An Empirical Analysis of Carbon Emissions in Higher Education Institutions: A Case Study of Zhejiang Ocean University Using Emission Factor Methodology
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe paper by Lin et al. estimating carbon emissions in higher education institutions using empirical analysis methods. The paper is well written and organized and I recommend its publication after a minor revision.
I only have some small concerns about the manuscript.
1. Line 18: I think it should be 3.39×107 kg and 3.34×105 kg?
2. Table 1: The table titles are confusing, two Emission source? what’s the differences?
3. Both axises of figures should have labels.
Comments on the Quality of English LanguageI think it's fine.
Author Response
comment 1： Line 18: I think it should be 3.39×107 kg and 3.34×105 kg?
reply 1：Agreed. We have revised this. [Line 18]
comment 2： Table 1: The table titles are confusing, two Emission source? what’s the differences?
reply 2：Thank you for pointing this out. We agree with this comment. Therefore, we have revised Table 1 to correct one of the “sources of emissions” to “emitting facilities or activities.” [Page 5, line 17]
comment 3：Both axises of figures should have labels.
reply 3：Thank you for pointing this out. We agree with this comment. We have added labels to the axes of the graph.
Reviewer 2 Report
Comments and Suggestions for AuthorsReview Comments
1. On page 1, line 30, “......soaring carbon dioxide emissions have turbocharged global warming.......”
I suggest replacing "turbocharged" with "accelerated" for a more formal tone.
2. On page 1, line 32, “This threatens human survival and ecosystem sustainability.......”
I suggest that this sentence can be expressed as “These changes pose significant threats to both human survival and ecosystem sustainability......”
3. On page 1, line 34, “curbing carbon emissions is.......”
I suggest replacing "curbing" with "reducing" for a more formal tone, it can be expressed as “reducing carbon emissions.......”
4. On page 1, line 35, “......China aims to decrease carbon emissions per unit of GDP by over 65% by 2030.”
According to Chinese policy, by 2030, China aims to reduce carbon dioxide emissions per unit of GDP by more than 65% compared to 2005. The 65% refers to the reduction relative to 2005. Please confirm and explain further.
5. On page 1, line 36, “This aligns with the “dual-carbon” goal, crucial for China’s socialist modernization and for fostering green industrialization and urbanization.”
“This” means “This target”, I suggest that this sentence can be expressed as “This target supports the "dual-carbon" goal, which is essential for China's socialist modernization and for advancing green industrialization and urbanization. ”
6. On page 2, line 50, “......calculation model 2 .”
On page 2, line 60, “......ecosystem 34 .”
On page 2, line 61, “......person or a group [5]”
On page 2, line 80, “......accounting boundaries [117]”
Please clarify and address the following issues:
l The reference format in the article is inconsistent. Specifically, the format used for reference 2 and 117 differs from that used for references 5, 6, 7, and others.
l There is ambiguity in the reference formatting for references 3 , 4 and 117, which may lead to potential misunderstandings.
l Reference 20 to 38 are missing from the article, I can’t found the references 20-38, but the reference section of this article lists a total of 38 documents.
l Please confirm and explain further.
7. On page 2, line 68, “Peters [9] defined carbon footprint as the sum of greenhouse gas emissions caused by production and consumption processes and land use in a specific time and space, taking land use and surface reflectivity into account. ”
I suggest that this sentence can be expressed as “Peters[9] expands the definition to encompass emissions from production, consumption, and land use within a specific time frame and region, considering factors such as land use and surface reflectivity.”
8. On page 2, line 81, “......but it presents certain limitations for carbon accounting of campuses [11][12]”.
Please explain and justify why the input-output method has certain limitations for campus carbon accounting.
9. On page 3, line 94, the article lacks a clearly defined research framework, as well as a comprehensive overview and analysis of the research content.
Please provide an overview and analysis of the research framework and content of the article, including how the research results will provide reference for low-carbon campus construction and student participation in sustainable development.
10. On page 3, line 108, “Climatic conditions determine that the energy consumption from heating Zhejiang Ocean University in the winter is small compared to that in the northern region of Zhejiang Province.”
Please explain and illustrate the impact of local climate on energy consumption, especially heating, to highlight the relevance of studying carbon emissions.
11. On page 3, line 116, “Zhejiang Ocean University covers a total area of 1.47×106 square meters (including 4.8×105 square meters of sea area);...... ”
I suggest using consistent units and formatting for numerical data ,for example, use "1.47 million square meters" instead of "1.47×106 square meters" .
12. On page 3, line 121, “......covering undergraduate, postgraduate, and international students, and the number of teaching staff is 1,563.”
“undergraduate, postgraduate” are are countable nouns, I suggest that this sentence can be expressed as “ ......including undergraduates, postgraduates, and international students, and 1,563 teaching staff.”
13. On page 3, line 128, “......commercial streets, and other buildings, and the year of calculation is 2021.”
Please clarify the year of data being analyzed. I suggest that this sentence can be expressed as “ .......commercial streets, and other structures, with the data referring to the year 2021.”
14. On page 3, line 130, “......and since carbon dioxide plays a dominant role in them, carbon dioxide emissions from universities are mainly accounted for when analyzing their carbon emission data.”
I suggest emphasizing that CO2 is the primary focus due to its dominance in emissions data. I suggest that this sentence can be expressed as “ ......but carbon dioxide (CO2) is the most significant contributor to campus carbon emissions. Therefore, the analysis focuses primarily on CO2 emissions.”
