Carbon Footprint of Honey in Different Beekeeping Systems
and Aldo Dal Prà 1,*Round 1
Reviewer 1 Report
Dear authors, your manuscript is very well written.
My comments are in the attached file.
Comments for author File: 
Comments.pdf
Author Response
Reviewer#1
Comments section
This work presents the results of research on the carbon footprint of beekeeping in Italy. Authors use the controversial Life cycle assessment method for their calculations. This a novel and very interesting scientific work. They used three different beekeeping operations situated in a region in Italy. The results are mainly interesting because authors introduce LCA to beekeeping and compare two types of beekeeping (migratory vs non-migratory). This a new for our industry and this research will surely initiate other research teams to do this type of study in the near future. Nevertheless, results are of limited use because of the restricted area that has been used for the study (three farms in the same region) and the relative bias associated with obtaining LCI data (dialogue and questionnaires to beekeepers). Results are not surprising but do confirm that a scientific analysis method LCA can be efficiently used for beekeeping.
This manuscript is very well written, science is very good and I suggest to publish after minor changes.
Specific comments
Introduction. I suggest that authors add a paragraph on existing results/data on the carbon footprint of a couple of major farm productions. This should also be discussed for comparison in discussion.
A: Suggestion accepted, carbon footprint of a couple of major farm productions were included in the introduction (and more citations). We have also included a part relating to honey substitute products, thanks for the good suggestion. Lines 31-40.
Line 40: missing word “beekeepers have to check” or maybe change to “colony management requires more work”
A: The sentence has been rewritten. Line 50.
Lines 52-53: incoherent phrase/words “also considered the protein containing drone broods” what is the meaning of “protein containing drone broods”?
A: Thank you for your suggestion. We have clarified the sentence. Lines 65-67.
Line 54: references should only be numbers, remove names
A: Suggestion accepted, the references have been modified. Now lines 68.
Line 81: typo: particolar replace with particular
A: Sorry for the typing error, the word has been rewritten. Line 97.
Discussion. Add a paragraph on comparison of the carbon footprint of beekeeping vs carbon footprint of a couple of major farm productions.
A: Suggestion accepted, we have added a specific carbon footprint of a couple of major farm productions (and substitutes). Lines 370-379.
Reviewer 2 Report
This is an interesting topic worth investigating and I would certainly encourage the authors to pursue publishing. However, some serious issues have to be resolved.
The third paragraph on page 2 indicates two types of beekeepers. The ninth paragraph on the same page is about three types, and only two types are explained.
This is later explained on page 4 under 2.2. However, farm 2 cannot be considered as a 'representative type' since represents just one specific combination of type 1 (16%) and type 3 (84%) operation.
An even bigger problem is the sample size, just one beekeeper per group. Additionally, low supplemental feeding at farm 3 is not an integral part of the stationary beekeeping technology, but just how this particular farm is doing business.
Table 3. on page 7 have to be corrected, the chemical formulas have to use subscript where appropriate.
Figure 3 on page 9 does not represent all the expenses clearly. Consider changing the type of the graph or color scheme to show all the expenses properly.
Figure 4 on page 9 - consider changing the type of the graph. Use absolute values instead of 100%.
Section 3.2. is deceiving. The black locust honey does not have significantly higher CF just because it's black locust honey, but because the beehives were moved to a region further away from the beekeeper's headquarter. Similar applies to several other honey types.
Use of such a small sample (three subgroups with just one observation each), inappropriate experiment design (3 instead of 2 subgroups), and inappropriate hypotheses (accounting distances traveled under honey type, and farm-specific technology as a default technology) lead to very questionable results.
Author Response
Reviewer#2
Comments section
This is an interesting topic worth investigating and I would certainly encourage the authors to pursue publishing. However, some serious issues have to be resolved.
Specific comments
The third paragraph on page 2 indicates two types of beekeepers. The ninth paragraph on the same page is about three types, and only two types are explained.
A: Thanks for the suggestion, the sentence has been improved, we added references in the 52-54 lines and we have better specified the characteristics of beekeeping management practices in the literature.
This is later explained on page 4 under 2.2. However, farm 2 cannot be considered as a 'representative type' since it represents just one specific combination of type 1 (16%) and type 3 (84%) operation.
A: In Table 1 we reported that Farm 1 moves/carries 79 % of its hives, farm 2 moves/carries 16 % of its hives and Farm 3 is stationary (0 % of beehives transported), therefore farm 2 in our experimental design was considered a mixed or semi-migratory system. In the semi-migratory system the percentage of transported hives is variable due to climate conditions and beekeeping management.
An even bigger problem is the sample size, just one beekeeper per group. Additionally, low supplemental feeding at farm 3 is not an integral part of the stationary beekeeping technology, but just how this particular farm is doing business.
A: This study has been applied to two different approaches: farms and honey types produced. The LCA analyses are the following: 8 for Farm 1 (Ms), 4 for farm 2 (SMs), 3 for farm 3 (NMs).
