Dear dr. Fettweis and co-authors,

Thank you for providing your responses to the reviewer comments. Based on those, we invite you to submit a revised manuscript.

The reviewers raised concerns that need to be addressed in the revised manuscript. The revised manuscript should 1) introduce and elaborate on existing geo-engineering methods, 2) provide more background and discuss the (in)feasibility of the used geo-engineering methods, 3) evaluate the sensitivity experiments in the present-day through a comparison with MAR-ERA.

Please be informed that the revised manuscript will be sent to reviewer #2 for re-evaluation.

Best wishes,

Brice Noël

Dear Xavier Fettweis and co-authors,

We have now received comments from reviewer #2. The reviewer is generally satisfied with your edits and requests minor revisions. The authors should give particular attention to reviewer #2 comments (1) in L185 and (2) on the conclusion section. (1) If the authors wish to include information about the SMB < 0 threshold, this should be first elaborated in the discussion section. (2) To keep the conclusion section focused and concise, statements about the method limitations should be moved to the discussion section.

In addition, some sentences in the revised manuscript remain long and/or unclear. In the current form, the manuscript would still benefit from copy-editing. The authors are therefore encouraged to address this as much as possible in their revised manuscript. The authors can find below a list of required clarifications and textual suggestions from the editor. The authors should also make sure that the data availability statement complies with the TC policy.

Based on the above, the editor invites the authors to submit a revised manuscript. Note that the revised manuscript will be reviewed by the editor before acceptance for publication in TC.

Best wishes,
Brice Noël

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Editor comments:

1) General remarks:
The authors should consider 1) replacing “vs” by e.g. “relative to/compared with”; 2) using “solar radiation/incoming shortwave radiation” instead of “sunlight”, “light” or “sun’s light”, and 3) using “incoming longwave radiation” instead of “downward infrared energy”.

For improved clarity, the authors should explicitly name the experiments abbreviations in the main text. For instance, in L148: “ssp585 (G6solar ssp585 in Table S2 and Fig. 2); L164: “G6solar experiment (G6solar solar cst -x% in Table S2)”; and L172: “snowfall (G6solar snowfall +x% in Table S2)”.

Fig. S1: Add a, b and c labels to the subpanels of Fig. S1. Please update the figure caption and the main text accordingly. As mentioned by reviewer #2, please increase the font of figures labels and legends where appropriate.

2) Long/unclear sentences:
L37-40: This sentence could be split into two.
L46: This sentence could be shortened as e.g. “to scatter incoming shortwave radiation or reduce the absorption of longwave radiation due to increased GHG concentrations”.
L82-84: This sentence is unclear. Do you mean that a bias in the present-day runoff will persist or further increase in future projections, as the latter bias either remains unchanged or increases as a result of climate warming? Please clarify.
L89-92: This sentence is long and unclear, could you reformulate?

3) Point clarification required:
L50: Could the authors clarify what “climate changes” means. Do you mean “global/atmospheric warming”? Please clarify.
L54: Could the authors clarify what they mean by “… mitigating the surface melt albedo feedback”? Do you mean that snow modules in Earth System Models are too simple to properly represent the surface melt albedo feedback? Please clarify.
L127: What do the authors mean by "mass loss rates"? Do you mean the passing of the SMB < 0 threshold? What does "by 30 years by 2100" mean? Please clarify.
L130: Could the authors clarify what they mean by “at the beginning”?
L174: Could the authors clarify what they mean by “in addition to add solid water mass.”

4) Point corrections/stylistic suggestions:
L21: “the local impact of a reduced solar constant on the projected GrIS …”.
L33: Replace “until 2100” by “by 2100”.
L44: “from the atmosphere”.
L67: “measures should be applied to maintain…”.
L72: Here and across the manuscript, use “dynamically downscale” instead of “downscale”.
L75: Here and across the manuscript, use “CNRM-ESM2-1” instead of “CNRM-ESM2”.
L100: “G6sulfur”.
L101: “evaluate the impact of reduced incoming solar radiation on the GrIS SMB”.
L113: “sensitivity experiments”.
L115: “we explore the SMB sensitivity to an additional decrease of the solar constant that is spatially limited to the MAR integration domain, …”.
L116: “SMB” instead of “mass balance”.
L127: “free atmosphere temperature”.
L129: “atmospheric forcing … the meltwater retention capacity”.
L151: “projected GrIS sea level contribution by ~6%.”.
L176: “This maintains the ice sheet in a state …”.
L193: “sheds light on … influence of geoengineering …”.
L195: Do the authors mean “quantify the ability”?

Dear Xavier Fettweis and co-authors,

Thank you very much for submitting your revised manuscript to TC. The editor joins the two reviewers and recommends publication in TC. The authors can consider the technical corrections/suggestions listed below.

Congratulations on the acceptance of your paper, and thank you for publishing your work with TC.

Best wishes,
Brice Noël

Technical corrections:
L45: “to space”
L47: Add a space after “concentrations”.
L53: “global model runs”
L58: “local impacts of geoengineering measures on the GrIS SMB with unchanged”
L71: “run at a resolution of 20 km”
L85: “over the current climate”
L88: “Fig. S1b”
L93: ”runoff in the north-east.”
L107: “would not be uniform”
L111: “Earth”
L130: “of about 10 years”
L132: “van Angelen et al. (2013)”.
L151: “solar radiation by ~+3 W/m2”
L154: Replace “seen” by “obtained”
L158: “ESM” instead of “ECM”
L170: “measures”
L178: “mitigate the warming at the global scale”
L184: “increasing the albedo”
L188: “ice sheet in a state”
L203: “influence of geoengineering approaches”

Additional editor suggestions:
L80: “to prescribe” instead of “deal with”
L83: “meltwater runoff has a pronounced impact on future projections since the bias … proportion as runoff …”
L100: “realistic case, as also evaluated by GeoMIP6, than G6sulfur,”
L104: “mean temperatures, G6sulfur produces a greater reduction of global-mean precipitation (-3.79 +- 0.76 %) than G6solar (-2.07 +- 0.40 %) relative to ssp245 averaged for 2081-2100 (Visioni et al., 2021a).”.
L155: “significant impact of the reduction”
L159: “dynamical downscaling” for consistency. The same holds in L157-160 and L205.
L168: “icebergs discharge will decrease as marine-terminating glaciers retreat inland. Therefore, …”.