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Despite computational and methodological uncertainties, and a wide range of potential greenhouse gas emissions, here millennial-scale simulations of the Antarctic Ice Sheet in a warming climate show that most of Antarctica’s fringing ice shelves will collapse, leading to a rise in sea level of up to 3 metres by 2300.

The Antarctic Ice Sheet’s sea-level contribution in a high-emissions scenario is indistinguishable from that in a low-emissions scenario for the next century, but its long-term contribution depends on warming this century, according to ice sheet simulations and an emulator-based analysis.

Sea salt data from an ice core record show that Antarctica’s Ronne Ice Shelf survived the last interglacial, the last period of enhanced and sustained global warmth about 125,000 years ago.

Ice melt from Antarctica is accelerating. Now, a study shows that more realistic treatment of how Earth’s mantle rebounds as Antarctic glaciers retreat can lower projections of mass loss and the associated sea-level rise.

The glaciers of the Antarctic Peninsula are experiencing faster melt because of increased temperatures; however, changes in precipitation may offset some of the future melt. This study looks at the relationship between glaciers and climate and finds a representative glacier is more sensitive to temperature change, rather than precipitation change. This indicates that precipitation increases are unlikely to counter the increased melt from warming.

Increased meltwater from the Greenland and Antarctic ice sheets will slow the Atlantic overturning circulation and warm the subsurface ocean around Antarctica, further increasing Antarctic ice loss.

Efficient statistical emulation of melting land ice under various climate scenarios to 2100 indicates a contribution from melting land ice to sea level increase of at least 13 centimetres sea level equivalent.

Using ice sheet model and glacio-isostatic adjustment model simulations and paleoclimate proxies, this work demonstrates that the most likely cause of past West Antarctic grounding-line reversal was a regime shift from a warm to cold ocean cavity.

Antarctic coastal polynyas have a critical role in the Earth system, influencing the atmosphere, hydrosphere, cryosphere and biosphere. This Review outlines the importance of Antarctic coastal polynyas and documents their changes over time.

It may have taken only a decade to repeatedly destabilize the Antarctic Ice Sheet after the last Ice Age as shown by a new data-model study. The ice sheet lost ice for centuries each time before it abruptly re-stabilized again.

The East Antarctic ice sheet retreated at the end of the last glacial period. Terrestrial and marine data suggest that the retreat began 14,000 years ago, indicating that the East Antarctic ice sheet probably did not contribute to meltwater pulse 1a 14,700 years ago.

By better quantifying uncertainties for marine ice-cliff instability, future Antarctic ice loss is predicted to be much lower than previously estimated.

A challenge for testing mechanisms of past climate change is the precise correlation of palaeoclimate records. Here, through climate modelling and the alignment of terrestrial, ice and marine ¹⁴C and ¹⁰Be records, the authors show that Southern Ocean freshwater hosing can trigger global change.

Contributions of iron sources to Southern Ocean CO₂sequestration during the last glacial period remain uncertain. Here, based on the biogeochemical analysis of subglacial calcites, the authors propose Antarctic volcanism, via subglacial drainage of Fe-rich waters, as a key contributor.

A reduction in the strength of the Atlantic Meridional Overturning Circulation initiated during the penultimate deglaciation led to excess polar ice losses, contributing to higher sea levels during the last interglacial period.

Analysis of cosmogenic isotopes from a marine sediment core shows that much of the land-based East Antarctic Ice Sheet has remained stable for the past eight million years, including during the warm Pliocene epoch.

Records of iceberg-rafted debris and climate model simulations reveal that fluctuations in Antarctic Ice Sheet discharge may have amplified climate fluctuations during the Holocene.

If elevated ice-melt rates in the Amundsen Sea Embayment, West Antarctica, can be restored to present levels within 100 years, rates of ice discharge and the sea level contribution from the region can be limited, suggest sensitivity experiments with an ice sheet model.

The extent to which sea level will rise under climate change is uncertain, with some of this uncertainty being quantifiable and some unquantifiable. This Review discusses past and present presentations of this uncertainty in IPCC and regional assessments, as well as their influence on users' interpretations.

Hugh Markus, Peter Donnelly and colleagues report a genome-wide association study for ischemic stroke. They identify a SNP in HDAC9, a histone deacetylase gene, that is associated with large vessel ischemic stroke and suggest subtype-specific associations to ischemic stroke.

Understudied in the Antarctic system are the subsurface interfaces between ice-sheet, ocean and geological substrate. Here, the authors review our understanding of these components and propose new avenues of holistic dynamic modeling to achieve a unified understanding of past, present and future polar climate.

This Review synthesizes knowledge on projections of the Antarctic and Greenland ice sheets at 1.5 °C and 2 °C of warming, discussing possible nonlinear responses, and outlining the need for more insight into future atmospheric and oceanic forcings.