Tool for Greener Tourism: Evaluating Environmental Impacts

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

1.      This study presents a tool to measure the environmental impact of tourism. While the tool appears interesting and well-structured and the infographic presented impressive, it is unclear whether a real footprint of tourism activity is estimated at any stage and whether the tourism value chain is considered at all in the estimate of the tourism footprint.   In any case, several improvements to the paper are needed to go beyond the mere description of convenient software.

2.       More specifically, before presenting the tool, the paper should address two key questions: (1) the theoretical basis of the methodologies to measure tourism environmental impact and (2) the studies available on this subject (for both, see, for example Miralles et al, 2023).

3.      While it may be true that no software tool may be available to measure the environmental effects of tourism, it is more important to clarify what and how this tool should approach both definitions and measurement problems. On one hand, tourism  as an economic activity presents several challenges both to identify its perimeter and its nature. Statistically, it is both an assemblage (with variable weights) of different industries (accommodation, food, transportation and leisure), and commodities. Its environmental footprint also appears potentially large and uneven. In the case of water, for example, it may be a major contributor to water stress because of its tendency to concentrate on visitors in lower income, water scarce countries during summer months.  The authors should try to account for these problems by reviewing the literature, and by clarifying their theoretical approach to defining and measuring tourism and tourism impact.

4.      At present, the paper lists a set of environmental effects of tourists travelling to a specific destination as if these were meaningful measurements of impacts in their own right. However, most of the numbers presented may be misleading, unless they are interpreted within an appropriate economic context, and some attempt is made to integrate them in some overall measurement of welfare effects and short- and long-term sustainability. Interaction with other activities and hidden costs of tourism through indirect pressure on natural resources may be also more important than the effects that may be the direct object of an inventory (Borucke et al., 2013).

5.      The tool does not appear to have an explicit economic basis, unless this can be traced to some of the many sources cited, but not discussed by the authors.  In particular, the authors should clarify (i) their definition of tourism and the corresponding statistical categories in terms of the international nomenclature, (ii) the economic and statistical basis for the choice of the data and the compilation of the inventory, (iii) the criterion for the selection of the indicators, (iv) the meaning and the measurement of the impact, (iv) the possible criteria for measuring the footprint, (v) the possible methodologies for aggregating the different impacts.

More specific questions

 

Section 2.1.1:

1.       “Primary data needed to compile the inventory is collected through a questionnaire that is accessed through a registration by the owner of the establishment on the Greentour tool website (Greentour, 2024) (Figure 3)”. Please explain briefly the characteristics of the questionnaire, the statistical basis of the data required, the consistency and reliability checks, if available.

2.      “Since inventory data collection is the most challenging stage of this tool's methodology—often due to the lack of available data faced by technicians responsible for calculating environ-mental impacts (Parvatker and Eckelman, 2019)—a series of assumptions have been made to develop the most detailed inventory possible. While these assumptions may increase the level of uncertainty in the LCA, they are necessary to fill the gaps in the data provided by the facilities.” The nature and the quality of these assumptions needs to be clarified since it is clearly relevant to judge the reliability of the impact estimates.

 

Section 2.1.2

 

1.      “The Environmental Footprint (EF) 3.0 method was used in order to quantify the environmental impacts of the goods and services included in the tool.” The method should be explained and its application clarified. It is noty only a matter of categorization but of specific applicability and sufficient information.

Section 2.1.3

 

1.      “In the tool, environmental results are generated directly from inventory data, which includes accommodation, restaurants, and tourist activities, along with the corresponding impact categories.” Please clarify how they are generated and on what basis. Are the same coefficients applied everywhere and for all tourists? Are value chain effects taken into account?

 

Section 3.1

1.      “In addition to the impacts of the different establishments, the tool provides the impacts at the destination level applying the extrapolation procedure detailed below. This extrapolation is not done directly in the tool, so it needs to be done manually by a technical partner. Therefore, the environmental impacts of accommodation, restaurants, and tour-ist activities are exported to an Excel file through the Greentour website.” It is not clear what the authors mean by “ extrapolation”. Whether  it is an estimation procedure, or the mere application of fixed coefficients, it should be explained in more detail, with its properties and limitations discussed also with reference to the literature.

 

 

 

References

 

 

 

M. Borucke, D. Moore, G. Cranston, K. Gracey, K. Iha, J. Larson, E. Lazarus, J.C. Morales, M. Wackernagel, A. Galli. (2013) Accounting for demand and supply of the biosphere's regenerative capacity: the National Footprint Accounts' underlying methodology and framework

Ecol. Indicat., 24 (2013), pp. 518-533, 10.1016/j.ecolind.2012.08.005

 

M.S. Mancini, M. Evans, K. Iha, C. Danelutti, A. Galli (2018). Assessing the ecological footprint of ecotourism packages: a methodological proposition. Resources, 7 (2) (2018).

 

Miralles, C.C., Barioni, D., Mancini, M.S., Jordà, J.C., Roura, M.B., Salas, S.P., Argelaguet, L.L. and Galli, A., 2023. The footprint of tourism: A review of water, carbon, and ecological footprint applications to the tourism sector. Journal of Cleaner Production, p.138568.

 

 

Author Response

Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding corrections highlighted in track changes in the re-submitted files.

Comment 1: This study presents a tool to measure the environmental impact of tourism. While the tool appears interesting and well-structured and the infographic presented impressive, it is unclear whether a real footprint of tourism activity is estimated at any stage and whether the tourism value chain is considered at all in the estimate of the tourism footprint.   In any case, several improvements to the paper are needed to go beyond the mere description of convenient software. More specifically, before presenting the tool, the paper should address two key questions: (1) the theoretical basis of the methodologies to measure tourism environmental impact and (2) the studies available on this subject (for both, see, for example Miralles et al, 2023).

Response 1: Thanks you for pointing this out. This paragraph was included from line 45-63: “Before evaluating specific tools, it is crucial to understand the theoretical foundations of tourism environmental impact measurement methodologies. Different approaches have been proposed, including the Life Cycle Assessment (LCA), which assesses the entire environmental impact of a product or service from raw material extraction to disposal, and footprint-based indicators such as Carbon Footprint (CF), Water Footprint (WF), and Ecological Footprint (EF). These methodologies differ in scope, data requirements, and applicability within the tourism sector (Miralles et al., 2023). Previous studies have applied these methods to assess tourism’s environmental performance at various levels. For example, Miralles et al. (2023) conducted a comprehensive review of footprint applications in tourism, highlighting the challenges of data availability, system boundary definitions, and methodological inconsistencies. Other studies have examined the carbon footprint of accommodations (Puig et al., 2017), the water footprint of tourist activities (Hof and Blázquez-Salom, 2015), and the ecological footprint of destinations (Hunter and Shaw, 2007). Despite these efforts, there is still no consensus on a standardized methodology for assessing tourism’s environmental impact at a broader scale”.

Comment 2:  While it may be true that no software tool may be available to measure the environmental effects of tourism, it is more important to clarify what and how this tool should approach both definitions and measurement problems. On one hand, tourism  as an economic activity presents several challenges both to identify its perimeter and its nature. Statistically, it is both an assemblage (with variable weights) of different industries (accommodation, food, transportation and leisure), and commodities. Its environmental footprint also appears potentially large and uneven. In the case of water, for example, it may be a major contributor to water stress because of its tendency to concentrate on visitors in lower income, water scarce countries during summer months.  The authors should try to account for these problems by reviewing the literature, and by clarifying their theoretical approach to defining and measuring tourism and tourism impact.

Response 2: Thank you for your insightful comment. We agree that tourism as an economic activity presents several challenges, particularly when it comes to defining its perimeter and measuring its impacts. As you mentioned, tourism comprises a range of industries, including accommodation, food, transportation, and leisure, each with different contributions to the overall environmental footprint. Moreover, certain aspects, such as water usage, can indeed present uneven and significant impacts, especially in water-scarce regions during peak seasons. However, we believe our tool represents a novel approach to addressing these challenges. Unlike other tools that primarily focus on climate change, our tool evaluates a broader set of environmental impacts across multiple categories, including water use, energy consumption, and waste generation. It is designed to be applicable to a wide range of establishments, from various types of accommodation to restaurants, pubs, and leisure activities. By providing both individual establishment-level and destination-level results, the tool enables a comprehensive understanding of the environmental impacts of tourism. This approach is essential for identifying areas for improvement and guiding decision-making processes for local governments, tourism authorities, and other stakeholders. In doing so, it helps address the environmental concerns specific to each destination and establish targeted measures to mitigate these impacts effectively.

We hope this explanation clarifies the scope and value of the tool. Please let us know if further elaboration is needed.

Comment 3: At present, the paper lists a set of environmental effects of tourists travelling to a specific destination as if these were meaningful measurements of impacts in their own right. However, most of the numbers presented may be misleading, unless they are interpreted within an appropriate economic context, and some attempt is made to integrate them in some overall measurement of welfare effects and short- and long-term sustainability. Interaction with other activities and hidden costs of tourism through indirect pressure on natural resources may be also more important than the effects that may be the direct object of an inventory (Borucke et al., 2013).

Response 3: Thank you for your valuable comment. We acknowledge that the environmental impacts of tourism should not be considered in isolation, but rather within a broader economic and social context. As you pointed out, integrating these effects into a comprehensive measurement of welfare and sustainability, taking into account indirect pressures on natural resources and the hidden costs of tourism, is crucial for a full understanding of the sustainability of the sector. However, the current version of our tool focuses primarily on the environmental pillar of sustainability, as this is where there is the greatest gap in tools available today. To our knowledge, no existing tool provides such a comprehensive environmental assessment that can be applied to any tourism destination or establishment globally. While we recognize the importance of considering the economic and social dimensions, this tool’s environmental perspective is already highly complete and provides valuable insights for addressing immediate sustainability challenges. That said, we agree with your point that integrating economic and social factors would offer a more holistic view of sustainable tourism. We believe that such an approach would be necessary to complement our tool, providing a fuller picture of sustainability in tourism.

We hope this explanation clarifies the scope of our tool and its current limitations. We are working towards enhancing its integration with other sustainability dimensions in the future.

Comment 4: The tool does not appear to have an explicit economic basis, unless this can be traced to some of the many sources cited, but not discussed by the authors.  In particular, the authors should clarify (i) their definition of tourism and the corresponding statistical categories in terms of the international nomenclature, (ii) the economic and statistical basis for the choice of the data and the compilation of the inventory, (iii) the criterion for the selection of the indicators, (iv) the meaning and the measurement of the impact, (iv) the possible criteria for measuring the footprint, (v) the possible methodologies for aggregating the different impacts.

Response 4: Dear reviewer, thank you for your comment. In the manuscript's introduction, tourism and its associated challenges in measuring environmental impacts are clearly defined. The tool is designed with an environmental focus, recognizing the challenges of assessing this sector’s impacts. While the economic and social dimensions are briefly mentioned, they are not the primary focus of the tool. Regarding the selection of data and indicators, the criteria used are based on the Sustainable Development Goals (SDGs) most relevant to tourism, which is explained in the manuscript. Furthermore, the process for measuring impacts, calculating the environmental footprint, and the criteria considered in the process are detailed. The methodology for aggregating the various impacts follows established practices, such as the Environmental Footprint (EF) method, ensuring the reliability and consistency of the results. Although the tool currently focuses on the environmental pillar, we acknowledge the importance of integrating economic and social aspects in the future to provide a more comprehensive view of sustainable tourism.

More specific questions

Section 2.1.1:

Comment 5: “Primary data needed to compile the inventory is collected through a questionnaire that is accessed through a registration by the owner of the establishment on the Greentour tool website (Greentour, 2024) (Figure 3)”. Please explain briefly the characteristics of the questionnaire, the statistical basis of the data required, the consistency and reliability checks, if available.

Response 5: Agree. We have all this detailed information to emphasize this point. All information suggested by the reviewer has been completed and added from lines 163-185 onwards:

“The primary environmental data required for the development of the inventory are collected through an online questionnaire, accessible through the establishment owner's registration on the Greentour platform (Greentour, 2024) (Figure 3). This questionnaire asks for general information about the establishment, such as its name, type, category, year of data collection, capacity and days of operation, as well as details about its facilities, the months it is open and other relevant aspects.

It also has a specific section for the collection of essential environmental data for analysis, covering the generation and consumption of energy, water, cleaning products for maintenance, food, beverages and other products used in leisure activities. All these inputs and emissions have been determined based on previous studies and assessments carried out in different establishments, in order to identify the key aspects to be considered according to the type of accommodation.

The statistical basis of the data follows internationally recognised sustainability assessment methodologies, including the Life Cycle Assessment (ISO 14040/44) and the Product Environmental Footprint (PEF) method. In addition, the questionnaire is in line with standards for environmental reporting in tourism, allowing comparability between different establishments. The results of each establishment are presented in relation to other establishments in the same destination and other destinations analysed, thus enabling a comparative assessment.

To ensure the consistency and reliability of the data, several validation mechanisms have been implemented. Firstly, the questionnaire incorporates predefined ranges and reference values based on previous studies and current regulations. Secondly, internal checks are applied to detect possible discrepancies. In case of inconsistencies, the technicians in charge review the quality of the data entered, identifying and correcting errors or anomalies. This ensures a robust and reliable data set for the environmental impact assessment.”

 

Comment 6:   “Since inventory data collection is the most challenging stage of this tool's methodology—often due to the lack of available data faced by technicians responsible for calculating environ-mental impacts (Parvatker and Eckelman, 2019)—a series of assumptions have been made to develop the most detailed inventory possible. While these assumptions may increase the level of uncertainty in the LCA, they are necessary to fill the gaps in the data provided by the facilities.” The nature and the quality of these assumptions needs to be clarified since it is clearly relevant to judge the reliability of the impact estimates.

Response 6: Thanks you for pointing this out. We have added the following information to detail all the assumptions that have been made to calculate the environmental impacts due to lack of data in order to be as accurate as possible. In addition, for better understanding and detail, tabs and figures have been added as well. All this information has been added from line 188 to 330.

Section 2.1.2

Comment 7: “The Environmental Footprint (EF) 3.0 method was used in order to quantify the environmental impacts of the goods and services included in the tool.” The method should be explained and its application clarified. It is noty only a matter of categorization but of specific applicability and sufficient information.

Response 7: Thanks you for pointing this out. We have added this paragraph to the lines 344-352 to better justify why we have used this method:

“…This method was chosen because it provides a comprehensive and standardized approach for assessing environmental performance across multiple impact categories, ensuring comparability and reliability. In the tourism sector, where diverse activities and supply chains contribute to environmental impacts, EF 3.0 enables a more holistic evaluation by integrating life cycle assessment principles. Additionally, its alignment with EU recommendations and its sector-specific applicability make it an appropriate methodology for measuring and improving sustainability in tourism establishments.”

 

 

Section 2.1.3

Comment 8: “In the tool, environmental results are generated directly from inventory data, which includes accommodation, restaurants, and tourist activities, along with the corresponding impact categories.” Please clarify how they are generated and on what basis. Are the same coefficients applied everywhere and for all tourists? Are value chain effects taken into account?

Response 8: Thank you for your comment and suggestion.

The environmental results in the Greentour tool are generated from a detailed data inventory, which includes information on the number of tourists or guests in each establishment. This allows to calculate the impacts both at the total level of the establishment and per tourist. The web platform is linked to an Excel database where the emission factors for each process flow and each impact category have been predefined. In this way, by entering the specific data of each establishment and the total number of customers, the corresponding environmental impact per tourist and per accommodation unit, restaurant or tourist activity is automatically obtained. As for geographical and sectoral variability, the tool has been applied in four different tourist destinations in two countries (Spain and Portugal). To reflect these differences, specific factors have been considered, such as the energy mix of each country, which influences the emissions derived from electricity consumption, and the modeling of the processes associated with food, adapted to the characteristics and consumption habits of each region. Therefore, the same coefficients are not applied in all locations or for all tourists, but variables have been integrated that reflect the specificity of each destination and establishment. Likewise, the effects of the value chain have been taken into account by incorporating inventory data based on Life Cycle Analysis methodologies (LCA), ensuring a comprehensive assessment of the environmental impacts associated with tourism activities.

In the article, this paragraph has been added for a better understanding of the lines 385-392: "… The calculations account for the number of tourists per establishment, providing results both at the total level and per visitor. The tool is linked to an Excel database with predefined emission factors, which, combined with input data, allows for automated impact assessment. It also incorporates geographical differences, such as variations in energy mixes and food-related processes in Spain and Portugal. Rather than applying uniform coefficients, the tool integrates location-specific variables and follows Life Cycle Assessment (LCA) methodologies to ensure a comprehensive evaluation of tourism-related environmental impacts.”

Section 3.1

Comment 9: “In addition to the impacts of the different establishments, the tool provides the impacts at the destination level applying the extrapolation procedure detailed below. This extrapolation is not done directly in the tool, so it needs to be done manually by a technical partner. Therefore, the environmental impacts of accommodation, restaurants, and tour-ist activities are exported to an Excel file through the Greentour website.” It is not clear what the authors mean by “ extrapolation”. Whether  it is an estimation procedure, or the mere application of fixed coefficients, it should be explained in more detail, with its properties and limitations discussed also with reference to the literature.

