Dear Thomas Kleinen,

Thank you for your responses to the reviewer comments on your manuscript. Both reviewers are clearly supportive of publication, though both also raise issues that they feel must be addressed prior to acceptance for publication.

I therefore recommend that you prepare a revised version of your manuscript, at your earliest convenience, that judiciously takes into consideration the points raised by both reviewers. I have indicated 'major revisions' only so as to be able to request a further review of your revised manuscript should this be necessary.

From my side, I would draw your attention in particular to the need to frame more clearly the motivation for the study (and the choice of interglacials), such that you are also able to spell out more clearly exactly what can be learned from your model results and how these results address the stated motivation of the study. I would urge you also to reconsider the extent to which your study strictly does show “…how the CO2 evolution during the Holocene and two recent interglacials can be explained consistently using an identical model setup” (as stated in the abstract) and that “…trends in interglacial atmospheric CO2 can be reproduced by a climate model with identical forcing” (as stated in the conclusions). More specifically I would propose that the abstract and conclusions might be softened somewhat to state more accurately (in my view) that the simulation of the trends in atmospheric CO2 across all of these interglacials is significantly *improved* by the inclusion of two key ‘slow’ carbon cycle processes; coral reef growth and peat accumulation. I think it is less clear that CO2 has truly been *reproduced* in each case, and always for the right reasons (e.g. given mismatches in simulated and observed d13CO2, or the lack- or uncertainty of data constraints to test simulated carbonate accumulation for example).

I look forward to receiving your revised manuscript. It would be helpful if you accompanied your revision with a succinct description of the changes included, or else a highlight the changes in the revised manuscript itself.

Yours sincerely,

Luke Skinner

Dear Thomas Kleinen and colleagues,

Thank you for your detailed response to the reviewers' comments, and for providing a fully revised manuscript. It is my view that these comments and revisions succeed in addressing all of the reviewers' comments; the section on the study weaknesses and gaps is particularly helpful. Although i do not wish to 'move the goal posts' at this stage i might suggest that one uncertainty that you do not mention is the possibility of intra-interglacial marine carbon cycle variability arising from ocean circulation perturbations that may not be captured by the model simulations (e.g. Galaasen et al., 2014; Hayes et al., 2014). If you wish to add a note of this, please do so when submitting your final manuscript version. I therefore propose to accept the manuscript for final acceptance 'subject to technical corrections' only to permit you to make such additions if you wish to do so.

Once again thank you for your initial submission and your work revising the manuscript.

All the very best,
luke skinner