The article by Darrell Kaufman and Valérie Masson-Delmotte provides a useful Opinion piece on the inclusion of paleoscience in the upcoming IPCC AR7.

This paper is an excellent example of how sophisticated climate reconstructions can be made on the basis of historical documentary data. The authors have not only succeeded in analysing the rich historical descriptions in a very valuable way, they have also applied various statistical approaches very skillfully in a remarkably interdisciplinary approach. The article stands out for its deep understanding of historical sources, drought processes, and various social processes.

This study presents an interesting attempt to reconstruct global surface temperature by combining sparse SST proxy data and PlioMIP2 simulations using a state-of-the-art data assimilation framework. The work highlights the potential of this method for providing key insights into past warming patterns, and will serve as a good starting point for future investigations.

Romero et al. mapped geomorphological features on the landscape and dated moraine boulders and outwash sediments to constrain past changes of the former Patagonian Ice Sheet in southern Argentina. They show that the Lago Argentino glacier expanded during Marine Isotope Stage 6 (153.0±14.7 ka) and during Marine Isotope Stage 3, culminating at 44.5±8.0 ka and at 36.6±1.0 ka, thus preceding the Last Glacial Maximum. They hypothesize that this was a result of longer and colder winters, as well as increased precipitation resulting from an equatorward shift of the Southern Hemisphere Westerlies.

The Atlantic Meridional Overturning Circulation (AMOC) is at its weakest of the last millennium and is projected to further weaken over the coming decades, with the risk of a collapse over the coming century non negligible. The geologic record provides examples of rapid and large AMOC variations, with phases of AMOC weakening, preceding an AMOC shutdown. One key question is whether CO2-driven AMOC weakening is reversible, or whether it represents a tipping point, which might lead to an AMOC collapse. The study by Willeit et al. offers a new diagnostic that is simple to implement and allows for comparing AMOC stability between different models, as well as different time periods. This offers a powerful new tool in understanding the conditions for AMOC stability, and thus the AMOC future.

This manuscript deserves to be highlighted as it presents an incredible dataset, analysed using state-of-the-art techniques and summarised in a clear and readable form. As the reviewers pointed out, the content could easily have resulted in two articles (or even more...) - a practice that is sometimes done to increase ‘academic output’. However, the authors have chosen to provide a comprehensive overview and interpretation of the results. In addition, the site studied is of great importance for Icelandic studies of Holocene climate change.

This Milankovic Medalist paper represents a tour de force, addressing a complex yet crucial question: the evolution of global climate over the past 4.5 million years. This paper makes a significant contribution to the geoscience community by providing a self-consistent decomposition of global mean benthic δ18O into its temperature and seawater (ice volume) components. This approach is consistent with independent estimates of global mean sea surface temperature (GMSST) and sea level constraints.The analysis incorporates numerous high-resolution records spanning this period and highlights two distinct climatic regimes: • Before 1.5 million years ago, a warm period characterized by smaller-amplitude ice sheet and sea level cycles, primarily driven by obliquity timescales. • Following the Mid-Pleistocene Transition (MPT), i.e. after 1 million years, a well-documented increase in the amplitude of glacial cycles became evident. The central finding of the study is that, during the MPT, there was a shift in ocean heat storage efficiency (HSE). Prior to this transition, HSE remained low and constant, whereas after the MPT, it doubled and stabilized at a higher value. This finding is supported by the observation of subtle differential changes in global mean SST and mean ocean temperature (MOT), which appear to be time-dependent. These observations suggest a potential fundamental shift in oceanic heat storage dynamics.

Understanding the stability of the Antarctic ice sheet during the Pliocene has important implications to future Antarctic ice sheet changes and sea level. However, changes in the eastern Antarctic ice sheet are still largely unknown. This work may provide key geological evidence to fill in this knowledge gap.