This review on sea level rise in Europe will be a very good reference for sea level scientists and users of sea level information. It is generally clearly written and covers all the important information. It is very long, to be completely honest I didn’t get the stamina to read it all. I did not read sections 6.3, 6.4 and Box 2 so I hope that the other reviewer will cover these regions which I am less familiar with. I have a suggestion to make the review a little shorter (see detailed comments bellow) but almost all the material covered is relevant. I have no major comments on the review but I have many small comments to help improve it.

Comments on figures 14-18:

- A “reconstructed” sea level time series is provided but no explanation for what it means is provided. Only a reference. I think this should be explained otherwise readers need to go to Dangendorf et al. 2019 to understand. 

- Which reference period is used to compare the time series? For the projections it is probably 1995-2014 which is the reference period of AR6 but it does not seem the be the case for the reconstructed sea level.

- I don’t think it is a good choice to add one tide gauge per basin in the same plot as the basin means. One can’t help but compare the past and the projections and see some clear mismatches for some tide gauges. I suggest that if individual tide gauges are shown, they are compared with projection for this particular location, not basin average.

- It would be useful to have mean sea level changes for the coast of this region in Figure 14-18 in the same format as panel b and c.

Abstract:

“Absolute sea-level change” -> I think geocentric sea-level change is now the standard terminology

Introduction:

l.61-62: References are needed to support those numbers.

l.90: “contemporary solid Earth deformation due to land ice mass loss” would fit better in the anthropogenic category than the natural one.

l.98 and l.106: What are those references? Sea Level Rise in Europe: knowledge gaps identified through a participatory approach, Sea Level Rise in Europe: A Knowledge Hub at the ocean-climate nexus.

l.99: I don’t think the concept of European Union (EU) is relevant to this review since the focus on Europe as a geographic continent rather political union.

3 Regional observations

Figure 5: Was the data adjusted for GIA and TOPEX-A instrumental drift? This information is given in the caption of figure 6. I think it would be useful here as well.

Figure 6: Consider using a map projection that deforms less the area 

l.318: “In Europe, sea level trends are slightly above the global mean rate, on average (Figure 6).”

I think this claim needs more foundations. Especially since it is also in the abstract. Which area is chosen here to represent Europe? What is the rate? 

Given the large spacial difference between the Baltic Sea (~5mm/yr) and the Mediterranean Sea (~2mm/yr) I wonder if it is very useful to make conclusions about the European average.

l.341: What is meant by “general circulation” here? Is it the ocean circulation in the Mediterranean Sea?

l.356: “The annual cycle amplitude ranges from 40 cm to 100 cm”

I think this is a typo, it should be mm instead of cm.

Additionally, Dangendorf et al. 2013 found mean amplitude of the seasonal cycle of 14 to 20 cm along the German Bight which indicates that the range provided here is too narrow.

Dangendorf, Sönke, Thomas Wahl, Christoph Mudersbach, and Jürgen Jensen. “The Seasonal Mean Sea Level Cycle in the Southeastern North Sea.” Journal of Coastal Research, no. 65 (10065) (January 1, 2013): 1915–20. https://doi.org/10.2112/SI65-324.1.

4 Drivers of sea level rise and extremes

l.426-437: This paragraph is important but it is too vague at the moment. It would benefit from some numbers. How much does a melting to Greenland resulting in 1cm GMSLR influences the European coast? Same for Antarctica. For Greenland the influence is so different between North-West and South-East Europe that general sentences like “If the contribution from Greenland increases in the future, this has not very large consequences for European coasts, …”  can be misleading.

Additionally, only gravitational effects are mentioned here, why not discuss also solid earth deformation, which is very important for the influence of Greenland mass loss, and rotational effects?

The next paragraphs of 4.1 are rather detailed but do not provide regional information and do not have a high added value compared to IPCC AR6 except that they are updated. So I would consider removing them.

l.481: “will be dominate” -> will dominate

5 Projections of sea level rise and extremes

l.598: “the amount of outgoing radiation amount”

Figure 11 is for the whole world but in the caption it is written Europe. I think it would be better to zoom in on Europe.

l.681: “with consequences for enhanced SLR in the early 21st century” should be 22nd century

6 Key developments per region

6.1 Atlantic Ocean

L.810-816: This whole paragraph is missing references. In which paper was the slope current described? The upwelling? 

This quote is also ambiguous without references: “On the continental shelf ocean dynamics are characterized by shorter timescales and spatial scales,” Especially the spatial scale. Since ocean meso-scale eddies can’t get on the shelf.

l.850: “skew surge” is not defined in the paper. I don’t think many users of sea level information know what it is.

l.854: MSL is not defined. Actually in the rest of the text mean sea level is written instead of the acronym. 

l.860: decreased amplitude over which period? The previous sentence says that the trend depends on the period.

l.880-883: Since this review is about sea level I would suggest to either mention the relation between those ocean circulation changes and sea level or not mention them as all. I also wonder if it is useful to catalogue papers that did downscaling without mentioning important conclusions. If there was important information for sea level then write it down explicitly otherwise do not cite the papers.

