Assessing the Potential Impacts of Climate Change on Drought in Uzbekistan: Findings from RCP and SSP Scenarios

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

COMMENT TO AUTHORS

Review for Assessing the potential impacts of climate change on drought in Uzbekistan: Findings from RCP and SSP Scenarios, by Rakhmatova et al. (2024).

This manuscript attempts to examine the potential impacts of climate change on drought in Uzbekistan: Findings from RCP and SSP Scenarios using newly released CMIP6 GCMs. Extreme climate events continue to pause threats and devastating impacts to society, economy, and ecosystem across many regions globally. A comprehensive understanding of their development and occurrences remains a relevant approach, with key mechanisms initiating and amplifying them. From this point of view, examining meteorological factors associated with the recent occurrence of compound dry and wet extremes over vulnerable regions is important and relevant to the scientific community. Overall, the study is interesting and well-written. However, major flaws exist in the present research approach and the results reported in the current manuscript. Therefore, The reviewer would like to recommend that this manuscript be returned to the authors for major revisions, as suggested below, before a revised manuscript may be re-submitted for publication. My comments are given below;

Abstract# The main result findings are lacking; instead of emphasizing motivation, even the research objective is missing. Thus, more results must be added to the abstract with a proper narrative. Besides, grammatical and scientific mistakes need attention; for instance, “In lines #28-38, the first impression is poorly gone.

In the Introduction: The authors should point out this manuscript's research goal and emphasise its significance. Moreover, the authors should introduce the implications of previous related published research from a broader perspective.

https://onlinelibrary.wiley.com/doi/10.1002/joc.7673

What are the main aims and motivations for selecting the GCMs from CMIP5/CMIP6, why different numbers of models are used? Provide details for each model in the table, which is unclear and not seen as the scientific reason in the entire manuscript.

Why statistical analysis is being used in the present study? Is there some problem with the output from the models/datasets? Statistical analysis is necessary if the output used is incompatible with the analysis. I do not believe this is the case here. In addition, many bias correction methods destroy the physical relationship between variables and climate change physics, and this begs the question, why use few models from CMIP6 at all?

I feel the authors need to discuss the study's limitations in the discussion section and what needs to be done to address those. For example, a comprehensive analysis of climate sensitivity, given the datasets (that are used in the study), has a significant uncertainty amongst their models. Although I see that the authors have mentioned this in their manuscript, it still needs more elaborate discussion. Finally, discuss some lights on the physical mechanism on which the dryness/wetness is increasing over the regions with the help of recent literature.

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2023EF003688

https://www.nature.com/articles/s43247-024-01390-y

https://doi.org/10.1016/j.scitotenv.2021.148162; https://www.mdpi.com/2073-4441/16/11/1492

Conclusions are not clarified. Besides, the data and results cannot support these findings well.

Comments on the Quality of English Language

Moderate editing of English language required

Author Response

Reply to Reviewers

We thank reviewers for very carefully reading the manuscript, providing critical comments, constructive and helpful suggestions. We have revised the manuscript following reviewers’ suggestions.

Here we would like to share the main directions for improving the article:

• The manuscript has undergone significant revisions, particularly in the Abstract, Introduction, and Conclusion sections.
• All sections have been thoroughly revised to improve clarity, coherence, and comprehensiveness.
• In addition, a new Discussion section has been added to provide a more in-depth analysis and context for the results. This section addresses the implications of the findings, compares them to existing literature, and outlines potential avenues for future research.
• These extensive revisions aim to improve the overall quality and impact of the manuscript.

The reviewer’s specific comments are addressed below.

 

 

Reviewer 1

Review for Assessing the potential impacts of climate change on drought in Uzbekistan: Findings from RCP and SSP Scenarios, by Rakhmatova et al. (2024).

