Dear Prof. Li,

Thank you for submitting your work to CPD. As you have seen, both referees considered that d13C of millet seed is a suitable proxy for quantitative construction of summer precipitation in northern China, and your study is worthy a publication in Climate of the Past after revisions. Towards this end, they both suggested a number of issues that you need to consider for improving the manuscript.

I have read carefully your responses and your pre-revised version, and found that you had considered most of their suggestions. However, I estimate that a further revision is needed on the following issues.

Both referees indicated that the text contains many superlative words or descriptions. Although your pre-revised version has toned down, there are still some lefts. As an example, lines 28 & 395: ‘innovative proxy’. To my view, ‘new proxy’ is largely enough. I request you to carry out a thorough check on this kind of problems.

As also indicated by the referees, the writing of the ms is in overall understandable, but is not yet in good English. Although you already made some improvements in the pre-revised version, a thorough language revision by a native English speaker is still indispensable for publishing in CP. For examples, it would be finer to revise the title as “Summer precipitation reconstructed quantitatively using…”to “Quantitative reconstruction of summer precipitation using…”. Line 14: the expression “to produce quantitative Holocene precipitation reconstructions…” is also not satisfactory. There are still many problems of this kind that I am not intending to list here. These could be fixed along with the issue of “superlative words’.

Given that the ms is not long, I think it would be better to remove the subtitles 3.1…, 5.1… in view of the serious length imbalance of them, and in view of some inaccurate expressions (e.g. 5.2, ‘validating the reliability of quantitative precipitation reconstruction’). You didn’t really ‘validated’ it, but just argued/discussed it.

I am not satisfied with the ‘conclusion’ section. It currently only focuses on repeating the estimated results but the significance of this new proxy is not really concluded. I would think the estimated results in this study are rather tentative, but the study provides a useful method for estimating the paleoclimate conditions of specific archeological layers that usually interests the archaeology community. It might be better to mention this.

The ‘summer’ here refers to the interval from mid-June to September, please also specified in the abstract.

All the bests

Zhengtang Guo
Editor, Climate of the Past