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The paper present results of cutting edge climate model simulations and reconstructions of volcanic eruption magnitude and timing to better understand the environmental context of the Ptolemaic era (305-30BCE). This important period of Ancient Egyptian history is known for its material and scientific advances, as well as for episodes of political and social unrest.

The manuscript presents a reconstruction of global temperature spanning the Holocene, which extends the scope of previous exercises in palaeoclimate data assimilation. The resulting reconstruction presents new insights into changes in global temperature over this period. Most notably, it confirms the results of previous studies that have shown a global cooling trend over the past 6,000 years. It also shows that a cooling trend is found even after allowing for potential biases in the proxies. These results are likely to be of considerable interest to the broader geoscience community.

This paper presents a new proxy application of permanent gas isotopes in ice core research based on the kinetic fractionation of gases in the firn column of polar ice sheets (offset from the diffusive equilibrium profile) which may be induced by synoptic atmospheric pressure variations at the surface. Although still exploratory in nature, this new proxy would allow to reconstruct changes in mean synoptic activity for different climate states based on ice core data.

This paper is providing new data about Southern Hemisphere ice sheet extent and dynamics during glaciations older than those occurring during the last climate cycle, a useful dataset that climate models require to calibrate their own reconstructions.

Causes for the Great Oxidation Event (GOE) has long been an outstanding question in Earth sciences. Yet, the exploration of this question has been limited to the 1D photochemical models. Here, the authors presented new insights to solve this question with a 3D photochemical-climate model. This model allows the investigation of influences of the atmospheric circulation on the GOE and the coupling between the climate and the dynamics of the oxidation. The results are highly interesting, and would be of wide interest in Earth science community.

Although previous studies addressed this original way of how deducing past climate conditions from color paintings, such as aerosol optical depth (AOD) the new results are critically reviewing these former publications and yield new critical elements in this original research. While concluding that reconstructions of AOD may be possible in some specific cases, the authors do warn about the strong uncertainties related to parameters not carefully considered, which restrains the field of possibilities. To assess the scientific soundness of the results, three reviewers from complementary fields of atmospheric sciences positively reviewed the original manuscript. They have contributed to improve the quality of this paper and all agreed upon the conclusions research, which is a fair guarantee that these results should broadly interest the geoscience community.

Knowledge of microparticle geometry is essential for accurate calculation of ice core volume-related dust metrics (mass, flux, and particle size distributions) and subsequent paleoclimate interpretations, yet particle shape data remain sparse in most of ice core records. The approach and results of this work are of interest for the broad geoscience community, since it potentially enables a better characterization of all data obtained from the dust in ice cores. This study of samples from South Pole ice core (SPC14) indicates that coarser particles (>5.0 μm diameter) show greater variation in measured aspect ratios than finer particles (<5.0 μm). While fine particle volumes can be accurately estimated using the spherical assumption, applying the same assumption to coarse particles has a large effect on inferred particle volumes.