This manuscript attempts to examine the potential impacts of climate change on drought in Uzbekistan: Findings from RCP and SSP Scenarios using newly released CMIP6 GCMs. Extreme climate events continue to pause threats and devastating impacts to society, economy, and ecosystem across many regions globally. A comprehensive understanding of their development and occurrences remains a relevant approach, with key mechanisms initiating and amplifying them. From this point of view, examining meteorological factors associated with the recent occurrence of compound dry and wet extremes over vulnerable regions is important and relevant to the scientific community. Overall, the study is interesting and well-written. However, major flaws exist in the present research approach and the results reported in the current manuscript. Therefore, The reviewer would like to recommend that this manuscript be returned to the authors for major revisions, as suggested below, before a revised manuscript may be re-submitted for publication. My comments are given below;

Comment 1: Abstract# The main result findings are lacking; instead of emphasizing motivation, even the research objective is missing. Thus, more results must be added to the abstract with a proper narrative. Besides, grammatical and scientific mistakes need attention; for instance, “In lines #28-38, the first impression is poorly gone.

Response 1: Agree. The manuscript has undergone significant revisions including the Abstract.

Comment 2: In the Introduction: The authors should point out this manuscript's research goal and emphasize its significance. Moreover, the authors should introduce the implications of previous related published research from a broader perspective.

Response 2: The research goal and significance are stated in the Introduction L.101-116:

This study examines the evolving characteristics of future drought events in Uzbekistan and highlights their spatiotemporal patterns under different climate scenarios. Using the data from the CMIP5 and CMIP6 MMEs, we assess projected temperature and precipitation trends under the different regions of Uzbekistan under the Representative Concentration Pathway (RCP) and Shared Socioeconomic Pathway (SSP) scenarios. To comprehensively capture the evolving drought picture, we use the Standardized Precipitation Evapotranspiration Index (SPEI), which incorporates variations in temperature and precipitation [34-36]. Our analysis reveals spatial and temporal shifts in drought intensity, frequency, and duration for two critical time periods: 2021-2060 and 2061-2100, commonly referred to as the "near future" and the "far future", respectively. The remaining sections of this paper are organized as follows: Section 2 provides a de-scription of the datasets, models, datasets, and methods used. Section 3 presents the comprehensive assessment of drought characteristics in Uzbekistan under different climate scenarios using CMIP5 and CMIP6 data. Section 4 discusses these findings in comparison with existing research. Finally, Section 5 synthesizes the main key research findings and draws insightful conclusions to guide future strategies for drought resilience in Uzbekistan.

https://onlinelibrary.wiley.com/doi/10.1002/joc.7673

The highlighted publication is discussed in Section 4.

Comment 3: What are the main aims and motivations for selecting the GCMs from CMIP5/CMIP6, and why are different numbers of models used?

Response 3: The main aims and motivations for selecting the GCMs is stated at L. 63-74: Scenarios describing future climate drivers from human activities are a major focus of climate research. The Coupled Model Intercomparison Project (CMIP), operational since 1995, coordinates international climate model experiments to improve the understanding of historical and future climate dynamics [7]. CMIP5 (initiated in 2008) [8] and CMIP6 (initiated in 2016) [9,10] have conducted extensive simulations using updated models and scenarios to project future climate change. These efforts contribute significantly to the IPCC assessments by providing insights into temperature patterns, precipitation trends, sea level variations, and climate mechanisms that are essential for the development of mitigation and adaptation strategies [7,9-13]. Despite the inherent uncertainties in model simulations, the multi-model ensemble mean (MME) is quite robust. Bias correction methods adjust model outputs, resulting in more accurate climate predictions and enabling policymakers to make informed decisions [14,15].

The primary reason lies in the varying number of CMIP5 and CMIP6 models involved in the experiments. Different research projects and climate studies may have access to or choose to utilize different subsets of these models based on availability, specific research goals, computational resources, and the particular aspects of climate they aim to investigate. Additionally, the CMIP6 initiative includes a broader and more diverse set of models compared to CMIP5, reflecting advancements in climate modeling and the inclusion of more institutions globally. Consequently, the number of models used can vary significantly between studies, influencing the robustness and range of the climate projections produced.

