Beyond Forests: A Strategic Framework for Climate-Positive Development from Thailand’s Net-Negative Provinces

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

While this submission represents an interesting and somewhat remarkable position, I find it is potentially fatally flawed in its overall analysis of the climate impacts of agriculture. In order to make a more compelling argument, the Authors would first need to demonstrate what was lost by converting these lands (in particular those in the SNI region) to agricultural production. And after doing this, the Authors would further need to demonstrate what the annual net flux of carbon is on these agricultural lands (i.e., they would need to assess the annual net increment, or growth, and subtract mortality and harvest from these numbers)... 

I do not know what the result of these calculations would be, but I think that significantly more work is required in order to show that such agricultural lands can potentially provide a climate-related carbon benefit from year to year. Further, if there is other literature which makes these claims, the Authors need to cite this literature. 

As is, I find it impossibly to come to a more refined conclusion. Far more work and detailed discussion is required. 

Comments for author File: Comments.pdf

Author Response

Reviewer 1 (Round 1):

Comments and Suggestions for Authors

While this submission represents an interesting and somewhat remarkable position, I find it is potentially fatally flawed in its overall analysis of the climate impacts of agriculture. In order to make a more compelling argument, the Authors would first need to demonstrate what was lost by converting these lands (in particular those in the SNI region) to agricultural production. And after doing this, the Authors would further need to demonstrate what the annual net flux of carbon is on these agricultural lands (i.e., they would need to assess the annual net increment, or growth, and subtract mortality and harvest from these numbers)... 

I do not know what the result of these calculations would be, but I think that significantly more work is required in order to show that such agricultural lands can potentially provide a climate-related carbon benefit from year to year. Further, if there is other literature which makes these claims, the Authors need to cite this literature. 

As is, I find it impossibly to come to a more refined conclusion. Far more work and detailed discussion is required. 

Reviewer Comment 1 (Line 52): This may overstate the case somewhat...? It is not as though AFOLU has never been addressed as an appropriate climate change mitigation framework...??

Response 1:

We sincerely thank the Reviewer for this critical observation. We agree that our initial phrasing may have inadvertently understated the established role of the Agriculture, Forestry, and Other Land Use (AFOLU) sector in global climate frameworks. Our intention was not to suggest that AFOLU is overlooked, but rather to highlight the lack of integrated, regional-scale diagnostic models that identify specific "climate-positive" archetypes for sub-national planning.

In addition to the conceptual changes mentioned above, we have systematically addressed each point highlighted in orange/yellow in the manuscript.

1. Abstract (Lines 20–22): (Revised Line 23) We have refined the primary claim of the Agro-Sink model. Instead of suggesting managed landscapes are inherently superior to forests, we now specify that "within specific regional and economic contexts, managed agricultural landscapes can surpass natural forests as the primary driver of carbon removal". This adjustment frames the finding as context-specific rather than a universal generalization.
2. Introduction (Lines 50–54): (Revised Line 57) We have revised the text to explicitly acknowledge AFOLU as a recognized pillar of mitigation. The updated text clarifies that the gap lies in "operationalizing these frameworks at the sub-national level to identify specific regional archetypes for net-negative development".
3. Discussion (Section 4.3): (Revised Line 518) We have significantly expanded the discussion on the Agro-Sink archetype to provide a more rigorous, evidence-based justification for our findings:
   • Net Carbon Flux: We now explicitly describe the mechanisms of "net primary production" and the "net ecosystem carbon budget," explaining how annual woody biomass accumulation in perennial crops outweighs the carbon exported via harvest.
   • Carbon Debt: We addressed the "What was lost" concern by introducing the concept of the "compensation point," arguing that stable, mature perennial systems in regions like Surat Thani have already repaid their historical carbon debt.
   • Empirical Support: We linked these arguments to our findings in Table 5, which show minimal recent forest-to-cropland conversion, confirming that the current sink status is not achieved at the expense of existing natural forests.

These revisions provide a much more nuanced and scientifically robust representation of the AFOLU sector's role within our proposed framework.

Reviewer Comment 2 (Line 90): Not previously introduced...???

Response 2: (Revised Line 100) We have addressed the Reviewer's concern regarding the abbreviation by providing the full term for "Gross Provincial Product (GPP)" at its first mention in the main text (Line 90). Furthermore, we have thoroughly revised all sections indicated by the yellow highlights to ensure all terms and indicators are clearly defined and properly contextualized.

 

Reviewer Comment 3 (Line 126): This of course brings many limitations...?

Response 3: (Revised Line 139)

We agree that the Tier 1 approach has limitations regarding localized precision. However, as localized Tier 2 or Tier 3 data are often unavailable at the sub-national level in developing countries like Thailand, we strategically chose Tier 1 to ensure the framework's scalability and accessibility for other regional governments in the Global South. We have revised the text to explicitly acknowledge these data constraints to highlight highlighting that the scientific validity of our findings is confirmed by the Monte Carlo uncertainty analysis in Section 2.4.

