Exploring Key Aspects of Sea Level Rise and Their Implications: An Overview

Round 1

Reviewer 1 Report

The authors carry out detailed data collection work on Exploring Key Aspects of Sea Level Rise and their Implications: An Overview.

Nothing to object to the synthesis, very complete and well structured. However, the authors justify the rise in sea level based on the effects produced by Climate Change. Although there are numerous allusions to other factors that cannot be attributed in any way to this concept generically called "non-climatic (geological)". From a geological point of view, changes in sea level, positive or negative, are in many cases due to geological causes such as plate tectonics, or to changes in the sea level that gravitates over continents or ocean basins. Glacioeustatism or hydroeustatism, or volcanosistasy must be equally considered and, at least, mentioned in the text. It is clear that glacioisostasis justifies changes in sea level due to changes in the weight that gravitates on the lithosphere. The same as, in the case of large volcanoes, the accumulation of large amounts of lava causes a depression in the lithosphere. We understand that the objective of the work is to list the key aspects of sea level rise and that the entire argument is directed towards immediate causes, leaving in the background the geological causes that have a more medium and long-term dynamic. But it would be appropriate to include the weight of geological factors in some section. We think that this complements the work. This implies including more specific bibliography on that topic. Mentioning the thermal expansion of seawater and the melting of ice sheets and glaciers and not mentioning glacioisostasis is not correct. I think that the only drawback I find in this work is not completing the inventory of the factors that influence the rise in sea level, which are geological ones, since they have undeniable importance.

Author Response

Comments 1: Nothing to object to the synthesis, very complete and well structured. However, the authors justify the rise in sea level based on the effects produced by Climate Change. Although there are numerous allusions to other factors that cannot be attributed in any way to this concept generically called "non-climatic (geological)". From a geological point of view, changes in sea level, positive or negative, are in many cases due to geological causes such as plate tectonics, or to changes in the sea level that gravitates over continents or ocean basins. Glacioeustatism or hydroeustatism, or volcanosistasy must be equally considered and, at least, mentioned in the text. It is clear that glacioisostasis justifies changes in sea level due to changes in the weight that gravitates on the lithosphere. The same as, in the case of large volcanoes, the accumulation of large amounts of lava causes a depression in the lithosphere. We understand that the objective of the work is to list the key aspects of sea level rise and that the entire argument is directed towards immediate causes, leaving in the background the geological causes that have a more medium and long-term dynamic. But it would be appropriate to include the weight of geological factors in some section. We think that this complements the work. This implies including more specific bibliography on that topic. Mentioning the thermal expansion of seawater and the melting of ice sheets and glaciers and not mentioning glacioisostasis is not correct. I think that the only drawback I find in this work is not completing the inventory of the factors that influence the rise in sea level, which are geological ones, since they have undeniable importance.

Response 1: Thank you for your thorough review and valuable feedback on our manuscript. We appreciate your acknowledgment of the completeness and structure of the synthesis. Your comments regarding the need for a more comprehensive consideration of geological factors in explaining sea-level rise have been addressed in the revised version of the manuscript. In response to your suggestions, we have restructured the subsections under the regional contribution factors section into climatic and non-climatic drivers and included more detailed discussion on geological processes and other factors that fall under non-climatic drivers. We have recognized the significance of these geological phenomena in influencing sea-level changes. Your point about the importance of glacioisostasis, particularly in justifying sea-level changes due to variations in lithospheric weight, has been addressed. Glacioeustatism, hydroeustatism, volcanosistasy were addressed based on their nature under the newly restructured subsections section. We believe that these enhancements not only complement the overall objective of our work but also contribute to a more comprehensive understanding of the diverse factors influencing sea-level rise.

You can find changes highlighted on pages 5-7 in the revised PDF version. Furthermore, an additional remark was added on page 23 line 929 to emphasize on the consideration of geological factors.