Comment 4: Provide details for each model in the table, which is unclear and not seen as the scientific reason in the entire manuscript.

Response 4: For the purposes of this article, it would be time-consuming and not particularly useful to delve into the detailed specifics of the models. However, for those seeking more comprehensive information, extensive datasets and model outputs are readily available online. CMIP5 model outputs can be found at https://esgf-node.llnl.gov/esgsearch. Meanwhile, output data for CMIP6 models are available at https://cds.climate.copernicus.eu. These resources provide a wealth of detailed data for those interested in further exploring the intricacies of climate models.

Comment 5: Why statistical analysis is being used in the present study? Is there some problem with the output from the models/datasets? Statistical analysis is necessary if the output used is incompatible with the analysis. I do not believe this is the case here. In addition, many bias correction methods destroy the physical relationship between variables and climate change physics, and this begs the question, why use few models from CMIP6 at all?

I feel the authors need to discuss the study's limitations in the discussion section and what needs to be done to address those. For example, a comprehensive analysis of climate sensitivity, given the datasets (that are used in the study), has a significant uncertainty amongst their models. Although I see that the authors have mentioned this in their manuscript, it still needs more elaborate discussion. Finally, discuss some lights on the physical mechanism on which the dryness/wetness is increasing over the regions with the help of recent literature.

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2023EF003688

https://www.nature.com/articles/s43247-024-01390-y

https://doi.org/10.1016/j.scitotenv.2021.148162

https://www.mdpi.com/2073-4441/16/11/1492

Response 5: Agree. The resid questions and the results of the above articles are discussed in Section 4.

Comment 6: Conclusions are not clarified. Besides, the data and results cannot support these findings well.

Response 6: Agree. The conclusion section was elaborated.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The study deals with an interesting topic and investigates also the potential impact of climate change on drought. Some minor comments prior to its acceptance are listed below: In the abstract some numerical results should be added. In the introduction • provide some official definitions of drought according to the World Meteorological Organization (WMO) • explain the difference of drought from other natural disasters (floods, wildfires, etc.) as it is a slow-onset hazard that becomes evident as societies and the environment begin to experience its impacts. Furthermore, highlighting the non-structural and extensive geographical impacts. • Specify the most widely used indices and the effect of timescale to drought recognition an severity as highlighted in recent publications • (https://doi.org/10.3390/hydrology10080167, https://doi.org/10.1007/s00704-023-04772-y) In the study domain increase the legend of the figure 1. In the 2.6 chapter, it is recommended to add table 1 and 2 as appendix.

Author Response

Reply to Reviewers

We thank the reviewers for very carefully reading the manuscript, and providing critical comments, and constructive and helpful suggestions. We have revised the manuscript following the reviewers’ suggestions.

Here we would like to share the main directions for improving the article:

• The manuscript has undergone significant revisions, particularly in the Abstract, Introduction, and Conclusion sections.
• All sections have been thoroughly revised to improve clarity, coherence, and comprehensiveness.
• In addition, a new Discussion section has been added to provide a more in-depth analysis and context for the results. This section addresses the implications of the findings, compares them to existing literature, and outlines potential avenues for future research.
• These extensive revisions aim to improve the overall quality and impact of the manuscript.

The reviewer’s specific comments are addressed below.

Reviewer 2

The study deals with an interesting topic and investigates also the potential impact of climate change on drought. Some minor comments prior to its acceptance are listed below:

Comment 1: In the abstract some numerical results should be added.

Response 1: The abstract was revised accordingly.

Comment 2: In the introduction provide some official definitions of drought according to the World Meteorological Organization (WMO)

Response 2: We don’t think it is necessary.