Response 9: Thank you for your comment. The extrapolation process is an estimation procedure that scales up the environmental impacts from individual establishments to the destination level. This is done by combining three key variables: (1) the total annual environmental impact of each establishment registered in the Greentour tool, (2) the number of customers in accommodations (measured in overnight stays), restaurants, and leisure activities, and (3) the capacity of establishments in each destination. These data, along with the information obtained from the Greentour tool, are exported to an Excel file, where the environmental impact at the destination level is calculated. This approach ensures a more accurate assessment by considering the representativeness of the registered establishments and integrating destination-specific parameters. The process is visually represented in Figure 7, which illustrates how the extrapolation is performed.

References

1. Borucke, D. Moore, G. Cranston, K. Gracey, K. Iha, J. Larson, E. Lazarus, J.C. Morales, M. Wackernagel, A. Galli. (2013) Accounting for demand and supply of the biosphere's regenerative capacity: the National Footprint Accounts' underlying methodology and framework

Ecol. Indicat., 24 (2013), pp. 518-533, 10.1016/j.ecolind.2012.08.005

M.S. Mancini, M. Evans, K. Iha, C. Danelutti, A. Galli (2018). Assessing the ecological footprint of ecotourism packages: a methodological proposition. Resources, 7 (2) (2018).

Miralles, C.C., Barioni, D., Mancini, M.S., Jordà, J.C., Roura, M.B., Salas, S.P., Argelaguet, L.L. and Galli, A., 2023. The footprint of tourism: A review of water, carbon, and ecological footprint applications to the tourism sector. Journal of Cleaner Production, p.138568.

Reviewer 2 Report

Comments and Suggestions for Authors

 

Manuscript Comments

 

Abstract. The study's findings are presented in a general manner, lacking specific quantitative data to substantiate the conclusions. Furthermore, no statistical significance measures or effect sizes are provided, which limits the robustness and precision of the claims. It is recommended to include at least one percentage or numerical value to strengthen the conclusion regarding the critical importance of tourist transport.

 

Introduction

First Paragraph. The reference "(WTO and UNEP, 2008)" is outdated, considering the data referenced spans 2009–2013. A more recent reference would be more appropriate. Additionally, the logical connection between economic opportunities and environmental impacts could be strengthened with additional quantitative data.

Third Paragraph. A clearer transition is needed between the discussion of existing tools and the introduction of new ones.

Fourth Paragraph. The mention of "different underlying methodologies" requires further elaboration or specific examples to clarify its significance. Additionally, the reference "Pandey et al., 2010" is outdated to support the current relevance of these measurements.

Fifth Paragraph. The discussion of limitations, particularly the "lack of consensus," would benefit from further development and specific examples to illustrate the issue.

Final Paragraph. The study's objective could be more clearly articulated by specifying the evaluation criteria. Moreover, the claim that this is "the first environmental analysis" considering all three subsectors requires a more comprehensive literature review to substantiate it.

 

2. Materials and Methods

2.1. Tool Development: Basic Structure of the Tool

Second Paragraph. The description of the "bottom-up approach" and "top-down approach" requires greater methodological detail to clarify their implementation. 

Third Paragraph. The list of tourist activities (e.g., "cruises, museum visits, horse riding") should either be exhaustive or include the selection criteria. Additionally, the relevance of these activities must be explained to justify their inclusion. 

Fifth Paragraph: Information on the management and storage of personal data is missing. Furthermore, the process for validating user-provided data is not addressed and should be included. 

2.1.1. Data Requested in the Tool

First Paragraph. The exclusion of "production of infrastructures" should be justified with additional data or references. Moreover, the types of "fossil fuels" considered must be explicitly specified.

Third Paragraph. The handling of missing or incomplete data is not described. The reference to a "series of assumptions" should be accompanied by an explicit list of these assumptions.

Fourth Paragraph. The "reference flows" mentioned require a more detailed explanation of how they are calculated to ensure clarity and reproducibility.

2.1.2. Environmental Indicators of the Tool

First Paragraph. The justification for excluding toxicity categories needs to be supported with quantitative data to strengthen the argument.

Second Paragraph: The method used to quantify the "significant influence" mentioned is not specified and should be detailed.

Third Paragraph (description of categories): The nine selected impact categories need more precise operational definitions to enhance their practical applicability.

2.2. Extrapolation Procedure: Environmental Impacts of Destinations

First Paragraph. The "representativeness of the sample" should be defined more precisely in statistical terms to validate its adequacy.

Second Paragraph: The exclusion of transport and waste management at the establishment level requires further justification to explain its methodological rationale. 

2.2.1. Transport of the Destinations

Second Paragraph. The process for validating data provided by tourism offices is not specified and should be outlined to ensure reliability.

Third Paragraph. The assumption of multiplying by two for round trips does not account for potential multi-destination routes, which could impact the accuracy of the results.

2.2.2. Waste Treatment of the Destinations

First Paragraph. The reference to "equivalent tourist" requires a more rigorous mathematical justification to support its use.

Second Paragraph. The choice of the month with the lowest MSW as a reference point is insufficiently justified. Additionally, a sensitivity analysis of this method should be included to evaluate its robustness.

 

3. Application of the Tool to Four Case Studies in the SUDOE Area

3.1. Description of the Destinations to Test the Functionality of the Tool

First Paragraph (page 9). A more robust explanation of the SUDOE area is required to provide geographic, economic, and environmental context.

Table 1: The table needs a statistical analysis, including justification for the variability in the number of establishments, sampling error, confidence level, and other relevant metrics to enhance its reliability.

Page 11

Second Paragraph. The radar chart lacks a technical analysis and detailed explanation. A thorough interpretation of the data represented in the chart is necessary.

Fourth Paragraph. The statement identifying FRD as the "most significant impact" requires statistical backing. Additionally, the causes of variations between destinations should be explained more thoroughly to provide deeper insight.

3.3. Comparison of the Results Obtained in the Destinations with the Bibliography

The analysis in this section is very limited. The results presented in section 3.2 lack coherence without a thorough discussion of the relevant findings. This represents a significant weakness in the manuscript, as critical insights remain unexplored.

 

4. Tool Limitations

A direct explanation should clarify which parts of the results were most vulnerable to the identified limitations and how these may have impacted the findings. This would add transparency and improve the credibility of the study. 

 

5. Conclusions

First Paragraph. The quantitative results presented (e.g., 152 kg CO₂ eq, 177 kg CO₂ eq) need to be contextualized with confidence intervals to indicate the precision and reliability of the estimates.

Second Paragraph: While this paragraph addresses methodological difficulties, it does not directly develop their implications for the results. A more explicit discussion on this is needed.

Third Paragraph. The section on future research is overly general. A stronger, more specific proposal should be included. Additionally, the mention of "science-backed sustainable initiatives" requires the specification of criteria and validation methods to ensure practical applicability.

Fourth Paragraph. The reference to "key partners" should include a more detailed description, specifying their roles, contributions, and relevance to the study.

Comments for author File: Comments.docx

Comments on the Quality of English Language

The quality of the English is acceptable, although certain parts of the writing could be improved with greater grammatical precision.

Author Response

Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding corrections highlighted in track changes in the re-submitted files.

Abstract

Comment 1: The study's findings are presented in a general manner, lacking specific quantitative data to substantiate the conclusions. Furthermore, no statistical significance measures or effect sizes are provided, which limits the robustness and precision of the claims. It is recommended to include at least one percentage or numerical value to strengthen the conclusion regarding the critical importance of tourist transport.

Response 1: Thanks you for pointing this out. Numerical data have been included to reinforce the conclusion on the critical importance of tourist transport as indicated by the reviewer.

Lines 19-37:“Travel and tourism are essential to global economies, generating social, economic, and environmental impacts. However, there is a lack of standardized methodologies to assess the environmental footprint of tourist destinations beyond carbon footprint analysis. This study introduces the Greentour tool, the first of its kind to evaluate the environmental impact of accommodation, restaurants, and tourism activities using nine environmental indicators from a Life Cycle Assessment (LCA) perspective. The tool applies a hybrid bottom-up and top-down approach, integrating data from tourist establishments and destination managers. The tool was tested in four tourist destinations in Spain and Portugal (Rías Baixas, Camino Lebaniego, Lloret de Mar, and Guimarães), revealing that transportation is the primary contributor to environmental impacts, ranging from 60% to 96% of total emissions, particularly in air-travel-dependent destinations. Food and beverage services are the second-largest contributor, accounting for up to 26% of emissions, while accommodation ranks third (1%–14%). The study highlights the significant role of electricity consumption and food choices (e.g., red meat and dairy) in greenhouse gas (GHG) emissions, emphasizing the need for sustainable alternatives. Despite challenges in data collection, particularly for food and transport statistics, the Greentour tool has demonstrated robustness and adaptability across diverse destinations, making it applicable worldwide. The tool provides key insights for policymakers, tourism stakeholders, and businesses, supporting the integration of sustainability strategies into public policies and industry best practices. Future research should focus on expanding its use to additional destinations to foster science-based decision-making and promote more sustainable tourism practices globally.”

Introduction

Comment 2: First Paragraph. The reference "(WTO and UNEP, 2008)" is outdated, considering the data referenced spans 2009–2013. A more recent reference would be more appropriate. Additionally, the logical connection between economic opportunities and environmental impacts could be strengthened with additional quantitative data.

Response 2: Agree. Thank you for your comment. We have now replaced the outdated WTO and UNEP (2008) reference with a more recent source (Gössling and Humpe, 2020), which reaffirms that transportation still accounts for approximately 75% of tourism’s total carbon footprint. Additionally, we have clarified the link between economic opportunities and environmental impacts by emphasizing tourism’s role in both conservation efforts and resource consumption.

Lines 45-49: “Between 2009 and 2013, tourism’s global carbon footprint accounted for approximately 8% of global GHG emissions (Campos et al., 2023), with transportation being responsible for the largest share. More recent studies confirm this trend, highlighting that transportation still accounts for nearly 75% of the sector’s total emissions (Gössling and Humpe, 2020)”

• Gössling, S., & Humpe, A. (2020). The global scale, distribution and growth of aviation: Implications for climate change. Global Environmental Change, 65, 102194. https://doi.org/10.1016/j.gloenvcha.2020.102194

Comment 3: Third Paragraph. A clearer transition is needed between the discussion of existing tools and the introduction of new ones.

Response 3: Thank you for your valuable feedback. We have improved the transition between the discussion of existing tools and the introduction of new ones, ensuring a clearer connection between both sections. Specifically, we have added an explicit link between the need identified in previous studies and the development of new tools designed to address these limitations.

Lines 81-84: “This lack of standardization has driven the development of new tools aimed at overcoming the limitations of traditional methods. In particular, more accessible and user-friendly solutions have been designed, prioritizing integration with commonly available data sources and smart devices, thus facilitating their implementation in the tourism industry.”

Comment 4: Fourth Paragraph. The mention of "different underlying methodologies" requires further elaboration or specific examples to clarify its significance. Additionally, the reference "Pandey et al., 2010" is outdated to support the current relevance of these measurements.

Response 4: Thanks you for pointing this out. In response to your corrections, we have deleted that reference and we have modified the paragraph a little so that it makes sense in the text of the article.

Lines 99-103: “Examples of such tools include the Hotel Footprinting tool (Greenview, 2024), Green-house Gas Abatement Cost Model (GACMO, 2024), MyEarthcheck (Earthcheck, 2024), and Weeva (Weeva, 2024). While these tools may apply different underlying methodologies, their primary purpose is to estimate GHG emissions from specific activities (Mulrow et al., 2019).”

Comment 5: Fifth Paragraph. The discussion of limitations, particularly the "lack of consensus," would benefit from further development and specific examples to illustrate the issue.

Response 5: Thank you for your thoughtful feedback. We acknowledge the importance of further elaborating on the lack of consensus regarding prioritizing metrics and the implications of such measurements. However, this issue has been widely discussed in existing literature, highlighting that discrepancies arise due to variations in methodological frameworks, data availability, and regional differences. Studies such as Miralles et al. (2023) and Campos et al. (2022) underscore the ongoing debate regarding system boundaries, impact categories required for meaningful assessments. Additionally, organizations such as the UNWTO (2023a) recognize the challenge of standardizing publicly available tools for emissions and impact assessments at the destination level, further reinforcing the complexity of achieving a unified approach.

Lines 111-119: “However, there remains a lack of consensus on which metrics should be prioritized and the implications of such measurements. This discrepancy stems from variations in methodological frameworks, data availability, and regional differences, which affect how environmental impacts are assessed and compared across destinations. Studies such as Miralles et al. (2023) and Campos et al. (2022) highlight the ongoing debate regarding system boundaries, impact categories, and the granularity of data required for meaningful assessments. Moreover, publicly available tools and methodologies to assess emissions and impacts at the destination level remain limited, as noted by UNWTO (2023a), further complicating efforts to establish a standardized approach."

Comment 6: Final Paragraph. The study's objective could be more clearly articulated by specifying the evaluation criteria. Moreover, the claim that this is "the first environmental analysis" considering all three subsectors requires a more comprehensive literature review to substantiate it.

Response 6: Thank you for your feedback. The objective of this study is to evaluate an LCA-based tool to assess environmental impacts across tourism subsectors, transportation, and waste management, identifying critical points for sustainability improvements. Regarding its novelty, our review indicates that no previous studies have integrated all these aspects at the destination level. The introduction highlights the absence of such tools, as most focus on climate change indicators and assess individual accommodations rather than entire destinations. Therefore, this tool represents an innovative approach.

 

Materials and Methods: 2.1Tool Development: Basic Structure of the Tool

Comment 7: Second Paragraph. The description of the "bottom-up approach" and "top-down approach" requires greater methodological detail to clarify their implementation. 

Response 7: Thank you for your comment and suggestion. The following clarifying paragraph has been added:

Lines 152-162: “The bottom-up approach is based on the extrapolation of environmental impacts from a sample of tourist establishments in each subsector (e.g., accommodation, dining, lei-sure activities). This approach uses detailed, process-specific data collected from individual establishments to build an environmental inventory, which is then scaled up to estimate the total environmental impacts for the destination. This method is particularly useful when more granular data is available and when the goal is to assess localized, specific impacts. On the other hand, the top-down approach is applied for waste management and transport, where it is used aggregated data or global models to estimate the environmental impacts. This approach takes a broader, more generalized perspective and is typically used when individual-level data is difficult to obtain or when a higher-level overview of impacts is required. By using aggregated data or models, the top-down approach provides an efficient way to estimate impacts at the destination level.”

Comment 8: Third Paragraph. The list of tourist activities (e.g., "cruises, museum visits, horse riding") should either be exhaustive or include the selection criteria. Additionally, the relevance of these activities must be explained to justify their inclusion. 

Response 8: Thanks you for pointing this out. Thank you for your insightful comments. We appreciate your suggestion to clarify the list of tourist activities included in the Greentour tool. The activities mentioned (e.g., cruises, museum visits, horse riding) are among the most prominent in the destinations analyzed, but we acknowledge that there are numerous other activities available in each destination.

 

Rather than providing an exhaustive list of every possible tourist activity, we focused on the most representative activities for each destination, which are typically the most impactful in terms of environmental consequences. The selection of activities was made based on their relevance and popularity within the local tourism market, as well as their potential contribution to environmental impact. This approach ensures that the tool is adaptable to various destinations and reflects the most significant activities within the context of each. . The following clarifying paragraph has been added:

Lines 166-168: “These activities were selected based on their prominence and impact in the specific destinations, reflecting the diversity of tourism offerings in each location.”

Comment 9: Fifth Paragraph: Information on the management and storage of personal data is missing. Furthermore, the process for validating user-provided data is not addressed and should be included. 

Response 9: Thank you for your valuable comments. In response to your suggestions, we have clarified the management and storage of personal data, as well as the process for validating user-provided data. The updated text now includes detailed information on the data security measures implemented on the Greentour platform, as well as the validation mechanisms used to ensure the accuracy and reliability of the data. We have made these modifications to ensure greater transparency and address your concerns.

Lines 201-209: “Users must register on the platform using a username and password to create a secure profile. Once registered, they can input and update data regarding the establishment, including general information such as its name, type, category, year of data collection, capacity, and days of operation, as well as details about its facilities, months of operation, and other relevant aspects. The platform ensures that all personal data is stored securely in compliance with data protection regulations, with access restricted to authorized personnel only. The questionnaire also includes a specific section for collecting environmental data, such as the generation and consumption of energy, water, cleaning products for maintenance, food, beverages, and other products used in leisure activities”

Lines 219-228: “To ensure the consistency and reliability of the data, several validation mechanisms have been implemented. Firstly, the questionnaire incorporates predefined ranges and reference values based on previous studies and current regulations. Internal checks are applied to detect discrepancies, and if any inconsistencies are found, the data is re-viewed by technicians to verify its accuracy. The data validation process ensures the accuracy and reliability of the information before proceeding with the environmental impact assessment. These validation steps are in place to ensure that only high-quality, reliable data is used in the evaluation. Additionally, the platform’s secure data management system guarantees that all collected data is handled with confidentiality and in accordance with privacy protection standards.”

Materials and Methods: 2.1.1. Data Requested in the Tool

Comment 10: First Paragraph. The exclusion of "production of infrastructures" should be justified with additional data or references. Moreover, the types of "fossil fuels" considered must be explicitly specified.