Author Response File: Author Response.pdf

Reviewer 2 Report

General comments:

The paper presents a sound review concerning the rise of global sea level, its causes, consequences, assessment methodologies, and mitigation measures. It could be interesting for both the international scientific and technical community.

The selected keywords behind the review work should be further explained and justified since it was limited to "sea level rise", "coastal vulnerability assessment", "factors of sea-level rise", "climate change impacts on sea level rise", "visualizing sea level changes", "sea level rise impacts", "adaptation", "modeling sea-level rise". For example, tectonics was not searched, but its relevance is stressed throughout the paper.

Minor changes:

Line 23: The SLR estimation of 98 cm is based on a reference [3] from 2015. Confirming or updating that estimation using a more recent reference is advised. Consider also rephrasing since, in the following sentences, more recent estimates are presented.

Line 64: Confirm and correct “Frontier” to “Frontiers” if adequate.

Line 92: Insert a proper reference number for Hoffmann, 1983

Line 223: Complete the sentence “(triple the global average rates)” to clarify it.

Line 232: Rephrase “Wave actions extents cause” and complete it with “marine environments”.

Lines 272-273: Why river sediment transport can cause coastal erosion is unclear. Rephrase.

Line 274: Using Brunn's rule is not consensual among the scientific community. The authors should make this clear.

Line 282: use “protect” instead of “reserve”.

Lines 295-297: The sentence is not clear. Rephrase.

Line 523: Delete the three dots, etc in “ (e.g.: humans, infrastructure, habitats, . . . , etc.)”, since they do not add any relevant information.

Lines 541-543: Format the text.

Lines 567-570: Format the text.

Line 575: Confirm the word “morality”. Should it be mortality?

Line 638: Confirm the word “armed”. Should it be aerial?

Line 659: Change “Wave” to wave.

Line 733: Correct “change,s”

Line 745: Delete “furthermore,”.

Line 765: Change to km³/year

Line 801: Insert a proper reference number “tides [? ].”

Line 806: Final mark is missing.

Line 903: Change “Incorporated” to “incorporated”.

Minor editing is required.

Author Response

General comments:

Comment 1: The paper presents a sound review concerning the rise of global sea level, its causes, consequences, assessment methodologies, and mitigation measures. It could be interesting for both the international scientific and technical community. The selected keywords behind the review work should be further explained and justified since it was limited to "sea level rise", "coastal vulnerability assessment", "factors of sea-level rise", "climate change impacts on sea level rise", "visualizing sea level changes", "sea level rise impacts", "adaptation", "modeling sea-level rise". For example, tectonics was not searched, but its relevance is stressed throughout the paper.

Response 1: Thank you for your insightful comments. We appreciate your attention to detail and your acknowledgment of our objective to comprehensively identify the diverse factors contributing to sea-level rise. The selection of keywords was a deliberate choice to encapsulate a broad spectrum of influences on this phenomena. It is important to note that tectonics falls under the broader umbrella of factors that influence sea-level rise, and we have implicitly considered tectonics as part of the overall analysis of the non-climatic drivers contributing to regional sea-level changes. The selected keywords were chosen to provide an outline that explains the overall picture of the phenomena of sea level rise starting with identifying and distinguishing between the influence of different contributing factors, exploring the impacts, coastal assessment approaches to those impacts, and addressing adaptation and mitigation measures. To improve the clarity and address your comment the regional contributing factors section has been restructured into climatic and non-climatic drivers. Additional information has been added regarding the geological process and other factors under non-climatic drivers. You can find changes highlighted on pages 5-7 in the revised PDF version. Furthermore, an additional remark was added on page 23 line 929 to emphasize on the consideration of geological factors.

Minor changes:

Comment 2: Line 23: The SLR estimation of 98 cm is based on a reference [3] from 2015. Confirming or updating that estimation using a more recent reference is advised. Consider also rephrasing since, in the following sentences, more recent estimates are presented.

