Consequences of Transport Low-Carbon Transitions and the Carbon, Land and Water Footprints of Different Fuel Options in The Netherlands

Round 1

Reviewer 1 Report

Dear authors,

your study is interesting and I expect that would be usable for a lot of readers. There is some important information which has to be added to the article for higher usability of the study. What is the scientific aim of the study? In the Introduction, you wrote: "The study answers the following research question: ´Which fuels and technologies might be applied in alternative transport fuel scenarios and what are the consequences for CO2 emissions, land and water footprints of the transport sector in the Netherlands compared to the reference situation in 2016?´". But there is missing deep discussion of consequences and usable conclusions for decision-makers. In total, the article does not describe the environmental impacts of different fuel options but mechanically calculates 3 three environmental footprints for different fuel scenarios. Here are the main notes:

1. What countries are affected by the described scenarios? I do not expect the Netherlands to be self-sufficient in all types of fuel. Also, some parts of the supply chain of fuel can be abroad. Are the factors described in the Appendixes same for all affected countries?   

2. It is important to quantify all three parts of the water footprint (blue, grey, green) individually. One aggregate number cannot provide important information for comparing different type of fuels. For example, the green water footprint does not (or very limited) describe a potential impact on the environment but is very important to the water managers. Similarly, the need for blue water can be met by grey water and therefore blue and grey water cannot simply be added together. After all, you yourself have described that resource use footprint and emission footprint are not the same on lines 237 and 238.

3. What environmental impact will have different fuel option? For example on water availability, ecological flows etc. Have the Netherlands (and other affected countries) available water resources to meet blue and grey water needs according to described scenarios or not?

4. What environmental impact will have different fuel option on land availability? Have the Netherlands (and other affected countries) available land resources to meet land needs according to described scenarios or not?

5. How many natural resources will be consumed in the Netherlands and abroad in described scenarios? And what portion of environmental footprints described in the article will be located in the Netherlands and abroad?

Other comments:

6. There is not clear what PES are in individual scenarios in Tabel 1.

7. Sometimes a different font is used, e.g. lines 269.

 

The article is focused on the application of different types of environmental footprint family but needs some improvements.

Author Response

We thank reviewer 1 for the constructive comments that helped to improve the paper, especially the remark to add a deep discussion and give consequences. The details are given below.

1. What countries are affected by the described scenarios? I do not expect the Netherlands to be self-sufficient in all types of fuel. Also, some parts of the supply chain of fuel can be abroad. Are the factors described in the Appendixes same for all affected countries?   
   
   The aim of our study as mentioned in the introduction is to: provide an environmental analysis of transport fuels, including the use of less CF intensive fuels, that covers three environmental footprints, the carbon, water and land footprint of transport in the Netherlands. It takes the Netherlands as the case study area, because of the importance of transport for the country, the policy initiatives to decrease transport CFs and the availability of reliable data. In the last two sentences of the introduction we mention that Although the study uses the Netherlands as the case study area, it provides information that can be applied to other countries and regions as well. And added: For example for the other 27 EU countries that need to comply to the same directive to replace 10% of transport fuel by renewables.
   
   The Netherlands is not self sufficient for coal and crude oil, only for natural gas. We also assumed that biofuels are produced in the Netherlands. For the footprints of fossil fuels we used general data, for biofuels data for the Netherlands. We mention in the tables of the factors the origin, sometimes the factors are general sometimes only for the Netherlands. We also discuss that LF and WFs for biofuels from the Netherlands are relatively small.
2. It is important to quantify all three parts of the water footprint (blue, grey, green) individually. One aggregate number cannot provide important information for comparing different type of fuels. For example, the green water footprint does not (or very limited) describe a potential impact on the environment but is very important to the water managers. Similarly, the need for blue water can be met by grey water and therefore blue and grey water cannot simply be added together. After all, you yourself have described that resource use footprint and emission footprint are not the same on lines 237 and 238.

Thank you for this relevant comment. The different colors of the WFs are indeed very important. Because figure 4 uses a logarithmic scale, it was not possible to add the colors. However, we included green, blue and grey WFs in table C1 of appendix C. And also added the sentence All biofuels have a large green component and a small grey one, all other WFs are blue WFs after figure 4.

3. What environmental impact will have different fuel option? For example on water availability, ecological flows etc. Have the Netherlands (and other affected countries) available water resources to meet blue and grey water needs according to described scenarios or not?
   
