The Disparity of Greenness Accessibility across Major Metropolitan Areas in the United States from 2013 to 2022

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Thank you to the esteemed editors for giving me the opportunity to review this interesting study. It is a study of differences in the accessibility of Urban Green Spaces (UGS) in major metropolitan areas in the United States. Overall the article is well structured and logical, but it should also be revised as follows my concerns before publication.

1.The article utilizes long time series data from 31 metropolitan areas, which is a robust research design. However, the authors are advised to consider whether it is necessary to include consideration of population mobility in the study methodology, as residents' daily activities may not be limited to their area of residence.

2.The use of NDVI as an indicator for assessing UGS is appropriate, but the authors are advised to provide further clarification on the source and processing of the data to ensure its accuracy and reliability.

3.The article points out inequalities in UGS accessibility among different racial-ethnic groups, which is an important finding. It is recommended that the authors further explore the possible causes of these inequalities and discuss possible solutions.

4.The article uses the Gini index to quantify inequality in UGS accessibility, which is a valid tool. However, it is recommended that the authors provide more statistical details, such as confidence intervals or standard deviations, to enhance the credibility of the results.

5.The authors mention a limitation of the study, which is the static analysis of the population distribution. It is recommended that the authors consider including consideration and discussion of population dynamics in the study.

6.The article concludes with policy recommendations that emphasize the role of urban planners and policy makers in addressing inequalities in UGS accessibility. It is recommended that the authors provide more specific policy recommendations, such as how to allocate resources or how to develop inclusive urban green space planning strategies.

7.The introduction needs to be supplemented with some recently published research related to urban green space, urban climate, environmental justice, and public health to support the currency and rigor of the content.

8.Last but not least, the last paragraph of the introduction should state the innovation of the paper rather than a repetition of similar studies to emphasize the relevance of the article.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

The paper is quite interesting and provides a quantitative approach to the problem of UGS access for different communities, but some parts need to be described in more detail. My comments below:

- Why were such large census divisions chosen? The results might be more interesting for smaller divisions - at this scale the data is too flattened.

- There was no information on median income in the areas analysed, which can be another important factor of inequality, apart from ethnicity. Was the population density in the selected areas similar?

- Please make a list of the metropolitan areas analysed (with population and population density) and mark them (i.e. with a number) on the map in Figure 1.

- Fig. 1: The font on the pie charts should be larger, now it's very hard to read.

- Please describe the trends in Figure 5 in more detail. There are a lot of (54!) graphs, but these results are described in a very laconic way. When you make a statement, you should indicate which graph it was taken from.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 3 Report

Comments and Suggestions for Authors

1. The manuscript will be read to international readers through many revisions. The flow of research should be reviewed. Therefore, it is not the stage to discuss detailed research methods. What is the Urban Green space? How are other studies defining it? Previous studies that examined the connection between the Urban Green space and race are not difficult to find. Please revise it from the beginning to appeal to readers.

2. The analysis process and results are too simple. In order to derive more in-depth results, overlapping of data other than NDVI is required. Race is a kind of population data, and it is judged that only the correlation between race and NDVI was analyzed. In terms of land cover, it is also necessary to define the type of definition of Urban green space that the authors consider important.

3. The Urban green space is deeply related to the Green infrastructure called GI. There are many studies to increase the equality of GI. Please review previous studies closely and describe the differences as well.

4. If so, how should we create and manage Urban green space for equality and universality? Please also describe the policies and institutions related to the US federal, state, and target area. If the results of the study are consistent with the policy direction of the target site, the decision maker believes that the results of the study will be helpful in promoting the policy.

Comments on the Quality of English Language

Moderate editing Eng. language required.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors addressed my concerns in this revised version.

Author Response

Thank you so much for accepting the paper.

Reviewer 3 Report

Comments and Suggestions for Authors

I believe that the quality of the manuscript has improved
significantly in a short period of time thanks to the efforts of the
authors.
The authors' research is expected to be widely read by readers around
the world who are interested in this field.
However, the question remains whether the results are race-related.
More scientific methods will have to be carried out in the future,
such as clinical trials with experimental equipment.

Comments on the Quality of English Language

Minor editing of English language required

Author Response

reviewer's comments:

I believe that the quality of the manuscript has improved significantly in a short period of time thanks to the efforts of the authors. The authors' research is expected to be widely read by readers around the world who are interested in this field.

However, the question remains whether the results are race-related. More scientific methods will have to be carried out in the future, such as clinical trials with experimental equipment.

Authors response:

Thank you very much for your insightful comments and suggestions, as well as your prompt response. Your feedback has significantly improved the quality of our manuscript. Regarding your question, we fully agree that future studies, including clinical trials and experimental research, are necessary to further elucidate the issue of race-related disparities in greenness exposure. However, this topic extends beyond the scope of our current work, and as such, we have not included further discussion on this matter in the manuscript.