef on the GWP indicator, or those of beer for the ADP indicator. Notwithstanding, they do not dive deeper to answer why in either of these cases. In a very general sense, I miss more discussion about the underlying cause-effect chains and the data to support all the comments.

*Lines 344 to 347: Disposable charcoal grill was presented as one of the charcoal devices and here it is not. It is indeed included in the analysis, (Figure 6), but the differentiation keeps being confusing throughout the paper.

*Lines 350 to 353: I am not sure if I agree with this appreciation. The disposable device has a much higher impact on climate change. From Figure 7b I can relate this GWP equally to production and use phases. Furthermore, what is LU during the use phase related to? Producing or treating these devices post-consumption should occupy more land than using them.

*Line 353: I quote: "In contrast, the gas grill has significant contribution in all other impact categories". Compared to disposable grills seems that is only worse in one category.

*Line 357: I quote: "This is due to the consumption of LPG during the use phase". Again, from Figure 7d I can see a great contribution to the production phase.

*Lines 360 to 362: This again contradicts Figure 7 for four out of five of the investigated categories, as you also acknowledge in line 367. 

*Line 369: "For example, the production phase of the gas grill contributes to 47 % of the GWP". Isn't it 64% according to Figure 7d?

*Lines 366 to 372: A lot of data are mentioned in this paragraph. A good addition to the manuscript would be to show these data systemically at some point in the manuscript (a table or similar) since the figures are valid for a quick assessment but they do not contain the exact values. 

*Figure 7: No conclusions on the EoL of disposable devices vs the rest of grills under study are presented. I really miss further elaboration on these numbers.

*Line 367: "By comparing the four types of grilling devices, this study concluded that reusable grills exhibit a lower environmental impact compared to disposable ones, underscoring the significance of long-term use and proper disposal in mitigating environmental burdens". Why is that? I did not find the discussion to support this. And it does not seem necessarily true for all the indicators. This comment goes along with my previous one.

*Lines 379 to 380: The use phase relative contributions are among the highest compared to the rest of the devices under study, so how does this conclusion relate to energy efficiency if electricity is consumed during the use phase?

*Lines 382 to 383: There is a lack of data shown to support this conclusion.

*Lines 392 to 394: Use phase contributes 86% according to Figure 7d. 0,525Kg of LPG then produce around 120MJ of ADP minus the contribution? That is a very high number, and I would say it requires more discussion (I would avoid saying "based on software simulation results"). What in the supply chain of LPG is causing this and why?

*Figure 8: Previous sections presented ingredients impact and devices impact. The ingredients needed to fulfil the functional unit are the same for all the devices  (consuming 1/75 of the reusable devices and 2 disposable devices). Thus, I assume the only difference in comparing the 4 displayed devices arises from the energy consumption (the ingredients contribution should be the same in all the cases to fulfil the same functional unit). Then I cannot understand the different profile in Figure 8 aggregating results in the same way as in Figure 6, since the addition of the same ingredients for the same FU should contribute the same in the four cases.

*Lines 413 to 415: From Figure 7, EoL contribution to evaluated indicators varies significantly among the different devices. Also materials and weights. Thus, although ingredients seem to be the main problem, I would either eliminate the S2, S3 and S5, S6 scenarios or include everything in the analysis. In any case, if the ingredients are responsible for almost all the impacts according to Figure 9, why S2 variation is more influential than S4? Additionally, S7 variation is more influential than S8. Maybe the focus should be on ingredients input in the scenario analysis (consumers' behaviour regarding a diet closer to vegetarianism), rather than food waste This is also valid on the negative behaviour side.

*Line 422: "This means that for grilling devices, a shortened lifespan and improper disposal at EoL would increase the GWP and AP". Which of these two is more influential and why?

*Lines 423 to 424: Authors indicate that an increase in the food waste of 10% would lead to an environmental improvement ranging from 6 to 8%. I am missing again a discussion for the studied indicators of why is that.

*Lines 425 to 428: At this point, authors draw conclusions about the influence of a larger or shorter energy consumption during the use phase. This is in contradiction with excluding different devices for the scenario analysis and only analyzing the gas device. Authors argue that the device selection is not significant, but different devices consume different energy carriers. Energy sources prove to be influential, so the argument for excluding the rest of the devices of the scenario analysis seems a bit loose.

*Line  439: Why is eutrophication potential reduced so drastically?

*Lines 455 to 459: Why there is no recommendation on using more vegetables? Is the ingredient with the lowest impact by far but it is never mentioned again in the recommendations. 

*Lines 472 to 474: "As an alternative, it may be worth considering using electric grills, which have the smallest environmental impacts in almost all categories". This is against the argument used for excluding grill types for scenario analysis. 

