Estimation of Reduced Air Emissions as a Result of the Implementation of the Measure to Reduce Burned Sugarcane in Thailand

Round 1

Reviewer 1 Report

The present manuscript is with original approach and with actual topic appropriate for the journal scope and with a sufficient merit for publication.

Thus, I suggest publication of the present manuscript after some minor revisions. 

a) I will very much appreciate if authors could explain how they determined the coefficient values  (a) and (b) and the intercept parameter (c) in Eq. (7) and previosly giben in Eq. (5).

b) The main approach in quantitative assesment of air pollution emissions during the production season  is based on theoretical, statistical, observational analysis using satellite data. However, some modeling results are missing.

I am just wondering if the authors carried out some atmospheric-chemistry modeling studies,  associated with the biomass burning emissions over Thailand, that will really approve the reliability of the results and enhance the overall conclusions from this research. 

c) If authors intend to do that in their further studies, then it would be usefull if they just acknowledge some other studies focused on the modeling of biomass burning over Thailand using the state of the art atmosheric chemistry models.

 

 

 

 

Author Response

March 22, 2020

Dear Reviewer #1

Re: Manuscript ID: atmosphere-743225

 

Please find attached a revised version of our manuscript “Estimation of reduced air emissions as a result of the implementation of the measure to reduce burned sugarcane in Thailand”, which we would like to resubmit for publication as an article in Atmosphere.

Your comments were highly insightful and enabled us to greatly improve the quality of our manuscript. In the following pages are our point-by-point responses to each of the comments of the reviewers. We hope that the revisions in the manuscript and our accompanying responses will be sufficient to make our manuscript suitable for publication in Atmosphere.

 

We shall look forward to hearing from you at your earliest convenience.

 

Yours sincerely,

Jirataya Pansuk, PhD

 

Responses to the comments of Reviewer #1

 

Comment 1: English language and style

(x) English language and style are fine/minor spell check required 

Response: According to the suggestion of the reviewer that this manuscript needs minor spell check required, we have already checked a common spelling errors and grammatical mistakes in manuscript.

 

Comments and Suggestions for Authors

a) I will very much appreciate if authors could explain how they determined the coefficient values  (a) and (b) and the intercept parameter (c) in Eq. (7) and previously given in Eq. (5).

Response: We do agree with the reviewer’s comment. In this study, the Regression Data Analysis Tool in Excel program was used to analyze a time series relationship between the sugarcane productions and year which is informed in the Eq. (5). We add more detail of a tool of statistical analysis as presented in lines 196-198. We also add the standard error of coefficient values and the intercept parameter in Eq. (7) on the paragraph as presented in line 273.

b) The main approach in quantitative assessment of air pollution emissions during the production season is based on theoretical, statistical, observational analysis using satellite data. However, some modeling results are missing. I am just wondering if the authors carried out some atmospheric-chemistry modeling studies, associated with the biomass burning emissions over Thailand, that will really approve the reliability of the results and enhance the overall conclusions from this research. 

c) If authors intend to do that in their further studies, then it would be useful if they just acknowledge some other studies focused on the modeling of biomass burning over Thailand using the state of the art atmospheric chemistry models.

Response: We do agree with the reviewer’s comment. According to the findings of our previous studies, the current estimating of biomass burning emissions in Thailand is based on the medium to coarse resolution fire data which has high uncertainties. And the current air quality modelling to support air quality management used global emission database for biomass burning emission, e.g. GFED which found insufficient to identify the area to control to reduce haze pollution in Thailand. To well manage air quality in Thailand, both national and regional scale, understanding of emissions and its potential reduction is necessary. Hence, we attend to estimate the emission from biomass open burning, especially including the emissions from pre-harvest sugarcane burning and rice straw burning. We are planning to use a high resolution gridded fire emission for supporting the air quality simulation in Thailand, especially understanding the impact of biomass burning in urban areas, such as the Bangkok Metropolitan Region.

 

Author Response File: Author Response.docx

Reviewer 2 Report

The present manuscript describes the estmation of reduced air emissions as the results of mesures to reduce burned sugarcane in Thailand.