15. On page 4, line 157, “Table 2 shows the types of GHG emissions.......”
It should be “Table 1” instead of “Table 2”. Please clarify what "GHG" refers to.
I suggest that this sentence can be expressed as“Table 1 shows the types of greenhouse gas (GHG) emissions......”
16. On page 4, line 168, “(1)Scope 1: Fossil energy usage from cafeterias and other places was obtained by visiting the logistics department.”
The source here refers to the data, and I suggest using “were” instead of “was”. So this sentence can be expressed as“Data on fossil energy usage from cafeterias and other sources were obtained by visiting to the logistics department.”
17. On page 4, line 170, “(3)Scope 3:Campus water consumption, paper consumption, and laboratory chemical consumption were obtained through visits to the logistics department.”
The source here refers to the data. I suggest that this sentence can be expressed as“Data on campus water consumption, paper usage, and laboratory chemical consumption were obtained from the logistics department.”
18. On page 4, line 177, “......which uses the formula CO2 emissions= things consumed * unit emission factor ( ).”
I suggest that this sentence can be expressed as:
“......The formula used is:
CO2 emissions =consumption×unit emission factor”
19. On page 4, line 187, “Table 1. Common types and sources of university carbon emissions.”
l The fourth column in Table 1 has the heading "Emission source", which does not match the content. The content in the table is the unit of the emission source.
l In the third row, "Scope 2：Indirect Emissions", the emission source include the renewable energy generation, what is the renewable energy generation? Please explain and clarify.
l In the third row, "Scope 2：Indirect Emissions", I think the emission source should be added as "dormitory electricity, public facilities, experimental facilities and cafeteria appliances".
l In the third row, "Scope 3：Other Indirect Emissions", I think the emission source should be added as "Transportation", Transportation includes Personal Vehicles(Emissions from vehicles owned by students and staff commuting to and from the campus) and Public Transportation (Emissions from public transportation used by campus community members.).
20. On page 5, line 189-194, the text size of this paragraph is inconsistent with that of other paragraphs in the full text. Please check and modify it.
21. On page 5, line 189, “In this study, the data on fossil energy use and water and electricity consumption of the university were obtained from the logistics service center of Zhejiang Ocean University.”
There are two “and”. I suggest that this sentence can be expressed as“In this study, data on fossil energy use, water consumption, and electricity consumption at Zhejiang Ocean University were obtained from the university's Logistics Service Center.”
22. On page 5, line 195, “Table 1. Visiting and researching carbon emission data inventories.”
l This Table should be “Table 2”, not “Table 1”.
l In the third row, "Scope 3：Other Indirect Emissions", I think the emission source should be added as “paper consumption, chemical consumption, personal energy use”.
23. On page 5, line 203, “In this study, a total of 231 students and 15 faculty members participated in the research, resulting in a total of 246 questionnaires.”
I suggest that this sentence can be expressed as“A total of 246 questionnaires were distributed, with responses from 231 students and 15 faculty members.”
24. On page 6, line 221, regarding to the formula:CF=Q×EF, Please briefly analyze the meaning of each term in the formula. And please provide example calculations to illustrate how the emission coefficient method is applied.
For example, where:
l CF is the carbon emissions,
l Q is the quantity of the consumed item or activity level,
l EF is the emission factor corresponding to each unit of activity.
l Provide example calculations. This calculation is performed for each source of emissions. Apply the emission factors to calculate carbon emissions using the formula mentioned above.
25. On page 6, line 224, “......emission factors are the carbon emissions corresponding to each unit of activity level and are usually determined and used according to national and international standards.”
Please provide sources and references of the data on carbon emission factors. Include detailed references for each emission factor to enhance credibility and allow for verification. For example, the sources and references of Gas is the National Standards / EPA.
26. On page 6, line 240, “Table 3. Data on carbon emission factors for common colleges and universities.”
l Please add another column to provide sources and references of the data on carbon emission factors. Include detailed references for each emission factor to enhance credibility and allow for verification. For example, the sources and references of Gas is the National Standards / EPA.
l I suggesting including more categories, for example, the Categorization should be added “Paper Consumption, Chemical Use in Laboratories,Personal Transportation (Car), Public Transportation.”
27. On page 7, line 248, “The data obtained from the visit to the logistics service center of Zhejiang Ocean University can be collated to list some of the kinds of energy consumption on the campus of Zhejiang Ocean University in 2021.”
If possible, could we compare the data from 2021 with that from 2022 or 2023? Since China has implemented its "dual carbon" goals, there has been significant growth in both the installed capacity of renewable energy and electricity generation. Additionally, Zhejiang has rapidly developed distributed photovoltaic and offshore wind power. Consequently, the proportion of renewable energy in the total electricity is increasing year by year, which could impact the analysis of the electricity carbon footprint.
28. On page 7, line 251, “Table 4. Energy consumption of part of the campus of Zhejiang Ocean University in 2021.”
l Please add other energy types, such as paper, laboratory chemicals, personal transportation,and disposable items.
l Please add some columns to clarify emission factors, the total emission and the source of each energy type. For example, for the personal transportation data, please provide specific data on personal transportation usage and associated emissions.
l I suggest using graphs or charts to illustrate the distribution of emissions across different categories for better visual comprehension.
29. On page 7, line 252-255, the text size of this paragraph is inconsistent with that of other paragraphs in the full text. Please check and modify it.