Response 10: Thank you for your comment. It has been explained more concisely in the text by adding the following information:

Lines 192-200: “The analysis excludes the production of infrastructures and their maintenance, including necessary construction work or repairs. This exclusion is justified by studies (Žigart et al., 2018) showing that these processes typically have a minimal impact on the overall environmental assessment when compared to other stages such as energy consumption or waste generation. Additionally, the focus of this study is on operational impacts, which are more directly related to the day-to-day activities of tourism establishments. Furthermore, the types of fossil fuels considered in the analysis are specified as natural gas, coal, and petroleum, which are the primary sources of energy in the tourism sector.”

Comment 11: Third Paragraph. The handling of missing or incomplete data is not described. The reference to a "series of assumptions" should be accompanied by an explicit list of these assumptions.

Response 11: Agree. From lines 243-378 all the hypotheses formulated have been incorporated, as well as the processes used and the different assumptions made during the development of the study.

Comment 12: Fourth Paragraph. The "reference flows" mentioned require a more detailed explanation of how they are calculated to ensure clarity and reproducibility.

Response 12: Thank you for your comment. We understand the importance of ensuring clarity and reproducibility in the methodology. As for the "reference flows" mentioned in the manuscript, we would like to clarify that further detailed explanations of these flows, including how they are calculated, can be found in the supplementary material. Regarding the remaining reference flows, these are primarily derived from widely recognized databases such as Ecoinvent, Agribalyse, and others, which are explained in the article. However, the specific data from these databases are proprietary and confidential, meaning we are unable to provide detailed figures in the main text. We hope this provides clarity on the matter, and the supplementary material is available for further insights into the calculations.

Materials and Methods: 2.1.2. Environmental Indicators of the Tool

Comment 13: First Paragraph. The justification for excluding toxicity categories needs to be supported with quantitative data to strengthen the argument.

Response 13: Thanks you for pointing this out. To better justify this, a paragraph from lines 404-410 of the manuscript has been added:

Lines 404-410: “Previous studies, such as those by Lenzen et al. (2018) and Smetschka et al. (2019), have shown that the environmental impacts from tourism are predominantly linked to resource consumption (energy, water) and waste generation, with significantly lower relevance of toxicity-related impacts in comparison to sectors like manufacturing or agriculture.”

• Lenzen, M., Sun, Y.Y., Faturay, F., Ting, Y.P., Geschke, A., Malik, A., 2018. The carbon footprint of global tourism. Nat. Clim. Chang. 8 (6), 522-528. https://doi.org/10.1038/s41558-018-0141-x
• Smetschka, B., Wiedenhofer, D., Egger, C., Haselsteiner. E., Moran, D., Gaube, V. , 2019.Time Matters: The Carbon Footprint of Everyday Activities in Austria. Ecological Economics. 164, 106357. https://doi.org/10.1016/j.ecolecon.2019.106357

Comment 14: Second Paragraph: The method used to quantify the "significant influence" mentioned is not specified and should be detailed.

Response 14: Thank you for your comment. The following sentences have been added to clarify the “significant influence”:

Lines 419-426: “To quantify this 'significant influence,' the tool evaluates a range of key indicators that are aligned with the SDGs, including but not limited to environmental impacts (such as carbon footprint, water usage, and waste generation) and social-economic factors (such as employment, income generation, and community engagement). These indicators are derived from established methodologies such as Life Cycle Assessment (LCA) and follow internationally recognized guidelines and standards, ensuring that the impact measurement is comprehensive, reproducible, and consistent with global sustainability frameworks.”

Comment 15: Third Paragraph (description of categories): The nine selected impact categories need more precise operational definitions to enhance their practical applicability.

Response 15: Thank you for your comment. The nine selected impact categories are carefully chosen based on their relevance to the tourism sector’s environmental performance and their alignment with the Sustainable Development Goals (SDGs). As shown in Figure 4, these categories are directly linked to the SDGs, highlighting their strategic importance for sustainable tourism. Furthermore, the operational definitions of these categories are grounded in internationally recognized methodologies such as Life Cycle Assessment (LCA) and Product Environmental Footprint (PEF), ensuring their practical applicability. We believe these definitions and their connection to the SDGs make the selection of categories both comprehensive and relevant for assessing environmental impacts in the tourism industry.

Materials and Methods: 2.2. Extrapolation Procedure: Environmental Impacts of Destinations

Comment 16: First Paragraph. The "representativeness of the sample" should be defined more precisely in statistical terms to validate its adequacy.

Response 16: Agee. It has been added in a detailed way how the representativeness of the sample has been worked on. The following information has been incorporated from paragraph '3. Application of the tool to four case studies of the SUDOE’ area, which is where it is explained how the representativeness of the sample has been analyzed, in this case, of the tourism subsectors analyzed in each destination considered. All this detailed information has been included between lines 582 and 612, also adding a table to facilitate the understanding of the categories considered, among other aspects.

Comment 17: Second Paragraph: The exclusion of transport and waste management at the establishment level requires further justification to explain its methodological rationale. 

Response 17: Thank you for your comment. In the tool it is possible to consider the environmental impacts of tourism establishments (which is applicable to any establishment worldwide). However, in the case of transport and waste management, specific data is required at the local level, provided by entities such as municipalities, tourism offices or regional administrations. This is because data on the amount of waste generated by each sub-sector or the transport of tourists to each destination are not recorded at the level of the establishments, as they do not have such information. Therefore, this aspect should be addressed separately, requesting the relevant data for each year from the responsible administrations, which will allow, at destination level, to extrapolate and provide more accurate information on these impacts. Hence, the tool is innovative: firstly, because it offers an assessment at establishment level, and secondly, because it allows extrapolating these data, integrating also the impacts of transport and waste management at destination level.

Materials and Methods: 2.2.1. Transport of the Destinations

Comment 18: Second Paragraph. The process for validating data provided by tourism offices is not specified and should be outlined to ensure reliability.

Response 18: Thanks you for pointing this out. The data provided by the tourist offices have been obtained from contracted databases, which have been carefully selected and verified by the technicians responsible for the project. In addition, these data have been checked with relevant bibliographic sources, which guarantees their reliability and validity. The validation process includes a thorough review of the quality of the data, which ensures that the impacts related to transport and waste management, provided by the tourism offices, are completely reliable and suitable for integration into the analysis conducted.

Comment 19: Third Paragraph. The assumption of multiplying by two for round trips does not account for potential multi-destination routes, which could impact the accuracy of the results.

Response 19: Thanks for your comment. It is true that predicting the exact movement of tourists within a destination is a complex task, as tourists' routes and behaviour can vary considerably depending on a number of factors, such as personal preferences, trip type or seasonality. However, the assumption of multiplying by two for round trips is based on an approach commonly used in environmental impact studies and is supported by the existing literature. In this sense, some studies such as Lenzen et al., 2018 adopt this approach to simplify the calculation of emissions and other impacts associated with transport, since, although the full complexity of trips within a destination is not captured, this assumption provides a reasonable estimate of the total impacts of transport from the origin destination to the arrival destination and vice versa.

Materials and Methods: 2.2.2. Waste Treatment of the Destinations

Comment 20: First Paragraph. The reference to "equivalent tourist" requires a more rigorous mathematical justification to support its use.

Response 20: Thank you for your valuable comments and suggestions. I really appreciate your observation about the mathematical justification of the concept of "equivalent tourist". I have revised the section and have included a further explanation of the mathematical reasoning behind this methodology, based on the fraction of 1/365 as a representation of a tourist equivalent to a full-time resident. In addition, I have added an additional reference (Fernández and Lazovski, 2020) that supports the use of this approach in previous studies related to waste management in tourist destinations. I think that with these modifications the justification becomes clearer and more rigorous. This paragraph has been added:

Lines 519-522: “According to this methodology, "equivalent tourist" is defined as a tourist whose one-day stay represents the fraction of a full-time resident (1/365), which is a standard way of converting the impact of tourists on an annual basis to facilitate its comparison with the resident population.”

 

Comment 21: Second Paragraph. The choice of the month with the lowest MSW as a reference point is insufficiently justified. Additionally, a sensitivity analysis of this method should be included to evaluate its robustness.

Response 21: Thank you for your insightful comments. Regarding the choice of the month with the lowest municipal solid waste (MSW) generation as a reference point, this approach is based on the assumption that, in the absence of tourists, the waste generated exclusively reflects the activity of permanent residents. This methodology has been widely used in studies analyzing the impact of tourism on waste generation. For example, Mateu-Sbert et al. (2013) and Pulido-Fernández et al. (2019) have applied similar approaches, leveraging seasonal variations in MSW production to estimate the contribution of tourism. Mateu-Sbert et al. (2013) specifically analyzed the correlation between waste generation and tourist seasonality in island destinations, concluding that selecting a low-season period as a reference allows for an effective distinction between resident-generated and tourist-generated waste. Similarly, Pulido-Fernández et al. (2019) used monthly variations in waste generation as an indirect indicator of tourist presence. Given that direct measurements of tourist-related waste are rarely available at the destination level, using the lowest MSW month as a baseline provides a practical and well-founded approach to estimating the additional waste generated by tourism. This method ensures that fluctuations in waste production throughout the year can be attributed to variations in tourist arrivals.

• Mateu-Sbert, J., Ricci-Cabello, I., Villalonga-Olives, E., & Cabeza-Irigoyen, E. (2013). The impact of tourism on municipal solid waste generation: The case of Menorca Island (Spain). Waste Management, 33(12), 2589-2593.

• Pulido-Fernández, J. I., Cárdenas-García, P. J., & Carrillo-Hidalgo, I. (2019). Does environmental sustainability contribute to tourism growth? An analysis at the country level. Journal of Cleaner Production, 213, 309-319.

3. Application of the Tool to Four Case Studies in the SUDOE Area

3.1. Description of the Destinations to Test the Functionality of the Tool

Comment 22: First Paragraph (page 9). A more robust explanation of the SUDOE area is required to provide geographic, economic, and environmental context.

Response 22: Thank you for your valuable comments. Regarding the need for a more robust explanation of the SUDOE area, we have chosen this region because it is where the project has been developed and serves as a pilot area to test the tool. The SUDOE region (comprising Southwestern European countries such as Spain, Portugal, and Southern France) presents significant geographic, economic, and environmental diversity, making it an ideal setting to evaluate the applicability of the methodology in different tourism contexts. This area has been selected due to its strong tourism sector, which includes a mix of urban, coastal, and rural destinations, allowing us to assess the tool’s effectiveness across varied environments. Additionally, the region faces key sustainability challenges related to tourism, such as waste management, resource consumption, and seasonal fluctuations, which align with the objectives of our study. We will clarify this in the revised manuscript to ensure the geographic, economic, and environmental context of the SUDOE area is properly explained:

Lines 550-554: “The SUDOE region, which includes Spain and Portugal, among other destinations, has been chosen as a pilot area due to its geographic, economic, and environmental diversity. This region represents a variety of tourism contexts—ranging from pilgrimage routes to historic cities and coastal destinations—allowing for a comprehensive assessment of the tool’s applicability.”

Comment 23: Table 1: The table needs a statistical analysis, including justification for the variability in the number of establishments, sampling error, confidence level, and other relevant metrics to enhance its reliability.

Response 23: Thank you for your comment. As mentioned above, this aspect has been explained in lines 586 to 616 to verify the reliability of the sample analysed in the selected destinations.

Comment 24: Page 11 Second Paragraph. The radar chart lacks a technical analysis and detailed explanation. A thorough interpretation of the data represented in the chart is necessary.

Response 24: Thank you for your comment. The explanation on the diagram has been expanded for a better understanding of the analysis of the impact categories. The following information has been added:

Lines 648-675: “The results indicate that the FRD (Fossil Resource Depletion) category exhibits the highest impact across all destinations, highlighting a significant reliance on non-renewable energy sources. This suggests that tourism-related activities in these areas are heavily dependent on fossil fuels, which could be linked to transportation, energy consumption in accommodations, and general infrastructure operations. In contrast, ODP (Ozone Depletion Potential) impacts remain relatively similar across all destinations, aligning with the European average. This consistency indicate that tourism-related activities do not significantly influence this category compared to other sectors. When analyzing individual destinations, Lloret de Mar consistently shows the highest environmental impact across most categories, particularly in AP (Acidification Potential), FEP (Freshwater Eutrophication Potential), MEP (Marine Eutrophication Potential), Ri (Resource Impact), WDP (Water Deprivation Potential), and FRD. These elevated values suggest intensive resource consumption and emissions, likely due to high tourist density, infrastructure demands, and water consumption patterns. Camino Lebaniego follows a similar trend but with slightly lower impacts than Lloret de Mar. However, its values in CC (Climate Change), POF (Photochemical Ozone Formation), and FRD remain above average, indicating a notable carbon footprint. This is attributed to the energy demands associated with transportation and accommodation along the pilgrimage route. Conversely, Rías Baixas and Guimarães present lower environmental impacts across most categories, generally approaching the European average. This suggests a different resource management strategy, potentially due to lower tourism intensity, sustainable infrastructure, or different tourist profiles with less resource-intensive behaviors. To contextualize these results, the environmental impact profile of an average European citizen in 2019, derived from the Ecoinvent database, is used as a benchmark. This allows for a comparison between the environmental footprint of a tourist visiting these destinations and that of a resident in Europe. The detailed numerical values supporting this comparison can be found in Table S1 of the supplementary material.In the following section, a more in-depth analysis of the carbon footprint of each destination will provide further insights into their specific contributions to environmental impacts.”

Comment 25: Fourth Paragraph. The statement identifying FRD as the "most significant impact" requires statistical backing. Additionally, the causes of variations between destinations should be explained more thoroughly to provide deeper insight.

Response 25:  Thanks for your suggestions. We have incorporated this information between lines 648 and 675 of the manuscript to improve the understanding of the content.

 

3.3. Comparison of the Results Obtained in the Destinations with the Bibliography

Comment 26: The analysis in this section is very limited. The results presented in section 3.2 lack coherence without a thorough discussion of the relevant findings. This represents a significant weakness in the manuscript, as critical insights remain unexplored.

Response 26: Thanks for your suggestions. However, we believe that the results obtained are very new and detailed in all subsectors, where previously there was no such analysis. The carbon footprint indicator has been employed to better understand the analysis, as it is one of the most significant contributors to the overall environmental impact in tourism. While the focus has been on carbon emissions, the environmental tool has been applied to assess the nine impact categories. This comprehensive approach allows for a more holistic evaluation of the environmental consequences of tourism across various sectors, providing insights into areas like water scarcity, acidification, and eutrophication. By emphasizing the carbon footprint, the analysis not only offers a clear understanding of its central role but also ensures that other environmental impacts are considered within the broader context of sustainability.

4. Tool Limitations

Comment 27: A direct explanation should clarify which parts of the results were most vulnerable to the identified limitations and how these may have impacted the findings. This would add transparency and improve the credibility of the study. 

Response 27: We really appreciate your comments and suggestions. In response to your request, a detailed section appears in the manuscript that clarifies how the identified limitations have impacted the obtained results. This section explains how the delay in data collection due to restrictions due to the COVID-19 pandemic affected the accuracy of data extrapolation and environmental impact assessment. In addition, I have detailed how the lack of automatic calculations for transport and waste management, which had to be evaluated manually in an Excel file, could have introduced variability and errors in the results, affecting consistency between destinations. Finally, the importance of continuous technical support and data updating has also been addressed, explaining how these limitations can compromise the reliability and validity of long-term results if constant monitoring of the tool is not maintained. These explanations provide greater transparency in the study by making clear how limitations may have influenced the findings and which parts of the results were most vulnerable to them.

5. Conclusions

Comment 28: First Paragraph. The quantitative results presented (e.g., 152 kg CO₂ eq, 177 kg CO₂ eq) need to be contextualized with confidence intervals to indicate the precision and reliability of the estimates.

Response 28: Thank you very much for your insightful comments and suggestions. Regarding your concern about the quantitative results, we appreciate the importance of including confidence intervals to indicate the precision and reliability of the estimates. It is important to note that these results are based on a comprehensive dataset collected from tourism establishments and destination managers. While confidence intervals have not been explicitly calculated, the methodology employed ensures robustness by integrating primary data from direct sources and applying a consistent extrapolation approach. Future research could further refine these estimates by incorporating statistical uncertainty analyses to enhance the precision of impact assessments.

Comment 29: Second Paragraph: While this paragraph addresses methodological difficulties, it does not directly develop their implications for the results. A more explicit discussion on this is needed.

Response 29: Thank you for your comment regarding the need for a more explicit discussion on the implications of methodological difficulties for the results. In response, we have now elaborated on how data limitations, particularly in areas requiring extrapolations such as food-related emissions and transportation usage, may have influenced our results. Additionally, we have clarified how these methodological constraints introduce a degree of uncertainty and suggested ways in which future research could enhance data collection and refine impact assessments:

Lines 897-910: “This limitation introduced a degree of uncertainty in the results, particularly in impact categories where extrapolations were necessary. For example, the reliance on estimated values for food-related emissions may have led to an underestimation or overestimation of the contribution of catering services to the total carbon footprint. Similarly, the absence of standardized data on transportation usage required assumptions based on available information, which could influence the variability observed between destinations. Despite these challenges, the methodology employed—combining a bottom-up approach with a top-down extrapolation—ensures a structured and coherent estimation process. However, the potential discrepancies highlight the need for more granular and systematically collected data in future applications of the tool. Addressing these limitations would enhance the precision of the impact assessments and allow for the incorporation of statistical confidence intervals in future research. Additionally, improving data collection mechanisms, such as direct integration with transportation and waste management systems, could minimize the reliance on assumptions and strengthen the accuracy of results.”