   Thank you for this comment. It shows that the purpose of the study was not completely clear. A WF study has four stages, 1 setting aim and scope; 2. Quantification; 3. Environmental impact analysis; and 4. Analyse options to decrease. This study focused on stage 1 and 2. We therefore changed the title of the paper and replaced impacts by consequences. In the Netherlands, and probably in many other countries, policy aims to decrease CO2 emissions. This is also general EU policy. For example, electric cars are heavily promoted, without considering where electricity comes from. In our study we show that also the origin of the electricity is important. The same for biofuels. Today, although the contribution of biofuels is small, they dominate WFs. The quantification of footprints for different fuel options is a first step in the environmental analysis of fuels for transport.
   
   To put WFs in perspective, we added a paragraph to the discussion:
   
   When WFs are put in perspective, the present transport system in the Netherlands has a green WF of 520 10⁶ m³ per year, a blue WF of 31 and a grey WF of 59 10⁶ m³ per year. Biofuels dominate the total WF and contribute 95%. If hydrogen is chosen as a transport fuel generated by electrolysis from coal, total WFs decrease to 381 10⁶ m³ per year, but the WF is completely blue and increases tenfold compared to the blue WF of the present transport system. Electricity from wind has the smallest blue WF, only 2,6 10⁶ m³ per year. If biofuels would be adopted, e.g. bioethanol from sugar beet, WFs would increase enormously. In 2011, the green WF in the Netherlands was 17591 10⁶ m³, the blue WF 2147 and the grey WF 4680 10⁶ m³ (Mekonnen and Hoekstra, 2011b). These WFs are mainly external, so water is used outside the country. The scenario providing ethanol from sugar beet has a green WF of 10416 and a grey WF of 2480 10⁶ m³ or 59 and 52% of the WFs in 2011. This would put a large pressure on WFs. The example for the Netherlands is relevant for other EU countries. The study shows the large impact on WFs.
   
   
4. What environmental impact will have different fuel option on land availability? Have the Netherlands (and other affected countries) available land resources to meet land needs according to described scenarios or not?

As is shown for water, land is mainly used outside the country. If there is enough land can be studied later.

5. How many natural resources will be consumed in the Netherlands and abroad in described scenarios? And what portion of environmental footprints described in the article will be located in the Netherlands and abroad?

We have shown the size of the footprints for different fuel scenarios and for water compared this to present WFs that are mainly external. It is really uncertain how this will develop.

Other comments:

6. There is not clear what PES are in individual scenarios in Tabel 1.
   
   Table 1 is updated.
   
   
7. Sometimes a different font is used, e.g. lines 269.
   
   The journal adapted the fonts.

Reviewer 2 Report

Research question of the study: “Which fuels and technologies might be applied in alternative transport fuel scenarios and what are the consequences for CO2 emissions, land and water footprints of the transport sector in the Netherlands compared to the reference situation in 2016?”. The goal was formulated correctly and answer the research question is possible and described.

Important and interesting topic; some remarks that I hope will be helpful:

