By exploiting three important new advances in ice sheet modelling, and major new Antarctic-wide datasets, we aim to predict how far and how fast the observed ocean-driven thinning of floating ice shelves will propagate into the interior of the Antarctic ice sheet, and assess the consequences for global sea level over decadal-to-century timescales. Whereas previous studies have used simplified models, idealised forcing, or limited domains, we will use a comprehensively initialised model of ice flow throughout Antarctica, including all mechanical processes that propagate thinning into the interior, to produce a highly-realistic simulation that can predict the response of the grounded ice sheet to the ice-shelf thinning observed by satellite. We will validate the simulations against further satellite observations, before using them with scenarios of ice-shelf melt, guided by ocean models, to produce a probabilistic forecast of the future sea-level contribution from Antarctica to 2100.