Reviewer Comment 4 (Line 288): This requires some explanation and discussion of what this consists of...??? Assuming this is primarily driven by palm oil and rubber tree production, more discussion is necessary...???

Response 4: (Revised Line 310) We agree that the exceptional removal capacity of Surat Thani (SNI) warrants a detailed explanation. We have updated the text in Section 3.1 to explicitly attribute these results to the province’s extensive perennial agricultural landscapes, particularly oil palm and rubber plantations. A comprehensive discussion on the underlying mechanisms and carbon dynamics of these systems has been added to the revised Section 4.3.

Reviewer Comment 5 (Line 330): Note that NONE of the measures used here or below highlight the COST of the original deforestation... Nor is there any relevant comparison here of the differences in net annual carbon sequestration from forest cover relative to net annual carbon sequestration rates from cropland...???

Response 5: (Revised Line 360) We acknowledge the Reviewer’s point regarding the historical "carbon debt" of land-use conversion. We have added text to Section 3.3 clarifying that while our current inventory reflects annual flux, these mature perennial systems in SNI have largely surpassed their initial carbon compensation points. We also clarified that while forests provide superior stability and biodiversity, these managed landscapes exhibit high annual sequestration rates during their productive growth phases.

Reviewer Comment 6 (Line 340): Where this represents a climate change mitigation advantage really requires more discussion... If most of this annual growth is harvested, how do you account for the harvesting...? Is this assumed to be an emission... and how is it related to annual growth...???

Response 6: (Revised Line 370) We have expanded the discussion in Section 3.3 to clarify the accounting of harvested biomass. For perennial crops like rubber and oil palm, carbon is primarily stored in the long-term structural woody biomass (trunks and roots), whereas the annual harvest (latex or fruit) represents only a minor fraction of the total net primary production. Thus, the net ecosystem carbon

Reviewer Comment 7 (Line 366): What really needs to be assessed here, however, is the net annual flux, which would include substracting the annual harvest from the net increment...??? This needs to be discussed and clarified...???

Moreover, using AREA measurements instead of net annual carbon flux measurements will simply disguise the most important features in terms of climate change mitigation potential...???

Response 7: (Revised Line 402) We thank the Reviewer for this important technical clarification. We wish to ensure that there is no misunderstanding: the results presented (e.g., the -9.61 million tCO₂eq for SNI) represent the net annual carbon flux, not just area measurements. Our methodology follows the IPCC Gain-Loss Method, which explicitly subtracts annual carbon losses (from harvesting and disturbances) from the annual biomass increment. We have revised the text in Section 3.3 to explicitly state that the net primary production and net ecosystem carbon budget were used to derive these figures, confirming that the structural carbon sequestration in perennial crops exceeds the annual harvest export.

Reviewer Comment 8 (Line 463): Given the above mentioned concerns, I do not know how or what to think of this... At best, a far more detailed argument is required in order to defend this...???

Response 8: (Revised Line 531) We acknowledge the Reviewer’s concern regarding the magnitude of the Agro-Sink. We have significantly expanded the discussion in Section 4.3 to provide a robust, evidence-based defense. We now explicitly describe the net ecosystem carbon budget of perennial systems, explaining how structural carbon sequestration in woody biomass and roots outweighs annual harvest exports. Furthermore, we address the "carbon debt" and "compensation point" to clarify why these mature plantations function as powerful net sinks today, supported by land-use stability data in Table 5 and established literature [31–33].

 

 

 

 

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

This study provides a significant contribution to the field of climate-positive development by introducing the Climate-Positive Pathways Framework (CPPF) and applying it to four diverse provinces in Thailand. The paper effectively highlights the role of both natural forests and managed agricultural landscapes in achieving net-negative emissions. It identifies three distinct archetypes of regional climate-positive development—Conservation-Dependent, Agricultural Frontier, and Agro-Sink—and offers practical, evidence-based policy recommendations for each pathway, and the methodology is thorough. However, there are still some issues. 
1. The current analysis is based on a single baseline year, without reflecting inter-annual fluctuations. If data is available, it is recommended to include a dynamic analysis of multi-year data to verify the stability of the pathways.
2. Some parameters use the IPCC Tier 1 default values. Although uncertainty is considered, the applicability of these defaults to Thailand's local vegetation types is insufficient. It is suggested to supplement with a sensitivity analysis of local parameter calibration, or clearly explain the necessity and limitations of using the Tier 1 method.
3. For the core driving mechanism of "agricultural carbon sink," only the biomass accumulation of perennial crops is emphasized. Further analysis should be added to link it with soil carbon stocks and crop management practices.
4. The conversion conditions between the three pathways are not clearly defined. It is recommended to explore the critical points and key interventions for pathway transitions.
5. Increase the resolution of Figure 5.
6. The full term of English abbreviations, such as LULUCF, should be provided upon first use.
7. Some technical terms, such as "Agro-Sink," "Climate-Positive Pathways Framework", are not defined in simpler terms when first introduced. It is suggested to add a more accessible definition.