1. Consider “carbon footprint” rather than “CO2e emissions” (like in the title)
2. Graphical abstract has low quality, the picture of vehicles is not readable to me. The second “vehicle” doesn’t have wheels – it looks like old TV set. Also the picture of land footprint is not friendly. I suggest to change it.
3. Abstract – You do not consider CO2 emissions (line 25) but CO2e. If you use equivalent of CO2 (line 24) – you should use name “GHG emissions”. The name of the measure related with carbon footprint should be unified in all text. In the title and discussion you use the term “carbon footprint” – that is the best term you can use in the article, like you did with water and land footprint. My suggestion: In all text please unify – not “CO2 e emissions” but “carbon footprint CF”
4. Line 111 – “(in)direct CO2 emission” – so direct or indirect?
5. Line 129 and 177 and many other places in all text – “production chain” Please explain precisely what you mean under the term “production chain” (you can also consider “cradle to gate” that is common term, but then “gate” should be explained (for example using of fuel or electricity in transport mode). There should be indicated which phases of life cycle are included and which are excluded) and why? You can consider graphical presentation of “production chain”.
6. Line 132 and all text – “Fuels, e.g. electricity” – Electricity is not fuel
7. 10⁹ = billion (bn); 10⁶ = million (mln) – if you use shortcuts in the describing text it could be more friendly in reading. Especially that you use “million” as well i.e. in line 139 “560 million tons”.
8. Line 156 – “the wheel to tank (WTT)” – mistake – should be “well to tank WTT”
9. Line 175 “the ‘combustion’ of electricity in vehicles does not emit CO2” – I suggest: use of electricity doesn’t involve direct CO₂ emission… (combustion of electricity sounds strange)
10. Lines 176-178 – “electricity must be generated by a PES without CO2 emissions” – I don’t understand – don’t you consider production of wind turbine or photovoltaic panel? If not, generation of PES is not without CO2 emissions, but you don’t consider these phases of life cycle.
11. Line 177 – “zero emission” – but it should be precised that you write about indirect emissions
12. Line 191 – “The combustion does not emit CO2” – earlier you have written about chemical reduction (electrolysis), not combustion (combustion is the second possible solution with using hydrogen but you don’t relate to this in your description).
13. Lines 223-225 – The Kyoto Protocol applies to the six greenhouse gases listed in Annex A: Carbon dioxide (CO2), Methane (CH4), Nitrous oxide (N2O), Hydrofluorocarbons (HFCs), Perfluorocarbons (PFCs), and Sulphur hexafluoride (SF6). These gases are taken into account during carbon footprint analysis. The sentences should be improved and you can base on the newer publications on this topic than 1993 (or just Kyoto Protocol).
14. Line 226 – I suggest CO2e not GHGe
15. Figure 1, table 1 – electric or electricity as fuel doesn’t exist
16. Line 269-270 – why the name “United Nations Convention to Combat Desertification” is underlined?
17. Line 296 – mistake not 200 but 2006
18. Step 1 (pages 8-9) – you describe de facto carbon footprint emission factors, water footprint factors and land footprint factors but you don’t use these names; on the other hand you use these names in appendixes (for example lines 267-268 – not data but factors, not CO2 e emissions but emission factors)
19. Table A1 – emission factors rather than emissions
20. Line 323 and 327 – not TWW but TTW
21. LPG = liquefied petroleum gas, in text mistakes
22. 465-466 – that is not true – WTW for LPG = 73,8; for diesel = 88,6; for gasoline = 87,2
23. Please unify significant figures sf – in different places you have one, two or three sf
24. Please argue choice of emission, water and land factor (for example if you choose DEFRA emission factors (2019) then TTW factor for diesel 100% mineral = 70,186 kg CO2e/GJ; in your calculation 73,2 kg CO2e/GJ). You should underline your choices of factor sources
25. Table B1, C1 – cannot find asterisks in the tables text, only under tables

Author Response

Reviewer 2 made really helpful and very detailed comments with which we could improve the paper a lot and take all minor errors out!

1. Consider “carbon footprint” rather than “CO2e emissions” (like in the title)

We have changed CO2e emissions into carbon footprints where possible.

2. Graphical abstract has low quality, the picture of vehicles is not readable to me. The second “vehicle” doesn’t have wheels – it looks like old TV set. Also the picture of land footprint is not friendly. I suggest to change it.
   
   The graphical abstract does not add much. We deleted it.

3. Abstract – You do not consider CO2 emissions (line 25) but CO2e. If you use equivalent of CO2 (line 24) – you should use name “GHG emissions”. The name of the measure related with carbon footprint should be unified in all text. In the title and discussion you use the term “carbon footprint” – that is the best term you can use in the article, like you did with water and land footprint. My suggestion: In all text please unify – not “CO2 e emissions” but “carbon footprint CF”
   
   We unified CO2e emissions not using the terminology carbon footprint. In the method section we explain how we calculated this, i.e. in terms of CO2e emissions.

4. Line 111 – “(in)direct CO2 emission” – so direct or indirect?
   
   The word (in)direct is indeed confusing and deleted, because we already mention the whole production chain.
   
   
5. Line 129 and 177 and many other places in all text – “production chain” Please explain precisely what you mean under the term “production chain” (you can also consider “cradle to gate” that is common term, but then “gate” should be explained (for example using of fuel or electricity in transport mode). There should be indicated which phases of life cycle are included and which are excluded) and why? You can consider graphical presentation of “production chain”.
   