Comment 30: Third Paragraph. The section on future research is overly general. A stronger, more specific proposal should be included. Additionally, the mention of "science-backed sustainable initiatives" requires the specification of criteria and validation methods to ensure practical applicability.

Response 30: Agree. Thank you for your comments regarding the section on future research. We truly appreciate your suggestion for a more specific and detailed proposal, as well as the need to clarify the criteria and validation methods for "science-backed sustainable initiatives. In response, we have revised this section to include more concrete research directions. Specifically, we have highlighted the need for expanding the geographical coverage of the tool to capture a broader range of tourism profiles, as well as exploring advanced data collection methods to reduce reliance on extrapolations. Additionally, we have refined the discussion on sustainability validation by focusing on the need to incorporate more context-specific criteria that align with local environmental goals and regulations, further enhancing the tool’s adaptability and practical impact. The following paragraph has been added:

Lines 925-945: “Future research should focus on enhancing the use of this tool beyond the current four destinations as sustainable tourism has been gaining momentum over the last decade. Specifically, research could explore expanding the geographical coverage to include destinations with varied tourism profiles, enabling a more robust assessment of the tool’s adaptability. Hotels, tour operators, and destinations now have access to a unified, free tool that can facilitate the implementation of science-backed sustainable initiatives and allow for public sharing of their impact data. This would make it easier for travelers to make responsible choices. Additionally, future research could explore integrating advanced data collection methods, such as IoT sensors or automated tracking systems, to capture real-time consumption data. This would minimize the need for extrapolation and improve the accuracy of the tool's impact estimates. Another promising direction is the application of machine learning models to refine impact predictions based on user data, helping to forecast future trends and assess the impact of various tourism scenarios. Furthermore, research could focus on the development of a framework that ties sustainable practices in tourism to local environmental goals and regulations, ensuring that the Greentour tool remains adaptable to diverse sustainability frameworks. The integration of localized standards would further enhance the practical applicability and impact of the tool. In this regard, key partners in the tourism sector—such as hotels, other accommodation providers, restaurants, local governments, and tourist offices—will play a fundamental role in promoting and adopting the products developed, as well as identifying opportunities for integrating the tool into public policies and broader sustainability frameworks.”

Comment 31: Fourth Paragraph. The reference to "key partners" should include a more detailed description, specifying their roles, contributions, and relevance to the study.

Response 31: Thanks you for pointing this out. A paragraph has been added in reference to the suggestion:

Lines 942-953: ”In this regard, key partners in the tourism sector—such as hotels, other accommodation providers, restaurants, local governments, and tourist offices—will play a fundamental role in promoting and adopting the products developed. Specifically, these partners will assist in the integration of the Greentour tool into their operational processes, ensuring that sustainability practices are implemented at the local and industry levels. Hotels and accommodation providers will benefit from the tool by using its data to improve their environmental practices, while restaurants can focus on sustainable sourcing and waste management. Local governments and tourist offices, on the other hand, will act as facilitators in spreading awareness and encouraging adoption of the tool through policy initiatives, incentives, and supporting programs. These partners will also be instrumental in identifying opportunities for integrating the tool into public policies and broader sustainability frameworks, ensuring a long-term, collective impact on the tourism sector.”

 

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

Review of the sustainability-3400033-peer review-v1

 

Despite the positive aspects of the tourism business for the economy of the host country, the activity of tourists can have negative sides. These are environmental issues, increased carbon emissions, and waste management issues. The Greentour project was created to implement the idea of sustainable tourism and its digital transformation.

This project was created recently and the number of studies is still small.

This work is actually devoted to testing the Greentour project and some conclusions about the four resorts. A lot of statistical material was used. Unfortunately, only for 2019. But the analysis of this material also revealed the main problems of tourism. The authors clearly outlined the material and drew the right conclusions. This applies to tourism and the Greentour project. The development of this project will help to increase the quality and promote the sustainable development of tourism.

The article contains 10 figures, 2 tables, 48 references.

The work can be printed after making some corrections:

 

1. Please write a few words about how these results relate to 2023 and 2024 due to inflation and technical upgrades.

 

2. Page 7 upper part - remove the inscription «Figure 5 shows how the owner of the establishment obtains the results in the tool by accessing the website».

 

3. Table 1 – adjust the numbers of the second row.

 

4. About literature. References in the text should be placed in square brackets [1]. I did not find all the literature in the text.

 

Review of the sustainability-3400033-peer review-v1

 

Despite the positive aspects of the tourism business for the economy of the host country, the activity of tourists can have negative sides. These are environmental issues, increased carbon emissions, and waste management issues. The Greentour project was created to implement the idea of sustainable tourism and its digital transformation.

This project was created recently and the number of studies is still small.

This work is actually devoted to testing the Greentour project and some conclusions about the four resorts. A lot of statistical material was used. Unfortunately, only for 2019. But the analysis of this material also revealed the main problems of tourism. The authors clearly outlined the material and drew the right conclusions. This applies to tourism and the Greentour project. The development of this project will help to increase the quality and promote the sustainable development of tourism.

The article contains 10 figures, 2 tables, 48 references.

The work can be printed after making some corrections:

 

1. Please write a few words about how these results relate to 2023 and 2024 due to inflation and technical upgrades.

 

2. Page 7 upper part - remove the inscription «Figure 5 shows how the owner of the establishment obtains the results in the tool by accessing the website».

 

3. Table 1 – adjust the numbers of the second row.

 

4. About literature. References in the text should be placed in square brackets [1]. I did not find all the literature in the text.

 

Review of the sustainability-3400033-peer review-v1

 

Despite the positive aspects of the tourism business for the economy of the host country, the activity of tourists can have negative sides. These are environmental issues, increased carbon emissions, and waste management issues. The Greentour project was created to implement the idea of sustainable tourism and its digital transformation.

This project was created recently and the number of studies is still small.

This work is actually devoted to testing the Greentour project and some conclusions about the four resorts. A lot of statistical material was used. Unfortunately, only for 2019. But the analysis of this material also revealed the main problems of tourism. The authors clearly outlined the material and drew the right conclusions. This applies to tourism and the Greentour project. The development of this project will help to increase the quality and promote the sustainable development of tourism.

The article contains 10 figures, 2 tables, 48 references.

The work can be printed after making some corrections:

 

1. Please write a few words about how these results relate to 2023 and 2024 due to inflation and technical upgrades.

 

2. Page 7 upper part - remove the inscription «Figure 5 shows how the owner of the establishment obtains the results in the tool by accessing the website».

 

3. Table 1 – adjust the numbers of the second row.

 

4. About literature. References in the text should be placed in square brackets [1]. I did not find all the literature in the text.

 

Comments for author File: Comments.pdf

Author Response

Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding corrections highlighted in track changes in the re-submitted files.

Comment 1: Despite the positive aspects of the tourism business for the economy of the host country, the activity of tourists can have negative sides. These are environmental issues, increased carbon emissions, and waste management issues. The Greentour project was created to implement the idea of sustainable tourism and its digital transformation.

This project was created recently and the number of studies is still small.

This work is actually devoted to testing the Greentour project and some conclusions about the four resorts. A lot of statistical material was used. Unfortunately, only for 2019. But the analysis of this material also revealed the main problems of tourism. The authors clearly outlined the material and drew the right conclusions. This applies to tourism and the Greentour project. The development of this project will help to increase the quality and promote the sustainable development of tourism.

The article contains 10 figures, 2 tables, 48 references. The work can be printed after making some corrections:

Comment 2: Please write a few words about how these results relate to 2023 and 2024 due to inflation and technical upgrades.

Response 2: Thanks you for pointing this out.  These lines of the 522-525 have been added to explain what happens in these years and how the tool is proceeding: “The developed tool is now being applied to 2023 and 2024 to assess year-over-year changes in the same establishments and determine if their environmental performance has improved. Some establishments have already started using it for this purpose, and a future project will focus on comparing results across multiple years and expanding its application to more countries worldwide.”

Comment 3: Page 7 upper part - remove the inscription «Figure 5 shows how the owner of the establishment obtains the results in the tool by accessing the website».

Response 3: Thanks you for pointing this out. This line has been removed from the manuscript of lines 400 and 401.

Comment 4: Table 1 – adjust the numbers of the second row.

Response 4: Agree. These changes have been modified in the manuscript.

Comment 5: About literature. References in the text should be placed in square brackets [1]. I did not find all the literature in the text.

Response 5: Thanks you for pointing this out. All the references have been analyzed (and the new ones added) and put with brackets. Thank you very much for reviewing this important part in the manuscript.

 

 

Author Response File: Author Response.pdf

Reviewer 4 Report

Comments and Suggestions for Authors I believe the potential significance of the Greentour tool. Nevertheless, the manuscript is written in a sub - optimal manner, making it arduous to follow. The concept of "Greener Tourism," which is central to the paper, lacks an explanation within the main text. This absence may lead to confusion among non - specialist readers. Moreover, the connection between the Greentour tool and this research has not been clearly delineated.

 

If the study pertains to the development of the tool, the methodology section ought to elaborate on the development process in detail. On the other hand, if the research is centered on testing and evaluating the tool, it should present a comprehensive set of metrics to demonstrate its usability and robustness. In the final paragraph of the introduction, the authors assert that the primary aim of the study is to test the tool; however, no corresponding evaluation criteria are provided in the manuscript.

 

Furthermore, Section 3 showcases four application cases of the tool. This indicates that the work could potentially be an applied case study. If that is the case, the authors should emphasize the findings derived from these cases. Overall, the positioning of this paper remains ambiguous, and the manuscript requires substantial revision to clarify its objectives and contributions.

Author Response

Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding corrections highlighted in track changes in the re-submitted files.

Comment 1: I believe the potential significance of the Greentour tool. Nevertheless, the manuscript is written in a sub - optimal manner, making it arduous to follow. The concept of "Greener Tourism," which is central to the paper, lacks an explanation within the main text. This absence may lead to confusion among non - specialist readers. Moreover, the connection between the Greentour tool and this research has not been clearly delineated.

 Response 1: Thanks you for pointing this out.  We appreciate the reviewer’s insightful comments regarding the need for a clearer explanation of the ‘Greener Tourism’ concept and its connection to the tool. In response, we have added a definition of ‘Greener Tourism’ in the introduction to ensure that non-specialist readers can grasp its relevance to this study. Additionally, we have explicitly outlined how the developed tool addresses current gaps in environmental impact assessment methodologies within the tourism sector. These additions clarify the novelty and contribution of the tool while improving the overall readability of the manuscript. For this reason, it has been considered to add in lines 36-42 this paragraph:

“The concept of "Greener Tourism" refers to an approach that prioritizes minimizing environmental impacts while ensuring the sustainability of tourism-related activities (Gössling and Peeters. 2015). This involves adopting strategies to reduce carbon emissions, improve resource efficiency, and promote environmentally responsible practices across various tourism sub-sectors, including accommodations, food services, leisure activities, and transportation (Bramwell et al. 2017).”

• Gössling, S., & Peeters, P. (2015). Assessing tourism's global environmental impact 1900–2050. Journal of Sustainable Tourism, 23(5), 639-659.
• Bramwell, B., Higham, J., Lane, B., & Miller, G. (2017). Twenty-five years of sustainable tourism and the Journal of Sustainable Tourism: Looking back and moving forward. Journal of Sustainable Tourism, 25(1), 1-9.

The following paragraph has also been added from lines 107 to 113:

“The designed tool has been specifically developed to fill the gaps in existing environ-mental assessment methodologies in tourism. Unlike previous tools that focus primarily on carbon footprint calculations, Greentour integrates a broader set of environ-mental impact indicators and evaluates tourism establishments and destinations holistically. By applying LCA principles, this tool provides a comprehensive framework for identifying environmental hotspots and supporting stakeholders in making more sustainable choices.”

Comment 2: If the study pertains to the development of the tool, the methodology section ought to elaborate on the development process in detail. On the other hand, if the research is centered on testing and evaluating the tool, it should present a comprehensive set of metrics to demonstrate its usability and robustness. In the final paragraph of the introduction, the authors assert that the primary aim of the study is to test the tool; however, no corresponding evaluation criteria are provided in the manuscript.

 

Response 2: We sincerely appreciate the reviewer’s comments and the opportunity to clarify the focus of our study. In response to this feedback, we have improved the methodology section by providing a detailed explanation of the tool’s development process. This includes how the tool was designed, what environmental indicators it considers, and how it calculates environmental impacts through the web-based platform. Additionally, to demonstrate the tool’s functionality, we have applied it to real-world case studies and published the results obtained. These case studies validate the tool’s ability to assess environmental impacts at both the establishment and destination levels. The results clearly show the environmental footprint of different tourism sub-sectors, thereby confirming the tool’s practical applicability.

 

Given this, the study not only presents the tool’s development but also provides empirical evidence of its effectiveness in assessing environmental impacts in the tourism sector. We have revised the manuscript accordingly to ensure that both aspects—development and validation—are clearly articulated.

 

Comment 3: Furthermore, Section 3 showcases four application cases of the tool. This indicates that the work could potentially be an applied case study. If that is the case, the authors should emphasize the findings derived from these cases. Overall, the positioning of this paper remains ambiguous, and the manuscript requires substantial revision to clarify its objectives and contributions.

Response 3: We appreciate the reviewer’s comments and understand the importance of clarifying the positioning of the study. While Section 3 presents four case studies, the primary aim of the manuscript remains the evaluation of the environmental tool rather than conducting an in-depth applied study on each destination. The case studies serve as a validation mechanism, demonstrating the tool’s ability to assess environmental impacts across different types of tourism destinations.

To ensure this is clear, we have structured the results to highlight key insights from the tool’s application, including variations in carbon footprint due to tourism type, infrastructure, and sectoral contributions. Additionally, we compare our findings with existing literature to reinforce the credibility of the tool’s outputs.

Given this, we believe the manuscript already provides a comprehensive evaluation of the tool through real-world applications. However, we are open to further clarifying this distinction if needed.

Author Response File: Author Response.pdf

Reviewer 5 Report

Comments and Suggestions for Authors

The paper presents a comprehensive study on the development and application of the Greentour tool, designed to evaluate the environmental impact of tourism destinations using a Life Cycle Assessment (LCA) approach. The research is well-structured, methodologically rigorous, and highly relevant given the increasing emphasis on sustainable tourism. However, certain areas could be strengthened to enhance the clarity, coherence, and impact of the study, like:

- Clarity and Structure: The introduction could be more concise and focused. While the background is important, a more streamlined introduction would help readers quickly grasp the research problem; and some sections (e.g., the methodology) contain excessive detail that could be summarized or moved to supplementary materials.

- Results: While the findings are well-documented, they could benefit from clearer visual representation. More simplified tables and graphs with succinct explanations would enhance readability; also the comparison of destinations could be better structured. Instead of listing findings in long paragraphs, a table summarizing key results per destination would improve clarity.

- Policy and Practical Implications: The paper briefly discusses how the tool can inform policymakers and tourism stakeholders, but this could be expanded. How can the findings influence regulations or industry best practices?; A clearer set of recommendations for policymakers, businesses, and tourists based on the study’s findings would increase its practical utility.

Author Response

Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding corrections highlighted in track changes in the re-submitted files.

The paper presents a comprehensive study on the development and application of the Greentour tool, designed to evaluate the environmental impact of tourism destinations using a Life Cycle Assessment (LCA) approach. The research is well-structured, methodologically rigorous, and highly relevant given the increasing emphasis on sustainable tourism. However, certain areas could be strengthened to enhance the clarity, coherence, and impact of the study, like:

Comment 1: Clarity and Structure: The introduction could be more concise and focused. While the background is important, a more streamlined introduction would help readers quickly grasp the research problem; and some sections (e.g., the methodology) contain excessive detail that could be summarized or moved to supplementary materials.

Response 1: Agree. We have removed some repetitive and unfounded sentences from the introduction, as they distracted the reader and made it harder to grasp the objective of the study.

The following sentence has been removed from the lines:

Lines 49-50: “This environmental information will help tourists to become more concerned about the environmental implications of their choices when travelling around.”

Lines 73-76: “There are various tools, employing distinct methodologies, that enable stakeholders to face the main challenge in the accommodation sector, as well as other stakeholders in the different sectors of the tourism industry (UNWTO, 2023a).”

Lines 86-88: “In parallel, various tools have been developed to specifically calculate the carbon foot-print of accommodations, with the aim of quantifying their greenhouse gas (GHG) emissions.”

Lines 92-93: “The importance of these measurements for assessing GHG emissions has grown significantly (Pandey et al., 2010).”

These modifications make the introduction more fluid and easier to follow by eliminating unnecessary sentences that did not directly contribute to the main objective of the study.