*Line 474: Authors say that electric device is much more beneficial if the energy used for electricity generation comes from renewable sources, but they do not include any data to support this conclusion (is for example using more nuclear power more beneficial for all the environmental categories?). To ensure that it is required to study the possible different mixes and their impact in all the impact categories of a methodology. 

Comments on the Quality of English Language

Overall quality is correct, although the manuscript would benefit from a detailed check for typos before the next round of corrections.

Author Response

Dear Reviewer 3,

Thank you very much for taking the time to review our manuscript. We greatly appreciate your valuable input as it helped refine our manuscript further in order to proceed with the publication.

Please find the detailed responses to your comments and suggestions in the table below. The corresponding revisions/corrections are highlighted/in track changes in the re-submitted file.

We hope all our comments are comprehensible. Please let us know, if we should provide further information or clarification.

On behalf of all authors,

Many thanks and best regards from Stuttgart

Kevin Christopher Dorling

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript can be accepted, but All figure quality is not good, so the author should improve it. 

Author Response

Dear reviewers,

Please find attached our response to your comments of the second review round. Thank you very much for your valuable suggestions that helped us improving the manuscript further.  

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

Broadly speaking, the manuscript has undergone significant improvement after revision. Minor details were still detected, after which being corrected, the manuscript should be ready to publish. I'll address those by the ID shown in the answer sheet. 

3.02 - Answers 1 and 2 are quite similar. Authors rely on previous studies for robustness and use secondary data to elucidate their conclusions. This argument is used to justify the impact categories selected, but the same argument is disregarded in the text for selecting the two calculation methods. It's a minor issue, but it should also be noted.

3.1 - Regarding the burden-shifting. Considering the whole life cycle of a product ensures that no burden-shifting occurs between life phases. However, this phenomenon can still happen between different environmental categories when not considering all of them. Thus, even if justified, this is a limitation of the study and should be stated as that.

3.2 - That is quite right. Both CML2001 and ReCiPe (H) rely on IPCC guidelines to account for CO2 flows. Notwithstanding, my point lies in the differences between the different perspectives developed within the ReCiPe method. Using the egalitarian approach for addressing the land use category implies a temporal horizon of 500 years. This temporal scope diverges from the one considered by the CML2001 for GWP calculations. Thus, carbon flow effects in the LU categories are accounted for differently as compared to GWP calculated with the CML method. I would recommend also proportioning the results of LU using the ReCiPe (H) method, at least as separate data, instead of only using the egalitarian perspective. 

3.3 - This is truly not that relevant, since these effects are very hard to calculate really. Just for clarification, my comment was related to the credits that might be taken if accounting that when barbecuing, attendants are not eating in their homes. That means that, despite the amount of food consumed, a similar amount would be eaten anyway, which would result in more impacts that might be deduced from the ones calculated in the event of barbecuing (instead of an isolated activity, eating is something that normally you do every day).

3.22 - The answer to the second comment is convincing enough to me. Might be a good idea to include it in the text for justification.

3.42 - I agree with the argument. Anyway, if the aim is to provide guidelines to improve environmental performance, the underlying cause-effect chains should be understood to correctly tackle all the specific issues. 

3.49 - Nice improvement, it allows understanding different aspects more easily and thoroughly. 

3.55 - What I mean is that the only difference between the two is the inclusion or exclusion of ingredients, as both 6 and 8 take into account the production of each device and the energy consumed during its use. If the consumption of ingredients is identical because it covers the same FU, why is the profile different?

3.56 - The justification of the second paragraph is completely valid. Why not include it in the main text? I'll elaborate further on the answer to 3.61.

3.58 - Understood. The only thing that still looks confusing to me is the use of the word "enhance" since a worse performance is obtained. I understand that the impact "enhances" but might be beneficial to rephrase. 

3.60 - Again, I understand not to get too involved in these discussions, but why does eutrophication increase when more beef is consumed? Is it to do with the feed, the waste produced, etc?

3.61 - I am not necessarily talking about a vegetarian diet, but it seems that if it is not mentioned, an obvious conclusion is omitted. Much of the impact assessed depends on meat consumption. I understand the justification based on the trend data studied for food in Germany, but if there is an interesting finding that is not published, it may be one of the most important conclusions of the study. There is a gap between vegetarianism and partial food substitution in these events, and given the importance revealed in this study, it seems to me that not mentioning it leaves out one of the most important observations. Even if this is unlikely to change in the near future, it is a fact that is consistent with the aim of providing guidelines for improving environmental performance. 

Author Response

Dear reviewers,

Please find attached our response to your comments of the second review round. Thank you very much for your valuable suggestions that helped us improving the manuscript further.  

Author Response File: Author Response.pdf