30. On page 7, line 256 and line 257, “Table 5. Per capita consumption of carbon emissions from students' daily lives.” and “Table 6. Per capita consumption of carbon emissions from the daily life of faculty and staff.”
l Please add some columns to clarify emission factors, the source of each category in the two Tables. Please provide details on how emission factors were determined for each category, citing sources or standards.
l Please add data on other activities, such as transportation, recreational activities or academic-related travel.
l I suggest using graphs or charts to illustrate the distribution of emissions across different categories for better visual comprehension.
l Please add other categories, such as “transportation”.
31. On page 7, line 261, “Table 7.Accounting for carbon emissions from natural gas flaring at Zhejiang Ocean University in 2021.”
l Please add some columns to clarify emission factors, the total emission and the source of each option.
l How were the carbon emissions in Table 7 calculated? According to Table 3, the emission factor for gas is 2.2. Given a gas volume of 1.54 × 10^5, the total emission should be 2.2 × 1.54 × 10^5 = 3.388 × 10^5. However, the data shows 3.34 × 10^5. It is crucial to clarify the emission factors used and the source of each data point to understand the discrepancy.
32. On page 8, line 274, “Based on the emission coefficient method, the direct carbon emissions was calculated as 3.34×10^5kg.”
How were the carbon emissions in Table 7 calculated? According to Table 3, the emission factor for gas is 2.2. Given a gas volume of 1.54 × 10^5, the total emission should be 2.2 × 1.54 × 10^5 = 3.388 × 10^5. However, the data shows 3.34 × 10^5. It is crucial to clarify the emission factors used and the source of each data point to understand the discrepancy.
33. On page 8, line 278, “Table 8. Accounting for carbon emissions from electricity consumption at Zhejiang Ocean University in 2021.”
Please add some columns to clarify emission factors, the total emission and the source of each option.
34. On page 8, line 290, “In Zhejiang Ocean University, building energy consumption mainly involves dormitories, cafeterias, teaching buildings, experimental buildings, etc. Electricity consumption has become the main part of building energy consumption, and saving electricity has become an urgent issue.”
Please provide a more detailed breakdown of electricity consumption across different facilities on campus. I would like to see relevant data and percentages for each facility to help identify specific areas where improvements can be made. This information will be crucial for pinpointing which areas have the highest energy use and targeting strategies for reducing overall consumption.
35. On page 8, line 300, “Table 9. Accounting for carbon emissions from water consumption at Zhejiang Ocean University in 2021.”
l Please add some columns to clarify emission factors, the total emission and the source of each option.
l I suggest collecting more detailed data on water usage by different campus facilities to better understand and target high-emission areas.
36. On page 8, line 302 and 303, “Table 10. Per capita carbon emissions generated by students per year,” and “Table 11. Per capita carbon emissions generated by faculty and staff per year.”
l Please clarify that the two tables refer to the average annual carbon emissions per student and faculty member respectively.
l I suggest that you add carbon emissions from transportation in these two tables.
l I suggest adding a row in each table to indicate the total annual carbon emissions.
37. On page 8, line 309, “it can be found that regarding clothing, food, and use, carbon emissions due to daily diet account for a larger proportion, and diet dominates in carbon emissions due to personal behavior.”
I suggest replacing words like "a greater proportion" with specific numbers or percentages, and analyzing the relevant reasons through specific data and proportions.
38. On page 12, line 404, “of which the direct carbon emissions were 3.34×105 kg.”, the line 406, “the indirect carbon emissions were 1.50×107 kg”, and the line 407, “and the other indirect carbon emissions were 1.85×107 kg”.
Please add “Scope 1”, “Scope 2” and “Scope 3” to indicate Scope 1, Scope2 and Scope 3 accounts for 0.99%, 44.33% and 54.68% respectively.
39.On page 12, the third paragraph of the section titled “4.1 Conclusions of This Study” discusses the implications and recommendations. Could you clarify the purpose of the section “4.2 Suggestions for Improvement”? Is there any overlap between these two sections?
40.On page 12, the section titled“4.2 Suggestions for improvement”.
First, it seems that this section overlaps with the previous in “4.1 Conclusions of This Study”. Second, the overall logical structure is not entirely clear. I recommend simplifying the content and presenting it with a more coherent structure to improve clarity.Finally, if possible, consider integrating this section with the previous in “4.1 Conclusions of This Study” to improve cohesion.
Comments for author File: 
Comments.pdf
The language quality of the article is generally average.
- Some sections lack clarity and precision, making the text difficult to follow.
- There are occasional grammatical errors throughout the article.
- The grammar and expression in several sentences need further improvement.
- There are significant errors in the citation of the reference article. Please verify and correct these issues.
Author Response
Comments 1: On page 1, line 30, “......soaring carbon dioxide emissions have turbocharged global warming.......”
I suggest replacing "turbocharged" with "accelerated" for a more formal tone.
Response 1: Agree. We have, accordingly, replaced it.[page 1, line 30]
Comments 2: On page 1, line 32, “This threatens human survival and ecosystem sustainability.......”
I suggest that this sentence can be expressed as “These changes pose significant threats to both human survival and ecosystem sustainability......”
Response 2: Agree. We have, accordingly, replaced it.[page 1, line 32]
Comments 3: On page 1, line 34, “curbing carbon emissions is.......”
I suggest replacing "curbing" with "reducing" for a more formal tone, it can be expressed as “reducing carbon emissions.......”
