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.

This study brings together an impressive amount of data to come up with an updated estimate of global glacier loss until the year 2100. This is an important result in a climate change context, and one of a global dimension.

This manuscript addresses the stability of one of the most vulnerable regions of West Antarctica. Focusing on the so-called "doomsday" glacier, Thwaites glacier, the authors use a novel model that combines ice sheet and ocean to investigate how the ice melts at the pinning point - the points where the glacier is "pinned" to the bedrock.

The study is one of the first to model fractures in ice sheets - a fascinating and visually stunning aspect of ice sheets. The model shows that crevasses may transport large volumes of water to the bed of a glacier very quickly and captures the opening of the crevasses due to the water inflow. The impact of surface lakes on the Greenland ice sheet dynamics and mass loss is now better described.

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.

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.