The methodology used for the experimantal part was appropriate and well done.The optained results well discussed with existibg literature and the conclusions well supported.The paper merits pablication to the ATMOSPHERE taking into consideration some remarks:

The intoductin is very extensive,more than two pages.General speaking the manuscript is very extensive with 8 figures and one more figure with the same numper(page 18) and 4 tables .

Author Response

March 22, 2020

Dear Reviewer #2

 

Re: Manuscript ID: atmosphere-743225

 

Please find attached a revised version of our manuscript “Estimation of reduced air emissions as a result of the implementation of the measure to reduce burned sugarcane in Thailand”, which we would like to resubmit for publication as an article in Atmosphere.

Your comments were highly insightful and enabled us to greatly improve the quality of our manuscript. In the following pages are our point-by-point responses to each of the comments of the reviewers. We hope that the revisions in the manuscript and our accompanying responses will be sufficient to make our manuscript suitable for publication in Atmosphere.

 

We shall look forward to hearing from you at your earliest convenience.

 

Yours sincerely,

Jirataya Pansuk, PhD

 

 

Responses to the comments of Reviewer #2

 

Comment 1: English language and style

 

(x) English language and style are fine/minor spell check required 

Response: According to the suggestion of the reviewer that this manuscript needs minor spell check required, we have already checked a common spelling errors and grammatical mistakes in manuscript.

 

Comments and Suggestions for Authors

The present manuscript describes the estimation of reduced air emissions as the results of measures to reduce burned sugarcane in Thailand.

The methodology used for the experimental part was appropriate and well done. The obtained results well discussed with existing literature and the conclusions well supported. The paper merits publication to the ATMOSPHERE taking into consideration some remarks:

The introduction is very extensive, more than two pages. General speaking the manuscript is very extensive with 8 figures and one more figure with the same number (page 18) and 4 tables.

Response: We do agree with the reviewer’s comment. We have revised the manuscript to be more concise by moving the figures 1, 2 and 3 in the section of introduction and the methodology to the appendix A. Therefore, there will be only 5 figures in this revised article. In addition, we apologize for the errors in numbering tables and figures. We have already revised the numbering of tables and figures as presented in the content and appendix A.

 

Author Response File: Author Response.docx

Reviewer 3 Report

This study estimates the trend of air pollutants emissions from sugarcane burning in Thailand from 2007/08 to 2022/23 and assesses the emissions reduction due to the recent implementation of a measure to reduce burned sugarcane. The study shows that without the implementation, air pollutants emissions would increase by about 21% between 2018/19 and 2022/23. The implementation is estimated to reduce the emissions by 53% in the first year and zero out the emissions by 2023. The authors also discuss about the monthly variation and spatial distribution of the emissions and evaluate an alternative scenario in which the measure is not 100% successful. The paper is well written. I only have one major concern and several comments. I would recommend publication if my concern is addressed.

Major concern: My major concern is about the estimation of the future emission trends affected by the implementation of the measure. As mentioned in the manuscript, the measure is to set caps of the relative amount of burned sugarcane accepted by sugar factories. Essentially, the burning of sugarcane is not banned by the measure. Farmers can still burn sugarcane wastes in their fields but just cannot sell that much of burned sugarcane to sugar factories. Is it possible that farmers will still burn a certain fraction of sugarcane by 2022/2023 just for convenience even if the measure if fully phased in? I’m raising this concern because for many types of crops, people burn them just for convenience. Monetary gain by selling burned crops is secondary. Maybe it is not the case for sugarcane in Thailand, but this needs to be clarified.

Specific comments:

1. Abstract, line 26: “the use human labor” should be “the use of human labor”.
2. Line 46, should be “according to the information from…”
3. Lines 109-110, there are two “In Thailand” in this sentence. Consider removing one.
4. Figure 2, it is not clearly stated, between box and mark, which one denotes absolute amount, which one denotes percentage.
5. Line 318, “due to of”, please rephrase
6. Line 323-324, sentence needs to be rewritten.
7. Line 342, “air emissions” should be “air pollutants emissions”.