Also considering Carbon Footprint of 1 kg of honey, globally this research includes 18 LCA analyses. As far as our knowledge is concerned, no research has ever been done with this approach by type of honey. For your good suggestion about supplemental feeding use, the sentence has been improved, we have specified at page 4 that the limited employment of supplementary feed is not specific to the beekeeping system but to the farm management. Lines 132-136.
Table 3. on page 7 have to be corrected, the chemical formulas have to use subscripts where appropriate.
A: Sorry for the typing error, the chemical formulas have been rewritten in table 3. Line 252.
Figure 3 on page 9 does not represent all the expenses clearly. Consider changing the type of the graph or color scheme to show all the expenses properly.
A: Thanks for the suggestion, we have added a new graph (figure 4) without the 3 main impact factors: transport, electricity, and supplemental feeding. Lines 300-304. More description details at lines 305-310.
Figure 4 on page 9 - consider changing the type of the graph. Use absolute values instead of 100%.
A: According to your remark, we have added a new graph (figure 5b) which explains the distribution of the impacts in the three production phases, expressed as kg CO2 equivalent per kg of honey. Line 320. More description details at lines 311-316 and 322-328.
Section 3.2. is deceiving. The black locust honey does not have significantly higher CF just because it's black locust honey, but because the beehives were moved to a region further away from the beekeeper's headquarter. Similar applies to several other honey types.
Use of such a small sample (three subgroups with just one observation each), inappropriate experiment design (3 instead of 2 subgroups), and inappropriate hypotheses (accounting distances traveled under honey type, and farm-specific technology as a default technology) lead to very questionable results.
A: Thank you for these remarks. We have better explained that different honey types’ impact is due to transportation (the kilometers introduced are not a mean value but they are specific for individual honey types). This means that the same type of honey can impact differently depending on the beekeeping system. Lines 339-353. The results on supplemental feeding have been modified as suggested (lines 133-135, 288 and also 382). As regards the technology, we used flows and processes more representatives of honey production, available on the Ecoinvent database, and also according to the literature.
Thanks for your time and the opportunity to improve our manuscript
Round 2
Reviewer 2 Report
Dear Authors,
You decided to keep three subgroups with one farm per group as an analysis framework, where the farm in subgroup 3 is very unusual and represents nothing but itself.
You decided to keep the former Figure 6 / now Figure 5, which is very deceiving, and you added a new paragraph explaining what if transportation costs are not included.
All minor changes are done and that's ok, but important remarks are simply ignored.
Author Response
Dear Authors,
You decided to keep three subgroups with one farm per group as an analysis framework, where the farm in subgroup 3 is very unusual and represents nothing but itself.
You decided to keep the former Figure 6 / now Figure 5, which is very deceiving, and you added a new paragraph explaining what if transportation costs are not included.
All minor changes are done and that's ok, but important remarks are simply ignored.
A: dear reviewer, the study has been adapted based on your suggestions. The sample of farms was expanded (3 farms added and LCA analysis of 14 other types of honey carried out) and beekeeping systems were divided into migratory (Ms) and non-migratory (NMs). The former Figure 5 / now Figure 6 it has been modified: the data on transport impact has been highlighted; an additional figure (7) has been added for non-migratory (NMs). We thank you for your helpful suggestions.
Round 3
Reviewer 2 Report
Dear authors,
increased number of beekeeping farms from 3 to 6 is a very welcome improvement. The major concerns from 1st version of the paper are still not handled properly:
- Role of transportation
- Analysis of honey variety impact which is based mostly on the difference in transportation costs.
The paper investigates the impact of the beekeeping system on GHG emissions. It's obvious that moving hives further burn more fuel and cause more emissions. But claiming that black locust honey produces more emissions than other honey varieties simply because this particular farmer moved his hive to that particular field in that particular year is simply deceiving. Other farmers with other circumstances will have significantly different numbers.
Additionally, the fact that black locust honey from semi-migratory operation (Figure 7, Farm 2 – SMs) causes more emissions than the same variety of honey in migratory operation (Figure 7, Farm 1 – Ms) without better explanation in text and information about distance traveled is confusing.
The way around this is to indicate the nature of transport and then, that applies to all honey varieties or none. And it's always accompanied with information about distances traveled.
Additional remarks
Page 1 – Abstract – line 18 dana about CO2 emissions amend with respective distance traveled in km.
Page 3
3rd paragraph doesn't belong here but to the literature review. However, it should be expanded by adding more information about distances traveled and additional revenues.
Figure 1. wrong placement and doesn't contain emissions from transport activities (and later we have so much about the impact of transportation).
Page 6.
Add information about the type of beehives at each farm and the beekeeping system.
Page 12.
The second part of the first sentence in chapter 3. Results is not clear.
Page 14. Figure 3.
It's 3a and 3b and it's not indicated what is what.
I didn't grasp why we need both graphs, Farms 1 & 2 are the same, 3 is different and 4-6 are omitted in the lower graph.
Page 15 & 16
Figures 5 a & 5b are presented twice, again with marginal benefits. Dropping the lower graph and inserting actual values in the upper graph is the better option.