Comment 3: Explain the difference of drought from other natural disasters (floods, wildfires, etc.) as it is a slow-onset hazard that becomes evident as societies and the environment begin to experience its impacts. Furthermore, highlighting the non-structural and extensive geographical impacts.

Response 3: We think that this is out of the scope of our research topic.

Comment 4: Specify the most widely used indices and the effect of timescale to drought recognition an severity as highlighted in recent publications (https://doi.org/10.3390/hydrology10080167, https://doi.org/10.1007/s00704-023-04772-y). In the study domain increase the legend of the figure 1.

Response 4: The highlighted recent publications are discussed in Section 4.

Comment 5: In the 2.6 chapter, it is recommended to add tables 1 and 2 as appendix.

Response 5: Tables 1 and 2 are moved to Appendix

Reviewer 3 Report

Comments and Suggestions for Authors

A well-written article, however, needs the following corrections to be acceptable:

1-    In the abstract, the word prediction should be replaced with projection. The work done is projection, not anticipation.

2-      In the introduction, mention should be made of the studies conducted on droughts in the West Asian region, especially the studies conducted using networked data. As an example article:

Long-term Analysis of the Spatiotemporal Standardized Precipitation Evapotranspiration Index for West Asia

Or the following articles

Characterization of drought dynamics in Iran by using S-TRACK method

 And Spatio-temporal Analysis of Dry and Wet Periods in Iran by Using Global Precipitation Climatology Center - Drought Index (GPCC-DI) In conclusion, the results of the above articles can be compared with the research results.

3-    After modifying the introduction, the conclusion section should be rewritten and the result of the work should be compared with the studies done.

4-    In studies where projection is done, it is necessary to analyze the uncertainty of the model, which was not done in this study. What answer do the authors have to this question?

5-    The size and quality of the figures are small and low and should be presented better and with better quality.

6-    I am not a native English speaker, but it is better for a native to comment on grammar and writing the article.

7-    The conclusion section is not based on the results of the output of the models and the drought index. In the conclusion, global warming and its effect on the drought of Uzbekistan are discussed without analyzing the temperature, and the results of the studies of the neighboring region, such as Iran and the whole of Middle Asia, are not considered. I recommend that the conclusion be rewritten with discussion.

Author Response

Reply to Reviewers

We thank the reviewers for very carefully reading the manuscript, and providing critical comments, and constructive and helpful suggestions. We have revised the manuscript following the reviewers’ suggestions.

Here we would like to share the main directions for improving the article:

• The manuscript has undergone significant revisions, particularly in the Abstract, Introduction, and Conclusion sections.
• All sections have been thoroughly revised to improve clarity, coherence, and comprehensiveness.
• In addition, a new Discussion section has been added to provide more in-depth analysis and context for the results. This section addresses the implications of the findings, compares them to existing literature, and outlines potential avenues for future research.
• These extensive revisions aim to improve the overall quality and impact of the manuscript.

The reviewer’s specific comments are addressed below.

 

Reviewer 3

A well-written article, however, needs the following corrections to be acceptable:

 

Comment 1: In the abstract, the word prediction should be replaced with projection. The work done is projection, not anticipation.

Response 1: Agree. Corrected.

Comment 2: In the introduction, mention should be made of the studies conducted on droughts in the West Asian region, especially the studies conducted using networked data. As an example article: Long-term Analysis of the Spatiotemporal Standardized Precipitation Evapotranspiration Index for West Asia

Or the following articles: Characterization of drought dynamics in Iran by using S-TRACK method, Spatio-temporal Analysis of Dry and Wet Periods in Iran by Using Global Precipitation Climatology Center - Drought Index (GPCC-DI).

In conclusion, the results of the above articles can be compared with the research results.

Response 2: Agree. The results of the above articles are discussed in Section 4

Comment 3: After modifying the introduction, the conclusion section should be rewritten and the result of the work should be compared with the studies done.

Response 3: Agree. The manuscript has undergone significant revisions, particularly in the Abstract, Introduction, and Conclusion sections.