Author Response

March 22, 2020

Dear Reviewer #3

 

Re: Manuscript ID: atmosphere-743225

 

Please find attached a revised version of our manuscript “Estimation of reduced air emissions as a result of the implementation of the measure to reduce burned sugarcane in Thailand”, which we would like to resubmit for publication as an article in Atmosphere.

Your comments were highly insightful and enabled us to greatly improve the quality of our manuscript. In the following pages are our point-by-point responses to each of the comments of the reviewers. We hope that the revisions in the manuscript and our accompanying responses will be sufficient to make our manuscript suitable for publication in Atmosphere.

 

We shall look forward to hearing from you at your earliest convenience.

 

Yours sincerely,

Jirataya Pansuk, PhD

 

Responses to the comments of Reviewer #3

(x) English language and style are fine/minor spell check required 

Response: According to the suggestion of the reviewer that this manuscript needs minor spell check required, we have already checked a common spelling errors and grammatical mistakes in manuscript.

 

Comments and Suggestions for Authors

This study estimates the trend of air pollutants emissions from sugarcane burning in Thailand from 2007/08 to 2022/23 and assesses the emissions reduction due to the recent implementation of a measure to reduce burned sugarcane. The study shows that without the implementation, air pollutants emissions would increase by about 21% between 2018/19 and 2022/23. The implementation is estimated to reduce the emissions by 53% in the first year and zero out the emissions by 2023. The authors also discuss about the monthly variation and spatial distribution of the emissions and evaluate an alternative scenario in which the measure is not 100% successful. The paper is well written. I only have one major concern and several comments. I would recommend publication if my concern is addressed.

Major concern: My major concern is about the estimation of the future emission trends affected by the implementation of the measure. As mentioned in the manuscript, the measure is to set caps of the relative amount of burned sugarcane accepted by sugar factories. Essentially, the burning of sugarcane is not banned by the measure. Farmers can still burn sugarcane wastes in their fields but just cannot sell that much of burned sugarcane to sugar factories. Is it possible that farmers will still burn a certain fraction of sugarcane by 2022/2023 just for convenience even if the measure if fully phased in? I’m raising this concern because for many types of crops, people burn them just for convenience. Monetary gain by selling burned crops is secondary. Maybe it is not the case for sugarcane in Thailand, but this needs to be clarified.

Response: We do agree with the reviewer’s concern that Thailand’s farmers ignore orders to stop burning off their sugarcane. In Thailand, sugarcane cultivation is done in groups having the group leaders, called sugarcane quotas. Group leaders have to record the information concerning sugarcane fields of himself and his group members, including fresh sugarcane and burned sugarcane sales. Authorities think that the enforcement of sugar factories and group leaders is more convenient than enforcing small farmers. So, the Cabinet on 11 June 2019 acknowledged two measures to tackle the problem of burned sugarcane by law enforcement proposed by the Ministry of Industry. The first measure involves legal matters, aimed at ending the practice of sugarcane burning among farmers within three years. In the second measure, the public sector will continue the project to extend credit for acquiring agricultural machinery in order to increase the efficiency in sugarcane harvesting. 

However, in the current production season (2019/20), the harvesting machines are in short supply and too expensive for farmers to buy. The farmers are reverting to the old practices of clearing residues with burning despite authorities’ ban on the practice. So, we have set scenario 2, in which only 50% of the goal is successful.  In addition, we are waiting for the sugarcane buying season to close and then re-evaluate the success of the implementation.

 

Specific comments:

1. Abstract, line 26: “the use human labor” should be “the use of human labor”.
2. Line 46, should be “according to the information from…”
3. Lines 109-110, there are two “In Thailand” in this sentence. Consider removing one.
4. Figure 2, it is not clearly stated, between box and mark, which one denotes absolute amount, which one denotes percentage.
5. Line 318, “due to of”, please rephrase
6. Line 323-324, sentence needs to be rewritten.
7. Line 342, “air emissions” should be “air pollutants emissions”.