   In the introduction we include an explanation of production chain where we mention:
   
   When sustainable transport is promoted, not only CFs of the transport mode itself, i.e. the emissions related to transport fuel consumption, but whole production chains, from cradle to gate, need to be included in the analysis so that also tradeoffs to other natural resources are taken into account. For sustainable transport, two phases, the well to tank (WTT) and the tank to wheel (TTW) phase need to be considered. WTT includes the production chain of a fuel and TTW the combustion of a fuel. Together, WTT and TTW are termed well to wheel (WTW) (JRC, 2014b-e).
   
   In line 157 we include:
   
   This study focusses on the entire production chain, from well to tank, and consumption, from tank to wheel, of transport fuels.
   
   
6. Line 132 and all text – “Fuels, e.g. electricity” – Electricity is not fuel
   
   We fully agree with the reviewer that electricity is not a fuel. However, for transport it can be regarded as an alternative fuel as stated in the energy policy act of the Senate and House of Representatives of Energy Policy of the United States of America, 1992. We emphasize this in the Introduction and mention that electricity is an alternative fuel.
   
   
7. 10⁹= billion (bn); 10⁶ = million (mln) – if you use shortcuts in the describing text it could be more friendly in reading. Especially that you use “million” as well i.e. in line 139 “560 million tons”.
   
   We changed million into 10⁶
   
   
8. Line 156 – “the wheel to tank (WTT)” – mistake – should be “well to tank WTT”
   
   Thank you for finding this mistake. We made the correction!
   
   
9. Line 175 “the ‘combustion’ of electricity in vehicles does not emit CO2” – I suggest: use of electricity doesn’t involve direct CO₂emission… (combustion of electricity sounds strange)
   
   We thank the reviewer for this constructive comment and changed the sentence.
   
   Lines 176-178 – “electricity must be generated by a PES without CO2 emissions” – I don’t understand – don’t you consider production of wind turbine or photovoltaic panel? If not, generation of PES is not without CO2 emissions, but you don’t consider these phases of life cycle.
   
   We agree with this comment and changed the sentence into:
   
   To evaluate whether an electric vehicle has small emissions, we need to consider the whole production chain, not only the TTW but also the WTT phase, because also the electricity must be generated by a PES with small CO₂ emissions, e.g. by a renewable PES like sun or wind (Fares, 2015 that also need energy for the construction of wind turbines and pv panels (JRC, 2014c; Turconi et al., 2013).
   
   
10. Line 177 – “zero emission” – but it should be precised that you write about indirect emissions
    
    See the rephrased sentence above.
    
    
11. Line 191 – “The combustion does not emit CO2” – earlier you have written about chemical reduction (electrolysis), not combustion (combustion is the second possible solution with using hydrogen but you don’t relate to this in your description).
    
    We changed combustion into conversion.
    
    
    
12. Lines 223-225 – The Kyoto Protocol applies to the six greenhouse gases listed in Annex A: Carbon dioxide (CO2), Methane (CH4), Nitrous oxide (N2O), Hydrofluorocarbons (HFCs), Perfluorocarbons (PFCs), and Sulphur hexafluoride (SF6). These gases are taken into account during carbon footprint analysis. The sentences should be improved and you can base on the newer publications on this topic than 1993 (or just Kyoto Protocol).
    
    We included more recent publications and added: The IPCC (Forster et al., 2007) recognizes four principal greenhouse gases related to human activities CO₂, CH₄, N₂O and the halocarbons (e.g. fluorine, chlorine and bromine). For transport fuels only CO₂, CH₄, N₂O are relevant (JRC, 2014a).
    
    
13. Line 226 – I suggest CO2e not GHGe
    
    We changed GHGe into CO2e.
    
    
14. Figure 1, table 1 – electric or electricity as fuel doesn’t exist
    
    In line 301 we added: The study considers electricity as an alternative fuel categorized as a fuel, although it is not a real fuel form an energy perspective. We adopted the view on alternative fuels from the energy policy act of the Senate and House of Representatives of Energy Policy of the United States of America, 1992.
    
    
15. Line 269-270 – why the name “United Nations Convention to Combat Desertification” is underlined?
    
    This is probably a typing error, we changed it.
    
    
16. Line 296 – mistake not 200 but 2006
    
    Thank you!
    
    
17. Step 1 (pages 8-9) – you describe de factocarbon footprint emission factors, water footprint factors and land footprint factors but you don’t use these names; on the other hand you use these names in appendixes (for example lines 267-268 – not data but factors, not CO2 e emissions but emission factors)
    
    Thank you for this comment. Emission factors and WF and LF factors are changed into CFs, LFs and WFs throughout the document.
    