Comment 2:  Results: While the findings are well-documented, they could benefit from clearer visual representation. More simplified tables and graphs with succinct explanations would enhance readability; also the comparison of destinations could be better structured. Instead of listing findings in long paragraphs, a table summarizing key results per destination would improve clarity.

Response 2: We appreciate the reviewer’s feedback regarding the clarity and structure of the results. To address this concern, we would like to clarify how the results have been structured and presented in the manuscript to ensure readability and facilitate comparisons. Firstly, a visual summary is provided through a radar chart (Figure 9), which allows for a quick and intuitive comparison of the environmental impacts across the four destinations. This graphical representation helps readers grasp key differences between the analyzed locations in a clear and concise manner. Secondly, Table 2 presents a structured breakdown of the results specifically for the Climate Change (CC) impact category, offering a detailed numerical comparison of the contributions from different tourism-related sub-sectors (accommodation, eating and drinking, leisure activities, transport, and waste management) at each destination. By normalizing the results per tourist and per year, the table enables a direct and meaningful comparison across destinations. Additionally, the subsequent sections (3.2.1 to 3.2.4) provide a destination-specific analysis, further detailing the contributions of each sub-sector at an individual destination level. These sections highlight key insights, such as the dominant role of transportation in CC impact and the variations in environmental performance across destinations.

Given this structure—combining visual representation, tabular data, and detailed explanatory sections—we believe the current format effectively balances clarity and depth, while ensuring that the comparisons between destinations are easy to follow.

Comment 3:  Policy and Practical Implications: The paper briefly discusses how the tool can inform policymakers and tourism stakeholders, but this could be expanded. How can the findings influence regulations or industry best practices?; A clearer set of recommendations for policymakers, businesses, and tourists based on the study’s findings would increase its practical utility.

Response 3: Thanks you for pointing this out.  We appreciate the reviewer’s insightful comments regarding the policy and practical implications of the study. Based on the feedback, we have expanded the discussion on how the findings can influence regulations and industry best practices. Specifically, we have clarified how the environmental tool provides data that can assist policymakers in designing regulations that promote sustainable tourism. Additionally, we have outlined a clearer set of recommendations for policymakers, businesses, and tourists to enhance the practical application of the tool. These revisions strengthen the study’s contribution to both academic research and real-world implementation. The following paragraph has been added:

Lines 815-843: “In this regard, the environmental tool offers valuable insights that can directly in-form policymakers, tourism stakeholders, and industry best practices. Given that tour-ism contributes significantly to global greenhouse gas emissions (UNWTO, 2022), inte-grating scientifically backed environmental impact assessments into decision-making is crucial. The tool's ability to quantify impacts beyond carbon footprint, including water scarcity, eutrophication, and resource depletion, provides a more holistic under-standing of tourism’s environmental footprint (Gössling & Higham, 2021). For poli-cymakers, the findings suggest the necessity of regulatory frameworks that encourage sustainable tourism practices. Destination managers could implement differentiated tax incentives for establishments that demonstrate lower environmental impact through Greentour’s metrics (Scott et al., 2019). Similarly, municipalities could man-date the integration of environmental performance reporting into tourism develop-ment plans, ensuring alignment with broader climate commitments, such as the EU Green Deal (European Commission, 2020). For businesses, particularly accommoda-tions and restaurants, the tool highlights key areas for improvement, such as energy efficiency, waste reduction, and sustainable sourcing of food and materials (Peeters et al., 2018). Establishments could use the tool to set reduction targets and publicly dis-close their performance, fostering transparency and consumer trust (Font & Hindley, 2017). This aligns with growing consumer demand for sustainable travel options, as seen in industry reports indicating that over 70% of travelers prefer environmentally responsible tourism services (Booking.com, 2023). Finally, for tourists, the tool offers a data-driven approach to responsible travel choices. Public access to destina-tion-specific environmental profiles could encourage travelers to select lower-impact accommodations and activities, reinforcing market-driven sustainability (Dubois et al., 2016). Encouraging sustainable tourism certifications based on Greentour’s methodol-ogy could further standardize best practices across the industry (WTTC, 2021). Incorporating these recommendations into policy frameworks and business strat-egies would enhance the practical impact of Greentour, facilitating a shift toward more sustainable and profitable tourism operations worldwide.”

• com. (2023). Sustainable Travel Report 2023. https://globalnews.booking.com/sustainable-travel-report-2023
• Dubois, G., Peeters, P., Ceron, J. P., & Gössling, S. (2016). The future of tourism mobility: Implications of high-speed rail developments in Europe. Journal of Sustainable Tourism, 24(2), 234-252. https://doi.org/10.1080/09669582.2015.1049492
• European Commission. (2020). The European Green Deal. https://ec.europa.eu/info/strategy/priorities-2019-2024/european-green-deal_en
• Font, X., & Hindley, A. (2017). Understanding tourists’ sustainability information needs through new media. Journal of Sustainable Tourism, 25(7), 866-881. https://doi.org/10.1080/09669582.2016.1241346
• Gössling, S., & Higham, J. (2021). The low-carbon imperative: Destination management under climate change. Journal of Destination Marketing & Management, 19, 100542. https://doi.org/10.1016/j.jdmm.2020.100542
• Peeters, P., Gössling, S., & Becken, S. (2018). Innovation towards tourism sustainability: Climate change and aviation. Tourism and Hospitality Research, 18(1), 99-107. https://doi.org/10.1177/1467358418759751
• Scott, D., Gössling, S., & Hall, C. M. (2019). The evolving climate change and tourism relationship: An update to Hall, Scott and Gössling (2015). Journal of Sustainable Tourism, 27(2), 205-225. https://doi.org/10.1080/09669582.2018.1529773
• (2022). Tourism and Climate Change Report 2022. https://www.unwto.org/tourism-and-climate-change
• WTTC (World Travel & Tourism Council). (2021). A Net Zero Roadmap for Travel & Tourism. https://wttc.org/Research/Net-Zero-Roadmap

 

 

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Comment 1: This study presents a tool to measure the environmental impact of tourism. While the tool appears interesting and well-structured and the infographic presented impressive, it is unclear whether a real footprint of tourism activity is estimated at any stage and whether the tourism value chain is considered at all in the estimate of the tourism footprint.   In any case, several improvements to the paper are needed to go beyond the mere description of convenient software. More specifically, before presenting the tool, the paper should address two key questions: (1) the theoretical basis of the methodologies to measure tourism environmental impact and (2) the studies available on this subject (for both, see, for example Miralles et al, 2023).

Response 1: Thanks you for pointing this out. This paragraph was included from line 45-63: “Before evaluating specific tools, it is crucial to understand the theoretical foundations of tourism environmental impact measurement methodologies. Different approaches have been proposed, including the Life Cycle Assessment (LCA), which assesses the entire environmental impact of a product or service from raw material extraction to disposal, and footprint-based indicators such as Carbon Footprint (CF), Water Footprint (WF), and Ecological Footprint (EF). These methodologies differ in scope, data requirements, and applicability within the tourism sector (Miralles et al., 2023). Previous studies have applied these methods to assess tourism’s environmental performance at various levels. For example, Miralles et al. (2023) conducted a comprehensive review of footprint applications in tourism, highlighting the challenges of data availability, system boundary definitions, and methodological inconsistencies. Other studies have examined the carbon footprint of accommodations (Puig et al., 2017), the water footprint of tourist activities (Hof and Blázquez-Salom, 2015), and the ecological footprint of destinations (Hunter and Shaw, 2007). Despite these efforts, there is still no consensus on a standardized methodology for assessing tourism’s environmental impact at a broader scale”.

 

Reviewer’s reply: Please review the literature on the environmental impact measurement, explain the key differences in the approaches proposed in the light of the underlying theories and related methodologies.

Comment 2:  While it may be true that no software tool may be available to measure the environmental effects of tourism, it is more important to clarify what and how this tool should approach both definitions and measurement problems. On one hand, tourism  as an economic activity presents several challenges both to identify its perimeter and its nature. Statistically, it is both an assemblage (with variable weights) of different industries (accommodation, food, transportation and leisure), and commodities. Its environmental footprint also appears potentially large and uneven. In the case of water, for example, it may be a major contributor to water stress because of its tendency to concentrate on visitors in lower income, water scarce countries during summer months.  The authors should try to account for these problems by reviewing the literature, and by clarifying their theoretical approach to defining and measuring tourism and tourism impact.

Response 2: Thank you for your insightful comment. We agree that tourism as an economic activity presents several challenges, particularly when it comes to defining its perimeter and measuring its impacts. As you mentioned, tourism comprises a range of industries, including accommodation, food, transportation, and leisure, each with different contributions to the overall environmental footprint. Moreover, certain aspects, such as water usage, can indeed present uneven and significant impacts, especially in water-scarce regions during peak seasons. However, we believe our tool represents a novel approach to addressing these challenges. Unlike other tools that primarily focus on climate change, our tool evaluates a broader set of environmental impacts across multiple categories, including water use, energy consumption, and waste generation. It is designed to be applicable to a wide range of establishments, from various types of accommodation to restaurants, pubs, and leisure activities. By providing both individual establishment-level and destination-level results, the tool enables a comprehensive understanding of the environmental impacts of tourism. This approach is essential for identifying areas for improvement and guiding decision-making processes for local governments, tourism authorities, and other stakeholders. In doing so, it helps address the environmental concerns specific to each destination and establish targeted measures to mitigate these impacts effectively.

We hope this explanation clarifies the scope and value of the tool. Please let us know if further elaboration is needed.

Reviewer’s reply. Please clarify the definition of tourism (as a sector, economic activity, a consumption category) and the theoretical and operational basis on which production activities, commodities and other economic entities are attributed to tourism in the application of the tool.  

Comment 3: At present, the paper lists a set of environmental effects of tourists travelling to a specific destination as if these were meaningful measurements of impacts in their own right. However, most of the numbers presented may be misleading, unless they are interpreted within an appropriate economic context, and some attempt is made to integrate them in some overall measurement of welfare effects and short- and long-term sustainability. Interaction with other activities and hidden costs of tourism through indirect pressure on natural resources may be also more important than the effects that may be the direct object of an inventory (Borucke et al., 2013).

Response 3: Thank you for your valuable comment. We acknowledge that the environmental impacts of tourism should not be considered in isolation, but rather within a broader economic and social context. As you pointed out, integrating these effects into a comprehensive measurement of welfare and sustainability, taking into account indirect pressures on natural resources and the hidden costs of tourism, is crucial for a full understanding of the sustainability of the sector. However, the current version of our tool focuses primarily on the environmental pillar of sustainability, as this is where there is the greatest gap in tools available today. To our knowledge, no existing tool provides such a comprehensive environmental assessment that can be applied to any tourism destination or establishment globally. While we recognize the importance of considering the economic and social dimensions, this tool’s environmental perspective is already highly complete and provides valuable insights for addressing immediate sustainability challenges. That said, we agree with your point that integrating economic and social factors would offer a more holistic view of sustainable tourism. We believe that such an approach would be necessary to complement our tool, providing a fuller picture of sustainability in tourism.

We hope this explanation clarifies the scope of our tool and its current limitations. We are working towards enhancing its integration with other sustainability dimensions in the future.

Reviewer’s reply. Please explain in some detail how the environmental effects have been chosen, how they relate to meaningful concepts of natural capital, natural resources and sustainability, and on what basis they are weighed. Try to clarify also the relationship to SDGs and the differences between causes and effects.

 

Comment 4: The tool does not appear to have an explicit economic basis, unless this can be traced to some of the many sources cited, but not discussed by the authors.  In particular, the authors should clarify (i) their definition of tourism and the corresponding statistical categories in terms of the international nomenclature, (ii) the economic and statistical basis for the choice of the data and the compilation of the inventory, (iii) the criterion for the selection of the indicators, (iv) the meaning and the measurement of the impact, (iv) the possible criteria for measuring the footprint, (v) the possible methodologies for aggregating the different impacts.

Response 4: Dear reviewer, thank you for your comment. In the manuscript's introduction, tourism and its associated challenges in measuring environmental impacts are clearly defined. The tool is designed with an environmental focus, recognizing the challenges of assessing this sector’s impacts. While the economic and social dimensions are briefly mentioned, they are not the primary focus of the tool. Regarding the selection of data and indicators, the criteria used are based on the Sustainable Development Goals (SDGs) most relevant to tourism, which is explained in the manuscript. Furthermore, the process for measuring impacts, calculating the environmental footprint, and the criteria considered in the process are detailed. The methodology for aggregating the various impacts follows established practices, such as the Environmental Footprint (EF) method, ensuring the reliability and consistency of the results. Although the tool currently focuses on the environmental pillar, we acknowledge the importance of integrating economic and social aspects in the future to provide a more comprehensive view of sustainable tourism.

Reviewer’s reply. Please  discuss extensively and clarify: (i) your definition of tourism and the corresponding statistical categories in terms of the international nomenclature, (ii) the economic and statistical basis for the choice of the data and the compilation of the inventory, (iii) the criterion for the selection of the indicators, (iv) the meaning and the measurement of the impact, (iv) the possible criteria for measuring the footprint, (v) the possible methodologies for aggregating the different impacts.

 

More specific questions

Section 2.1.1:

Comment 5: “Primary data needed to compile the inventory is collected through a questionnaire that is accessed through a registration by the owner of the establishment on the Greentour tool website (Greentour, 2024) (Figure 3)”. Please explain briefly the characteristics of the questionnaire, the statistical basis of the data required, the consistency and reliability checks, if available.

Response 5: Agree. We have all this detailed information to emphasize this point. All information suggested by the reviewer has been completed and added from lines 163-185 onwards:

“The primary environmental data required for the development of the inventory are collected through an online questionnaire, accessible through the establishment owner's registration on the Greentour platform (Greentour, 2024) (Figure 3). This questionnaire asks for general information about the establishment, such as its name, type, category, year of data collection, capacity and days of operation, as well as details about its facilities, the months it is open and other relevant aspects.

It also has a specific section for the collection of essential environmental data for analysis, covering the generation and consumption of energy, water, cleaning products for maintenance, food, beverages and other products used in leisure activities. All these inputs and emissions have been determined based on previous studies and assessments carried out in different establishments, in order to identify the key aspects to be considered according to the type of accommodation.

The statistical basis of the data follows internationally recognised sustainability assessment methodologies, including the Life Cycle Assessment (ISO 14040/44) and the Product Environmental Footprint (PEF) method. In addition, the questionnaire is in line with standards for environmental reporting in tourism, allowing comparability between different establishments. The results of each establishment are presented in relation to other establishments in the same destination and other destinations analysed, thus enabling a comparative assessment.

To ensure the consistency and reliability of the data, several validation mechanisms have been implemented. Firstly, the questionnaire incorporates predefined ranges and reference values based on previous studies and current regulations. Secondly, internal checks are applied to detect possible discrepancies. In case of inconsistencies, the technicians in charge review the quality of the data entered, identifying and correcting errors or anomalies.

Reviewer’s reply: Please clarify the methodology followed in designing the questionnaire, including the balance between qualitative and quantitative questions, the relationship to the methodological basis of the study, the relationship to the methods of contingent evaluation or other established methods of eliciting behavioral and impact statistics from interviews. If possible, provide data on means and variances of the responses obtained. Was the questionnaire pretested for reliability?

Comment 6:   “Since inventory data collection is the most challenging stage of this tool's methodology—often due to the lack of available data faced by technicians responsible for calculating environ-mental impacts (Parvatker and Eckelman, 2019)—a series of assumptions have been made to develop the most detailed inventory possible. While these assumptions may increase the level of uncertainty in the LCA, they are necessary to fill the gaps in the data provided by the facilities.” The nature and the quality of these assumptions needs to be clarified since it is clearly relevant to judge the reliability of the impact estimates.

Response 6: Thanks you for pointing this out. We have added the following information to detail all the assumptions that have been made to calculate the environmental impacts due to lack of data in order to be as accurate as possible. In addition, for better understanding and detail, tabs and figures have been added as well. All this information has been added from line 188 to 330.

 

Section 2.1.2

Comment 7: “The Environmental Footprint (EF) 3.0 method was used in order to quantify the environmental impacts of the goods and services included in the tool.” The method should be explained and its application clarified. It is noty only a matter of categorization but of specific applicability and sufficient information.

Response 7: Thanks you for pointing this out. We have added this paragraph to the lines 344-352 to better justify why we have used this method:

“…This method was chosen because it provides a comprehensive and standardized approach for assessing environmental performance across multiple impact categories, ensuring comparability and reliability. In the tourism sector, where diverse activities and supply chains contribute to environmental impacts, EF 3.0 enables a more holistic evaluation by integrating life cycle assessment principles. Additionally, its alignment with EU recommendations and its sector-specific applicability make it an appropriate methodology for measuring and improving sustainability in tourism establishments.”

Reviewer’s reply: Please clarify the method in more detail. The fact that it integrates life cycle assessment principles per se is not a clarification but an additional item to explain.

 

 

Section 2.1.3

Comment 8: “In the tool, environmental results are generated directly from inventory data, which includes accommodation, restaurants, and tourist activities, along with the corresponding impact categories.” Please clarify how they are generated and on what basis. Are the same coefficients applied everywhere and for all tourists? Are value chain effects taken into account?

Response 8: Thank you for your comment and suggestion.