6.2 North Sea

l.999-1001: It is not clear which contributions this refers to and how this paragraph is linked to the previous one. 

6.5 Baltic Sea

l.1282-1283: What does “energetically insignificant” mean? The question to answer here is: what is the impact of seiches on sea level variability? 

l.1296-1306: In this paragraph there is no reference to Figure 6 with the trend in geocentric sea level from satellite altimetry while the Baltic Sea really stands out in that figure as the region with the largest rate of sea level rise, with most places rising faster than 5mm/yr. I think this should be discussed in this paragraph.

l.1307: “no long-term rising trend was found for ESLs in the Baltic Sea compared to mean changes” I don’t understand the logic of this sentence. Why “compared to mean changes”? 

l.1320-1321: “Therefore, projections for this basin require high-resolution regional climate models”. I think it would be useful to separate projection of MSL and projections of ESL. In lines 1285-1286 it is written “On time scales longer than 1 month, the mean sea level in the Baltic Sea approximately follows the sea level in Kattegat, outside the Baltic Sea” which would imply that there is no need for models to resolve the complex local physical processes to get the long term MSL projections right. It would be useful to clarify this contradiction.

l.1329: “will approximately rise by about 87% of the global mean rate”. This is a good one. If it is “approximately” and “about” then the very precise number is not appropriate. 

Conclusion

l.1484: Two “Finally”  

In this manuscript, the authors present a comprehensive assessment of sea-level literature along European coasts. They use literature and data from the literature to summarize the state of the art. This is, of course, a huge effort, that should be very helpful to both scientists, planners and decision makers. However, in its current form, the manuscript is, in my opinion, not ready for publication. The use of acronyms is rather wild, the structure at times unclear and heterogenous among subsections and some important literature is missing. It seems to me that authors have worked individually on sections, but not enough effort has been undertaken to bring the different sections together. Therefore, I recommend major revisions. I’ll further clarify these points below. Please also note that I could only read this massive manuscript once, so the authors should really make sure that everything is in shape for resubmission.

General comments

• Acronyms are a mess (to be honest). The number of acronyms is huge and not homogeneous throughout the manuscript (way too many to specify them here). I feel that the readability would be way better if the authors would decide on a few really important acronyms that are then properly introduced and used consistently used throughout the manuscript.
• The subsections in chapter 6 are very heterogeneous, both in terms of structure and content. For instance, some sections summarize VLM under past sea-level changes, while others use a full subsection (differently positioned among chapters). All chapters present the same type of figure, which is useful, but the figures are only discussed for the MedSea and the concepts presented are not really introduced. I also could not find references to these figures in some chapters. I would suggest introducing basic concepts, such as the use of the hybrid sea level reconstruction (Dangendorf et al., 2019), at the very beginning and report the associated numbers (also in reference to the figures) homogeneously for each section; also, in context to numbers presented in other literature. The same applies to the use of VLM information, which seems to follow Oelsmann et al. (2024; https://www.nature.com/articles/s41561-023-01357-2; not yet referenced)?
• Somewhat related to points 1 and 2, the authors make use of extreme value statistics very heterogeneously throughout the manuscript. While the abstract and parts of the text frequency mention “historical centennial events”, all figures in section 6 use water levels corresponding to a 50yr return period. I would suggest homogenizing that. I would also suggest to properly introduce jargon, e.g., amplification factors, very clearly. It would also not hurt to explain the meaning of the amplification factors in the caption of Figure 12 in support of readability again.
• The concept of relative and absolute sea level changes is not properly used in terms of the hybrid sea level reconstruction presented in section 6. The reconstruction contains Gravitation, Rotational and Deformational effects related to present day barystatic mass changes. Thus, even after the removal of GIA, it still contains solid earth components. These can make an important contribution to relative sea level, particularly in the Nordic Seas (as mentioned for the Baltic Sea). Therefore, I would suggest using the term: Relative sea level after the removal of GIA.
• The role of the NAO is in my opinion overstated in this manuscript. First, it is the dominant atmospheric mode only during winter. Second, many publications have shown that it only explains a fraction of the variability (e.g., Jevrejeva et al., 2006: https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1600-0870.2005.00090.x), which is either due to the presence of other important teleconnection patterns (e.g. Chafik et al., 2017: https://www.mdpi.com/2077-1312/5/3/43) or more complex oceanic processes that are communication through ocean circulation and therefore integrated over time.
• There are some important references missing for some of the subsections that are provided in the specific comments below.

Specific Comments:

Line 75: To be consistent with the concepts in Gregory et al. (2020), I would suggest introducing the term sterodynamic at this point, which is also used in later parts of the manuscript.