Response 3: Agree. We have, accordingly, replaced it.[page 1, line 34]
Comments 4: On page 1, line 35, “......China aims to decrease carbon emissions per unit of GDP by over 65% by 2030.”
According to Chinese policy, by 2030, China aims to reduce carbon dioxide emissions per unit of GDP by more than 65% compared to 2005. The 65% refers to the reduction relative to 2005. Please confirm and explain further.
Response 4: Thank you for pointing this out. We have, accordingly, replaced it.[page 1, line 35]
Comments 5: On page 1, line 36, “This aligns with the “dual-carbon” goal, crucial for China’s socialist modernization and for fostering green industrialization and urbanization.”
“This” means “This target”, I suggest that this sentence can be expressed as “This target supports the "dual-carbon" goal, which is essential for China's socialist modernization and for advancing green industrialization and urbanization. ”
Response 5: Agree. We have, accordingly, replaced it.[page 1, line 36]
Comments 6:
On page 2, line 50, “......calculation model 2 .”
On page 2, line 60, “......ecosystem 34 .”
On page 2, line 61, “......person or a group [5]”
On page 2, line 80, “......accounting boundaries [117]”
Please clarify and address the following issues:
l The reference format in the article is inconsistent. Specifically, the format used for reference 2 and 117 differs from that used for references 5, 6, 7, and others.
l There is ambiguity in the reference formatting for references 3 , 4 and 117, which may lead to potential misunderstandings.
l Reference 20 to 38 are missing from the article, I can’t found the references 20-38, but the reference section of this article lists a total of 38 documents.
l Please confirm and explain further.
Response 6:The citation format has been preliminarily modified, and the article cites some literature in terms of idea writing, which is not specifically reflected in the content of the text, so it is marked in the second half of the reference.
Comments 7: On page 2, line 68, “Peters [9] defined carbon footprint as the sum of greenhouse gas emissions caused by production and consumption processes and land use in a specific time and space, taking land use and surface reflectivity into account. ”
I suggest that this sentence can be expressed as “Peters[9] expands the definition to encompass emissions from production, consumption, and land use within a specific time frame and region, considering factors such as land use and surface reflectivity.”
Response 7: Agree. We have, accordingly, replaced it.[page 2, line 70]
Comments 8: On page 2, line 81, “......but it presents certain limitations for carbon accounting of campuses [11][12]”.
Please explain and justify why the input-output method has certain limitations for campus carbon accounting.
Response 8: Thank you for pointing this out. We detail the limitations of data collection and processing methods and identify key gaps in existing research. [Page: 2, paragraph: 3, line number: 82-88]
Comments 9: On page 3, line 94, the article lacks a clearly defined research framework, as well as a comprehensive overview and analysis of the research content.
Please provide an overview and analysis of the research framework and content of the article, including how the research results will provide reference for low-carbon campus construction and student participation in sustainable development.[page 3, line 98]
Response 9: Thank you for pointing this out.We have made changes to this section to refine the research framework.
Comments 10: On page 3, line 108, “Climatic conditions determine that the energy consumption from heating Zhejiang Ocean University in the winter is small compared to that in the northern region of Zhejiang Province.”
Please explain and illustrate the impact of local climate on energy consumption, especially heating, to highlight the relevance of studying carbon emissions.
Response 10: Due to its location in the south, Winter temperatures are relatively high .Climatic conditions determine that the energy consumption from heating Zhejiang Ocean University in the winter is small compared to that in the northern region of China. Due to its location in the south, Winter temperatures are relatively high .Climatic conditions determine that the energy consumption from heating Zhejiang Ocean University in the winter is small compared to that in the northern region of China.[page 3, line 126]
Comments 11: On page 3, line 116, “Zhejiang Ocean University covers a total area of 1.47×106 square meters (including 4.8×105 square meters of sea area);...... ”
I suggest using consistent units and formatting for numerical data ,for example, use "1.47 million square meters" instead of "1.47×106 square meters" .
Response 11: Thank you for pointing this out.We've made corrections to the text,The correct data should be 1.47×106 square meters.[page 3, line 135]
Comments 12: On page 3, line 121, “......covering undergraduate, postgraduate, and international students, and the number of teaching staff is 1,563.”
“undergraduate, postgraduate” are are countable nouns, I suggest that this sentence can be expressed as “ ......including undergraduates, postgraduates, and international students, and 1,563 teaching staff.”
Response 12: Agree. We have, accordingly, replaced it.[page 3, line 140]
Comments 13:On page 3, line 128, “......commercial streets, and other buildings, and the year of calculation is 2021.”
Please clarify the year of data being analyzed. I suggest that this sentence can be expressed as “ .......commercial streets, and other structures, with the data referring to the year 2021.”
Response 13: Agree. We have, accordingly, replaced it.[page 4, line 147]
Comments 14:On page 3, line 130, “......and since carbon dioxide plays a dominant role in them, carbon dioxide emissions from universities are mainly accounted for when analyzing their carbon emission data.”
I suggest emphasizing that CO2 is the primary focus due to its dominance in emissions data. I suggest that this sentence can be expressed as “ ......but carbon dioxide (CO2) is the most significant contributor to campus carbon emissions. Therefore, the analysis focuses primarily on CO2 emissions.”
Response 14: Agree. We have, accordingly, replaced it.[page 4, line 149]
Comments 15:On page 4, line 157, “Table 2 shows the types of GHG emissions.......”
