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.