Page 18. Again the same case as before, two graphs not properly named. Different color-coding.
I propose to drop the transport costs from the graph and add a better description in the text.
Page 19
Figure 7. It's not clear why we have so much more emissions of CO2 from used electricity per kg of acacia honey compare to wildflower honey?
Page 20. line 498
Please add the distances traveled for both emission numbers.
Page 21. Line 517 Explain why and how the production of Argentine honey differs.
Author Response
Dear authors,
increased number of beekeeping farms from 3 to 6 is a very welcome improvement. The major concerns from 1st version of the paper are still not handled properly:
- Role of transportation
- Analysis of honey variety impact which is based mostly on the difference in transportation costs.
The paper investigates the impact of the beekeeping system on GHG emissions. It's obvious that moving hives further burn more fuel and cause more emissions. But claiming that black locust honey produces more emissions than other honey varieties simply because this particular farmer moved his hive to that particular field in that particular year is simply deceiving. Other farmers with other circumstances will have significantly different numbers.
Additionally, the fact that black locust honey from semi-migratory operation (Figure 7, Farm 2 – SMs) causes more emissions than the same variety of honey in migratory operation (Figure 7, Farm 1 – Ms) without better explanation in text and information about distance traveled is confusing.
The way around this is to indicate the nature of transport and then, that applies to all honey varieties or none. And it's always accompanied with information about distances traveled.
Dear Reviewer, in this latest version of the paper we have detailed the transportation role by combining the (CF) results with kilometers (seasonal medium or total) travelled per system and per farm. Related to your suggestion we have better explained the (CF) of different honey types excluding transport input. This approach, has improved the paper and it allowed us to evaluate separately the LCA main impact factors.
the line numbers refer to file .PDF
Additional remarks
Page 1 – Abstract – line 18 dana about CO2 emissions amend with respective distance traveled in km.
Author: line 20. We have included in the abstract the distance traveled (average of kilometers for each hive) by nomadic beekeepers for hives management.
Page 3
3rd paragraph doesn't belong here but to the literature review. However, it should be expanded by adding more information about distances traveled and additional revenues.
Author: lines 125-127 and 131-136. We have included in the first part of paragraph 2.2 (“The beekeeping farms”) the number of kilometers travelled by nomadic beekeeping farms and the percentage of transported hives. We have also added information about co-products. The impact of co-products is also quantified by the allocation (paragraph 3.3) LCA phase.
Figure 1. wrong placement and doesn't contain emissions from transport activities (and later we have so much about the impact of transportation).
Author: line 103. Thanks for this reporting we corrected the typo in figure 1.
Page 6.
Add information about the type of beehives at each farm and the beekeeping system.
Author: lines 157-166. In the second part of paragraph 2.2 “The beekeeping farms” we have added more details about beehives type and beekeeping system. We have also included more information about seasonal transportation.
Page 12.
The second part of the first sentence in chapter 3. Results is not clear.
Author: lines 318-319 and lines 326-327. We have explained the results and we have corrected a typo related to the impact of electricity in (NMs) farms.
Page 14. Figure 3.
It's 3a and 3b and it's not indicated what is what.
I didn't grasp why we need both graphs, Farms 1 & 2 are the same, 3 is different and 4-6 are omitted in the lower graph.
Author: lines 330-333. Thanks for this suggestion. We have delated figure 4 and we have better explained the main results reported in figure 3.
Page 15 & 16
Figures 5 a & 5b are presented twice, again with marginal benefits. Dropping the lower graph and inserting actual values in the upper graph is the better option.
Author: lines 349-351. In agreeing with your remark, we have dropped figures 5a and 5b and we have elaborated an only graph (now figure 4) with the explanation of honey production phases’ impact in the farms examined.
Page 18. Again the same case as before, two graphs not properly named. Different color-coding.
I propose to drop the transport costs from the graph and add a better description in the text.
Author: lines 368-411. Thanks to this suggestion, we have explained the honey types results dropping the transport input (Figure 5 and explanations in the text). Figure 6 with the transport (only for migratory honey types) has been added according to the ISO14040-14044, which includes all inputs in the Life Cycle analysis.
Page 19
Figure 7. It's not clear why we have so much more emissions of CO2 from used electricity per kg of acacia honey compare to wildflower honey?
Author: lines 394-396. Electric consumption as well as other inputs is equal for all honey types produced by the same farm, as we have better explained in the first sentence of “Carbon Footprint of honey types”. For farm 6, the different electricity impact in the acacia and wildflower honey (CF) is due to the yield. In fact, Acacia honey has a lower yield than wildflowers honey, so the emission related to electricity input estimated in kg CO2 on one kilogram of honey produced is higher than wildflower honey one.
Page 20. line 498
Please add the distances traveled for both emission numbers.
Author: lines 443-444. Thanks for the suggestion, we added what was indicated.
Page 21. Line 517 Explain why and how the production of Argentine honey differs.
Author: line 461-464. Thanks for this suggestion. We have added more information about the differences between Argentine and Italian production