Line 98: I am not sure what the text in the parenthesis is referring to

Line 103: I would suggest: “These contrasting atmospheric and oceanic environments lead to…”

Line 105: I guess you mean SL changes; SLR changes mean acceleration

Section 2.1.: Although summarizing the last IPCC report, I think it is important to give proper references to the original sources in the text. Just as an example, the statement in line 127 should cite Kopp et al. (2016, https://www.pnas.org/doi/full/10.1073/pnas.1517056113)

Line 132: Recent literature suggests that the acceleration started in the 1960s/1970s and was initiated by steric expansion, while mass input from the ice-sheets came into play over the past few decades.

Line 135-139: I am not sure what this statement means for Europe. Tropical cyclones primarily affect the other Western Atlantic region.

Line 175: GIA is more than only VLM, geoid contributions are significant particularly in northern Europe

Line 223: Forecasted (i.e., initialized from observations) or projected sea levels?

Line 262: What are low-frequency global mean sea level records? What is low frequency, what is global mean?

Figure 3: Might make sense to add the longest period covered by those tide gauge records.

Figure 4: I suggest to add uncertainty bands to these plots.

Line 301: sea level dynamics are highly….

Figure 5: What’s the meaning of the two periods; why only since 2001?

Line 322: Cloud and rain patterns lead to changes in thermal expansion?

Line 330: What is an “effective temporal resolution”, and why is it 34 days? Isn’t every along-track point tracked every 10 days?

Line 349: estimates

Line 384: InSAR can image the spatial pattern of VLM…

Line 413: I think this statement refers to extreme sea levels rather than storm surges. Jänicke et al (2021) assessed changes in the mean tidal range, so those do not correspond to any changes in storm surge. An additional reference here is Dangendorf et al., 2013: https://link.springer.com/article/10.1007/s10236-013-0614-4

Line 467: What ranges do these numbers refer to?

Line 513: I am not sure whether that statement is correct. This is period dependent and does not hold for each individual contributions, right? Maybe state: Since the late 1960s, the sum of individual contributions have led to a persistent acceleration.

Line 548: To be fair, I would add that uncertainty exists in this region with respect to VLM estimates. For instance, the reported numbers in Frederikse et al. (2016) for a slightly different period are smaller than in Dangendorf et al. (2021).

Line 589 following: Treu et al. (2024; https://essd.copernicus.org/articles/16/1121/2024/) produced the first full sea level reconstruction based on a combination of different reconstruction and modelling approaches.

Section 5.2.: I feel that MISI and MICI might be explained more thoroughly in terms of the associated physics.

Section 5.3.2.: The literature summary is rather recent. I would suggest incorporating early attempts such as Woth (2005): https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2005GL023762 , Woth et al. (2005): https://link.springer.com/article/10.1007/s10236-005-0024-3; WASA (1998): https://www.webofscience.com/wos/woscc/full-record/WOS:000073809200001?SID=USW2EC0FB7RmlUpG8iI3Cn6Fxd3jY; Sterl et al. (2009): https://os.copernicus.org/articles/5/369/2009/

Line 782: Here and throughout the manuscript, SLR is handled as the only driving factor behind changes in tides and corresponding extremes. However, recent literature (including the cited Jänicke paper) suggests significant contributions by density changes. Thus, it should be noted that the reported numbers in projections are lacking those mechanisms.

Line 830: Where are these numbers coming from? From the trend assessment tool? Why not plot them for those periods? Also, the reference PSMSL is not in the list

Line 834: Is this true? Isn’t GIA, or VLM in general, the dominant driver of regional sea level trends in the region?

Line 885: What’s the historical centennial climate extreme event?

Section 6.2.2.:  An important reference here is Wahl et al. (2013): https://www.sciencedirect.com/science/article/abs/pii/S0012825213000937 that has not been included yet. I am also missing all the Woodworth (e.g., https://academic.oup.com/gji/article/213/1/222/4757068 and some more earlier assessments) and Hogarth (e.g., https://www.sciencedirect.com/science/article/pii/S0079661120300720) UK sea level assessments that the authors should be very familiar with.

Line 1015: Please quantify “large effect”

Line 1070: I think there is a link missing?

Line 1099: Isn’t GIA the biggest factor in those areas?

Line 1171: Black Sea sea level

Line 1180: This information should go at the beginning of section 6 as it is used for the figures in all regions. I would also suggest to pick the results up in each section in the context of the corresponding literature. Furthermore, the approach requires a bit more introduction in general. Is it based on Oelsmann et al. (2024; https://www.nature.com/articles/s41561-023-01357-2)?

Line 1287: Again, shouldn’t GIA be the dominant factor, leading to far lower than global projections? Shouldn’t that factor first be emphasized given its importance?

Section 6.5.2.: This section is lacking some literature: e.g., Gräwe et al. (2019): https://journals.ametsoc.org/view/journals/clim/32/11/jcli-d-18-0174.1.xml; Donner et al. (2012): https://npg.copernicus.org/articles/19/95/2012/; some of the Ekman studies (https://psmsl.org/products/author_archive/ekman_2003.pdf and references therein)