Comment 4: In studies where projection is done, it is necessary to analyze the uncertainty of the model, which was not done in this study. What answer do the authors have to this question?

Response 4: The CMIP5/6 MEM identifies three main sources of uncertainty in climate projections:

1. Future emissions: Future emissions are a significant source of uncertainty because they depend on socio-economic, technological and political developments. Scenarios such as the Representative Concentration Pathways (RCPs) in CMIP5 and the Shared Socioeconomic Pathways (SSPs) in CMIP6 outline possible futures with different levels of greenhouse gas emissions. These scenarios are based on assumptions about population growth, economic development, energy use, and land use change, all of which are inherently uncertain. The range of emissions pathways creates a spectrum of possible climate futures, making it difficult to pinpoint precise outcomes.
2. Internal variability of the climate system: Internal variability refers to the natural variations within the climate system that occur in the absence of external forcing. It includes phenomena such as the El Niño-Southern Oscillation (ENSO), volcanic eruptions, and oceanic and atmospheric circulation patterns. Internal variability can significantly affect climate projections over short to medium-time scales by superimposing natural variability on long-term trends. This variability is unpredictable and adds a layer of uncertainty, especially when projecting regional climate changes.
3. Model Response Uncertainty: Model response uncertainty arises from differences in how different climate models simulate processes and respond to external forcing. Climate models differ in their structure, parameterizations, and sensitivity to changes in greenhouse gas concentrations. These differences lead to variations in projected temperature, precipitation, and other climate variables. Uncertainty in model response is addressed through the use of multi-model ensembles (MME), such as CMIP5 and CMIP6, which average the results of the individual models.

 

MMEs, such as CMIP5 and CMIP6, reduce uncertainty in model response by combining projections from multiple models. This approach leverages the strengths of different models and helps identify common trends while accounting for individual model biases. By averaging results, MMEs provide a more comprehensive range of possible futures and reduce the impact of individual model idiosyncrasies.

The use of multiple emissions scenarios (RCPs and SSPs) helps to capture the range of possible futures based on different socio-economic pathways. Scenario analysis allows researchers to assess the impacts of different levels of greenhouse gas emissions and provides insights into the effectiveness of different mitigation strategies.

Advanced statistical techniques, such as Bayesian methods, can quantify and reduce uncertainty. These techniques help estimate the likelihood of different outcomes by incorporating prior knowledge and updating it with new data. Probabilistic approaches provide a way to express uncertainty in terms of confidence intervals or probability distributions, providing a clearer picture of possible climate futures.

To refine uncertainty estimates, future research will focus on improving model independence and weighting in MMEs. Understanding the interdependencies between models and assigning appropriate weights based on their performance and similarity can improve the accuracy of projections. In addition, efforts will be made to integrate more high-resolution regional models that can better capture local climate characteristics and reduce uncertainty in regional projections.

Comment 5: The size and quality of the figures are small and low and should be presented better and with better quality.

Response 5: We are sorry about that. However, it is a technical issue. All figures were provided of high quality, but it was compressed during the submission procedure. We hope it will be fixed in the final version.

Comment 6: I am not a native English speaker, but it is better for a native to comment on grammar and writing the article.

Response 6: I agree. The grammar and writing of the manuscript have been edited by a native speaker to improve clarity and readability.

Comment 7: The conclusion section is not based on the results of the output of the models and the drought index. In the conclusion, global warming and its effect on the drought of Uzbekistan are discussed without analyzing the temperature, and the results of the studies of the neighboring region, such as Iran and the whole of Middle Asia, are not considered. I recommend that the conclusion be rewritten with discussion.

Response 7: Agree. The conclusion section was elaborated along with the Abstract, and Introduction.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

I have no further comments

Comments on the Quality of English Language

Extensive editing of English language required

Reviewer 2 Report

Comments and Suggestions for Authors

The article in the current version is accepted