<p>Antarctic ice-shelf melt constitutes a major source of epistemic uncertainty in future sea level rise, yet the interplay between melt and ocean circulation is not captured in climate model projections. Consequently, the relative importance of feedbacks from increased ice-shelf melting versus directly forced ocean change is poorly understood. Here we examine how externally forced changes and melt-driven feedbacks each influence the continental-shelf response to future climate change, using a circumpolar Antarctic ocean–sea-ice model that incorporates interactive ice shelves. These simulations show that the melt feedback is of comparable importance and in some regions opposite in sign to the forced response. In dense shelf regions, warming creates a feedback loop: as the high-salinity shelf water becomes lighter, it lets warmer ocean water flow underneath the ice shelf, which then increases ice-shelf melting. Westward transport of meltwater from these dense shelf regions freshens the continental shelf further downstream and obstructs warm water intrusions, establishing a negative feedback. The positive melt feedback accounts for two-thirds of the increased melt rate over all ice shelves. This work highlights the importance of representing Antarctic ice-shelf melt feedbacks to predict future climate.</p>