It should be “Table 1” instead of “Table 2”. Please clarify what "GHG" refers to.
I suggest that this sentence can be expressed as“Table 1 shows the types of greenhouse gas (GHG) emissions......”
Response 15: Agree. We have, accordingly, replaced it.[page 4, line 173]
Comments 16:On page 4, line 168, “(1)Scope 1: Fossil energy usage from cafeterias and other places was obtained by visiting the logistics department.”
The source here refers to the data, and I suggest using “were” instead of “was”. So this sentence can be expressed as“Data on fossil energy usage from cafeterias and other sources were obtained by visiting to the logistics department.”
Response 16: Agree. We have, accordingly, replaced it.[page 4, line 188]
Comments 17:On page 4, line 170, “(3)Scope 3:Campus water consumption, paper consumption, and laboratory chemical consumption were obtained through visits to the logistics department.”
The source here refers to the data. I suggest that this sentence can be expressed as“Data on campus water consumption, paper usage, and laboratory chemical consumption were obtained from the logistics department.”
Response 17: Agree. We have, accordingly, replaced it.[page 4, line 191]
Comments 18:On page 4, line 177, “......which uses the formula CO2 emissions= things consumed * unit emission factor ( ).”
I suggest that this sentence can be expressed as:
“......The formula used is:
CO2 emissions =consumption×unit emission factor”
Response 18: Agree. We have, accordingly, replaced it.[page 5, line 198]
Comments 19:On page4, line 187, “Table 1. Common types and sources of university carbon emissions.”
l The fourth column in Table 1 has the heading "Emission source", which does not match the content. The content in the table is the unit of the emission source.
l In the third row, "Scope 2：Indirect Emissions", the emission source include the renewable energy generation, what is the renewable energy generation? Please explain and clarify.
l In the third row, "Scope 2：Indirect Emissions", I think the emission source should be added as "dormitory electricity, public facilities, experimental facilities and cafeteria appliances".
l In the third row, "Scope 3：Other Indirect Emissions", I think the emission source should be added as "Transportation", Transportation includes Personal Vehicles(Emissions from vehicles owned by students and staff commuting to and from the campus) and Public Transportation (Emissions from public transportation used by campus community members.).
Response 19: First, we've changed the header of column 4. Second, we do not believe that there is a need for a detailed explanation of renewable energy generation here, as this is not the main content of this study. Third, because the carbon emission data generated by different modes of transportation varies greatly, it is considered that the data is not suitable for statistical calculation when conducting the survey, so the questionnaire does not include this content, and it is now impossible to make statistics on the current year's data.[page5, line 208]
Comments 20:On page 5, line 189-194, the text size of this paragraph is inconsistent with that of other paragraphs in the full text. Please check and modify it.
Response 20: Thank you for pointing this out. We've made changes to the font size for this paragraph.[page 5, line 210]
Comments 21:On page 5, line 189, “In this study, the data on fossil energy use and water and electricity consumption of the university were obtained from the logistics service center of Zhejiang Ocean University.”
There are two “and”. I suggest that this sentence can be expressed as“In this study, data on fossil energy use, water consumption, and electricity consumption at Zhejiang Ocean University were obtained from the university's Logistics Service Center.”
Response 21: Agree. We have, accordingly, replaced it.[page 5, line 210]
Comments 22:On page 5, line 195, “Table 1. Visiting and researching carbon emission data inventories.”
l This Table should be “Table 2”, not “Table 1”.
l In the third row, "Scope 3：Other Indirect Emissions", I think the emission source should be added as “paper consumption, chemical consumption, personal energy use”.
Response 22:Thank you for pointing this out. We have corrected the table numbering. Since this part is a list of survey data, some data such as personal energy use cannot be obtained through this visit, so it is no longer presented in this table.[page 5, line 217]
Comments 23:On page 5, line 203, “In this study, a total of 231 students and 15 faculty members participated in the research, resulting in a total of 246 questionnaires.”
I suggest that this sentence can be expressed as“A total of 246 questionnaires were distributed, with responses from 231 students and 15 faculty members.”
Response 23: Agree. We have, accordingly, replaced it.[page 6, line 235]
Comments 24:On page 6, line 221, regarding to the formula:CF=Q×EF, Please briefly analyze the meaning of each term in the formula. And please provide example calculations to illustrate how the emission coefficient method is applied.
For example, where:
l CF is the carbon emissions,
l Q is the quantity of the consumed item or activity level,
l EF is the emission factor corresponding to each unit of activity.
l Provide example calculations. This calculation is performed for each source of emissions. Apply the emission factors to calculate carbon emissions using the formula mentioned above.
Response 24:Thank you for pointing this out. We have added to the main text.[ page 6, line 253]
Comments 25:On page 6, line 224, “......emission factors are the carbon emissions corresponding to each unit of activity level and are usually determined and used according to national and international standards.”
Please provide sources and references of the data on carbon emission factors. Include detailed references for each emission factor to enhance credibility and allow for verification. For example, the sources and references of Gas is the National Standards / EPA.
Response 25: Agree. We have, accordingly, replaced it.[page 6, line 269]
Comments 26:On page 6, line 240, “Table 3. Data on carbon emission factors for common colleges and universities.”
l Please add another column to provide sources and references of the data on carbon emission factors. Include detailed references for each emission factor to enhance credibility and allow for verification. For example, the sources and references of Gas is the National Standards / EPA.
l I suggesting including more categories, for example, the Categorization should be added “Paper Consumption, Chemical Use in Laboratories,Personal Transportation (Car), Public Transportation.”
