Antarctica in 2025: Drivers of deep uncertainty in projected ice loss

Antarctica is a vital component of Earth's climate system, influencing global sea level, ocean circulation, and planetary albedo. Major knowledge gaps in critical processes-spanning the atmosphere, ocean, ice sheets, underlying beds, ice shelves, and sea ice-create uncertainties in future projections, hindering climate adaptation and risk assessments of ice intervention strategies. Antarctica's ice sheet could contribute 28 centimeters to sea level by 2100, and potentially more if we surpass warming thresholds that trigger instabilities and rapid retreat. We review recent advances in understanding the changing stability of the ice sheet margins and identify key processes that require further research. Progress requires high-resolution satellite data, targeted field campaigns, improved modeling, and refined theory. Increased investment and interdisciplinary collaboration are essential to uncovering Antarctica's hidden processes and reducing uncertainties in future projections.