This interesting study investigates the vulnerability of the Greenland ice sheet to climate warming. Specifically, the article addresses what it takes to make the Greenland ice sheet disappear—an event that would cause several metres of sea-level rise. The authors show that a tipping-point behaviour can be identified in their model, demonstrating that once a threshold has been crossed, Greenland becomes almost completely ice-free.

The manuscript investigates the future stability of the West Antarctic Ice Sheet (WAIS) exploring how ice-sheet models may be initialised in a way that incorporates present-day satellite observations of ice mass loss. The study shows that with present-day ocean water temperatures large parts of WAIS will deglaciate, with major implications for global sea levels, particularly in Europe. Model simulations also show that current ocean-driven melting trends will destabilize the Thwaites and Pine Island glaciers over the next several centuries even in the absence of further change, leading to rapid ice loss.

Ice streams are dynamical features that control the ice flow from an ice sheet's interior to its margin. Due to their dynamical nature, ice streams may change flow speed and direction in response to external forcing or due to internal variability. This study investigates the interplay between neighbouring ice streams that feed the Dotson and Crosson Ice Shelves in West Antarctica. The authors use satellite observations to measure the change in ice speed and flow direction from 2005 to 2022, and their observations reveal a highly complex pattern of dynamical changes and the redirection of ice flow from one stream to another. These observations reveal previously undocumented impacts of spatially varying ice flow, which may influence the ice shelf and ice sheet.

For most countries dealing with the consequences of sea-level rise, a constructive discussion about actionable science is critical. There is a need to strengthen the lines of evidence for sea-level projections and at the same time there is a strong need for practitioners to understand which science they should rely on to plan adaptation actions. This manuscript outlines when scientific results may be considered actionable and discusses the risks in using novel results to inform decision-making. The case study discussed in the manuscript is also valid for other climate-change-related fields.

This study explores how choice of glacier and GCM model can impact prediction of future runoff for 75 of the world's major river basins. It is a very timely piece of research given ongoing pressures on river flow in glaciated regions which are on track to worsen, and offers a framework from which modellers can produce policy-relevant information related to future contribution of glaciers to freshwater resources, including consideration of uncertainty.

The Northeast Greenland is one of the most remote and inaccessible areas in the world. This study presents a comprehensive overview of numerous observations from the region as well as results from numerical model simulations. The results highlight the dynamics of Greenland's largest marine-terminating glacier, revealing key differences between the two neighbouring glacier outlets. The authors also discuss the impact of glacier melt on the ocean, including the potential impact on the Atlantic meridional overturning circulation - a key topic of concern in the community and the general public.

This paper presents a multi-year, multi-method survey of a very large surface melt feature in Northeast Greenland. The feature includes a supraglacial lake that drains into the englacial and subglacial system of the Nioghalvfjerdsfjorden glacier, adding a volume of up to 1.23 * 10^8 m3 of water to the bed of the glacier. The drainage causes uplift of the local area and likely impacts glacier dynamics by lubricating the base. Notably, the authors argue that this feature has only existed since the 1990s, when increased air temperatures led to enhanced surface melt. In this way, the glacier surface has been transformed from lake-free to undergoing frequent, abrupt drainage

This manuscript investigates the Amundsen Sea region in West Antarctica. The region has been the focus of numerous studies in recent years since the glaciers of the Amundsen Sea are a major source of uncertainty for global sea level rise projections. In this study, the authors use ice-sheet model simulations to investigate the region's response to climate change (specifically, scenarios RCP8.5 and Paris2C). Their results indicate that the region will have contributed approximately 19 mm of sea-level rise by 2100. The authors do not find any indication of rapid retreat or an unstable calving front. Although the ice shelf area significantly decreases in their model simulations, this has little effect on the ice dynamic mass loss. Thus, the manuscript results indicate that by the year 2100, the sea-level contribution from the Amundsen Sea area is almost an order of magnitude less than those estimated by previous studies.

The study presents a highly relevant, large new data set and a related analysis on ground temperatures in the central Andes.

The orientation and size of ice crystals play a crucial role in the movement of ice and, consequently, how ice sheets and glaciers respond to changes in climate. In this study, results from the analysis of the ice crystal fabric of the EastGRIP ice core are presented. This is the first ice core to be collected in an ice stream, uniquely addressing issues related to ice dynamics. As a result, the work provides new insights into the processes, kinematics, and conditions within an ice stream, greatly advancing our understanding of fast-flowing ice streams.

This manuscript presents a significant step forward in presenting a new method to combine extensive satellite data (ice thickness retrievals from radar altimetry in this case) that were accumulated over a long time of one month. As the sea ice can move several hundred kilometers during this time period, averaging data without correcting for drift can significantly blur the results. With the new method, only data that have remained in the same sea ice regime are averaged. The method has received widespread attention, and the audience in the recent ESA Living Planet Symposium mentioned and recognized this work during the public discussion. The community is aware of this work and I am convinced that numerous data providers will implement the method shortly.