Response 26:because the carbon emission data generated by different modes of transportation varies and chemical use in laboratoriesgreatly, it is considered that the data is not suitable for statistical calculation when conducting the survey, so the questionnaire does not include this content, and it is now impossible to make statistics on the current year's data.
Comments 27:On page 7, line 248, “The data obtained from the visit to the logistics service center of Zhejiang Ocean University can be collated to list some of the kinds of energy consumption on the campus of Zhejiang Ocean University in 2021.”
If possible, could we compare the data from 2021 with that from 2022 or 2023? Since China has implemented its "dual carbon" goals, there has been significant growth in both the installed capacity of renewable energy and electricity generation. Additionally, Zhejiang has rapidly developed distributed photovoltaic and offshore wind power. Consequently, the proportion of renewable energy in the total electricity is increasing year by year, which could impact the analysis of the electricity carbon footprint.
Response 27:Thank you for your suggestion, which we think is a very good suggestion, but since this study is based on carbon emissions in 2021, we do not focus on other years, and we do not have data for other years, so we will definitely listen to your suggestions if we have the opportunity to study further.
Comments 29:On page 7, line 252-255, the text size of this paragraph is inconsistent with that of other paragraphs in the full text. Please check and modify it.
Response 29: Thank you for pointing this out. We've made changes to the font size for this paragraph.[page 7, line 277]
Comments 31:On page 7, line 261, “Table 7.Accounting for carbon emissions from natural gas flaring at Zhejiang Ocean University in 2021.”
l Please add some columns to clarify emission factors, the total emission and the source of each option.
l How were the carbon emissions in Table 7 calculated? According to Table 3, the emission factor for gas is 2.2. Given a gas volume of 1.54 × 10^5, the total emission should be 2.2 × 1.54 × 10^5 = 3.388 × 10^5. However, the data shows 3.34 × 10^5. It is crucial to clarify the emission factors used and the source of each data point to understand the discrepancy.
Response 31:Thanks for pointing out the bug. We found that there was a mistake in the data filling process, and the amount of natural gas used should be 1, and we have made changes in the text.[page 8, line 296]
Comments 32:On page 8, line 274, “Based on the emission coefficient method, the direct carbon emissions was calculated as 3.34×10^5kg.”
How were the carbon emissions in Table 7 calculated? According to Table 3, the emission factor for gas is 2.2. Given a gas volume of 1.54 × 10^5, the total emission should be 2.2 × 1.54 × 10^5 = 3.388 × 10^5. However, the data shows 3.34 × 10^5. It is crucial to clarify the emission factors used and the source of each data point to understand the discrepancy.
Response 32:Thanks for pointing out the bug. We found that there was a mistake in the data filling process, and the amount of natural gas used should be 1, and we have made changes in the text.[page 8, line 309]
Comments 33:On page 8, line 278, “Table 8. Accounting for carbon emissions from electricity consumption at Zhejiang Ocean University in 2021.”
Please add some columns to clarify emission factors, the total emission and the source of each option.
Response 33:Since the unit emission factors used in the study have been fully listed above, they are not separately listed in this table.[page 8, line 312]
Comments 34:On page 8, line 290, “In Zhejiang Ocean University, building energy consumption mainly involves dormitories, cafeterias, teaching buildings, experimental buildings, etc. Electricity consumption has become the main part of building energy consumption, and saving electricity has become an urgent issue.”
Please provide a more detailed breakdown of electricity consumption across different facilities on campus. I would like to see relevant data and percentages for each facility to help identify specific areas where improvements can be made. This information will be crucial for pinpointing which areas have the highest energy use and targeting strategies for reducing overall consumption.
Response 34:Due to the management of the data by the relevant departments, the usage of different regions is not recorded, and we are unable to obtain more detailed data.
Comments 35:On page 8, line 300, “Table 9. Accounting for carbon emissions from water consumption at Zhejiang Ocean University in 2021.”
l Please add some columns to clarify emission factors, the total emission and the source of each option.
l I suggest collecting more detailed data on water usage by different campus facilities to better understand and target high-emission areas.
Response 35:Since the unit emission factors used in the study have been fully listed above, they are not separately listed in this table.Due to the management of the data by the relevant departments, the usage of different regions is not recorded, and we are unable to obtain more detailed data.
Comments 36:On page 8, line 302 and 303, “Table 10. Per capita carbon emissions generated by students per year,” and “Table 11. Per capita carbon emissions generated by faculty and staff per year.”
l Please clarify that the two tables refer to the average annual carbon emissions per student and faculty member respectively.
l I suggest that you add carbon emissions from transportation in these two tables.
l I suggest adding a row in each table to indicate the total annual carbon emissions.
Response 36:We think the titles of these two tables can be explained "the two tables refer to the average annual carbon emissions per student and faculty member respectively".Because the carbon emission data generated by different modes of transportation varies greatly, it is considered that the data is not suitable for statistical calculation when conducting the survey, so the questionnaire does not include this content, and it is now impossible to make statistics on the current year's data.
Comments 37: On page 8, line 309, “it can be found that regarding clothing, food, and use, carbon emissions due to daily diet account for a larger proportion, and diet dominates in carbon emissions due to personal behavior.”