    
18. Table A1 – emission factors rather than emissions
    
    See the reply above.
    
    
19. Line 323 and 327 – not TWW but TTW
    
    Thank you, we made the necessary changes.
    
    
20. LPG = liquefied petroleum gas, in text mistakes
    
    Thank you, we made the necessary changes.
    
    
21. 465-466 – that is not true – WTW for LPG = 73,8; for diesel = 88,6; for gasoline = 87,2
    
    Initially the numbers were rounded. Giving a range is indeed more precise. We added: emissions between 74 (LPG) and 89 (diesel) kg CO₂e per GJ.
    
    
22. Please unify significant figures sf – in different places you have one, two or three sf
    
    We unified figure 6a-d, and for all figures made the color of the histograms black.
    
    
23. Please argue choice of emission, water and land factor (for example if you choose DEFRA emission factors (2019) then TTW factor for diesel 100% mineral = 70,186 kg CO2e/GJ; in your calculation 73,2 kg CO2e/GJ). You should underline your choices of factor sources
    
    For water footprints we selected the most comprehensive database there is, published in Mekonnen and Hoekstra (2011) and freely available at the website of the water footprint network. For land we did the same and derived data from the United Nations and Börjesson. For carbon footprints there are indeed a lot of different sources with slight differences in absolute numbers, e.g. 70,186 or 73,2 kg CO2e/GJ for diesel. However, the study is about the broad picture showing the consequences of efforts to decrease carbon footprints on land and water, indicating the best options. The JRC provided easily accessible information for our purpose.

We tried to make it more clear and changed the data collection in step 1 emphasizing why a specific number was taken and include a data range in table B1.

24. Table B1, C1 – cannot find asterisks in the tables text, only under tables
    
    Thank you, we inserted *.

 

Round 2

Reviewer 1 Report

Authors have appropriately revised the manuscript. However, some things need more clarification in the manuscript.

Major comments:

1. How much of the CF, WF, LF is located outside the Netherlands? You added new text on line 508 that most of the WFs are external. Are you able to quantify external part of footprints? On comment no 5 from the 1 round of review you answer: "We have shown the size of the footprints for different fuel scenarios and for water compared this to present WFs that are mainly external." I am sorry, but I really do not see arguments for statement "WFs are mainly external" in the article.

2. The main message of the article is the importance to combine different environmental assessments in a complex assessment. How you argue in different places of the article, focus on one type of fuel can decrease CFs, but will lead to increase LFs or WFs. This statement is difficult to visualize by the current figures in the article. I suggest looking for more innovative ways to combine footprints data in figures and better support these statements. For example, comparison of CFs, LFs, and WFs of fuels is problematic to readers, if these are in the three individual figures (Figure 2-4). The reader will have an even bigger problem with Figures 7-9, due to different sorting of items displayed in these figures.

3. On lines 299-300 you argue, "all biofuels are produced in the Netherlands itself, because the country produces more biofuels than it exports".  The only comparison of production and export does not say anything about internal consumption. You can assume that biofuels are produced in the Netherlands itself, if the country produces more biofuels than it consumes or if the export is higher than import. Can you explain it?

4. On line 510, there is "WFs in 2011"; is it correct if the base year is 2016?

5. On line 511, there is the sentence: "The example for the Netherlands is relevant for other EU countries." What is the background for this statement? I can find no arguments for this statement in the article.

Minor Comments

1 - line 55 - Directive 2009/28/EC (not "EG")

2 - abbreviations should be explained when they first appear in the text (for example MDO, pv)

3 - on line 428 is used "Scenario 1"; on other places in the text, the term "reference scenario" is used for the same scenario - it would be better for readers if one term was used in the whole text.

4 - On lines 511-512, there is the sentence: "The study shows the large impact on WFs". A large impact of what?

 

I wish to commend the authors for an interesting study. The article can be very important for discussions with policymakers. In this case, all arguments must be clear and well-reasoned.

Author Response

Reply to reviewer #1

Authors have appropriately revised the manuscript. However, some things need more clarification in the manuscript.

