Greenhouse Gas Emission Reduction Based on Social Recycling: A Case Study with Waste Picker Cooperatives in Brasília, Brazil

Round 1

Reviewer 1 Report

The study shows of solid waste recycling results with waste picker organizations allowed to obtain the 60% reduction in carbon dioxide emissions over the period of one year that these organizations have achieved. However, this study also indicates that small-scale WPOs projects that use the AMS-III. AJ methodology may not be economically viable due to current market criteria, as well as the verification parameters of the methodology. The evolution of the methodology is necessary to allow for the inclusion of WPOs projects, together with a possible development of a new carbon certification standard focused on recycling and the implementation of public policies that enable smaller projects to access the carbon credits and green bond market. The handling and management of waste, in Brazil, still has a long way to go to effectively reduce the environmental impacts and prevent climate change related diseases arising from this situation. Most people forget that achieving a better waste management system depends on those individuals and groups of workers directly involved in urban waste management, the waste pickers. The study also highlights that those WPOs that conduct door-to-door collection of the recyclable materials receive a better material quality, with less waste mixed among the recyclables. This fact demonstrates that involving waste pickers in the collection allows them to interact with households, educating them about clean source separation, which in the end improves the waste pickers’ income and reduces the amount of rejected materials that need to be transported to the landfill. It is necessary to conduct similar studies, to allow for the quantification of the impacts and benefits from recycling and to demonstrate how integrating WPOs into waste management increases material diversion and recycling and ultimately helps governments progress towards the achievement of the sustainable development goals.

The paper content valuable data but it could be published after major revision as below.

General Remarks

Abstract

Please do not use abbreviation in abstract or provide the full name.

Abstract content is too overall. Some research results should be added

Conclusions are too overall. More detailed research results should be added

The goal of research should be more clearly presented at the end of Introduction

Detailed remarks

1.      Lines 319-320  ….”Recicle a Vida collects 327 tons of recyclable material per year, Coopere receives 1237.75 tons and Plasferro receives 1309.01 tons”... These capacities are very low. Figure 2 shows that separation method is very simplified. How is possible to propose some wider results and solution on such type base? Comment please.

2.        Lines 381-386. …”Carbon, CO2 or GHG”… Clarify please.

3.        Table 1,2,3,6,7,8,9,10  should be self-explaining. Please add proper information.

4.        Figure 1 should be self-explaining. Please add proper information.

Author Response

Dear Reviewers,

we are very grateful for your constructive comments and suggestions. They have helped us improve our manuscript substantially, allowing for a more comprehensive reading. We have addressed all your comments and please view the attached list, where we outline exactly how and where we have addressed those changes made to the text. We will also upload a version that shows all the changes made by using track changes. 

Again, many thanks for your support.

Kind regards,

The authors

Author Response File: Author Response.pdf

Reviewer 2 Report

Overall, this work is well-writen and could be a contribution to the field; however, authors must reference data used in a proper manner, correct typo, and extend the study's discussion and its implications. Find comments in the attached file. Please, respond in a separated file the main issues.

Comments for author File: Comments.pdf

Author Response

Dear Reviewers,

we are very grateful for your constructive comments and suggestions. They have helped us improve our manuscript substantially, allowing for a more comprehensive reading. We have addressed all your comments and please view the attached list, where we outline exactly how and where we have addressed those changes made to the text. We will also upload a version that shows all the changes made by using track changes. 

Again, many thanks for your support.

Kind regards,

The authors

Author Response File: Author Response.pdf

Reviewer 3 Report

I thank the author for choosing this important point, but the large number of abbreviations without a table of abbreviations is difficult for the reader to understand - a table of abbreviations must be added before references

The Tables in the research are written in more than one form - please unify the form of the Table in the entire search

Delete the word equation and write a number at the end of the line

Emphasize all chemical formulas (some are highlighted for review)

Author Response

Dear Reviewers,

we are very grateful for your constructive comments and suggestions. They have helped us improve our manuscript substantially, allowing for a more comprehensive reading. We have addressed all your comments and please view the attached list, where we outline exactly how and where we have addressed those changes made to the text. We will also upload a version that shows all the changes made by using track changes. 

Again, many thanks for your support.

Kind regards,

The authors

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The authors make corrections to the manuscript and I think that it can be accepted for publication in this form. I have no more comments.

Reviewer 2 Report

The authors have addressed all suggestions. In my opinion, it could be benefitial for this manuscript to include numerical data in the abstract. Overall, findings are interesting and add the existing literature.