I suggest replacing words like "a greater proportion" with specific numbers or percentages, and analyzing the relevant reasons through specific data and proportions.
Response 37:Thank you for pointing this out. We agree with this comment.Therefore,We analyze the reasons for this in the text.
Comments 38:On page 12, line 404, “of which the direct carbon emissions were 3.34×105 kg.”, the line 406, “the indirect carbon emissions were 1.50×107 kg”, and the line 407, “and the other indirect carbon emissions were 1.85×107 kg”.
Please add “Scope 1”, “Scope 2” and “Scope 3” to indicate Scope 1, Scope2 and Scope 3 accounts for 0.99%, 44.33% and 54.68% respectively.
Response 38:We've made changes to the wording in the text.
Comments 39:On page 12, the third paragraph of the section titled “4.1 Conclusions of This Study” discusses the implications and recommendations. Could you clarify the purpose of the section “4.2 Suggestions for Improvement”? Is there any overlap between these two sections?
Response 39:On page 12, the third paragraph of the section titled “4.1 Conclusions of This Study” discusses the implications and recommendations. Could you clarify the purpose of the section “4.2 Suggestions for Improvement”? Is there any overlap between these two sections?
Comments 40:On page 12, the section titled“4.2 Suggestions for improvement”.
First, it seems that this section overlaps with the previous in “4.1 Conclusions of This Study”. Second, the overall logical structure is not entirely clear. I recommend simplifying the content and presenting it with a more coherent structure to improve clarity.Finally, if possible, consider integrating this section with the previous in “4.1 Conclusions of This Study” to improve cohesion.
Response 40:Thank you for your suggestion. We agree with that. Therefore, we have adjusted the content of this section to make the logical structure clearer.
Reviewer 3 Report
Comments and Suggestions for AuthorsGeneral Comments:
This study employs the emission factor method to conduct a quantitative analysis of carbon emissions at Zhejiang Ocean University, focusing on the contribution ratio of different emission sources within the campus, and proposes corresponding energy-saving and emission-reduction measures. The research demonstrates innovation in data collection and emission structure analysis, and by conducting a comprehensive analysis of multiple emission scopes, the results provide valuable references for low-carbon management in universities. The overall structure of the article is clear, but improvements are needed in terms of chart formatting, language fluency, and detail accuracy. Some expressions are not concise and smooth enough, and the chart descriptions could be more intuitive to enhance readability.
Specific suggestions for revision:
1.Introduction
Page: 2, Paragraph: 2, Line Numbers: 54-74
This section introduces the definitions of carbon emissions and carbon footprints, as well as different calculation methods. Lines 55-56 mention that "many universities have begun to assess their campus emissions" but do not discuss existing research on university carbon emissions in detail, resulting in a lack of clarity regarding the relationship between existing research and this study. It is suggested to include a summary and comparison of existing university carbon emission studies, and to clarify the innovative points.
Page: 2, Paragraph: 3, Line Numbers: 75-89
Lines 80-82 mention that the input-output method has certain limitations in campus carbon accounting. This could be made more specific, such as detailing the limitations of data collection and processing methods, and identifying key gaps in existing research.
2.Materials and Methods
Page: 7, Paragraph: 1, Line Numbers: 143-165
The research methodology section clearly introduces the use of the emission factor method and the data collection process, with a strong logical approach. However, further clarification is needed for some details. For instance, the design of the questionnaire survey should further explain how representativeness is ensured, and how the ratio of faculty to student samples affects the results. Additionally, it is recommended to clarify the data cleaning and screening process, especially the explanation of outlier treatment, to enhance the transparency of data handling.
Page: 7, Table 1
Table 1 displays the main sources of carbon emissions at Zhejiang Ocean University, but the table title is not detailed enough. It is suggested to revise it to "Classification Table of Carbon Emission Sources at Zhejiang Ocean University Campus." Also, it is recommended to increase the font size of the category items to improve readability.
3.Results
Page: 9, Paragraph: 2, Line Numbers: 299-350
The results section presents a detailed calculation of carbon emissions for different scopes (Scope 1, 2, 3), but the discussion of the results for each scope is rather superficial. For instance, Scope 3 has the highest proportion of carbon emissions, and the paper only mentions its importance. It is suggested to further explore the reasons behind this result, such as the impact of individual student behavior on carbon emissions, and how specific measures can reduce this part of the emissions.
4.Conclusions
Page: 12, Paragraph: 3, Line Numbers: 404-427
The discussion section lacks in-depth analysis of the results. Although the paper mentions the impact of individual behavior on carbon emissions, it does not deeply explore how policies or campus management strategies can effectively reduce these emissions. It is suggested to combine successful cases from universities at home and abroad to further discuss feasible emission reduction measures. Additionally, the discussion section could include predictions of long-term trends in carbon emission structure and potential policy impacts to enhance the forward-looking nature of the argument.
Page: 13, Paragraph: 3, Line Numbers: 468-470
The conclusion section briefly summarizes the main research findings but is too brief to fully demonstrate the importance and application prospects of the research. It is recommended to add a perspective on future research, especially suggestions on how to further improve carbon emission calculation methods or how to apply intelligent technology to enhance campus carbon emission monitoring.
5.References
Some references are outdated and lack the latest research findings from recent years. It is recommended to supplement with the latest literature on university carbon emission management and carbon footprint calculation from the past two years to enhance the timeliness and cutting-edge nature of the theoretical background.
Comments on the Quality of English LanguageThe entire manuscript needs to be polished to improve its readability.