Major comments:

1. How much of the CF, WF, LF is located outside the Netherlands? You added new text on line 508 that most of the WFs are external. Are you able to quantify external part of footprints? On comment no 5 from the 1 round of review you answer: "We have shown the size of the footprints for different fuel scenarios and for water compared this to present WFs that are mainly external." I am sorry, but I really do not see arguments for statement "WFs are mainly external" in the article.

We added the following sentences:

95% of the water is used outside the country⁷⁷

When LFs are put in perspective, the present Dutch transport system has a LF of 1,267 km², or 3% of the surface area of the Netherlands of 41,000 km^{2 12}. This LF is dominated by biofuel use. The scenarios based on biofuels have LFs similar or exceeding the Dutch surface area indicating that it is not possible to produce all fuels in the Netherlands itself. For CFs, it does not matter whether emissions take place in the Netherlands or abroad, because emissions have a global impact. For CFs, the smallest footprints are most favorable.

2. The main message of the article is the importance to combine different environmental assessments in a complex assessment. How you argue in different places of the article, focus on one type of fuel can decrease CFs, but will lead to increase LFs or WFs. This statement is difficult to visualize by the current figures in the article. I suggest looking for more innovative ways to combine footprints data in figures and better support these statements. For example, comparison of CFs, LFs, and WFs of fuels is problematic to readers, if these are in the three individual figures (Figure 2-4). The reader will have an even bigger problem with Figures 7-9, due to different sorting of items displayed in these figures.
   
   We understand that it is difficult to compare the footprints. However, it is important to show the different footprints separately. We now add a reader manual to better understand the figures and what they indicate. The starting point is the CF. If policy only aims to decrease CFs, the consequences for land and water can be large. We not write:
   
   The main message of this article is the importance to combine different environmental assessments in a complex assessment. Policy aims to decrease CFs. Figure 6 shows the present CF and related LF and WF. Figure 7 shows the different options to decrease CFs compared to the situation in 2016 (reference scenario), indicating that not all options are favorable and that the choice of PES is important. Figure 8 and 9 show the consequences of a specific fuel choice on LF and WFs. In order to decrease CFs a shift towards biofuels generates large LFs and WFs. This is even the case for the reference scenario in which a contribution of only 2.5% of the energy in the form of biofuel to the total energy use of transport generates large LFs and WFs. If a decrease of CFs is the policy priority, the best fuel choices, if also LFs and WFs are taken into account, are electricity from wind or sun, followed by hydrogen from wind or solar.
   
   
3. On lines 299-300 you argue, "all biofuels are produced in the Netherlands itself, because the country produces more biofuels than it exports".  The only comparison of production and export does not say anything about internal consumption. You can assume that biofuels are produced in the Netherlands itself, if the country produces more biofuels than it consumes or if the export is higher than import. Can you explain it?
   
   This is vague indeed. We changed the sentence into: We assumed that all biofuels used are produced in the Netherlands itself, because the country produces more biofuels itself than it imports or exports⁵⁷
   
   
4. On line 510, there is "WFs in 2011"; is it correct if the base year is 2016?
   
   This is indeed vague. We compared the scenario WFs with the results from a study for the Netherlands in 2011 (reference 77). We added: Dutch green and grey WFs in 2011.
   
   
5. On line 511, there is the sentence: "The example for the Netherlands is relevant for other EU countries." What is the background for this statement? I can find no arguments for this statement in the article.
   
   We added: The example for the Netherlands is relevant for other EU countries too. Total transport energy use in the EU in 2030 could be around 24,000 PJ per year¹² or fifty times the present Dutch energy use. All countries have to comply to the same EU directive to replace 10% of the fuel by renewables, so that wise choices need to be made to avoid that LFs or WFs become too large.

Minor Comments

1 - line 55 - Directive 2009/28/EC (not "EG")

Thank you, correction made.

2 - abbreviations should be explained when they first appear in the text (for example MDO, pv)

Thank you, we made the changes.

3 - on line 428 is used "Scenario 1"; on other places in the text, the term "reference scenario" is used for the same scenario - it would be better for readers if one term was used in the whole text.

We changed scenario 1 and reference scenario into: scenario 1, the reference scenario in the whole text.

4 - On lines 511-512, there is the sentence: "The study shows the large impact on WFs". A large impact of what?

Agree, this is vague. We deleted the sentence.

I wish to commend the authors for an interesting study. The article can be very important for discussions with policymakers. In this case, all arguments must be clear and well-reasoned.

Thank you for this compliment! With your help, the paper improved substantially.