Author Response

Reviewer 2 (Round 1):

Comments and Suggestions for Authors

This study provides a significant contribution to the field of climate-positive development by introducing the Climate-Positive Pathways Framework (CPPF) and applying it to four diverse provinces in Thailand. The paper effectively highlights the role of both natural forests and managed agricultural landscapes in achieving net-negative emissions. It identifies three distinct archetypes of regional climate-positive development—Conservation-Dependent, Agricultural Frontier, and Agro-Sink—and offers practical, evidence-based policy recommendations for each pathway, and the methodology is thorough. However, there are still some issues.

Reviewer Comment 1:

1. The current analysis is based on a single baseline year, without reflecting inter-annual fluctuations. If data is available, it is recommended to include a dynamic analysis of multi-year data to verify the stability of the pathways.

Response 1:

We thank the Reviewer for this insightful suggestion. We agree that verifying the stability of these pathways over time is crucial. To address this, we have integrated a dynamic trend analysis using multi-year land-use data (2014–2019) as presented in Tables 5 and 6. This longitudinal evidence confirms that the land-use patterns driving each archetype are stable and consistent over time. We have added a paragraph to Section 3.3 (highlighted in green in the revised manuscript) to explicitly discuss these multi-year dynamics and to verify the robustness of our identified pathways.

Reviewer Comment 2:

2. Some parameters use the IPCC Tier 1 default values. Although uncertainty is considered, the applicability of these defaults to Thailand's local vegetation types is insufficient. It is suggested to supplement with a sensitivity analysis of local parameter calibration, or clearly explain the necessity and limitations of using the Tier 1 method.

Response 2:

We appreciate the Reviewer’s critical point regarding parameter calibration. We have updated Section 2.2.1 (highlighted in green) to more clearly explain the necessity of using the Tier 1 method, which focuses on ensuring the framework's scalability and accessibility for other data-constrained regions in developing countries. To address the concern about local applicability, we have supplemented our methodology with a sensitivity analysis of key parameters. This analysis confirms that the identified "climate-positive archetypes" are structurally robust; although absolute sequestration values may vary with local calibration, the overall pathway classifications remain stable. This further justifies Tier 1 as a reliable tool for regional-level diagnostics in Thailand's context.

Reviewer Comment 3: For the core driving mechanism... only the biomass accumulation... is emphasized. Further analysis should be added to link it with soil carbon stocks and crop management practices.

Response 3:

We appreciate this insightful suggestion to broaden the scope of our Agro-Sink discussion. We have expanded Section 4.3 (indicated with green highlight) to explicitly discuss the role of soil organic carbon (SOC) and crop management practices. We now highlight how the lack of annual tillage in perennial systems, combined with management techniques such as organic mulching and ground cover maintenance, contributes to the stabilization and enhancement of soil carbon stocks. By linking biomass accumulation with these soil-based mechanisms, we provide a more holistic defense of the Agro-Sink’s role in regional climate-positive development.

Reviewer Comment 4: The conversion conditions between the three pathways are not clearly defined. It is recommended to explore the critical points and key interventions for pathway transitions.

Response 4:

We thank the Reviewer for this constructive suggestion, which adds a dynamic policy dimension to our framework. We have added a dedicated discussion on pathway transitions in Section 4.3 (indicated with green highlight). We now define the "critical points" for each transition, such as the point where perennial expansion 'closes' the agricultural frontier, and identify "key interventions" like land-use zoning and financial incentives for high-biomass crop conversion. This expansion clarifies how regional planners can strategically guide their provinces from precarious states toward more stable, climate-positive archetypes.

Reviewer Comment 5: Increase the resolution of Figure 5

Response 5: We have addressed this request by re-exporting Figure 5 at a higher resolution to ensure maximum clarity and legibility. The updated figure has been integrated into the revised manuscript.

Reviewer Comment 6: The full term of English abbreviations, such as LULUCF, should be provided upon first use.

Response 6:

We thank the Reviewer for this practical suggestion. We have thoroughly reviewed the entire manuscript to ensure that all technical abbreviations are defined in full upon their first mention. This includes LULUCF (Land Use, Land-Use Change, and Forestry), AFOLU (Agriculture, Forestry, and Other Land Use), GHG (Greenhouse Gas), and CPPF (Climate-Positive Pathways Framework). All these instances are indicated with green highlights in the revised manuscript to facilitate your review.

Reviewer Comment 7: Some technical terms, such as "Agro-Sink," "Climate-Positive Pathways Framework", are not defined in simpler terms when first introduced. It is suggested to add a more accessible definition.

Response 7:

We agree that providing accessible definitions for our core conceptual terms is essential for a broader readership. In response, we have added simplified definitions for the Climate-Positive Pathways Framework (CPPF) and the Agro-Sink archetype in the final paragraph of the Introduction (indicated with green highlights). Specifically, the CPPF is now defined as a systematic diagnostic tool for identifying regional net-negative strategies, while the Agro-Sink is described as a landscape where managed perennial agricultural systems serve as the primary engine for carbon removal.

 

 

 

 

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

There are no further comments.

Author Response

We thank the reviewer for their positive assessment and for noting that no further comments were necessary in this round.