I want to thank the reviewers and the authors for your insightful review and response. I have been learning a lot from the paper and through the review process. I am sure that all that will translate in a much improved paper. Also, I would like to apologize to the authors because it took me so long to arrange the reviews, not sure if I can put all the blame on covid-19.

Both reviewers and I agree that the paper is interesting and important (I will be flattered if anyone labelled one of my papers as ‘provocative’). However both reviewers raise important concerns about considering uncertainty and limitations of the theory, and fair discussion of alternative explanations. After reading the authors’ response, I believe that the authors are engaging with the reviewers’ comments, but I am going to activate another round of review because of the importance of the concerns.

Just to be clear, I am not looking for a few accommodating sentences here and there, I would like that the constructive discussion with the reviewers fully permeates the new version of the paper.

Carlos Martin

Both reviewers and I agree that the paper has improved considerably and it is much clearer. However, reviewer #1 still has a few minor suggestions and reviewer #2 believes, and I agree, that the changes in the manuscript do not fully reflect points discussed in the response to the reviewers. I have learnt a lot through the discussion of the paper, and my view is that it would be a shame if that discussion doesn’t make it to the final version of the paper.
To be more specific, I would like the authors to go through the main comments in the previous round of reviews and make sure that the points in your response to reviewers are fully reflected in the manuscript. Reviewer #2 highlights two of these points, n=3 and CPO, and I ask the reviewers to consider these suggestions for the next version of the manuscript.

Dear Authors,

Thanks for your response and apologies for my slow reply.

I have just gone again through the comments of the reviewers and your response. Neither of the reviewers fully support the hypothesis presented in the paper, that crystal size evolution blurs the different crystallographic deformation mechanisms so that ice deformation is not dissimilar to that described by Glen flow law with a rheological index 3. However, both reviewers appreciate the introduction of the model presented, the 'watmetter', and they believe, and I agree, that the manuscript is contributing to the understanding of the role of crystal size evolution in ice rheology. For these reasons I am happy to move the manuscript forward.

Carlos Martin