Author Response
Comments1:This section introduces the definitions of carbon emissions and carbon footprints, as well as different calculation methods. Lines 55-56 mention that "many universities have begun to assess their campus emissions" but do not discuss existing research on university carbon emissions in detail, resulting in a lack of clarity regarding the relationship between existing research and this study. It is suggested to include a summary and comparison of existing university carbon emission studies, and to clarify the innovative points.
Response 1:Thank you for your suggestion, we have added to the main text.
Comments2: Lines 80-82 mention that the input-output method has certain limitations in campus carbon accounting. This can be done more specifically, such as detailing the limitations of data collection and processing methods and identifying key gaps in existing research.
Response 2: Thank you for pointing this out. We detail the limitations of data collection and processing methods and identify key gaps in existing research. [Page: 2, paragraph: 3, line number: 82-88]
Comment 3: The research methods section clearly describes the use of the emission factor method and the data collection process, with a strong logical approach. However, some details require further clarification. For example, the design of the questionnaire should further explain how representation is ensured and how the ratio of the teacher to student sample affects the results. In addition, it is recommended to clarify the data cleaning and screening process, especially the interpretation of outlier processing, in order to improve the transparency of data processing.
Response 3: Agreed. Therefore, we have increased the sample selection ideas and added data screening methods to improve the transparency of data processing.
Comments 4: Table 1 shows the major sources of carbon emissions from Zhejiang Ocean University, but the table title is not detailed enough. It is suggested to change it into "Classification Table of Carbon Emission Sources on Campus of Zhejiang Ocean University". In addition, it is recommended to increase the font size of category items to improve readability. [Page 5, paragraph: 2, line number: 210-220]
Response 4: Agree. Therefore, we modify the title of Table 1 to "Classification Table of Carbon Emission Sources on Campus of Zhejiang Ocean University". [Page 4, Table 1]
Comment 5: The results section presents detailed calculations of carbon emissions for different ranges (ranges 1, 2, 3), but the discussion of the results for each range is rather superficial. For example, range 3 has the highest percentage of carbon emissions, and the paper only mentions its importance. It is recommended to further explore the reasons behind this result, such as the impact of individual student behavior on carbon emissions, and specific measures to reduce this part of the emissions. Response 5: The impact of students' individual behaviors on carbon emissions, and specific measures to reduce this part of emissions. A detailed analysis is given in the conclusion section below.
Comment 6: The discussion section lacks in-depth analysis of the results. Although the paper mentions the impact of individual behavior on carbon emissions, it does not delve into how effective policies or campus management strategies can be in reducing these emissions. It is suggested that combining the successful cases of universities at home and abroad, the feasible emission reduction measures are further discussed. In addition, the discussion section could include projections of long-term trends in the carbon emission structure and potential policy impacts to enhance the forward-looking nature of the argument.
Response 6: An in-depth look at how policies or campus management strategies can effectively reduce these emissions is covered in the next section. This section includes projections of long-term trends in the carbon emissions structure and potential policy implications.[Page: 13, paragraph: 5, line: 472]
Comment 7: The conclusion briefly summarizes the main research results, but it is too brief to fully illustrate the importance and application prospects of the research. It is recommended to add a perspective to future research, especially suggestions on how to further improve carbon emission calculation methods or how to apply smart technologies to enhance carbon emission monitoring on campus.
Response 7: Thank you for pointing this out. We have added some perspectives for future research, particularly on how to further improve carbon emissions calculations or how smart technologies can be applied to improve campus carbon emissions. Page: 15, paragraph: 2, line: 541]
The relevant literature has been appropriately supplemented.
Reviewer 4 Report
Comments and Suggestions for AuthorsThe study focuses on Zhejiang Ocean University, as representative case study, investigating its carbon emissions, identifying main sources, and providing data for goal setting and action plans.
The authors obtained very interesting results for Scope 3 (indirect emissions resulting from activities within the school but occurring outside the school). However, I suggest to clearly specify within the paper that the Scope 3 emissions are not reported in other economy’s sections (food processing, chemical industry - e.g. plastic production, clothes manufacturing etc.). For the latter scenario, would mean a double regional reporting for these types of equivalent CO2 emissions.
In any case, the study opens interesting perspectives for the individuals’ behaviors in relation to CO2 emissions, for the university campus building type.
Several observations:
- The state of the art has a very shallow approach in the Introduction section. What other research was undertaken related with the topic? What methods were used? What results were obtained?
- Line. 116. The surface of the University it is not clear. The University’s facilities cover an area of 1.47 m x 106 m (a line of 106 m length with a 1.47 m width)? From the civil engineering perspective, technically is not feasible.
Author Response
Comments 1: The state of the art has a very shallow approach in the Introduction section. What other research was undertaken related with the topic? What methods were used? What results were obtained?
Response 1: Agree. We have, accordingly,modified it to emphasize this point.
Comments 2: Line. 116. The surface of the University it is not clear. The University’s facilities cover an area of 1.47 m x 106 m (a line of 106 m length with a 1.47 m width)? From the civil engineering perspective, technically is not feasible.
Response 2:Thank you for pointing this out.We've made corrections to the text,The correct data should be 1.47×106 square meters.[Line135]
We have made it clear in the paper that the Scope 3 emissions are not reported in other economy’s sections (food processing, chemical industry - e.g. plastic production, clothes manufacturing etc.).[Line142]