The environmental results in the Greentour tool are generated from a detailed data inventory, which includes information on the number of tourists or guests in each establishment. This allows to calculate the impacts both at the total level of the establishment and per tourist. The web platform is linked to an Excel database where the emission factors for each process flow and each impact category have been predefined. In this way, by entering the specific data of each establishment and the total number of customers, the corresponding environmental impact per tourist and per accommodation unit, restaurant or tourist activity is automatically obtained. As for geographical and sectoral variability, the tool has been applied in four different tourist destinations in two countries (Spain and Portugal). To reflect these differences, specific factors have been considered, such as the energy mix of each country, which influences the emissions derived from electricity consumption, and the modeling of the processes associated with food, adapted to the characteristics and consumption habits of each region. Therefore, the same coefficients are not applied in all locations or for all tourists, but variables have been integrated that reflect the specificity of each destination and establishment. Likewise, the effects of the value chain have been taken into account by incorporating inventory data based on Life Cycle Analysis methodologies (LCA), ensuring a comprehensive assessment of the environmental impacts associated with tourism activities.

In the article, this paragraph has been added for a better understanding of the lines 385-392: "… The calculations account for the number of tourists per establishment, providing results both at the total level and per visitor. The tool is linked to an Excel database with predefined emission factors, which, combined with input data, allows for automated impact assessment. It also incorporates geographical differences, such as variations in energy mixes and food-related processes in Spain and Portugal. Rather than applying uniform coefficients, the tool integrates location-specific variables and follows Life Cycle Assessment (LCA) methodologies to ensure a comprehensive evaluation of tourism-related environmental impacts.”

Reviewer’s reply Please clarify the nature, the origin and the interpretation of the combination of predefined emission factor, input data and automatic impact assessment. If needed,  provide equations and basic statistics.

Section 3.1

Comment 9: “In addition to the impacts of the different establishments, the tool provides the impacts at the destination level applying the extrapolation procedure detailed below. This extrapolation is not done directly in the tool, so it needs to be done manually by a technical partner. Therefore, the environmental impacts of accommodation, restaurants, and tour-ist activities are exported to an Excel file through the Greentour website.” It is not clear what the authors mean by “ extrapolation”. Whether  it is an estimation procedure, or the mere application of fixed coefficients, it should be explained in more detail, with its properties and limitations discussed also with reference to the literature.

Response 9: Thank you for your comment. The extrapolation process is an estimation procedure that scales up the environmental impacts from individual establishments to the destination level. This is done by combining three key variables: (1) the total annual environmental impact of each establishment registered in the Greentour tool, (2) the number of customers in accommodations (measured in overnight stays), restaurants, and leisure activities, and (3) the capacity of establishments in each destination. These data, along with the information obtained from the Greentour tool, are exported to an Excel file, where the environmental impact at the destination level is calculated. This approach ensures a more accurate assessment by considering the representativeness of the registered establishments and integrating destination-specific parameters. The process is visually represented in Figure 7, which illustrates how the extrapolation is performed.

Reviewer’s reply. Please explain what you mean by combination of the three key variables mentioned. If needed, provide equations and statistics.

 

 

Author Response

REVIEWER 1

Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding corrections highlighted in track changes in the re-submitted files.

Comment 1: This study presents a tool to measure the environmental impact of tourism. While the tool appears interesting and well-structured and the infographic presented impressive, it is unclear whether a real footprint of tourism activity is estimated at any stage and whether the tourism value chain is considered at all in the estimate of the tourism footprint.   In any case, several improvements to the paper are needed to go beyond the mere description of convenient software. More specifically, before presenting the tool, the paper should address two key questions: (1) the theoretical basis of the methodologies to measure tourism environmental impact and (2) the studies available on this subject (for both, see, for example Miralles et al, 2023).

Response 1: Thanks you for pointing this out. This paragraph was included from line 45-63: “Before evaluating specific tools, it is crucial to understand the theoretical foundations of tourism environmental impact measurement methodologies. Different approaches have been proposed, including the Life Cycle Assessment (LCA), which assesses the entire environmental impact of a product or service from raw material extraction to disposal, and footprint-based indicators such as Carbon Footprint (CF), Water Footprint (WF), and Ecological Footprint (EF). These methodologies differ in scope, data requirements, and applicability within the tourism sector (Miralles et al., 2023). Previous studies have applied these methods to assess tourism’s environmental performance at various levels. For example, Miralles et al. (2023) conducted a comprehensive review of footprint applications in tourism, highlighting the challenges of data availability, system boundary definitions, and methodological inconsistencies. Other studies have examined the carbon footprint of accommodations (Puig et al., 2017), the water footprint of tourist activities (Hof and Blázquez-Salom, 2015), and the ecological footprint of destinations (Hunter and Shaw, 2007). Despite these efforts, there is still no consensus on a standardized methodology for assessing tourism’s environmental impact at a broader scale”.

 

Reviewer’s reply: Please review the literature on the environmental impact measurement, explain the key differences in the approaches proposed in the light of the underlying theories and related methodologies.

Response Comment 1: Thank you for your comment. The requested literature review on environmental impact measurement has been conducted, highlighting the key differences in the proposed approaches in light of the underlying theories and related methodologies. It should be noted that, while it is important to explain these theoretical bases, the introduction of the article should not be too long so as not to detract from the main focus of the study. For this reason, a brief explanation has been included highlighting the differences between the use of specific indicators such as carbon footprint or water footprint, and the LCA methodology, which encompasses these indicators and can be equally applied to the tourism sector. This paragraph has been amended in the article:

Lines 62-82: “Before evaluating specific tools, it is crucial to understand the theoretical foundations of tourism environmental impact measurement methodologies. The measurement of tourism’s environmental impact can be approached using different methodologies, each grounded in distinct theoretical foundations. Life Cycle Assessment (LCA) is based on systems thinking and evaluates the entire life cycle of a tourism product or service, considering all environmental impacts from raw material extraction to disposal. It provides a comprehensive, holistic analysis but is data-intensive and complex. In contrast, footprint-based indicators, such as Carbon Footprint (CF), Water Footprint (WF), and Ecological Footprint (EF), focus on specific environmental issues like greenhouse gas emissions, water usage, and land consumption. These methods are more straightforward and easier to calculate, but they are less comprehensive than LCA. While LCA is suitable for a broad environmental assessment, footprint indicators offer more targeted insights, especially useful for specific impacts like emissions or water use. Previous studies have applied these methods to assess tourism’s environ-mental performance at various levels. For example, [41] conducted a comprehensive review of footprint applications in tourism, highlighting the challenges of data availability, system boundary definitions, and methodological inconsistencies. Other studies have examined the carbon footprint of [46], the water footprint of tourist activities and the ecological footprint of destinations [30]. Despite these efforts, there is still no consensus on a standardized methodology for assessing tourism’s environmental impact at a broader scale, with both LCA and footprint-based approaches facing challenges related to data availability, consistency, and sector-specific applications.”

 

Comment 2:  While it may be true that no software tool may be available to measure the environmental effects of tourism, it is more important to clarify what and how this tool should approach both definitions and measurement problems. On one hand, tourism  as an economic activity presents several challenges both to identify its perimeter and its nature. Statistically, it is both an assemblage (with variable weights) of different industries (accommodation, food, transportation and leisure), and commodities. Its environmental footprint also appears potentially large and uneven. In the case of water, for example, it may be a major contributor to water stress because of its tendency to concentrate on visitors in lower income, water scarce countries during summer months.  The authors should try to account for these problems by reviewing the literature, and by clarifying their theoretical approach to defining and measuring tourism and tourism impact.

Response 2: Thank you for your insightful comment. We agree that tourism as an economic activity presents several challenges, particularly when it comes to defining its perimeter and measuring its impacts. As you mentioned, tourism comprises a range of industries, including accommodation, food, transportation, and leisure, each with different contributions to the overall environmental footprint. Moreover, certain aspects, such as water usage, can indeed present uneven and significant impacts, especially in water-scarce regions during peak seasons. However, we believe our tool represents a novel approach to addressing these challenges. Unlike other tools that primarily focus on climate change, our tool evaluates a broader set of environmental impacts across multiple categories, including water use, energy consumption, and waste generation. It is designed to be applicable to a wide range of establishments, from various types of accommodation to restaurants, pubs, and leisure activities. By providing both individual establishment-level and destination-level results, the tool enables a comprehensive understanding of the environmental impacts of tourism. This approach is essential for identifying areas for improvement and guiding decision-making processes for local governments, tourism authorities, and other stakeholders. In doing so, it helps address the environmental concerns specific to each destination and establish targeted measures to mitigate these impacts effectively.

We hope this explanation clarifies the scope and value of the tool. Please let us know if further elaboration is needed.

Reviewer’s reply: Please clarify the definition of tourism (as a sector, economic activity, a consumption category) and the theoretical and operational basis on which production activities, commodities and other economic entities are attributed to tourism in the application of the tool.  

Response Comment 2: Thank you for your comment. We agree that tourism as an economic activity presents several challenges, especially when it comes to defining its perimeter and measuring its environmental impacts. Tourism encompasses a diverse set of industries, such as accommodation, food, transport and leisure, each with a different contribution to the global environmental impact. In addition, some factors, such as water use, can have uneven and significant impacts, especially in regions with water scarcity during high seasons.

The definition of tourism in our tool is addressed in an integral way, considering tourism as both an economic activity and a category of consumption. In this sense, tourism is seen not only as an economic sector in itself, but as a set of productive activities that involve various interconnected industries. These activities include, for example, the use of resources in tourist accommodation, the consumption of food in restaurants, passenger transport and leisure activities, all of which contribute to the environmental impact directly or indirectly. To attribute production activities and basic products within the framework of our tool, we have adopted a theoretical basis based on the theory of value chains, which allows us to identify and measure environmental impacts along the various phases of the tourism production chain. That is, instead of approaching tourism as an isolated activity, our tool examines the interactions between the different sectors that make up tourism (accommodation, transport, food, leisure, etc.) and how these contribute to a global environmental impact. The tool is also based on methodologies that make it possible to accurately and comprehensively assess environmental impacts, not only in terms of carbon footprint, but also in water use, waste generation and energy consumption. By considering these multiple factors, we offer a more complete and holistic view of the environmental impact of tourism, allowing the identification of specific areas where mitigation measures can be implemented. We hope that this explanation clarifies how we have defined and measured tourism in the context of our tool, and how we have addressed specific problems, such as the concentration of impacts in certain sectors or regions. We remain at your disposal for any other questions or additional clarification.

For this reason, in order to make it clear in the text, a paragraph has been added to the article to clarify this:

Lines 62-68: “Tourism is an economic activity that encompasses several interconnected sectors, such as accommodation, transportation, food, and leisure, each with its own environmental impact. It is understood as a value chain where different productive activities contribute to the overall environmental impact, both directly and indirectly. A tool is needed that adopts a holistic approach to measure these impacts, evaluating not only the carbon footprint but also water use, energy consumption, and waste generation, allowing for a comprehensive view of tourism's environmental impact and identifying areas for improvement [52].”

 

Comment 3: At present, the paper lists a set of environmental effects of tourists travelling to a specific destination as if these were meaningful measurements of impacts in their own right. However, most of the numbers presented may be misleading, unless they are interpreted within an appropriate economic context, and some attempt is made to integrate them in some overall measurement of welfare effects and short- and long-term sustainability. Interaction with other activities and hidden costs of tourism through indirect pressure on natural resources may be also more important than the effects that may be the direct object of an inventory (Borucke et al., 2013).

Response 3: Thank you for your valuable comment. We acknowledge that the environmental impacts of tourism should not be considered in isolation, but rather within a broader economic and social context. As you pointed out, integrating these effects into a comprehensive measurement of welfare and sustainability, taking into account indirect pressures on natural resources and the hidden costs of tourism, is crucial for a full understanding of the sustainability of the sector. However, the current version of our tool focuses primarily on the environmental pillar of sustainability, as this is where there is the greatest gap in tools available today. To our knowledge, no existing tool provides such a comprehensive environmental assessment that can be applied to any tourism destination or establishment globally. While we recognize the importance of considering the economic and social dimensions, this tool’s environmental perspective is already highly complete and provides valuable insights for addressing immediate sustainability challenges. That said, we agree with your point that integrating economic and social factors would offer a more holistic view of sustainable tourism. We believe that such an approach would be necessary to complement our tool, providing a fuller picture of sustainability in tourism.

We hope this explanation clarifies the scope of our tool and its current limitations. We are working towards enhancing its integration with other sustainability dimensions in the future.

Reviewer’s reply: Please explain in some detail how the environmental effects have been chosen, how they relate to meaningful concepts of natural capital, natural resources and sustainability, and on what basis they are weighed. Try to clarify also the relationship to SDGs and the differences between causes and effects.

Response comment 3: Thank you for your insightful comments. We understand the importance of explaining the rationale behind the selection of environmental effects and their connection to meaningful sustainability concepts such as natural capital, natural resources, and sustainability. Below, we provide a more detailed justification of our methodological choices.

1. Selection of Environmental Effects

The environmental effects considered in our tool have been chosen based on the Environmental Footprint (EF) 3.0 method, a scientifically robust and standardized framework for quantifying environmental impacts. This method ensures comparability and reliability by integrating life cycle assessment (LCA) principles. The selection of impact categories follows the guidelines provided in the Product Environmental Footprint Category Rules (PEFCR), which recommend 16 impact categories to comprehensively assess environmental performance. However, recognizing the specificities of the tourism sector, we have applied the PEFCR criteria to refine the selection, prioritizing the categories most relevant to tourism activities.

2. Relationship to Natural Capital, Natural Resources, and Sustainability

The environmental effects selected in our tool are directly linked to the concepts of natural capital and resource sustainability. Natural capital refers to the stock of renewable and non-renewable environmental resources that provide essential ecosystem services. Tourism, as an industry, interacts significantly with these resources, primarily through energy and water consumption, waste generation, and emissions that contribute to climate change and other environmental pressures. To ensure a meaningful connection to sustainability, the chosen impact categories reflect the critical pressures tourism places on natural systems:

• Climate Change (CC): Tourism is a significant contributor to greenhouse gas emissions, primarily through transportation, accommodation, and food services. Addressing this impact is crucial for long-term climate resilience.
• Water Use (WDP): Tourism establishments and activities exert substantial pressure on water resources, particularly in water-scarce regions, making this a key sustainability concern.
• Resource Use – Fossil (FRD): The sector’s dependence on fossil fuels for transport and operations directly affects energy security and sustainability.
• Acidification (AP) and Eutrophication (FEP, MEP): These categories capture the impacts of tourism-related emissions on air and water quality, which are critical for preserving ecosystem services and biodiversity.
• Ozone Layer Depletion (ODP), Particulate Matter (Ri), and Photochemical Ozone Formation (POF): These categories relate to air quality and human health, ensuring a more comprehensive environmental evaluation.

 

3. Justification for Excluded Categories

Certain impact categories, such as human toxicity (cancer and non-cancer) and freshwater ecotoxicity, have been excluded as they are predominantly associated with industrial activities involving direct emissions of hazardous substances. In contrast, tourism impacts are primarily linked to resource consumption and emissions from transportation and accommodation. Similarly, categories like ionizing radiation, terrestrial eutrophication, land use, and resource use (minerals and metals) were excluded due to their lower relevance in the tourism sector compared to industries like agriculture and manufacturing.

 

4. Connection to the Sustainable Development Goals (SDGs)

Our tool aligns with global sustainability frameworks by integrating environmental indicators that directly support the achievement of the Sustainable Development Goals (SDGs). For example:

• SDG 13 (Climate Action): Addressed through climate change impact assessment.
• SDG 6 (Clean Water and Sanitation): Linked to water consumption and eutrophication impacts.
• SDG 12 (Responsible Consumption and Production): Promoted through resource efficiency and waste management assessments.

By systematically selecting relevant environmental indicators and ensuring alignment with sustainability frameworks, our tool provides a scientifically grounded and policy-relevant approach to assessing and improving the environmental performance of the tourism sector. This comprehensive assessment helps destinations and establishments implement more effective sustainability strategies while ensuring the responsible management of natural capital and resources.

We hope this explanation clarifies our methodological approach and the rationale behind our choices. These lines have been added to make these points clearer in the article:

Lines 401-403: “This approach connects directly to natural capital and sustainability by addressing key environmental pressures while aligning with SDGs, particularly climate action, water management, and responsible consumption.”

Lines 419-421: “In addition, the tool seeks to reach the Sustainable Development Goals (SDGs), as tourism has a significant influence on the global economy and can positively or negatively impact local communities, the environment, and the economy in general [52].”

 

Comment 4: The tool does not appear to have an explicit economic basis, unless this can be traced to some of the many sources cited, but not discussed by the authors.  In particular, the authors should clarify (i) their definition of tourism and the corresponding statistical categories in terms of the international nomenclature, (ii) the economic and statistical basis for the choice of the data and the compilation of the inventory, (iii) the criterion for the selection of the indicators, (iv) the meaning and the measurement of the impact, (iv) the possible criteria for measuring the footprint, (v) the possible methodologies for aggregating the different impacts.

