Large uncertainties in model parameterizations and input datasets make projections of future sea level rise contributions of outlet glaciers challenging. Here, we introduce a novel technique for weighing large ensemble model simulations that uses information of key observables. The approach is robust to input errors and yields calibrated means and error estimates of a glacier's mass balance. We apply the technique to Jakobshavn Isbr\ae{}, using a model that includes a dynamic calving law, and closely reproduce the observed behavior from 1985 until 2018 by forcing the model with ocean temperatures only. Our calibrated projection suggests that the glacier will continue to retreat and contribute about 5.1 mm to eustatic sea level rise by 2100 under present-day climatic forcing. Our analysis shows that the glacier's future evolution will strongly depend on the ambient oceanic setting.

Data generated using the Ice Sheet System Model (ISSM).