 

Response: We have made revisions according to reviewer’s comments and suggestions, as described below.

1. Abstract, line 26: “the use human labor” should be “the use of human labor”.

• We have re-written this phrase as shown in line 26.

2. Line 46, should be “according to the information from…”

• We have re-written this sentence as shown in line 46.

3. Lines 109-110, there are two “In Thailand” in this sentence. Consider removing one.

• We have re-written this sentence as shown in lines 109-110.

4. Figure 2, it is not clearly stated, between box and mark, which one denotes absolute amount, which one denotes percentage.

• We apologize for any confusion. We have revised the graph description as shown in lines 531-532.

5. Line 318, “due to of”, please rephrase.

• We have re-written this word as shown in line 319.

6. Line 323-324, sentence needs to be rewritten.

• We apologize for any confusion. We have revised this sentence as shown in lines 323-325.

7. Line 342, “air emissions” should be “air pollutants emissions”.

• We have re-written this phrase as shown in line 345.

 

 

Author Response File: Author Response.docx

Reviewer 4 Report

The MS presents efforts to quantify the emissions from pre-harvest sugarcane open burning activities in Thailand, with future projections following the implementation of current policies. The financial burden of farmers resulted from the implementation of the measures are also included. The MS is well structured and the content is clearly presented. The open burning of crop residues including sugarcane is a problem of great concern in the region hence the MS should be of interest to readers. I would recommend the MS for publication after some minor revisions as follows:  

• Please try to use more commonly accepted terms, i.e. use "fine particles" or "fine particulate matter (PM2.5)" instead of "small dust (line 14)" and other places in the MS.
•  WHO provides the guideline values and not safety standards. Please correct the terms in lines 70-74.
•  Figure 2A shows the monthly levels of PM2.5 at 3 stations which peaked during the dry months. In the discussion, lines 60-70, the authors appear to attribute the peaks to the sugarcane burning activities. Please note that high PM2.5 levels are observed in these dry months in Thailand, not only in these 3 stations. It happens because of the more stagnant atmosphere, less wet removal and more open burning of biomass, among other reasons. If the data available, the authors may compare the relative increase in the monthly PM2.5 levels (in these months) of the year with those obtained for other places/provinces where similar conditions exist but without sugarcane burning. Otherwise, the authors should discuss the peaks with cautions. In addition, the monthly levels are not to compare with 24h or annual WHO guidelines.
•  Figure 1b: missing legends of 2 lines
•  Line 216: it is confusing to define SC2 as "50% of goal ..". The authors may wish to change into "only 50% of the plantation/production would comply with the regulation…"  
•  Conclusions: Lines 451-454: the content is not clear enough; Line 460: suggest to use word "adequately" instead of "very well"
•  Table A3 and A4: what the emissions range means and how the ranges have been calculated? This detail should be detailed in the text. 

Author Response

April 4, 2020

 

Dear Reviewer #4

 

Re: Manuscript ID: atmosphere-743225

 

Please find attached a revised version of our manuscript “Estimation of reduced air emissions as a result of the implementation of the measure to reduce burned sugarcane in Thailand”, which we would like to resubmit for publication as an article in Atmosphere.

 

Your comments were highly insightful and enabled us to greatly improve the quality of our manuscript. In the following pages are our point-by-point responses to each of the comments of the reviewers. We hope that the revisions in the manuscript and our accompanying responses will be sufficient to make our manuscript suitable for publication in Atmosphere.

 

We shall look forward to hearing from you at your earliest convenience.

 

Yours sincerely,

 

Jirataya Pansuk, PhD

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The modified manuscript is in better shape and now can be published to the ATMOSHERE.

Author Response

April 4, 2020

 

Dear Reviewer #2

 

Re: Manuscript ID: atmosphere-743225

 

Thank you for your guidance and support. Your comments and suggestions were highly insightful and enabled us to greatly improve the quality of our manuscript.

 

Yours sincerely,

 

Jirataya Pansuk, PhD