Response 2: The text has been modified as following: According to the Intergovernmental Panel on Climate Change (IPCC), the Global Mean Sea Level (GMSL) has been increasing at accelerating rates since the past century, reaching a rate of 3.7 mm/year in 2018 and is estimated to reach up to 77 cm by the end of the century . It is also projected that the GMSL could reach up to 5.4 m by 2300.

Comment 3: Line 64: Confirm and correct “Frontier” to “Frontiers” if adequate.

Response 3: Fixed to Frontiers

Comment 4: Line 92: Insert a proper reference number for Hoffmann, 1983.

Response 4: Reference added

Comment 5: Line 223: Complete the sentence “(triple the global average rates)” to clarify it.

Response 5: Rewritten as “exhibiting a temperature three times higher than the global average temperature rates”

Comment 6: Line 232: Rephrase “Wave actions extents cause” and complete it with “marine environments”.

Response 6: Rewritten as “Wave and tidal actions lead to coastal erosion, cliff erosion and marine erosion”

Comment 7: Lines 272-273: Why river sediment transport can cause coastal erosion is unclear. Rephrase.

Response 7: Explanation added to the text as following” In addition to variations in wave activities, erosion is also influenced by changes in sediment supply transported from rivers and onshore overwash activities. The imbalance in sediment supply and removal can lead to coastal erosion and affect the stability of delta formations”

Comment 8: Line 274: Using Brunn's rule is not consensual among the scientific community. The authors should make this clear.

Response 8: The following paragraph was added into the text with relevant references to address the reviewer comment “Although Bruun's Rule is widely used for its simplicity in linking shoreline changes to sea level changes and the absence of straightforward alternative models, concerns have been raised in the scientific community about its general applicability. A study by Le Cozannet  evaluated different approaches in predicting shoreline changes due to sea level changes and found that Bruun's rule lacks accuracy and validation capability for some types of shorelines, particularly those subject to complex sediment transport changes. Overall, the application of Brunn's rule necessitates the selection of consistent subsets of coastal sites that are not influenced by morphological changes, along with understanding other potential factors influencing shoreline changes. It is also worth noting that while other approaches such as incorporating sediment budget into Bruun's rule or applying passive submersion model may result in better accuracy, they also come with their own underlying uncertainties and limitations that impact the results. “

Comment 9: Line 282: use “protect” instead of “reserve”.

Response 9: Changed as advised

Comment 10: Lines 295-297: The sentence is not clear. Rephrase.

Response 10: The sentence was rewritten as following “SLR has the potential to induce short-term flooding, resulting from sudden climatic and non-climatic events, through immediate changes in tidal hydrodynamics including the increased height and intensity of waves and storm surge flooding. Furthermore, SLR can induce long-term flooding in the form of inundation. This process can lead to an increase in water salinization as more saline seawater penetrates further inland and reaches groundwater and aquifers.

Comment 11: Line 523: Delete the three dots, etc in “ (e.g.: humans, infrastructure, habitats, . . . , etc.)”, since they do not add any relevant information.

Response 11: Deleted

Comment 12: Lines 541-543: Format the text.

Response 12: Fixed

Comment 13: Lines 567-570: Format the text.

Response 13:Fixed

Comment 14: Line 575: Confirm the word “morality”. Should it be mortality?

Response 14: Changed to “sensitivity”

Comment 15: Line 638: Confirm the word “armed”. Should it be aerial?

Response 15: Type error fixed to “Aerial”

Comment 19: Line 659: Change “Wave” to wave.

Response 19: Changed as advised

Comment 20: Line 733: Correct “change,s”

Response 20: fixed to “changes”

Comment 21: Line 745: Delete “furthermore,”.

Response 21: Deleted

Comment 22: Line 765: Change to km3/year

Response 22: changed as advised

Comment 23: Line 801: Insert a proper reference number “tides [? ].”

Response 23 reference citation fixed

Comment 24: Line 806: Final mark is missing.

Response 24: Added

Comment 15: Line 903: Change “Incorporated” to “incorporated”.

Response 25: Fixed as advised