Response 4: Dear reviewer, thank you for your comment. In the manuscript's introduction, tourism and its associated challenges in measuring environmental impacts are clearly defined. The tool is designed with an environmental focus, recognizing the challenges of assessing this sector’s impacts. While the economic and social dimensions are briefly mentioned, they are not the primary focus of the tool. Regarding the selection of data and indicators, the criteria used are based on the Sustainable Development Goals (SDGs) most relevant to tourism, which is explained in the manuscript. Furthermore, the process for measuring impacts, calculating the environmental footprint, and the criteria considered in the process are detailed. The methodology for aggregating the various impacts follows established practices, such as the Environmental Footprint (EF) method, ensuring the reliability and consistency of the results. Although the tool currently focuses on the environmental pillar, we acknowledge the importance of integrating economic and social aspects in the future to provide a more comprehensive view of sustainable tourism.

Reviewer’s reply: Please  discuss extensively and clarify: (i) your definition of tourism and the corresponding statistical categories in terms of the international nomenclature, (ii) the economic and statistical basis for the choice of the data and the compilation of the inventory, (iii) the criterion for the selection of the indicators, (iv) the meaning and the measurement of the impact, (iv) the possible criteria for measuring the footprint, (v) the possible methodologies for aggregating the different impacts.

Response comment 4: Thank you for your valuable comments. Below, we address each of your points in detail to clarify the economic and statistical basis of our tool and methodology.

• Definition of Tourism and Corresponding Statistical Categories

Our definition of tourism aligns with international standards such as those provided by the United Nations World Tourism Organization (UNWTO) and the Statistical Framework for Measuring the Sustainability of Tourism (SF-MST). Tourism is understood as an economic activity that includes multiple interconnected sectors, such as accommodation, transportation, food, and leisure, all of which contribute to its environmental footprint. The classification of activities follows established statistical nomenclatures, such as the International Standard Industrial Classification (ISIC) and the Tourism Satellite Account (TSA) framework, ensuring consistency with global reporting systems.

• Economic and Statistical Basis for the Choice of Data and Compilation of the Inventory

The Greentour tool applies a hybrid approach that integrates primary data collected from tourism establishments through structured questionnaires and secondary data from recognized sources such as Ecoinvent v3.7.1, Agribalyse 3.0, and World Food LCA. The inventory compilation follows the principles of Life Cycle Assessment (LCA) and Product Environmental Footprint (PEF), ensuring a scientifically sound and replicable methodology. Additionally, official tourism records and statistical sources were used to define the most relevant tourism activities, ensuring robust and comparable data across destinations.

• Criterion for the Selection of Indicators

The indicators selected in the tool are based on the Sustainable Development Goals (SDGs) most relevant to tourism, particularly SDG 12 (Responsible Consumption and Production), SDG 13 (Climate Action), and SDG 6 (Clean Water and Sanitation). The environmental impact categories were selected following the PEFCR guidelines, ensuring consistency with European Commission recommendations. Categories such as climate change, resource use (fossil), and water consumption were prioritized due to their relevance to tourism activities, while categories with lower significance in the sector, such as human toxicity and ionizing radiation, were excluded based on prior literature and empirical evidence.

• Meaning and Measurement of Impact

The concept of impact in our tool is aligned with LCA principles, where environmental burdens are quantified in terms of midpoint impact categories. The results are expressed per functional unit, defined as 'guest stay per day' for accommodation, 'number of meals served' for restaurants, and 'number of activities (entries)' for leisure activities. These units allow for standardized impact comparisons and benchmarking across different establishments and destinations.

• Possible Criteria for Measuring the Footprint

The environmental footprint is measured using EF 3.0 methodology, which quantifies environmental pressures in terms of resource depletion, emissions, and pollution across the full life cycle of tourism services. The tool applies a combination of bottom-up (establishment-level data) and top-down (destination-wide extrapolation) approaches to estimate overall tourism-related impacts, incorporating destination-level factors such as energy mix, waste management practices, and transportation emissions.

 

• Methodologies for Aggregating Different Impacts

The aggregation of environmental impacts follows standard LCA normalization and weighting methods, allowing for comparative analysis across impact categories. The normalization process references baseline environmental impacts per capita within the EU, ensuring that results are interpretable and relevant for policymakers and industry stakeholders. Additionally, results are provided both in disaggregated form (per impact category) and in a more synthesized manner through radar charts and comparative benchmarking with other establishments.

We hope this explanation provides the necessary clarifications. While the tool currently focuses on the environmental dimension of sustainability, we acknowledge the importance of integrating economic and social aspects in future developments. All this is explained in the article. We have not added more comments in this comment because if not, the article will be very long and all these parts have already been clearly explained with the rest of the reviews.

 

More specific questions

Section 2.1.1:

Comment 5: “Primary data needed to compile the inventory is collected through a questionnaire that is accessed through a registration by the owner of the establishment on the Greentour tool website (Greentour, 2024) (Figure 3)”. Please explain briefly the characteristics of the questionnaire, the statistical basis of the data required, the consistency and reliability checks, if available.

Response 5: Agree. We have all this detailed information to emphasize this point. All information suggested by the reviewer has been completed and added from lines 163-185 onwards:

“The primary environmental data required for the development of the inventory are collected through an online questionnaire, accessible through the establishment owner's registration on the Greentour platform (Greentour, 2024) (Figure 3). This questionnaire asks for general information about the establishment, such as its name, type, category, year of data collection, capacity and days of operation, as well as details about its facilities, the months it is open and other relevant aspects.

It also has a specific section for the collection of essential environmental data for analysis, covering the generation and consumption of energy, water, cleaning products for maintenance, food, beverages and other products used in leisure activities. All these inputs and emissions have been determined based on previous studies and assessments carried out in different establishments, in order to identify the key aspects to be considered according to the type of accommodation.

The statistical basis of the data follows internationally recognised sustainability assessment methodologies, including the Life Cycle Assessment (ISO 14040/44) and the Product Environmental Footprint (PEF) method. In addition, the questionnaire is in line with standards for environmental reporting in tourism, allowing comparability between different establishments. The results of each establishment are presented in relation to other establishments in the same destination and other destinations analysed, thus enabling a comparative assessment.

To ensure the consistency and reliability of the data, several validation mechanisms have been implemented. Firstly, the questionnaire incorporates predefined ranges and reference values based on previous studies and current regulations. Secondly, internal checks are applied to detect possible discrepancies. In case of inconsistencies, the technicians in charge review the quality of the data entered, identifying and correcting errors or anomalies.

Reviewer’s reply: Please clarify the methodology followed in designing the questionnaire, including the balance between qualitative and quantitative questions, the relationship to the methodological basis of the study, the relationship to the methods of contingent evaluation or other established methods of eliciting behavioral and impact statistics from interviews. If possible, provide data on means and variances of the responses obtained. Was the questionnaire pretested for reliability?

Response comment 5: Thank you for this clarification and comment. We have added this paragraph in the article that clarifies more all this that you comment:

Lines 241-247: “In addition to these internal validation mechanisms, the questionnaire was pretested in the pilot destination of Lloret de Mar. This pilot phase allowed us to assess the relia-bility and consistency of the questions, as well as to identify any issues related to the clarity of the questions and the data obtained. The results from the pilot were analyzed to ensure that the questions effectively captured the necessary information and pro-vided reliable data for the environmental impact assessment. The feedback from the pilot phase led to adjustments in the questionnaire, ensuring that it would be suitable for use in other destinations.”

 

Section 2.1.2

Comment 7: “The Environmental Footprint (EF) 3.0 method was used in order to quantify the environmental impacts of the goods and services included in the tool.” The method should be explained and its application clarified. It is noty only a matter of categorization but of specific applicability and sufficient information.

Response 7: Thanks you for pointing this out. We have added this paragraph to the lines 344-352 to better justify why we have used this method:

“…This method was chosen because it provides a comprehensive and standardized approach for assessing environmental performance across multiple impact categories, ensuring comparability and reliability. In the tourism sector, where diverse activities and supply chains contribute to environmental impacts, EF 3.0 enables a more holistic evaluation by integrating life cycle assessment principles. Additionally, its alignment with EU recommendations and its sector-specific applicability make it an appropriate methodology for measuring and improving sustainability in tourism establishments.”

Reviewer’s reply: Please clarify the method in more detail. The fact that it integrates life cycle assessment principles per se is not a clarification but an additional item to explain.

Response comment 7: We appreciate your suggestion and have expanded our explanation to clarify both the applicability and methodological rigor of the EF 3.0 method. Specifically, we have emphasized that EF 3.0 goes beyond impact categorization by integrating characterization factors tailored to the evaluation of tourism-related products and services. This ensures a scientifically sound and harmonized assessment, allowing for comparability across tourism establishments. Moreover, we have detailed how EF 3.0 enables the identification of environmental hotspots along the supply chain, helping businesses and policymakers implement targeted sustainability improvements. Its alignment with EU policies and environmental certification schemes further justifies its selection as a robust methodology for assessing environmental performance in tourism. We trust this clarification addresses your concerns and strengthens the rationale for using EF 3.0 in our study. These lines have been added in the manuscript:

Lines 399-412: “This method was chosen because it provides a comprehensive and standardized approach for assessing environmental performance across multiple impact categories, ensuring comparability and reliability. EF 3.0 is based on Life Cycle Assessment (LCA) principles, incorporating specific characterization factors that allow for a detailed quantification of environmental impacts. This ensures that the results are both scientifically robust and aligned with EU methodological recommendations. In the tourism sector, where diverse activities and supply chains contribute to environmental impacts, EF 3.0 enables a more holistic evaluation by considering both direct and indirect impacts throughout the life cycle of goods and services used in tourism establishments. Its structured approach facilitates the identification of key environmental hotspots, providing actionable insights for decision-makers. Furthermore, its sector-specific applicability and compatibility with environmental certification schemes enhance its relevance for measuring and improving sustainability in tourism businesses.”

 

Section 2.1.3

Comment 8: “In the tool, environmental results are generated directly from inventory data, which includes accommodation, restaurants, and tourist activities, along with the corresponding impact categories.” Please clarify how they are generated and on what basis. Are the same coefficients applied everywhere and for all tourists? Are value chain effects taken into account?

Response 8: Thank you for your comment and suggestion.

The environmental results in the Greentour tool are generated from a detailed data inventory, which includes information on the number of tourists or guests in each establishment. This allows to calculate the impacts both at the total level of the establishment and per tourist. The web platform is linked to an Excel database where the emission factors for each process flow and each impact category have been predefined. In this way, by entering the specific data of each establishment and the total number of customers, the corresponding environmental impact per tourist and per accommodation unit, restaurant or tourist activity is automatically obtained. As for geographical and sectoral variability, the tool has been applied in four different tourist destinations in two countries (Spain and Portugal). To reflect these differences, specific factors have been considered, such as the energy mix of each country, which influences the emissions derived from electricity consumption, and the modeling of the processes associated with food, adapted to the characteristics and consumption habits of each region. Therefore, the same coefficients are not applied in all locations or for all tourists, but variables have been integrated that reflect the specificity of each destination and establishment. Likewise, the effects of the value chain have been taken into account by incorporating inventory data based on Life Cycle Analysis methodologies (LCA), ensuring a comprehensive assessment of the environmental impacts associated with tourism activities.

In the article, this paragraph has been added for a better understanding of the lines 385-392: "… The calculations account for the number of tourists per establishment, providing results both at the total level and per visitor. The tool is linked to an Excel database with predefined emission factors, which, combined with input data, allows for automated impact assessment. It also incorporates geographical differences, such as variations in energy mixes and food-related processes in Spain and Portugal. Rather than applying uniform coefficients, the tool integrates location-specific variables and follows Life Cycle Assessment (LCA) methodologies to ensure a comprehensive evaluation of tourism-related environmental impacts.”

Reviewer’s reply Please clarify the nature, the origin and the interpretation of the combination of predefined emission factor, input data and automatic impact assessment. If needed,  provide equations and basic statistics.

Response comment 8: Thank you for your comment and suggestion. Indeed, a statistical equation has been introduced to provide a clearer understanding of the combination of predefined emission factors, input data, and the automatic impact assessment process. Additionally, the entire text has been revised to enhance clarity and ensure a more comprehensive explanation of the methodology, making the process more transparent and easier to interpret. Lines 481-523 have been added:

“In addition to assessing the environmental impacts of individual establishments, the tool enables impact estimation at the destination level through an extrapolation procedure that is not performed directly within the tool but must be carried out manually by a technical partner to ensure accuracy and consistency. To achieve this, the environmental impacts of accommodations, restaurants, and tourist activities are exported to an Excel file via the Greentour website, including data for the nine environmental impact indicators as well as information on the capacity of each establishment and the number of customers, measured in overnight stays for accommodations. Additionally, tourism offices provide key data on the total number of accommodations, restaurants, and tourist activities within each destination, which is essential for assessing the representativeness of the sample included in the designed tool, as it may not cover all establishments within a given destination.

It is important to highlight that when analyzing individual establishments, the environmental tool does not account for tourist transportation from their place of origin to the hotel, restaurant, or activity, nor does it assess the waste management practices of each establishment. However, at the destination level, these aspects are considered using data provided by tourism offices, including monthly waste generation and transportation statistics for tourists arriving and departing. All this information is detailed in sections 2.6.1 and 2.6.2. The results are standardized using a common reference unit—the tourist—ensuring consistency in evaluating the three subsectors: accommodations, restaurants, and leisure activities.

For the extrapolation process, predefined emission factors from various sources such as Ecoinvent and EMEP/CORINAIR are used, adjusted based on the specific characteristics of each destination and combined using a statistical approach represented mathematically by the equation:

 

Where:

• is the resulting emission factor.
• represents the emission factor from each data source.
• is the weight or relative contribution of each source in the final calculation.

This equation is applied in the Excel file where emission factors for the nine environmental impact indicators are compiled and the final extrapolated results are obtained based on the emission factors, the population capacity of accommodations, restaurants, and leisure activities in each destination, and the number of customers or overnight stays.

Once these elements are integrated, the environmental impacts for the nine indicators are calculated in Excel and not in the environmental tool, after which the processed data is uploaded to the web platform for destination-wide environmental impact assessment.

 By following rigorous validation steps and criteria, the data used in the analysis remains robust, reliable, and consistent with recognized methodologies, ensuring that the results obtained are coherent and comparable across different destinations (figure 7).”

Section 3.1

Comment 9: “In addition to the impacts of the different establishments, the tool provides the impacts at the destination level applying the extrapolation procedure detailed below. This extrapolation is not done directly in the tool, so it needs to be done manually by a technical partner. Therefore, the environmental impacts of accommodation, restaurants, and tour-ist activities are exported to an Excel file through the Greentour website.” It is not clear what the authors mean by “ extrapolation”. Whether  it is an estimation procedure, or the mere application of fixed coefficients, it should be explained in more detail, with its properties and limitations discussed also with reference to the literature.

Response 9: Thank you for your comment. The extrapolation process is an estimation procedure that scales up the environmental impacts from individual establishments to the destination level. This is done by combining three key variables: (1) the total annual environmental impact of each establishment registered in the Greentour tool, (2) the number of customers in accommodations (measured in overnight stays), restaurants, and leisure activities, and (3) the capacity of establishments in each destination. These data, along with the information obtained from the Greentour tool, are exported to an Excel file, where the environmental impact at the destination level is calculated. This approach ensures a more accurate assessment by considering the representativeness of the registered establishments and integrating destination-specific parameters. The process is visually represented in Figure 7, which illustrates how the extrapolation is performed.

Reviewer’s reply. Please explain what you mean by combination of the three key variables mentioned. If needed, provide equations and statistics.

Response comment 9: Thank you for your comment. The combination of the three key variables refers to the process of estimating the total environmental impact at the destination level by integrating data from different sources. Specifically, these variables are:

• The total annual environmental impact of each establishment registered in the Greentour tool, which provides impact values for the nine environmental indicators based on inventory data and predefined emission factors.
• The number of customers in accommodations (measured in overnight stays), restaurants, and leisure activities, provided by tourism offices. This data allows for weighting the impact of each establishment according to its actual usage.
• The capacity of establishments in each destination, also provided by tourism offices, which helps assess the representativeness of the establishments registered in the tool compared to the total number of businesses in the destination.

These three variables are essential for performing the extrapolation, a process that allows estimating the environmental impact at the destination level. This is achieved by combining the environmental data of individual establishments from the Greentour tool with additional information provided by tourism offices. Since not all establishments in a destination may be registered in the tool, extrapolation is necessary to ensure a comprehensive assessment. All this has been explained in the previous correction and stated in the article.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Manuscript Comments

I appreciate the authors' responses and clarifications regarding the observations and recommendations made during the first review, most of which have been satisfactorily addressed. However, a small number of them still require further explanation to fully resolve the indicated observations, which I outline below:

Comment 8: Third Paragraph. The list of tourist activities (e.g., "cruises, museum visits, horse riding") should either be exhaustive or include the selection criteria. Additionally, the relevance of these activities must be explained to justify their inclusion.

Response 8: Thanks you for pointing this out. Thank you for your insightful comments. We appreciate your suggestion to clarify the list of tourist activities included in the Greentour tool. The activities mentioned (e.g., cruises, museum visits, horse riding) are among the most prominent in the destinations analyzed, but we acknowledge that there are numerous other activities available in each destination.

Rather than providing an exhaustive list of every possible tourist activity, we focused on the most representative activities for each destination, which are typically the most impactful in terms of environmental consequences. The selection of activities was made based on their relevance and popularity within the local tourism market, as well as their potential contribution to environmental impact. This approach ensures that the tool is adaptable to various destinations and reflects the most significant activities within the context of each. . The following clarifying paragraph has been added:

Lines 166-168: “These activities were selected based on their prominence and impact in the specific destinations, reflecting the diversity of tourism offerings in each location.”

Reviewer’s Response:

The justification statement mentioned above, “…as well as their potential contribution to environmental impact…,” remains ambiguous for a study that requires a high degree of certainty. I recommend including specific criteria to help the reader better understand the scope and reproducibility of the research.

 

Comment 17: Second Paragraph: The exclusion of transport and waste management at the establishment level requires further justification to explain its methodological rationale.

Response 17: Thank you for your comment. In the tool it is possible to consider the environmental impacts of tourism establishments (which is applicable to any establishment worldwide). However, in the case of transport and waste management, specific data is required at the local level, provided by entities such as municipalities, tourism offices or regional administrations. This is because data on the amount of waste generated by each sub-sector or the transport of tourists to each destination are not recorded at the level of the establishments, as they do not have such information. Therefore, this aspect should be addressed separately, requesting the relevant data for each year from the responsible administrations, which will allow, at destination level, to extrapolate and provide more accurate information on these impacts. Hence, the tool is innovative: firstly, because it offers an assessment at establishment level, and secondly, because it allows extrapolating these data, integrating also the impacts of transport and waste management at destination level.

Reviewer’s Response:

I understand the comment; however, it is necessary to specify how the exclusion affects the limitations of the results.

 

Comment 18: Second Paragraph. The process for validating data provided by tourism offices is not specified and should be outlined to ensure reliability.

Response 18: Thanks you for pointing this out. The data provided by the tourist offices have been obtained from contracted databases, which have been carefully selected and verified by the technicians responsible for the project. In addition, these data have been checked with relevant bibliographic sources, which guarantees their reliability and validity. The validation process includes a thorough review of the quality of the data, which ensures that the impacts related to transport and waste management, provided by the tourism offices, are completely reliable and suitable for integration into the analysis conducted.

Reviewer’s Response:

The justification is insufficient; at the very least, the criteria should be established to ensure what is stated above: “…which guarantees their reliability and validity.”

Comment 22: First Paragraph (page 9). A more robust explanation of the SUDOE area is required to provide geographic, economic, and environmental context.

Response 22: Thank you for your valuable comments. Regarding the need for a more robust explanation of the SUDOE area, we have chosen this region because it is where the project has been developed and serves as a pilot area to test the tool. The SUDOE region (comprising Southwestern European countries such as Spain, Portugal, and Southern France) presents significant geographic, economic, and environmental diversity, making it an ideal setting to evaluate the applicability of the methodology in different tourism contexts. This area has been selected due to its strong tourism sector, which includes a mix of urban, coastal, and rural destinations, allowing us to assess the tool’s effectiveness across varied environments. Additionally, the region faces key sustainability challenges related to tourism, such as waste management, resource consumption, and seasonal fluctuations, which align with the objectives of our study. We will clarify this in the revised manuscript to ensure the geographic, economic, and environmental context of the SUDOE area is properly explained:

Lines 550-554: “The SUDOE region, which includes Spain and Portugal, among other destinations, has been chosen as a pilot area due to its geographic, economic, and environmental diversity. This region represents a variety of tourism contexts—ranging from pilgrimage routes to historic cities and coastal destinations—allowing for a comprehensive assessment of the tool’s applicability.”

Reviewer’s Response:

The addition is insufficient; supporting data should be included, such as the number of visitors, economic spillover, and impact on the local GDP, among others, to demonstrate that it is a representative site.

Comments for author File: Comments.docx

Author Response

REVIEWER 2

I appreciate the authors' responses and clarifications regarding the observations and recommendations made during the first review, most of which have been satisfactorily addressed. However, a small number of them still require further explanation to fully resolve the indicated observations, which I outline below:

Comment 8: Third Paragraph. The list of tourist activities (e.g., "cruises, museum visits, horse riding") should either be exhaustive or include the selection criteria. Additionally, the relevance of these activities must be explained to justify their inclusion.

Response 8: Thanks you for pointing this out. Thank you for your insightful comments. We appreciate your suggestion to clarify the list of tourist activities included in the Greentour tool. The activities mentioned (e.g., cruises, museum visits, horse riding) are among the most prominent in the destinations analyzed, but we acknowledge that there are numerous other activities available in each destination.

Rather than providing an exhaustive list of every possible tourist activity, we focused on the most representative activities for each destination, which are typically the most impactful in terms of environmental consequences. The selection of activities was made based on their relevance and popularity within the local tourism market, as well as their potential contribution to environmental impact. This approach ensures that the tool is adaptable to various destinations and reflects the most significant activities within the context of each. . The following clarifying paragraph has been added:

Lines 166-168: “These activities were selected based on their prominence and impact in the specific destinations, reflecting the diversity of tourism offerings in each location.”

Reviewer’s Response:

The justification statement mentioned above, “…as well as their potential contribution to environmental impact…,” remains ambiguous for a study that requires a high degree of certainty. I recommend including specific criteria to help the reader better understand the scope and reproducibility of the research.

Response Comment 8: Thank you for your valuable feedback. We acknowledge the need to provide a more rigorous justification for the selection of tourist activities included in the environmental tool. To determine which activities to include for each destination, we conducted an exhaustive analysis based on official records from local tourism offices. These offices systematically collect and maintain data on the types and frequencies of tourist activities within their respective destinations. This data allowed us to identify the most relevant and representative activities for each location.

The selection process considered several key criteria:

• Destination-Specific Relevance: Activities were chosen based on their predominance in each destination. For instance, coastal destinations prioritized water-based activities such as cruises and diving, while mountainous destinations focused on hiking and skiing.
• Environmental Impact Potential: The selected activities were those with a documented or anticipated environmental footprint, as reported in existing literature or environmental assessments conducted at the destination level.
• Tourist Demand and Popularity: We incorporated activities that are most frequently engaged in by visitors, ensuring that the selection accurately reflects the tourism market and its associated environmental burdens.

By following this methodological approach, we ensured that the activities considered in our study are representative, reproducible, and aligned with both the characteristics of each destination and the broader objectives of environmental impact assessment.

To clarify this point in the manuscript, we have modified the text in lines 160-167 as follows:

"The selection of activities was based on official tourism records, which document the most frequent and economically significant tourist activities in each destination. We prioritized activities that are characteristic of the destination type (e.g., coastal, mountainous) and that exhibit notable environmental impact potential. This selection process was guided by quantitative data on visitor participation rates, as well as qualitative assessments of each activity’s environmental burden, ensuring a robust and reproducible methodology applicable across different tourism contexts."

Comment 17: Second Paragraph: The exclusion of transport and waste management at the establishment level requires further justification to explain its methodological rationale.

Response 17: Thank you for your comment. In the tool it is possible to consider the environmental impacts of tourism establishments (which is applicable to any establishment worldwide). However, in the case of transport and waste management, specific data is required at the local level, provided by entities such as municipalities, tourism offices or regional administrations. This is because data on the amount of waste generated by each sub-sector or the transport of tourists to each destination are not recorded at the level of the establishments, as they do not have such information. Therefore, this aspect should be addressed separately, requesting the relevant data for each year from the responsible administrations, which will allow, at destination level, to extrapolate and provide more accurate information on these impacts. Hence, the tool is innovative: firstly, because it offers an assessment at establishment level, and secondly, because it allows extrapolating these data, integrating also the impacts of transport and waste management at destination level.

Reviewer’s Response:

I understand the comment; however, it is necessary to specify how the exclusion affects the limitations of the results.

Response Comment 17: Thank you for your comment. We understand the importance of clarifying the methodological limitations arising from the exclusion of transport and waste management data at the establishment level. The main limitation of this exclusion is that, while individual establishments can automatically obtain their environmental impact results by entering their data into the tool, assessing these impacts at the destination level requires additional calculations and methodologies. Specifically:

• Technical Expertise Required for Destination-Level Calculations: Unlike establishments, which can directly retrieve their results from the tool, destinations require specialized personnel to collect and process additional data. This includes integrating regional waste management and transport data, which are not directly available at the establishment level.
• Necessity of External Data Sources: Transport and waste management data must be sourced from municipal, regional, or tourism office records, as establishments do not typically record such information. This creates an additional layer of complexity, as it requires collaboration with local authorities to obtain the necessary data.
• Separate Methodologies for Transport and Waste Management: The methodology for estimating transport and waste-related impacts is explained in the manuscript and involves extrapolating establishment-level data to the destination scale. However, these calculations cannot be performed automatically within the tool and require additional processing steps.
• Challenges in Destination-Level Comparisons: Since the accuracy of destination-level impact assessments depends on the availability and quality of external data, the tool's applicability varies depending on the ability to access and integrate local records.

However, despite this limitation, the methodologies applied for both transport and waste management have been tested in different tourist destinations with highly diverse characteristics. The results obtained have been consistent with existing data in relevant literature and comparable to previous environmental assessments. This validation confirms that, while additional calculations are required at the destination level, the methodologies employed are robust and provide meaningful insights into tourism-related environmental impacts.

To ensure that this limitation and its implications are clearly addressed in the manuscript, we have added the following clarification:

Lines 480-490: "A key limitation of the tool is that, while it enables establishments to automatically obtain their environmental impact results, destination-level assessments require additional calculations and external data. The impacts of transport and waste management are not directly available at the establishment level and must be estimated using supplementary methodologies, as detailed in this study. This requires technical personnel to process data from local authorities, such as tourism offices and municipalities, making destination-level calculations more complex and dependent on external data availability. However, despite these challenges, the methodologies applied have been validated across multiple tourism destinations with distinct characteristics, demonstrating consistency with findings from relevant literature and previous environmental studies. This confirms that, while the approach requires additional steps, the results remain reliable and applicable across diverse tourism contexts."

 

Comment 18: Second Paragraph. The process for validating data provided by tourism offices is not specified and should be outlined to ensure reliability.

Response 18: Thanks you for pointing this out. The data provided by the tourist offices have been obtained from contracted databases, which have been carefully selected and verified by the technicians responsible for the project. In addition, these data have been checked with relevant bibliographic sources, which guarantees their reliability and validity. The validation process includes a thorough review of the quality of the data, which ensures that the impacts related to transport and waste management, provided by the tourism offices, are completely reliable and suitable for integration into the analysis conducted.

Reviewer’s Response:

The justification is insufficient; at the very least, the criteria should be established to ensure what is stated above: “…which guarantees their reliability and validity.”

Response Comment 18: Thank you for pointing this out. The data provided by the tourist offices have been obtained from contracted databases, which have been carefully selected and verified by the technicians responsible for the project. In addition, these data have been cross-checked with relevant bibliographic sources, ensuring their reliability and validity. The validation process includes a thorough review of data quality to ensure that the impacts related to transport and waste management, as provided by the tourism offices, are both reliable and suitable for integration into the analysis. To further clarify the reliability of these data, it is essential to highlight the specific criteria employed by tourism offices in their data collection and validation processes:

• Official Records and Standardized Reporting: Tourism offices maintain official registries of accommodations, restaurants, and tourist activities within each destination. These records are regularly updated and audited to ensure consistency and accuracy.
• Use of Quantified and Sector-Specific Data: The data collected by these offices are not estimations but rather quantified figures based on systematic reporting. For example, waste generation data are typically derived from municipal waste management systems, which track waste streams by type (plastic, cardboard, glass, mixed, and organic waste) on a monthly basis. Similarly, transport data are compiled using passenger flow statistics from airports, ports, and local transport authorities.
• Integration of Multiple Data Sources: Tourism offices cross-reference their records with other institutional sources, such as municipal and regional government reports, industry surveys, and statistical agencies. This triangulation ensures that discrepancies are minimized and that the data are as representative as possible.
• Consistency with National and International Methodologies: The data collection processes align with national tourism and environmental reporting standards, as well as international guidelines where applicable. This ensures methodological consistency and allows for comparability across destinations.

These lines have been added to make it clearer in the article:

Lines 467-482: “Additionally, the tourism offices provide accurate data on the total number of accommodations, restaurants, and tourist activities in each destination. This information is crucial for assessing the representativeness of the sample included in Greentour, as it may not cover all establishments within a given destination.

It is important to highlight that, in the analysis of establishments, the environmental tool does not assess the transport of tourists from their place of origin to the hotel, restaurant, or tourist activity, nor the waste management of each establishment. However, at the destination level, these two aspects are studied. The tourist offices of each destination provide relevant data, such as the amount of waste generated monthly and transport data for tourists traveling to and from the destination. All this information is detailed in sections 2.6.1 and 2.6.2. The results are provided using a common reference unit for the entire destination, applicable to the three subsectors; in this case, the chosen unit is the 'tourist'.

By following these rigorous validation steps and criteria, the data employed in the analysis remain robust, reliable, and consistent with recognized methodologies, ensuring that the results obtained through the designed tool are coherent and comparable across different destinations.”

 

Comment 22: First Paragraph (page 9). A more robust explanation of the SUDOE area is required to provide geographic, economic, and environmental context.

Response 22: Thank you for your valuable comments. Regarding the need for a more robust explanation of the SUDOE area, we have chosen this region because it is where the project has been developed and serves as a pilot area to test the tool. The SUDOE region (comprising Southwestern European countries such as Spain, Portugal, and Southern France) presents significant geographic, economic, and environmental diversity, making it an ideal setting to evaluate the applicability of the methodology in different tourism contexts. This area has been selected due to its strong tourism sector, which includes a mix of urban, coastal, and rural destinations, allowing us to assess the tool’s effectiveness across varied environments. Additionally, the region faces key sustainability challenges related to tourism, such as waste management, resource consumption, and seasonal fluctuations, which align with the objectives of our study. We will clarify this in the revised manuscript to ensure the geographic, economic, and environmental context of the SUDOE area is properly explained:

Lines 550-554: “The SUDOE region, which includes Spain and Portugal, among other destinations, has been chosen as a pilot area due to its geographic, economic, and environmental diversity. This region represents a variety of tourism contexts—ranging from pilgrimage routes to historic cities and coastal destinations—allowing for a comprehensive assessment of the tool’s applicability.”

Reviewer’s Response:

The addition is insufficient; supporting data should be included, such as the number of visitors, economic spillover, and impact on the local GDP, among others, to demonstrate that it is a representative site.

Response Comment 22: Thank you for this comment. All this information has been added to the article between lines 560 and 593:

Lines 560-593:  “Camino Lebaniego (Cantabria, Spain): This 72.73 km pilgrimage route has gained increasing popularity, attracting around 75,000 pilgrims annually from around the world to the Monastery of Santo Toribio de Liébana, where the "Lignum Crucis", the largest surviving fragment of the Cross of Christ, is located. Recognized as a UNESCO World Heritage Site since 2015, the route generates over 10 million euros annually in economic spillover, with pilgrims spending between 40 to 60 euros per day. This economic impact contributes significantly to approximately 3.5% of Cantabria’s regional GDP [19].

Guimarães (Braga, Portugal): Guimarães, recognised as the "cradle of Portugal", attracts around 1.5 million tourists annually, with a significant influx of interna-tional visitors. The city's tourism-generated economic spillover is estimated at 150 million euros per year, contributing to about 6% of Braga’s local GDP. As a UNESCO World Heritage Site since 2001, Guimarães is a key economic driver for the region, particularly in cultural tourism, thanks to its well-preserved medieval architecture and vibrant historical character [24].

Rías Baixas (Galicia, Spain): The inner and coastal areas of the province of Pon-tevedra, which include its three bays—Vigo, Pontevedra, and Arousa—are a highly visited destination in Galicia, Spain. With over 3 million tourists annually, Rías Baixas is one of the region's most popular tourist destinations. The primary motivation for 39.7% of visitors is to explore the region’s natural landscapes, beaches, and cultural attractions like museums, festivals, and the renowned Saint James Way. The economic spillover from tourism in the region is estimated at 1.5 billion euros annually, with an average spend of 55 euros per tourist. Tourism contributes around 5% to the GDP of the province of Pontevedra, with the region’s offerings in nature, gastronomy, and culture playing a crucial role in its economic success [20].

Lloret de Mar (Catalonia, Spain): Lloret de Mar is a lively Mediterranean beach town in the Costa Brava, located just 75 km from Barcelona and 40 km from Girona. The town is renowned for its excellent beaches, coves, and vibrant nightlife, including bars, nightclubs, and restaurants. Receiving over 2.5 million tourists annually, Lloret de Mar is one of the most popular destinations on the Costa Brava. The economic impact generated by tourism reaches 1.2 billion euros per year, with an average spend of 50 euros per tourist. Tourism accounts for approximately 7% of the GDP of the Girona region, with beach tourism driving the economy year-round [36].”

 

Author Response File: Author Response.pdf

Reviewer 4 Report

Comments and Suggestions for Authors

The authors have adequately addressed my previous concerns. I have no further comments on this submission.

Author Response

Thank you very much for your reply.

Round 3

Reviewer 1 Report

Comments and Suggestions for Authors

Thanks for your replies and clarifications.